FISH ECOLOGICAL STUDIES AND ITS APPLICATION IN ASSESSING ECOLOGICAL INTEGRITY OF RIVERS IN NEPAL

By

Bibhuti Ranjan Jha

Thesis Submitted in partial fulfillment of the requirement for the degree of

Doctor of Philosophy

in

The Department of Biological Sciences and Environmental Science School of Science Kathmandu University Dhulikhel, Nepal

January 2006 FISH ECOLOGICAL STUDIES AND ITS APPLICATION IN ASSESSING ECOLOGICAL INTEGRITY OF RIVERS IN NEPAL

By

Bibhuti Ranjan Jha

Supervisors:

Dr. Herwig Waidbacher & Dr. Subodh Sharma Ao. Univ. Professor Associate Professor Universität für Bodenkultur (BOKU) Kathmandu University (KU) Vienna, Austria Dhulikhel, Nepal

Kathmandu University

January 2006

ACKNOWLEDGEMENT

Writing thesis for me was indeed a long journey covering two continents Asia and Europe and spanning almost three years. However, it was the first time I realized that I was surrounded by wonderful people and institutions. Let me start with my two supervisors, Prof. Dr. Herwig Waidbacher, Head of the Department of Water Atmosphere and Environment, BOKU and Dr. Subodh Sharma, Department of Environmental Science and Engineering, KU both of whom have given me all the support, guidance and confidence to carry out this work. I would like to express my sincere gratitude and honor to them.

It was so nice to feel that I had a similar level of easiness in approaching Dr. Rana Bahadur Chhetri, then Head of the Department of Biological and Environmental Sciences, KU and now Associate Dean, and Prof. Dr. Mathias Jungwirth, Head of the Institute of Hydrobiology, BOKU. I found both of them full of virtues.

I am also grateful to KU for providing all kinds of support including the equipment and logistics to complete this work. The Dean of School of Science, Prof. Dr. Pushpa Raj Adhikari was particularly after me to push into this work. Thank you so much sir. Dr. Sanjay N. Khanal, my department head at KU not only gave me the tips on academic matter but also on the life in Vienna. In addition I sincerely acknowledge the encouragement and moral support received from the entire KU family. I am sure my colleague in the department and other friends in KU are just waiting for me to host a party.

BOKU family, especially the members at the institute were equally inspiring. Prof. Moog, Prof. Muhar and Prof. Schmutz were always friendly and ready to help in every matter. I also remember the warm friendliness of benthos group upstairs and fish group downstairs. The guys with whom I was working together in Keller are just amazing. Gü, Manu, Frangez, Wiesel, Ande, Andreas, Thomas, Patrick, Gonzalo, Doris, Nicole, Catherine, Helmut, Philipp and Jonathan were all wonderful friends and never allowed my spirit go down. The songs of Berthold will always ring in my ears. All of you will remain in my memory forever.

Franziska, the coordinator of the institute is a super lady. Not only she was helping me in all office and domestic matters but also provided me motherly advices whenever we met. Christian Dorninger is another person who has been seen always in helping mood.

I feel proud to name my sampling team members who helped me during the field trips. Sujan, Arbinda, Shekhar, Bibhuti, Amul, Paras, Anil, Sushil, Amir, Keshab, Khadak, Paras, Sujeet, Swastik, Diwas and Ramesh! I love you all. Pancha and Shiva, who also work in the laboratory, were also integral part of the sampling team. Among colleagues Subhash, Bed, Manoj and Dr. Sanjaya were always with me one time or another.

Among the institution, I always find the central department of Zoology of Tribhuvan University very homely, may be because I used to be a student there. Prof. Dr. Jiwan Shrestha particularly, provided me with unselfish help in identifying the sample. I would like to express my heartfelt thanks to you, madam. Thanks also to Dr. Mana Wagley, who helped me in developing the objectives of the study.

Dharani Man Singh is not only my close neighbor but was also closely watching my progress during field studies. Many times I made use of his good office, Department of Fisheries, Balaju for literature and taxonomy of fish. There I also got the opportunity to talk with Dr. Swar and took some help from Ramola madam. Sincere thanks to all of you.

I would also like to acknowledge the cooperation of Department of National Parks and Wildlife Conservation (DNPWC), Royal Chitwan National Park, Shivapuri National Park, Department of Hydrology and Meteorology (DHM), World Conservation Union (IUCN), Water and Energy Commission (WECS), National Agriculture Research Center (NARC) and ICIMOD, Nepal.

Austrian Academic Exchange Service (ÖAD) and The World Conservation Union (IUCN, Nepal) deserve very special thanks as the institutions providing scholarship and grant to complete this research work.

One man from the Institute of Hydrobiology, BOKU stood very tall in terms of cooperation to complete this work. Michael Straif (MUCH)! I am not finding words to express my gratitude to you. The Nepalese community in Vienna also deserves big thanks as it provided the homely environment whenever I was homesick. Similarly thanks also to my friends and well- wishers in Nepal. Haus Panorama 7th floor, where I was staying in Vienna was like a home with a beautiful garden comprising wonderful people from all over the world.

I know there are many names missing in this text, who made valuable contributions to this work. Let me acknowledge you all.

Finally, the members of my family who beared my absence many times during the studies and waiting eagerly to receive me back naturally deserve a warm heart full of thanks.

And to my father I owe a debt of deepest gratitude, for the help I could not at the time appreciate: his tireless urging and prodding towards the realization of this work was crucial, and I as his son remain in his tutelage.

Bibhuti

ABSTRACT

This work was, mainly, intended to assess the integrity of rivers in Nepal by some fish community base parameters such as the number of species, composition and the abundance. However, the variety of other information regarding fish resource and river morphology such as spatial and temporal distribution and density of fish species, size structure of a species, and substrate and physico-chemical parameters of the river are also well documented.

Four different important disturbances, agriculture, urbanization, dams and weir, and industries were studied here to assess if there were any impairments on the integrity of the rivers by them. This work comprised nine rivers of Nepal in Central and Western Development Region facing those disturbances. There were three case studies for each of the four disturbances each having two sampling sites, the reference and the disturbed. Fish sampling was done by standard wading method using backpack electro-fishing gear. Four replicates of data corresponding to each major season were collected to give temporal dimension to the study.

There were new findings regarding the range of distribution of many species as well as their size. The seasonal variation in the distribution of fish species was also documented for all the rivers, which were studied. In addition, the abundance and density of each species in each river were calculated to help manage the fisheries resources. The classification of rivers and river systems were also tried by using both fish community base variables and abiotic factors using cluster analysis and discriminant analysis respectively. The results for these were remarkable as both classifications corresponded to the age-old regional classification of the Nepalese river systems.

Finally, it was seen that the fish population dynamics was sensitive to varieties of disturbances the rivers are facing indicating that the fish base methods of assessing water quality and river integrity could be developed for Nepalese rivers as well. It was found that the impacts of all the disturbances on river integrity were not same and thus, could not be generalized. Even the case studies of same disturbance produced mixed results pointing that the regional and seasonal factors too modify the impacts.

It was found that high diversity and abundance of fish may not necessarily point toward a good water quality. The impacts of agriculture in disturbed sites were quite visible characterized by relatively higher diversity and abundance of fish indicating the nutrient input in water by runoff through cultivated areas. It was found that the impacts of agriculture also depend upon the river morphology and flow regime.

The impacts of the city on the integrity of river were not found to be big enough among the cases studied. However, some trends were shown by fish community structure for this disturbance indicating that it has potential to change the river conditions. On the other hand, the impacts produced by dams and weirs were of mixed type. In general, the upstream sites supposed to be the reference site was found to be more affected than the downstream sites indicating that the upstream migration of some of the fish species was not possible due to the fragmentation of the river.

Among the disturbance, the industrial disturbance was found to be the most serious one as it clearly indicated a strong relationship of the industries and the water quality and integrity of the rivers. It was even evident in Narayani River, one of the largest rivers of the country with huge water discharge. In other cases, it showed seasonal fluctuations of the impact pointing towards the biggest influential event, the monsoon, which truly rules over every aspects of the river ecology.

Fish ecological studies and its numerous applications are very important to the country, as it is extremely rich in both, the fish resource and the water resource. This work is just a beginning in this direction. Once the sufficient fish base data of all the rivers and regions are collected then a country level regional IBI metrics could be developed. It will then play a significant role in conservation, management and monitoring of both the resources. Abbreviations

AC Alternate Current AIC Agricultural Inputs Corporation BOD Biological Oxygen Demand BOKU Universität für Bodenkultur CA Cluster Analysis CBS Central Bureau of Statistics CDA Canonical Discriminant Analysis CDC Curriculumn Development Center CPUE Catch per Unit Effort DA Discriminant Analysis DC Direct Current DHM Department of Hydrology and Meteorology DNPWC Department of National Parks and Wildlife Conservation DO Dissolved Oxygen DOPP Directorate of Plant Protection EIA Environmental Impact Assessment EIFAC European Inland Fisheries Advisory Committee EU European Union FAO Food Agriculture Organization FPC Flood Impulse Concept GDP Gross Domestic Product GIS Geological Information System GLOF Glacial Lakes Outburst Floods GPS Geological Positioning System ha Hectare HAI Health Assessment Index HID Hetauda Industrial District HMG/N His Majesty’s Government /Nepal IBI Index of Biotic Integrity ID’s Industrial Districts IDM Industrial District Management Limited IE’s Industrial Estates INGO International Non Governmental Organization IUCN World Conservation Union KU Kathmandu University KW KilloWatt MASL Meter Above Sea Level MOIC Ministry of Information and Communication MOPE Ministry of Population and Environment MW Mega Watt NCAP Northwest Coalition for Alternatives to Pesticides NCS National Conservation Strategy NEA Nepal Electricity Authority NEPBIOS Nepalese Biotic Score NEPBIOS- brs Nepalese Biotic Score (Bagmati River system) NGO Non Governmental Organization NPB Nepal Pesticide Board NPC National Planning Commission NPK Nitrogen Phosphorus Potassium ÖAD Österreichischer Austauschdienst RCC River Continuum Concept RCNP Royal Chitwan National Park RONAST Royal Nepal Academy of Science and Technology RPM River and Productivity Model SDC Serial Discontinuity Concept SNP Shivapuri National Park TL Total Length TSP Total Suspended Particle TSS Total Suspended Solid TU Tribhuvan University UNDP United Nation's Development Program WECS Water and Energy Commission Secretariat WFD Water Framework Directive

Chapter Index

S.N. Title Page Chapter I 1. Introduction 1

1.1 Background 1

1.2 Rational of the work 6

1.3 Objectives 6

1.4 Hypothesis of the study 7 Chapter II 2. Integrity of the river system 8

2.1 Ecological integrity 8

2.2 Integrity and human beings 10

2.3 Integrity and economy 11

2.4 Integrity and sustainability 13

2.5 Integrity and health 15

2.6 Integrity, equilibrium and disequilibrium 16

2.7 Integrity revisited 18

2.8 Ecological integrity and the rivers 20 Chapter III 3. Fish as an indicator 25

3.1 Bioindication and bioindicators 25

3.2 Fish as bioindicators 27

3.2.1 History and development 27

3.2.2 Advantages of use of fish as bioindicator 29

3.2.3 The index of biotic integrity (IBI) 31 3.2.4 Modification of the index of biotic integrity (IBI) 34 Chapter IV 4. Electrofishing 37

4.1 Definition and history 37

4.2 Fish response 39

4.3 Factors affecting the efficiency of electrofishing 41

4.3.1 Abiotic factors 41

4.3.2 Biotic factors 43

4.3.3 Technical factors 44

4.4 The equipment 45

4.5 Uses and significance of electric fishing 46

4.6 Safety and precautions 47

4.7 Electric fishing in Nepal 48 Chapter V 5. Issues in context of Nepal 52

5.1 Rivers and river system 52

5.1.1 An overview 52

5.1.2 Geography and the rivers 53

5.1.3 Types of river 55

5.2 Scientific studies on Nepalese water 61

5.2.1 Early phase 62

5.2.2 Middle phase 63

5.2.3 Modern phase 65

5.3 Fishes of Nepal 68

5.4 River disturbances in Nepal 69

5.4.1 Agriculture 71

5.4.2 City (Urbanization) 75

5.4.3 Dams and weirs 78 5.4.4 Industries 82 Chapter VI 6. Materials and methods 85

6.1 Strategy 85

6.2 Types of disturbances 85

6.3 Site selection 85

6.4 Sampling 89

6.4.1 Time and duration 89

6.4.2 Fish collection and measurement 89

6.4.3 Physico-chemical parameters 90

6.4.4 Geo-morphology of the sampling sites 90

6.5 Data processing and analysis 91

6.6 Results and interpretation 91 Chapter VII 7. Description of the sites 92

7.1 Andhikhola 94

7.2 Arungkhola 95

7.3 Bagmati 96

7.4 Jhikhukhola 98

7.5 Karrakhola 99

7.6 Narayani 100

7.7 East Rapti 102

7.8 Seti 103

7.9 Tinau 104 Chapter VIII 8. Results 111

8.1 Distribution, abundance and density of fish 111 8.2 River classification based on biotic and abiotic factors 144

8.3 Study of the size structure of sucker head, Garra gotyla 151 gotyla (Gray, 1830)

8.4 Assessment of ecological integrity of the rivers 187

8.4.1 Disturbances due to agriculture 187

8.4.2 Disturbances due to urbanization 194

8.4.3 Disturbances due to dams 201

8.4.4 Disturbances due to industries 208

8.5 Statistical verifications 216

8.5.1 Non parametric Kruskal Wallis Test 226

8.5.2 Parametric one way ANOVA (for seasonal variation of 227 impacts)

8.5.3 Non parametric Mann Whitney Test (for impacts) 228

8.5.4 Parametric one way ANOVA (for impacts) 229 Chapter IX 9. Discussion 230

9.1 Distribution, abundance and density of fish 230

9.2 River classification based on biotic and abiotic factors 234

9.3 The size structure of sucker head Garra gotyla gotyla 236 (Gray 1830)

9.4 Assessment of integrity of the river system 240

9.4.1 Disturbances due to agriculture 243

9.4.2 Disturbances due to urbanization (city) 247

9.4.3 Disturbances due to dams 251

9.4.4 Disturbances due to industries 256 Chapter X 10. Conclusions and recommendations 262

11. Executive summary 269 12. References 274 13. Appendix Page

I Working time table 287 II Field protocol 288 III Field protocol (Fish base) 289 IV Checklist of fishes of Nepal 290

V Letter from Defense Ministry for safety during sampling 296

VI Letter from university for cooperation during sampling 297

VII Permission letter from DNPWC for sampling in RCNP 298

VIII Permission letter from DNPWC for sampling in SNP 299 IX Permission letter from SNP for sampling 300 X Permission letter from NEA for sampling 301

Map Index S.N. Title Page 7.1 Country map with sampling sites 93 7.2 Part of the country map enlarged with sampling sites 93 7.3 Showing sampling sites in Aandhikhola 108 7.4 Showing sampling sites in Karrakhola, East Rapti, Narayani and 108 Arungkhola 7.5 Showing sampling sites in Bagmati river 109 7.6 Showing sampling sites in Jhikhukhola 109 7.7 Showing sampling sites in Seti river 110 7.8 Showing sampling sites in Tinau river 110

Figure Index S.N. Title Page 5.4.1 Bioaccumulation and biomagnifications 75 8.1.1 Abundance of different fish species during one year of sampling 141 8.2.1 Clusters of river 145 8.2.2 Classification of the river system by CDA 150 8.3.1 Length frequency of Garra species- Aandhikhola 153 8.3.2 Length frequency of Garra species -Arungkhola 153 8.3.3 Length frequency of Garra species- Jhikhukhola 153 8.3.4 Length frequency of Garra species- Karrakhola 153 8.3.5 Length frequency of Garra species- Narayani 156 8.3.6 Length frequency of Garra species- East Rapti 156 8.3.7 Length frequency of Garra species- Seti 156 8.3.8 Length frequency of Garra species- Tinau 156 8.3.9 Length frequency of Garra species- Spring 158 8.3.10 Length frequency of Garra species- Premonsoon 158 8.3.11 Length frequency of Garra species- Autumn 158 8.3.12 Length frequency of Garra species- Winter 158 8.3.13 Length-weight relationship of Garra gotyla gotyla in different seasons 160 8.3.14 Length-weight relationship of Garra gotyla gotyla in different river 162 system - Premonsoon 8.3.15 Length-weight relationship of Garra gotyla gotyla in different river 162 system - Postmonsoon 8.4.1 - Distribution and abundances of fish species in all seasons and rivers 164-186 8.4.92 for all disturbances 8.4.93 Impact of agriculture in Jhikhukhola- Upstream 189 8.4.94 Impact of agriculture in Jhikhukhola- Downstream 189 8.4.95 Impact of agriculture in East Rapti- Upstream 191 8.4.96 Impact of agriculture in East Rapti- Downstream 191 8.4.97 Impact of agriculture in Tinau- Upstream 193 8.4.98 Impact of agriculture in Tinau- Downstream 193 8.4.99 Impact of city in Narayani- Upstream 196 8.4.100 Impact of city in Narayani- Downstream 196 8.4.101 Impact of city on in Seti- Upstream 198 8.4.102 Impact of city in Seti- Downstream 198 8.4.103 Impact of city in Tinau- Upstream 200 8.4.104 Impact of city in Tinau- Downstream 200 8.4.105 Impact of dam in Aandhikhola- Upstream 203 8.4.106 Impact of dam in Aandhikhola- Downstream 203 8.4.107 Impact of dam in Bagmati- Upstream 204 8.4.108 Impact of dam in Bagmati- Downstream 204 8.4.109 Impact of dam in Tinau- Upstream 207 8.4.110 Impact of dam in Tinau- Downstream 207 8.4.111 Impact of industry in Arungkhola- Upstream 210 8.4.112 Impact of industry in Arungkhola- Downstream 210 8.4.113 Impact of industry in Karrakhola- Upstream 212 8.4.114 Impact of industry in Karrakhola- Downstream 212 8.4.115 Impact of industry in Narayani- Upstream 215 8.4.116 Impact of industry in Narayani- Downstream 215 8.5.1 Abundance of fish (CPUE) in all impacts in all seasons 218 8.5.2 Number of fish species in all impacts in all seasons 218 8.5.3 Abundance of fish (CPUE) in agricultural impacts 219 8.5.4 Number of fish species in agricultural impacts 219 8.5.5 Abundance of fish (CPUE) in impacts of city 220 8.5.6 Number of fish species in impacts of city 220 8.5.7 Abundance of fish (CPUE) in impacts of dam 221 8.5.8 Number of fish species in impacts of dam 221 8.5.9 Abundance of fish (CPUE) in impacts of industry 222 8.5.10 Number of fish species in impacts of industry 222 Table Index S.N. Title Page 3.2.1 Typical effects of environmental degradation on biotic assemblages 32 3.2.2 Parameters used in assessment of fish communities 32 3.2.3 Evaluation criteria for IBI 33 3.2.4 IBI modified from Karr (1981) 35 3.2.5 Fish based assessment of ecological integrity 36 4.3.1 Factors affecting electrofishing 41 4.7.1 Specification of the fishing gear used in this work 49 5.1.1 Estimated runoff of the rivers 53 5.1.2 Classification of the rivers studied in this work 61 5.4.1 Consumption of chemical fertilizers in Nepal by type 73 5.4.2 Growth of urban population and urban places in Nepal 76 5.4.3 Percent distribution of urban population 77 5.4.4 Urban densities in different regions of the country 77 5.4.5 List of the hydro power projects 79-81 5.4.6 Details of the industrial districts 83 5.4.7 Industrial pollution load in developing regions 84 6.1 Rivers and the locations of the sampling sites 86 6.2 Rivers and the disturbances studied 87 6.3 Rivers and details of the sampling sites 88 7.1.1 Details of Aandhikhola Hydel and Rural Electrification Project 95 7.3.1 Details of the Sundarijal Hydropower Plant 97 7.6.1 Material for production of 1 ton of paper 101 7.9.1 Details of Tinau Hydropower Project 106 8.1.1 List of fish species recorded in this study 111-112 8.1.2 Distribution of fish species in sampled rivers and seasons 135-137 8.1.3 Abundances of fish in different rivers (Number/10 minutes of fishing) 139 8.1.4 Density of fish in different rivers (Number/100m²) 143 8.2.1 Statistical details of the cluster analysis 145 8.2.2 Valid and missing variables in CDA 146 8.2.3 Summary of canonical discriminant functions 147 8.2.4 Standardized canonical discriminant function coefficient 147 8.2.5 Correlation details of the discriminant variables 148 8.2.6 Classification processing summary 148 8.2.7 Prior probabilities for groups 148 8.2.8 Classification results 149 8.3.1 The details of the statistics for each season for length weight 159 relationship 8.3.2 Summary of the statistics of three river systems in premonsoon and 161 postmonsoon seasons 8.5.1 Abundances of fish in all impacts in all seasons 223 8.5.2 Number of species in all impacts in all seasons 223 8.5.3 Abundances of fish in agriculture impacts 223 8.5.4 Number of species in agriculture impacts 223 8.5.5 Abundances of fish in impacts of city 224 8.5.6 Number of species in impacts of city 224 8.5.7 Abundances of fish in impacts of dam 224 8.5.8 Number of species in impacts of dam 224 8.5.9 Abundances of fish in impacts of industry 225 8.5.10 Number of species in impacts of industry 225 8.5.11 Test of homogeneity of variance 226 8.5.12 Tests of normality of variables 226 8.5.13 Values of asymptotic significance from Kruskal-Wallis Test 227 8.5.14 Values of significances in one way ANOVA 228 8.5.15 Values of 2 tailed asymptotic significances from Mann Whitney test 229 8.5.16 Significances in one way ANOVA 229 10.1 Summary of the impacts in different rivers 266

Picture Index S.N. Title Page 4.7.1 Electro fishing gear and its use in this research 51 4.7.2 Electro fishing gear and its use in this research 51 6.4.1 Length measuring instrument 91 6.4.2 Digital weighing machine 91 8.1.1 Gudusia chapra (Hamilton-Buchanan 1822) 127 8.1.2 Neolissochilus hexagonolepis (McClelland 1839) 127 8.1.3 Cirrhinus reba (Hamilton-Buchanan 1822) 127 8.1.4 Labeo dero (Hamilton-Buchanan 1822) 127 8.1.5 Puntius chola (Hamilton-Buchanan 1822) 127 8.1.6 Puntius conchonius (Hamilton-Buchanan 1822) 127 8.1.7 Puntius sophore (Hamilton-Buchanan 1822) 128 8.1.8 Semiplotus semiplotus (McClelland 1839) 128 8.1.9 Tor putitora (Hamilton-Buchanan 1822) 128 8.1.10 Tor tor (Hamilton-Buchanan 1822) 128 8.1.11 Naziritor chelynoides (McClelland 1839) 128 8.1.12 Aspidoparia morar (Hamilton-Buchanan 1822) 128 8.1.13 Barilius barila (Hamilton-Buchanan 1822) 129 8.1.14 Barilius barna (Hamilton-Buchanan 1822) 129 8.1.15 Barilius bendelisis (Hamilton-Buchanan 1822) 129 8.1.16 Barilius shacra (Hamilton-Buchanan 1822) 129 8.1.17 Barilius vagra (Hamilton-Buchanan 1822) 129 8.1.18 Brachydanio rerio (Hamilton-Buchanan 1822) 129 8.1.19 Danio aequipinnatus (McClelland 1839) 130 8.1.20 Danio dangila (Hamilton-Buchanan 1822) 130 8.1.21 Esomus danricus (Hamilton-Buchanan 1822) 130 8.1.22 Crossocheilus latius (Hamilton-Buchanan 1822) 130 8.1.23 Garra annandalei (Hora 1921) 130 8.1.24 Garra gotyla gotyla (Gray 1830) 130 8.1.25 Schizothorax richardsonii (Gray 1832) 131 8.1.26 Schizothoraichthys progastus (McClelland 1839) 131 8.1.27 Psilorhynchus pseudecheneis (Menon and Datta 1961) 131 8.1.28 Nemacheilus corica (Hamilton-Buchanan 1822) 131 8.1.29 Acanthocobitis botia (Hamilton-Buchanan 1822) 131 8.1.30 Schistura beavani (Günther 1868) 131 8.1.31 Schistura rupecula (McClelland 1839) 132 8.1.32 Botia almorhae (Gray 1831) 132 8.1.33 Botia lohachata (Chaudhuri 1912) 132 8.1.34 Lepidocephalus guntea (Hamilton-Buchanan 1822) 132 8.1.35 Amblyceps mangois (Hamilton-Buchanan 1822) 132 8.1.36 Clupisoma garua (Hamilton-Buchanan 1822) 132 8.1.37 Myersglanis blythii (Day 1870) 133 8.1.38 Glyptothorax pectinopterus (McClelland 1842) 133 8.1.39 Glyptothorax telchitta (Hamilton-Buchanan 1822) 133 8.1.40 Glyptothorax trilineatus (Blyth 1860) 133 8.1.41 Pseudecheneis sulcatus (McClelland 1842) 133 8.1.42 Heteropneustes fossilis (Bloch 1794) 133 8.1.43 Channa orientalis (Bloch & Schneider 1801) 134 8.1.44 Channa punctatus (Bloch 1793) 134 8.1.45 Glossogobius giuris (Hamilton-Buchanan 1822) 134 8.1.46 Macrognathus pancalus (Hamilton-Buchanan 1822) 134 8.1.47 Mastacembelus armatus (Lacepede 1800) 134 1 Introduction

CHAPTER I: INTRODUCTION

Background:

Global freshwater resources are not only over-exploited or poorly managed but also ecologically degraded. Ecological degradation of fresh water bodies are mostly because of encroachment along the river systems. Ironically, much of the degradation of fresh water resources occur due to its tremendous utilities. The best source of water for humans, always, has been rivers and streams as they are the symbol of freshness, continuity and eternity. This is also a reason behind the establishment of most of the human civilization on the bank of rivers. From ancient times rivers and streams are serving human beings for most of their water requirements. In addition these water bodies have also served as a sink for mankind’s wastes and sewerage.

With ever growing global population, increase in agriculture production, expansion of industries and new demands for energy have to be met. All these involve the fresh water and put tremendous pressure on this crucial resource. Thus, agricultural intensification, urbanization, industrialization and the construction of dams and weirs, are considered as some of the major human activities or disturbances potential to affect the ecological status or integrity of the river system. Further, the human activities on water resources are usually a local phenomenon but the impacts transcend the national boundaries.

On the other hand there are thousands of aquatic living organisms too, which spend their entire lives in water and need this resource the most. Every life on earth constitutes a system and no life is inherently superior to another. These living communities in aquatic systems suffer more than human beings by degrading qualities of water resource. The living communities in water include fish and other aquatic species all of which for our advantage act as biological indicators of water quality and any alterations. They respond to the cumulative effects of both physical and chemical disturbances to the water in which they live.

The present work tries to assess the ecological integrity of the rivers and river systems by using the information from fish ecological studies. The integrity of rivers is a very difficult concept to define. The streams and rivers are complex ecosystems that take part in physical

-1- 1 Introduction and chemical cycles that shape our planet and allow life to sustain. In general, the integrity of the river system refers to its natural and wholesome state supporting all life forms; aquatic and terrestrial, and capable of doing its usual geological functions.

Further, current ecological theories and concepts describe running waters as four- dimensional systems, their longitudinal, lateral and vertical linkages, interactions and exchange processes varying over time and over different scales (Jungwirth et al. 2000). According to which, river systems are interactive at basically three spatial dimensions: in the longitudinal (river/river or tributary), vertical (riverbed/aquifer) and lateral dimension (riverbed/floodplain). The fourth dimension, the temporal scale is also crucial. The relative importance of all these dimensions vary according to the terrain the river is passing through but all are critical on themselves at their places.

There are various human activities and associated disturbances having potential to affect the ecological status or integrity of the rivers and streams. This study has tried to analyze four important disturbances in this regard such as agriculture, urbanization, dams and weirs, and the industries. Pollution of water bodies is not restricted to urban and industrialized area only. In our time even in rural areas the water pollution is common. The reason behind it is the indiscriminate use of chemicals, both as a pesticide and fertilizer, which are then mixed in the river system through run off.

In addition, the problem is not restricted to the developing countries alone but is present in developed countries too from where these modern agricultural chemicals originated. According to a U.S. Geological Survey (NCAP 1999), over 95% of river and stream samples, as well as over 50% of well samples contained at least one pesticide and hence they concluded, "Pesticides are widely found in rivers, streams, and wells". The rural areas, mostly famous for the agriculture are more susceptible to this problem.

Thus, chemical intensive and faulty agricultural practices have become a threat to the ecological integrity of the running waters. Some of the studies of selected areas in Nepal show that deterioration of water quality through agricultural runoffs is quite alarming, particularly in small rivers, streams and shallow groundwater. Hence, the study of the impacts of agricultural disturbances in some of the Nepalese rivers has been chosen in this work.

-2- 1 Introduction

In the same way, the process of urbanization is also one of the important causes that can threat the normal ecology of the river. The relationship between human settlements and the body of water, especially the river has always been intimate. The river in an urbanized area could be seen used in many ways. Embankment and channelization for landscape management, navigation and transportation, dumping of the wastes and recreation are only some of them. And these, when put together with as the source of water supply, put tremendous pressure on the ecological integrity of the river.

Urban areas in Nepal have increased and developed haphazardly without any plan and projections creating wide range of problems that touch all sectors such as, environment, economy and society. The urban population of Nepal according to the latest census stands at 14.2% of the total population (CBS 2001). This is not too much but what are alarming are the rate and the way it is increasing. Therefore, the impacts of the cities or the urban areas on the rivers also have been chosen for the analysis in this work.

The fragmentation of rivers through hydropower dams and other hydraulic measures is a common phenomenon all over the world and the first thing it does by so is the disruption of the longitudinal river continuum. These measures also fragment the population of many species threatening their survivability. In addition, these engineering feats may also alter some geo-morphological and physico-chemical characteristics of the river and that in turn again adversely affect the living components.

The history of modern hydropower technology in Nepal dates back to 1911 AD, almost a century before. Today Nepal produces about 526.44 MW of energy from hydropower and many dams are under construction as the energy is in high demand (MOPE 2001). This demands more and more assessments of the conditions of the Nepalese rivers. Most of the dams are built in by bilateral assistance and hence carries design, operation and maintenance from the donors or through their guidelines. This provides another series to select from, as research sites and subsequent impacts. Thus, the disturbances due to dams and weirs on rivers have also been selected for study in this work.

Another disturbance this research intended to work on is the effects of industrialization on rivers. Nepal is not regarded as an industrialized country. In 1992 the total industrial units were about 4271 of which 57% were only in the capital, Kathmandu (MOPE 2001). Also a

-3- 1 Introduction very few of these total industrial units are big ones. Thus, superficially, there seems an insignificant environmental problem coming out of these units. But different studies have shown that the true pictures are quite different. Many of the studies in the field of chemistry and toxicology of the effluents have revealed that the industries are putting tremendous impacts on the rivers where they are drained.

All industrial wastes, in most cases, are directly discharged into local water bodies without treatment. With innumerous types of effluents coming from them, we can be certain about the grave impacts it adds to the water body, mostly the lotic one. The history is proof that the industrialized nations too had serious problems on their rivers and streams from industrial effluents. The impacts of industries are thus included in this work for the study.

There are altogether four types of disturbances, as described above, been selected to study for their impacts. The impacts of agricultural disturbances are studied in the rivers Jhikhukhola, East Rapti and Tinau, whereas the impacts of city are studied in the rivers Narayani, Tinau and Seti. Similarly, the impacts of dams and weirs are studied in Aandhikhola, Bagmati and Tinau, and the industrial impacts are studied in Arungkhola, Karrakhola and Narayani. Thus altogether 12 case studies spreading over nine rivers are included in this work.

The impacts of all these disturbances are studied by taking fish and their attributes as the indicators. We can simply take fish as an example as its population and distribution clearly reflect how much ecological integrity of rivers and streams has been compromised by human actions. Assessment of river quality by taking fish as an indicator is a well established and developed method in many parts of the world. For example, fish base index, IBI (index of biotic integrity), is extensively used in United States and Europe.

However, in Nepal the fish based assessment of the river integrity is in premature stage. Moreover, the water quality assessment by taking macrozoobenthos as an indicator is well developed for Nepalese rivers and streams (Sharma 1996). Nepal is blessed by a very high diversity of fresh water fishes and cannot afford to lose that. It possesses 182 fish species belonging to 93 genera, under 31 families and 11 orders (Shrestha 2001). Thus, fish are not just valuable as food resource but could also be utilized in many other ways. This work

-4- 1 Introduction intends to assess the entire health or integrity of the river system by taking fish as a fundamental indicator.

Assessing the integrity of rivers facing various disturbances is not the only goal of this study. Fish being the important protein resource of the poor country like Nepal, some aspects of the fisheries and fish ecological studies such as their diversity, spatial and temporal distribution, abundance and a rough estimate of their densities in various rivers are also included in this work. The technique of quantitative data acquired during this work could be very helpful to calculate the biomass and productivity of the rivers as well as for the conservation and management of fisheries resources. Thus, information collected and the analysis done in this work would be very helpful to various sectors such as local people and authority, the government and the institutions working in the field of management of natural resources.

The example of size structure analysis, which is so important to evaluate the habitat conditions, knowing the biology and estimating the crop, is also included in this study for the benefit of society in general. In addition to that, another important application of fish base and physico-chemical information collected during this work is the classification of the rivers and river systems of Nepal. Two ways of classifying the rivers are included in this work, one each utilizing biotic and abiotic variables.

The technique of using electrofishing gear for fish sampling, though common in fisheries research elsewhere is relatively new technique in Nepal. The data acquired by this technology are normally regarded as the standard data. A separate chapter is included in this thesis to explain this sampling method. Thus, it is expected that many of the findings of this work should not only be new but also authentic. It is expected that the findings of this work are a valuable contribution to the database of the country regarding fish and water resources and thereby to the general society.

The work was completed as planned without much constrains. The only major constrain faced during the study was the political situation in the country. The administrative procedures were increased so as to obtain permission letters from different departments and organizations to carry the equipment and complete the sampling. The field visits were done

-5- 1 Introduction rather in hurry due to the fear of unrest at some of the sites and thus, the socio-economic linkages of the study could not be established as it was expected earlier.

Rational of the work:

Water is the most important natural resource throughout the world and in case of Nepal it is much more than that. It is regarded as the means pf prosperity for the country. The water flowing through its more than six thousands rivers and streams, settled in numerous ponds and lakes and reserved as snow in countless majestic peaks of Himalayas have been subjected to multiple uses. Of these, rivers and streams, particularly, have been providing water to the people for drinking, washing, industrial use, irrigation, hydropower generation, subsistence fishing and various recreative activities.

Thus, it is of prime concern to all sectors to know the ecological constrains of this vital resource thrusted upon by its multiple uses. It is also equally important to develop the tools and techniques that express and quantify the extent of impact produced by various disturbances so as to manage and conserve this resource. This work that uses the first systematic application of electro fishing gear in Nepal is intended to give the fair picture of the quality of the resource by using fish as an indicator. The result of this could be taken as the guidelines for monitoring and conservation of this precious resource as well as for the sustainable harvest of the fishery resource.

Objectives:

The broad objective of this work is to find wide varieties of information regarding the impacts of modern agriculture, urbanization, hydropower dams and weirs, and the industries in the selected rivers in Nepal by focusing on various aspects of fish and its population. The information and results obtained are considered to be helpful to many sectors such as government, academics, environmentalists, development planners, industrialists, farmers, power companies, businessmen, NGO's and INGO’s, and above all the local communities.

The information and result obtained from this work could be categorized into two types: the first type is scientific, technical and academic in nature while the second type is related with general knowledge to link it with local community and local economy. The main objective

-6- 1 Introduction of this research work is to put together these two sets of information so as to get a holistic picture of situation of the selected rivers. However, this grand objective could be divisible into the following constituents.

1. To study spatial and temporal distribution of fish diversity in selected rivers of Nepal.

2. To calculate the abundance and density of fish species that helps in biomass estimation and conservation measures.

3. To find out the methods to classify Nepalese rivers and river systems based on the information of biotic and abiotic factors.

4. To show example of size structure analysis, which helps in understanding the habitat conditions, knowing the biology of the species and estimating the crop.

5. To investigate the impacts of agriculture, cities, dams and industries on the rivers by taking some fish attributes as indicator.

6. To put forward some recommendations in the basis of investigations for utilization and management of the water and fisheries resources.

Hypothesis of the study:

The fundamental hypothesis of this study is that the fish fauna is able to reflect the differences influenced by variety of disturbances in river conditions and quality through the change in their composition, diversity, and other population and community measures. Matrices based on their population dynamics are able to show the picture of the impacts.

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CHAPTER II: INTEGRITY OF THE RIVER SYSTEM

2.1 Ecological Integrity:

The term ‘ecological integrity’ is very widely used in environmental debate, discourse, seminar, plans and in literature but is equally difficult to define in a single universal sense. The definitions available so far are all subjective in nature and vary with individuals, contexts and time. Integrity normally implies a condition, which is unimpaired or a state of being complete or undivided. Ecosystems are usually made up of physical, chemical and biological components and their interactions. In this background, one of the broadest definitions of ecological integrity is given by Karr and Dudley (Karr and Chu 1995 and the references therein) as the sum of physical, chemical and biological integrity.

The first reference to integrity in the environmental literature was Aldo Leopold’s (1949) famous aphorism: “A thing is right when it tends to preserve the integrity, stability and beauty of the biotic community. It is wrong when it tends otherwise” (Noss 1995 and the references therein). But Leopold himself never explained the term integrity and the generations of biologists and conservationists, since then, are still in search of the unambiguous meaning of the term. The more they are trying, the more elaborate the definition is becoming. For example, Westra (1995) has included the following in the definition of ecological integrity: (1) ecosystem health, which may apply to some nonpristine or degraded ecosystems provided that they function successfully; (2) ecosystems’ abilities to regenerate themselves and withstand stress, specially nonanthropogenic stress; (3) ecosystems’ optimum capacity for undiminished developmental options; and (4) ecosystems’ abilities to continue their ongoing change and development unconstrained by human interruptions past or present.

Kay and Schneider (Lemons and Westra 1995 and the references therein) have the similar views on the concept of ecological integrity, which include three facets of ecosystems: (1) the ability to maintain optimum operations under normal conditions; (2) the ability to cope with changes in environmental conditions; and (3) the ability to continue the process of self- organization on an ongoing basis, that is, the ability to continue to evolve, develop, and proceed with the birth, death and renewal cycle. In one of the oldest concept, Cairns (in Lemons and Westra 1995 and the references therein) defines ecological integrity as “the

-8- 2 Integrity of the river system maintenance of the community structure and function characteristics of a particular locale or deemed satisfactory to society”.

Many have argued that the characteristics and essence of ecological integrity is found only in nature or wild area or pristine area, without human activities. In yet another definition, Westra (1995) has said that an ecosystem can be said to possess integrity when it is wild, that is, free as much as possible today from human intervention, when it is an unmanaged ecosystem, although not a necessarily pristine one. Karr and Chu (1995) also put integrity in the similar way as the condition of sites with little or no influence from human actions; that is, the resident biota is the product of evolutionary and biogeographic process at a site. These types of ecologists see the wilderness or pristine nature as the entities having ecological integrity.

To provide a space for humans and their activities, these scientists put forward a couple of principles, that we must respect and protect core wild areas, and that we must view all our activities as taking place within a buffer zone. To make it easy for human beings, some ecologists have proposed some guidelines to leave some areas of wilderness without interference. For example Naess (Westra et al. 2000 and the references therein), proposes a 30/30/30 percent guideline: 30% human activities, 30% carefully orchestrated activities compatible with the wild (buffers) and 30% of wild areas of ecological integrity.

Among the components of ecological integrity, often the literature is biased towards the biological integrity. According to Karr (2000), biological integrity refers to the condition of places at one end of a continuum of human influence, places that support a biota that is the product of evolutionary and biogeographic processes with little or no influence from industrial society. This biota is a balanced, integrated, adaptive system having its full range of elements (genes, species, assemblages) and processes (mutations, biotic interactions, nutrient and energy dynamics, and metapopulation processes) expected in areas with minimal human influence.

Brown et al. (2000) also put living being at the center of the concept. According to them, ecosystems comprise thousands of species interacting in dynamic relationships, the properties of which cannot be predicted from knowledge of the individual species in isolation. Species invade or disappear, evolve or become extinct, and many systems

-9- 2 Integrity of the river system variables are in constant flux. Yet ecosystems have structure, pattern, and predictability despite the radically contingent forces that may have created them. In the same vain, Noss (1995) confesses that for him native biodiversity is one of the best expressions of ecological integrity.

2.2 Integrity and human beings:

Interestingly, there are conflicting views about and including human beings as a natural being in the definition focusing biodiversity within ecological integrity. Lemon and Westra (1995) define “natural” as a condition existing prior to human perturbation of ecosystems. Many do not agree with this definition because it ignores the fact that human beings are part of nature. However, human beings through their wisdom have made a tremendous progress, according to Karr and Chu (1995), the consequences is the homogenization of global society; human language, technology, and culture are becoming more homogenous as we become more independent of the idiosyncrasies of local natural systems. They further add that the legacy we inherit and the one we pass on, continue generations of toxic effluents, destroyed and fragmented landscapes, depleted forests and fisheries and collapsing cultures throughout the world. The failure to maintain human bonds with place, biology and culture – our connections to living systems is what is emerging out.

Though past few decades were marked by tremendous increase in environmental awareness the quality of the environment continues to decline. Today, human beings and the natural world are on a collision course. Certainly, the world at present is very different from the one during early human evolution and to add, this difference is not a natural one. This is also explained by Karr and Chu (1995), when they say, “we have created a hybrid world – one neither entirely natural nor entirely mechanical. The so called all round development seemed to promise escape from dependence on, or even, connections with, other living systems. Now the “information age” gives us “virtual reality”, completing our isolation from the rest of the living world.

These are the reasons why many who believe and put forward some of the above definitions of ecological integrity either ignore or reluctant to accept the fact that humans are part of a nature and therefore need to be included. Only humans need to be blamed for this as we have forgotten to live within the limitations of the physical environment. Thus, in many

-10- 2 Integrity of the river system biocentric views regarding integrity humans are treated differently. One of the criticisms against biocentrism ethics is that they treat humans as superior than other creatures. Biocentrists talk a lot about the equality of species, but when they get around to the practical applications of their view, time and again, they show their bias in favor of the human species (Sterba 1998).

However, Sterba is one of those who have well defended the concept of integrity with the eye of biocentrism. He has proposed to distinguish between basic and nonbasic needs of human. It is only when the basic needs of humans are not satisfied, they seriously endanger their mental and physical well-being. The basic needs include food, shelter, medical care, protection, companionship and self-development. These needs of life are also comparable to the needs of other living being, and if humans can live within this they are very near to the rest of the natural beings. Westra (1995) also is of the same view when she says that neither humans nor panthers nor frogs have any place in wild systems, if they come riding Jeeps and carrying computers and electrical generators and insist on using and then dumping alien/toxic matters within the wild. It is a fallacy to assume that “human” equals “technological human,” and it is only the latter who is not welcome in the wild.

2.3 Integrity and economy:

Another aspect, which is closely linked with the ecological integrity, is the economy. The field of economy normally covers the activities and relationships by which human beings acquire, process, and distribute the material necessities and wants of life, including the energy and material resources needed to power the industrial machine. It therefore subsumes that subset of activities by which humankind interacts with the rest of the ecosphere (Miller and Rees 2000). This also means that the essential goods and services for human beings come only from the planet Earth and from nowhere else. The fact is also explained by Karr (2000), when he says that for millennia, nature – specifically living systems – provided food and fiber to nourish and clothe us and materials to build us homes and transport. Living systems conditioned the air we breath, regulated the global water cycle, and created the soil that sustained our developing agriculture. They decompose and absorb our wastes. Beyond practicality, nature feeds the human spirit.

-11- 2 Integrity of the river system

However, ever since the mankind became capable of using tools, and during most of the industrial age, we have forgotten the fact that the Earth is finite and has limitations. The “cowboy” mentality as explained by Herman Daly (Mark Sagoff 1995 and the references therein) as the one that views nature as an unlimited frontier for exploitation, has played a greater role for the impoverished condition of the planet. According to this view, there is no need to worry about the “integrity” of nature – no need to recycle anything – because technological progress makes resources essentially infinite.

In addition, the “cowboy” regards nature not only as an unlimited frontier to exploit but also as a hostile foe to conquer. In ancient time, exploration of the nature always offered misery to people in the form of heat and cold, hunger, disease and desolate wilderness. As the nature was considered basically hostile to human purposes, it has been dammed, plowed, blasted, cut, drained, dredged, poisoned, fenced, hunted, exterminated, genetically reengineered, and in general controlled (Sagoff 1995). Interestingly, some economists still believe that the destruction of nature in favor of industrial development is good and not bad for human beings.

The economy is normally governed by money and market and its analysis ignores biophysical conditions and the behavior of the ecosystem. For example, economists virtually put zero marginal value on nonmarket species severing the concept of maintaining biodiversity. Such analytic blindness creates a false sense of well-being even as economic growth threatens disastrous ecological consequences (Miller and Rees 2000). In short, economy separates human beings from rest of the species and the nature as a whole, similar to ecology, which does this in a different way. Ecologists give a very high value on other species, expending little effort on humans as ecological entities in their own right. They study the impacts induced by humans, but ignore the impacts on humans as components of affected ecosystems.

The conflict between the economy and ecological integrity mainly arises due to some characteristics of former such as scale, equity and distribution. It is due to the huge growth of economy that the life supporting system of the Earth is in serious state today. There are several indicators to judge the scale of this growth – shrinking wild or natural space, rate of depletion of tropical natural forest, amount of consumption of nonrenewable energy, volume of greenhouse gases in the atmosphere, area of depletion of ozone layer, rate of

-12- 2 Integrity of the river system extinction of species, and the stocks of toxic and other wastes. The problem of equity and distribution of the resources in modern market shows amusing picture as well. For example, if the available world food supply for the past 20 years had been evenly divided and distributed, each person would have received more than the minimum number of calories. The reality is that a large section of the world population is under famine.

Similar example is put forward by Sterba (1998) when he says that presently the amount of grain fed to American livestock is as much as all the people of China and India eat in a year. These two countries constitute around one third of the world’s population. Yet, in another of such example, it has been estimated that presently a North American uses fifty times more resources than an Indian. This means that in terms of resource consumption the North American continent’s population is the equivalent of 12.5 billion Indians. These examples are mentioned here just to highlight the problem of equity and distribution in the modern economy, which in turn are the threat to the integrity of natural systems.

However, there is an emergence of new breed of economists who see the earth with its natural environment as a “spaceship” or a “lifeboat”, where the nature surrounds us with life support systems minutely calibrated to our needs. They foresee an ecological disaster when the global economy exceeds the limits of nature. Daly, who himself is this brand of economists, imagines that the spaceman in a small capsule lives off tight material cycles and immediate feedbacks, all under total control subservient to his needs (Sagoff 1995), Thus, if for “cowboy” the integrity of ecosystem has no value, for the spaceman it is utmost.

2.4 Integrity and sustainability:

Another concept with which the ecological integrity is often compared is the sustainability. The last decade of the last century perhaps was the decade of the paradigm called “sustainable development”. It was taken as a remedy for all environmental and developmental issues especially after the World Summit of 1992 though the seed had been planted way back in 1972 United Nations Stockholm Conference on the Human Environment. Agenda 21, one of the most important outcomes of the summit, carries the complete legacy of sustainable development. The legacy continued till recently, when number of flaws appeared in it.

-13- 2 Integrity of the river system

The flaws in sustainability starts right from the famous statement “yield the greatest sustainable development to present generations while maintaining its potential to meet the needs and aspirations of future generations.” But the question is whose generations. According to Noss (1995), the “needs and aspiration” of present and future generations considered in the World Conservation Strategy, were of human generations only. According to this philosophy, the needs of nonhuman species can be ignored at least unless it can be shown that the species in question benefit humans. Thus, the concept of sustainability was proven to be too anthropocentric whereas that of integrity is much broader.

The other shortcomings of sustainability as noted by Irvine (Noss 1995 and the references therein) include a failure of those who promote sustainability to consider environmental and social limits to growth. This means the growth could be limitless as long as it is defendable with general people and the society. For example, a housing company may justify the draining of wetland as to provide more benefits. Likewise, other shortcomings include the unwillingness to address the unsustainability of the current human population, much less its expected growth and reluctance to confront the implications of the lifestyles of average citizens of the more affluent societies. These two flaws appear as a bargaining point of highly populated developing world and highly consumptive developed world not to provoke each other.

An unrealistically optimistic faith in “alternative” technologies, institutional reform, redistribution of wealth, decentralization, and personal empowerment is another shortcoming of the sustainability concept, where the terms have become buzzwords of politicians, economists, industrialists, development planner, and even some environmental agencies. The last and perhaps the most important flaw of the concept is a failure to recognize the claims of other species to their share of the planet's resources. Irvin himself said that this failure is the most troubling one as it carries the belief that humans worth more than other species. According to him this conclusion has no objective basis and is a prejudice every bit as pernicious as the belief that whites are superior to blacks or males are superior to females (or vice versa).

A good thing sustainability points toward is the sustainable use of resources, which no one can deny. However, ecological integrity is a concept potentially broader and more biocentric than sustainability. It not only includes sustainable use of resources, but also

-14- 2 Integrity of the river system sustenance of ecological and evolutionary processes, viable populations of native species, and other non-human qualities of ecosystems, for their own sake. Brown et al. (2000) even go further and say that in protecting ecosystem integrity, it is not individual species, the quantities of stock and productivity, or resources used by humans that is of paramount importance, but the ecological system they all depend upon that is the focus of concern.

2.5 Integrity and health:

One of the concepts often confused with ecosystem integrity is ecosystem health. The two terms do not contradict with each other but the former is much broader and within it includes the latter. Health has been defined as the capacity to resist adverse environmental impacts and as “the imputed capacity to perform tasks and roles adequately”. Also the health paradigm is concerned with the present time and perhaps the immediate future, whereas the integrity perspective poses no time limits and envisions birth, maturity, and death cycles that may also produce different paths and trajectories, according to the largely natural, evolutionary development of the system (Westra 1995).

Ecosystem health at its best connotes a stable state of well-being but does not speaks of process of change, response to stress and self-organization, which are the features of integrity. The integrity generally applies to the sites with little or no human interference, while in contrast the health describes the preferred state of sites modified by human activity (Westra 1995 and references therein). For example, the healthy conditions could be found in cultivated areas, plantation forests and even in the cities but integrity in evolutionary sense is nowhere there. Thus, a site may be considered healthy when their management neither degrades the site for future use nor beyond their boundaries.

According to Karr and Chu (1995), health implies a flourishing condition, well-being, vitality or prosperity. An organism is healthy when it performs all its vital functions normally and properly with minimal outside care. And this concept of health applies to individual organisms as well as to national or regional economies, industries and to natural resources. Thus, an environment is regarded as healthy when the supply of goods and services required by human and nonhuman residents is sustained. Interestingly, much of the policymakers and scientists these days are addressing the problems of ecosystem health, and this, in a way, is good because managed and supported ecosystems are the only ones we

-15- 2 Integrity of the river system should consider alternative for sustainable use such as alternative agriculture or sustainable forestry.

2.6 Integrity, equilibrium and disequilibrium:

The concept of ecological integrity was developed by keeping ecosystem in equilibrium. Westra (Shrader-Frechette 1995 and the references therein) speaks of “integrity” together with “health”, “wholeness”, “stability”, “balance” and “harmony". While Sagoff (1995) emphasizes the interconnectivity within ecosystems, the interdependency of their parts and their progress, toward increased stability and diversity, the literal meaning of integrity too points toward a valuable whole, “the state of being whole, entire or undiminished” or “a sound, unimpaired, or perfect condition”. In short, the ecosystems without human interference are taken as the system in full equilibrium and integrity. However, many modern scientists and philosophers have serious questions on these attributes of integrity.

The beginning of the questions perhaps started some 40 years before when we were able to see the Earth from the space and found how we were isolated in a small piece of space debris. From the distance of space, we saw ourselves and our planet exposed in an unexpected fragility and vulnerability (Karr and Chu 1995). This could be the first time humans have realized that our home is not so stable and powerfully balanced as we had presumed. Further, the change and the disturbance are the norms and the environments do not typically tend toward balanced, stable and integrated states. On the large scale, it is marked by glacial and climatic changes that show little recurring pattern and tells that over the long run natural environments will remain in constant flux. On a smaller scale, this is evidenced by fires, storms, floods, droughts, invasion by exotic species and many more that continually modify natural environments in ways that do not create the repeating patterns of return to the same equilibrium state (Sterba 1998).

Thus Worster (Sterba 1998 and the references therein) claims that nature is fundamentally, erratic, discontinuous and unpredictable. Similarly, systems ecologists and other systems analysts now recognize that the behavior of most of the natural world is nonlinear, discontinuous, irreversible, and characterized by lags and thresholds.

-16- 2 Integrity of the river system

Often, the natural ecosystems are described as a complex and dynamic system with the interrelationship of physical, chemical and biological factors. Scientifically and artistically many have proved that the complexity of the ecosystem results in stability and balance and its development has some predictable route. However, after chaos theory these facts too look like vulnerable. The theory notes that any real dynamic system, even one described by a set of deterministic equations, is ultimately not predictable because of the accumulation of individually small interactions between its components. This applies to balls on a billiard table and the planets in heavens. This means that our ability to forecast and predict will always be limited regardless of how sophisticated our computers are or how much information we have (Westra 1995 and the references therein).

It is difficult to characterize integrity in systems that are not static. Ecosystems changes over time due to purely natural factors and their changes are often chaotic and unpredictable (Noss 1995). He further adds that even over much shorter spans of time, natural ecosystems are far from stable and unvarying. Natural disturbances occur at a variety of spatial and temporal scales, so that a landscape is more of a shifting mosaic of patches than a homogenous vegetation in equilibrium with its physical environment. Thus, it is difficult to assign integrity to a system, which is continuously varying, frequently disturbed, unstable and unpredictable. Van Valen and Pitelka (Sagoff 1995 and the references therein) even go on to say that “ecology has no known regularities.” Likewise, an ecologist has said recently, “whenever we seek to find consistency in nature, we discover change.”

Even if we consider the concept of evolution, the traditional definition of integrity has to face a lot of criticisms. It has been observed that most species respond to environmental change in an individualistic manner. As a result, the species composition of communities is continuously changing. Species we see together today may have been separated for most of their evolutionary histories (Noss 1995). Thus, he further adds that if communities are just transient aggregations of species, how can they be said to possess integrity? In addition, when we talk about adaptations, it is populations and not ecosystems that adapt. Adaptation is restricted to heritable characteristics; no alleged knowledge of the past operates in natural selection, and the individual, which is better adapted to the present environment, is the one that leaves more offspring and hence transmits its traits (Shrader-Frechette 1995).

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Every kind of organisms that we see today has reached this moment in time by threading one needle after another, throwing up brilliant artifices to survive and reproduce against nearly impossible odds (Sagoff 1995). It is the enormous and timeless labor of evolution that invests its products – the plants and animals we encounter – with a dignity and meaning. Their legitimacy is based not in any purpose they may serve – ours or that of some superorganism that contains them – but in the circumstances of their coming hither. Ecosystems do not have desires, aims or wants rather individuals have. Thus, it is difficult to define good or bad for ecosystems, as they cannot experience pleasure or pain.

The complex systems like ecosystem response to the change or stress in a multitudes of way, (1) the system could eventually continue to operate as before, or (2) it could operate with a reduction or increase in species number, or (3) it could exhibit new paths in the food web, or (4) it could take on a largely different structure with different species and food webs (Shrader-Frechette 1995 and the references therein). Any of these changes are possible but it is difficult to decide which one is the most natural and acceptable one, or which one possess or lack of integrity. Similar view is expressed by Noss (1995) as he puts, “after disturbance, an ecosystem may have multiple potential pathways of successional development and multiple potential endpoints.” Thus an intermediate stage in forest succession is not with less integrity than a climax forest.

In many cases it is even difficult to identify the climax stage as the communities continue evolving. This is normally identified by those who carry equilibrium concept. In addition, there is a general lack of empirically measurable conditions of integrity. Moreover, there are confusions and vagueness in the words that describe the integrity. Like many other concepts in science, the integrity too cannot be defined strictly in mechanistic way. All these facts and arguments are on the side of those who believe the disequilibrium paradigm. However, this paradigm leads to the path of inaction, as it believes nothing is certain. Equilibrium concept on the other hand defines the goal and gives the guideline for governments and policy makers to develop plans related with environment and natural resources.

2.7 Integrity revisited:

It is generally accepted that ecological integrity is essential to maintain and protect life- support systems, which are basic to both humans and nonhumans. The base of the

-18- 2 Integrity of the river system economies and social sustainability is nature and its resources, without which neither of them flourish.

Of course, change is the eternal law. Even some species such as fire-adapted pines and the animals dependent on them, require frequent disturbance that brings change to cope competition by fire-intolerant species. But accepting that change and disturbance is necessary to keep ecosystems healthy and diverse does not require that we accept all changes (Noss 1995). Let the changes be brought about by nature itself rather than by humans, who are now equally capable of inducing a change of same magnitude. Botkin (Noss 1995 and the references therein) too emphasized that the rate of change associated with human disturbances are often far beyond what organisms are adapted to coping with.

It is not generally acceptable that the human activities do whatever to bring the change in environment even though change is natural. This will be clearer if we see ecosystems in functional and evolutionary context. Nature has functional constraints because organisms have physiological limits to what they can tolerate. Human induced stresses often exceed these limits. Likewise nature has evolutionary constraint as species are limited in how quickly they can adapt the changing environment. Here too, the rate of change induced by modern human activities exceeds rates experienced by species over their evolutionary histories. Thus, those who believe integrity concept are right when they ask mankind to restrict their activities below the functional and evolutionary limits the nature creates for each ecosystem.

All natural changes are not deleterious to human beings. Nature is full of examples showing miracles that could inspire and satisfy our needs and desire. Many will agree that the basic requirement for these things to happen is the absence of human influence and manipulations. One of the best examples we can mention here is about El Nino episode that happened some years back in South America. The episode was vastly described as a very bad climatological event, though it also showed how unmanipulated systems keep their integrity intact. A desert area in Chile dramatically changed into a wonderland of flowers and grasses due to the unusual rain brought in by El Nino.

This burst of life in once barren land has been interpreted in various ways by Westra et al. (2000) to highlight the integrity of nature. The first conclusion they made was that the

-19- 2 Integrity of the river system desert retained its biological potential because its vital state had not been reduced by human disturbance. The area where the vital state has been changed by human activities is less likely to experience such positive changes. The rapid bloom of desert organisms illustrates in a dramatic fashion some of the autopoietic (self-creative) capacities of life to organize, regenerate, reproduce, sustain, adapt, develop and evolve. This was their second conclusion. Even a landscape like desert has such natural capacities to wonder how much capacity a more fertile landscape might possess.

As another conclusion, they said that the self-creative capacities are dynamically temporal. The display of new forms of life in the desert gains significance through its past and its future. Thus, nature’s rhythms are displayed over time and no momentary snapshot captures all of nature's potential. Finally they said that ecological integrity is valuable and valued. The story of the Chilean desert is one simple example that provoked wonder and appreciation. Some ecological communities, such as tropical forest show their marvels in a more continuous, less seasonal or episodic fashion. More generally, the biological and physical processes work together to give rise to the totality of life on Earth, including ourselves, and maintain the conditions for the continuation of life.

Thus, natural ecosystems are valuable to themselves for their continuing support of life on earth, as well as for the aesthetic value and the goods and services they provide to mankind. This is why there is a growing concern about the policies and law regarding ecological integrity. Ecological integrity is taken as an umbrella concept in the management and conservation of nature and ecosystems. The concept joins natural science with the different fields of social sciences including economy and very much helps in the formulation of public policies. In addition, the works of Karr, Ulanowicz etc has made the measurement of ecological integrity much easier and meaningful through creation of multimetric indices.

2.8 Ecological integrity and the rivers:

Although rivers and streams represent only a small portion of a landscape, their state is indicative of the condition of the whole watershed. Rivers, like blood samples from a human, are indicative of the health of the landscape (Karr 1999). In addition, looking at the rich biotic characteristics rivers are like lifelines of a continent with a picture of the condition of surrounding landscapes and connecting landscapes over a great distance. Thus,

-20- 2 Integrity of the river system integrity of the river system in many ways also contributes to the maintenance of the integrity of the other ecosystems.

The integrity of the river system refers to its natural and wholesome state, supporting all life forms; aquatic and terrestrial, and capable of doing its usual geological functions. The streams and rivers are complex ecosystems that take part in physical and chemical cycles that shape our planet and allow life to sustain. Thus, rivers and streams are not just a strip of water cutting its way through the hills and mountains and finding its way downhill meandering slowly toward the sea. It is much more than that. Certainly its bottom extends beneath the ground and the sides into its floodplains. Because of its complexity series of ecological concepts have evolved time to time regarding the river system. Khanal (2001) has enumerated most of these concepts in his work that describe the function and structure of river in time and space. These concepts are important in order to gauze the integrity of the running waters.

Among these the Zonation Concept is one of the earliest river ecology concept and according to this, along the longitudinal course of a river as and when the physiographic and physiochemical conditions change the typical zone change as a phenomenon of spatial succession. The features such as current and water temperature are particularly able to distinguish the different zones. This subdivision of rivers into successive zones is also characterized by biological inputs. Therefore in a typical river there is a clear trout zone or barble zone etc. Similar zonation could also be obtained in the basis of benthic invertebrates and other groups of organism as well.

The second river ecological concept is the river continuum concept (RCC), which describes the structural and functional characteristics of aquatic communities along the whole length of a river. According to this concept the biotic community of the stream adapts it structural and functional characteristic to the abiotic environment, which forms a continuum with a continuous gradient from headwaters to the river mouth (Vannote et al. 1980). Particularly, this concept divides rivers into three parts based on the stream size such as headwaters (stream orders 1-3), medium sized streams (stream orders 4-6) and large rivers (order above 6), which in turn is based on the size of particular organic matter and primary productivity.

-21- 2 Integrity of the river system

There is an intermediate concept between the first two concepts called the theory of stream hydraulics (Statzner and Higler 1986). This concept states that there appears a distinct change in species assemblages related with transitions in stream hydraulics. The stream hydraulic is governed by geomorphological and hydrological characteristics such as current velocity, depth, substrate and the slope.

Another ecological concept that explains a lotic system is resource spiraling concept. The concept explains the processing of organic matter along the length of the river. According to this concept, downstream flow of river results in downstream displacement of material which creates a partially open cycle or ‘spiraling’. Spiraling can be measured with the unit ‘spiraling length’ (S), defined as the average distance along which the river flows during one cycle of a nutrient element, such as carbon and shorter the spiraling length, the more efficiently the nutrient is utilized.

Serial discontinuity concept (SDC) developed by Ward and Stanford (1983) describes about the consequences of putting dams and weirs on rivers. Natural flow of river is a continuum and the construction of dams and weirs disrupts this, which results in upstream-downstream shifts in abiotic and biotic parameters and processes. The concept considers two parameters to assess the relative impact of dams on river ecosystem. The discontinuity distance is the first, which is the distance over which the values of physical or biological variable are shifted upstream or downstream. And the second is the intensity, which is the change in the values of variables as a result of these disruptive structures.

Another important concept regarding river systems is the flood-impulse concept (FPC) put forward by Junk et al. (1989) and it describes the effects of floods on river channel as well as in its floodplain in an unmodified river system. The nutrient cycle, that is, the release and storage of nutrients in floodplains mainly depends on the flood cycle, vegetation cover and in temperate regions also in the growth cycle of the vegetation. The fertility of the floodplain is determined by the quality of the sediment. The river-floodplain system is characterized by a variety of habitats from plains, bars, levees and swales to ox-bows, backwaters and side-channels. Thus, a little fluctuation in flood cycle affects the diverse habitats associated with it, which together form a rich biodiversity. FPC agrees that the periodic floods in the rivers are vital for the survival of these large communities.

-22- 2 Integrity of the river system

Riverine productivity model (RPM) introduced by Thorpe and Delong (1994) also highlights the productivity of the river system, but differs with RCC in that, the carbon in constrained large rivers is not solely supplied from downstream transport but also from local autochthonous production and inputs from riparian zone. The composition of macroinvertebrates and the phytoplankton productivity measurements in large rivers suggest that in-stream primary production is an important energy source in the downstream part of the river, which is the main statement of this model.

Patch dynamic concept has received the inputs from Fisher et al. (1982), Power and Stewart (1987), Pringle et al. (1988) etc. According to them the organisms in the streams exhibit patchwork nature where different patch types are the result of different disturbances. A ‘patch’ could be defined as a spatial unit, which is determined, by both organisms and disturbances. This concept mainly argues that the species with similar ecologies coexist in stream systems. It also emphasizes that the community composition changes with such patches and that there occurs a significant variation in community structure even in a small spatial scales.

The next concept worthy regarding river system is the mosaic dynamic concept. Normally a river shows a sequence of ecological gradient in terms of water flow, organic matter, fish populations, and many other factors which change more or less gradually from head waters to river mouth as a continuum (Frissell et al. 1986). However, there exists a relatively clear boundaries for these characteristics and appear as a mosaic of series of unit. Thus, according to this concept a river appears as a series of mosaic superimposed on the underlying gradients.

Habitat templet theory is another important theory that explains the dynamics of a river system. Proposed by Townsend and Heldrew (1994), the theory sees the river habitats as a templet with axis of temporal and spatial heterogeneity. They explained that the temporal variation bear a relationship with the disturbance regime to which organisms are subjected while the spatial heterogeneity tends to ease or modify the influence of disturbances by providing refugia where survival is more likely.

Yet, the broadest and perhaps among the widely accepted concepts regarding river is the catchment concept. Several scientists have given argument in favor of catchment-oriented

-23- 2 Integrity of the river system approach. Frissel et al. (1986) put forward a framework for stream habitat classification that emphasizes a stream’s relationship to its watershed over a wide range of scales in time and space. Similarly Gardiner (1990) came up with a manual for holistic appraisal of river on a catchment scale. The structure and function of river is highly dependent on the characteristics of whole catchment area.

Finally Petts (Khanal 2001 and the references therein) combined and integrated all the important research on the functioning of river systems into a number of principles. According to this rivers are: 1) three dimensional systems – longitudinal, vertical and lateral; 2) driven by hydrology and fluvial geomorphology; 3) structured by food-webs; 4) characterized by spiraling processes; and 5) dependent upon change – changing flows, moving sediments and shifting channels. Thus, as any ecosystem, rivers too are a highly complex system.

-24- 3 Fish as an indicator of ecological integrity

CHAPTER III: FISH AS AN INDICATOR

3.1 Bioindication and bioindicators:

Organisms, populations, biocoenoses and, ultimately, whole ecosystem are naturally influenced by numerous biotic and abiotic stress factors such as fluctuations in climate, varying radiation and food supply, predator-prey relationships, parasites diseases, and competition within and between species (Markert et al. 2003). Naturally, the living organisms react to such stressors and that’s how the ecosystem develops and together forms the raw material of the evolution. Within one evolutionary epoch, the range of variation of stress factors, generally, remains constant allowing the species to adjust to changing environment.

In recent times, however, the environmental changes have increased in terms of both quality and quantity. Through human activity the environment has been confronted with totally new substances that did not previously exist (xenobiotics, radionuclides) and potentially harmful substances (heavy metals) released in quantities unthinkable in the past (Markert et al. 2003). These new stressing factors together with the one occurring in nature result in a multiplying effect, which often exceed the tolerance level of the organisms and diminish the ability to cope or adjust. In the same time, the extent of effects on the living organisms reflects the quantity and quality of different stress factors. The organisms then are called as biomonitors and bioindicators, and the process bioindication.

There are some differences between the terms bioindicators and biomonitors as pointed out by Markert et al. (2003). A bioindicators is an organism (or part of an organism or a community of organisms) that contains information on the quality of the environment (or part of the environment). A biomonitors on the other hand, is an organism (or part of an organism or a community of organisms) that contains information on the quantitative aspects of the quality of the environment. Though the term biomonitors is more inclusive, bioindicators is more popular and is in extensive use. The bioindicators, also sometimes called as indicator taxa or ecological indicators are species which are known to be sensitive to processes or pollutants that lead to a change in biodiversity and are taken as surrogates

-25- 3 Fish as an indicator of ecological integrity for larger communities and act as a gauge for the condition of a particular habitat, community or ecosystem (Markert et al. 2003).

Bioindication is the analysis of the informational structure of living systems, ranging from single organisms to complex ecosystems, in order to define environmental quality or assess environmental hazards and risks (Fränzle 2003). Thus, the bioindicators contribute to the information need of ecosystem management. The organism has significance beyond what is actually measured; in addition to the information of its presence and abundance, it provides information on the occurrence of ecological processes (Lorenz 2003). For example, occurrence and abundance of predator’s species indicate that the food web functions sufficiently. According to Lorenz (2003), bioindicators can provide the following information for ecosystem management:

• A description of ecosystem processes and structures • The ecosystem condition by comparing the ecosystem with a reference level of good ecological functioning. • Cause-effect relationships within an ecosystem.

Besides those utilities, one of the important advantage of bioindication is that there are different groups of living organism to chose from, such as bacteria, algae, plants and animals, which can serve the purpose depending upon the objective and type of ecosystem under investigation and monitoring. For example, plant species are very good bioindicator of air pollution, whereas animals, generally with a greater arsenal of stress coping mechanism, are perhaps best used in aquatic ecosystem. Another advantage of biomonitoring approaches is the low cost in comparison to those of instrumental measurements. Finally, species are spectacular and more appealing to the policymakers and public and thus get a quick political acceptance and investment for investigation.

Many groups of organisms have been proposed as indicators of environmental quality, but no single group has emerged as the favorite of most biologists (Karr 1981). He further says that diatoms and benthic invertebrates have most frequently been cited as ideal organisms for biological monitoring because of the availability of a theoretical structure that allows an integrated ecological approach. However, their use in monitoring has many drawbacks, such

-26- 3 Fish as an indicator of ecological integrity as, it needs specialized taxonomists; life-history information is often lacking; difficult and time consuming to sample, sort and identify; and the values less meaningful to the general public (Karr 1981). Fish has clear advantages as indicator organisms for biological monitoring program and thus its use for this purpose is ever increasing.

3.2 Fish as Bioindicators:

3.2.1 History and development: Fish have been and remain a major part of any aquatic study designed to evaluate water quality (Simon 1999). This sentence indicates that the use of fish as environmental indicators has passed a considerable time and is continue to grow stronger. Simon (1999) further adds that beginning around 1900 and accelerating greatly in about last 20 years, fish community characteristics have been used to measure relative ecosystem health. In fact the study of relationship between the fish and water bodies, arguably, started with human civilization in ancient time. There are evidences in the form of stories that the fishermen always knew the particular site or stretch of water bodies for desired type and amount of fish.

The same approach, that is, the spatial changes of fish communities along the course of river systems and the use of fish zonation patterns for river classification are examples of some of the most traditional bioindication approaches as could be seen from the work of Fritsch, 1872 and Thienemann, 1912 and 1925 (Chovanec 2003 and the references therein). The use of fish communities as indicators of biological integrity was documented as early as the turn of the last century on the Illinois River (Simon 1999). Simon (1999) further documents the numerous studies on the changes in fish distribution as a result of pollution plumes and sewerage outfalls such as Brinley 1942; Katz and Gaufin 1953; and Karr et al. 1985a.

Fish as a bioindicator, mainly, developed from the United States, where the fish have been one of the most studied groups of aquatic organisms since 18th century. There are documentation of earlier work on distribution and composition of the fish faunas of the region’s rivers and streams, such as Rafinesque (1820), Kirtland (1838), Jordan (1890), Kirsch (1895), and others. These works latter in 20th century led to the development of inventories of composition and distribution of the fish faunas in many states. Fish fauna of

-27- 3 Fish as an indicator of ecological integrity

Illinois (1920) was one of the first to appear followed by Indiana (1945), Ohio (1957; 1981), Missouri (1975), Kentucky (1975) etc. By now United States and Canada have almost a complete list of composition and distribution of their fish according to regions and rivers. These not only provided a baseline against which changes through the 19th and 20th centuries were evaluated, but provided the impetus for future developments including the routine use of fish assemblage as an indicator of the condition of water resources as a whole (Yoder and Smith 1999).

Thus, starting from around 1800, gaining some movement from the beginning of 1900s and accelerating tremendously in the last 25 years or so, fish community characteristics have been used to measure relative ecosystem health. A variety of quantitative indices are now at our disposal to measure the various impacts on the water bodies. Perhaps, the first of this kind is the Index of Well-Being (Iwb) developed by Gamon (1973) to evaluate structural components in numbers, biomass and species richness for assessing water resources (Simon 1999 and the references therein). Several modifications of this index called as Modified Index of Well-Being (MIwb) also exists such as the one referred in Ohio EPA, 1987b where the species designated as highly tolerant, exotic, and hybrid are eliminated from the numbers and biomass components of the Iwb.

There is another index called Health Assessment Index (HAI), which is an extension and refinement of a previously published field necropsy system developed by Goede and Barton (1990) that provides a health profile of fish based on the percentages of anomalies observed in the tissues and organs of individuals sampled from a population (Adams et al. 1993). This index is based on the assumption that the biotic integrity of an ecological system is often reflected by the health of organisms that reside in that system and in aquatic ecosystems, fish, and particularly those species near the top of food chain, are generally regarded as representative indicators of overall system health.

However, it is the Index of Biotic Integrity (IBI), first proposed and developed by Karr (1981) is the most widely accepted and extensively used assessment method, where the fish and their attributes are in center of investigation. The IBI is based on the hypothesis that there are predictable relationships between fish assemblage structure and the physical, chemical and biological condition of stream systems. The IBI was originally developed for Midwestern US streams, and integrated 12 attributes of fish assemblages to determine biotic

-28- 3 Fish as an indicator of ecological integrity integrity or ‘health’ of the system (Hughes and Oberdorff 1999). Since its formulation, the IBI has been modified almost annually and used in other regions and types of ecosystems throughout the US and Canada.

Today, the fishery scientists and environmentalists all over the world use different types of IBI, all with slight modifications in the original one to suit their own climatic and geographic region. Hughes and Oberdorff (1999) have located at least 10 applications of the IBI outside the US and Canada in small rivers and wadeable streams on six continents: Europe (Oberdorff and Hughes, 1992; Oberdorff and Porcher, 1994; Oberdorff, 1996, in France; Didier et al. 1996, in Belgium), Africa (Hugueny, 1996, in Guinea; Hocutt et al. 1994 in Namibia), Asia (Ganasan and Hughes, 1998, in India), South America (Gutierrez, 1994, in Venezuela), Australia (Harris, 1995), and North America (Lyons et al. 1995, in Mexico).

Many parameters used in assessment of fish communities in IBI requires a sound knowledge of physical and chemical characteristics of the stream, and the variables or metrics like species composition and richness, trophic level of the species, fish abundance and fish condition. Although originally developed for the Midwestern US, the IBI has been adapted for use in a variety of other ecoregions and such adaptations usually necessitate the substitution, addition, or deletion of metrics from the original IBI and the development of new scoring criteria for some metrics because of zoogeographic, geological, or climatological factors that affect faunal composition (Paller et al. 1996). The full fledged application of this index in Nepalese condition still needs more studies on the fish fauna of the country, however, the present work, which tests some of the metrics, marks the beginning.

3.2.2 Advantages of use of fish as bioindicator: There are several reasons why fish are widely used and accepted to describe natural conditions as well as the alterations of aquatic systems. The advantages mentioned here are the compilations of the advantages listed by many scientists working in this field such as Karr (1981), Fausch et al. (1984), Leonard and Orth (1986), Hughes and Noss (1992), Paller et al. (1996), Simon (1999), Yoder and Smith (1999), Hughes and Oberdorff (1999), Chovanec et al. (2003), Fränzel (2003), Lorenz (2003).

-29- 3 Fish as an indicator of ecological integrity

• Life-history information is extensive for most fish species. • Fish communities generally include a range of species that represent a variety of trophic levels (omnivores, herbivores, insectivores, planktivores, piscivores) and include foods of both aquatic and terrestrial origin. Their position at the top of the aquatic food web in relation to diatoms and invertebrates also helps to provide an integrative view of the watershed environment. • Fish are relatively easy to identify. Indeed, most samples can be sorted and identified at the field site, with release of study organisms after processing. • Both acute toxicity (missing taxa) and stressed effects (depressed growth and reproductive success) can be evaluated. Careful examination of recruitment and growth dynamics among years can help to pin point periods of unusual stress. • Fish are typically present, even in the smallest streams and in all but the most polluted waters. • The general public can relate to statements about conditions of the fish community. • A long tradition of ecological, physiological and ecotoxicological research on fish has led to an advanced knowledge of the ecological requirements of a large number of fish species. The effectiveness of bioindication approaches depends on the sound knowledge of the indicator’s ecological demands and physiology. • As migratory organisms fish are suitable indicators of habitat connectivity or fragmentation. • Due to the size of fish (and their organs) a great variety of analytical procedures can be carried out. • Due to the longevity of fish certain indication effects, e.g. accumulation processes are increased and thus a long-term effects can be studied. • The reconstruction of pristine reference communities is possible due to the existence of historical information. • Fish have larger ranges and are less affected by natural microhabitat differences than smaller organisms. This makes fish extremely useful for assessing regional and macrohabitat differences. • While assessing the environmental quality by fish assemblage stock assessment also goes side by side which is important for the sustainable harvest of this resource.

-30- 3 Fish as an indicator of ecological integrity

• They have both economic and aesthetic values and thus help raise awareness of the value of conserving aquatic systems.

However, there is a couple of drawback of using fish as a bioindicators. • Fishery caused alterations, such as species transfer, stocking and overfishing make it more difficult to discuss other man-induced degradations of aquatic ecosystems. • The mobility of many species makes it difficult to identify not only the exact source of pollution, but also the time and duration of exposure.

It is seen from the above list of advantages and disadvantages that the advantages distinctly outweigh the drawbacks, and thus, the use of fish as a bioindicator is becoming more and more popular all over the world.

3.2.3 The Index of Biotic Integrity (IBI): There is an increasing demand for quantitative, easily applied and sensitive biological measures of ecological integrity of aquatic system both in developed and developing countries. A variety of quantitative indices using bio-criteria exist to assess the quality of rivers and streams. Of these, the most commonly used and, arguably the most effective, has been the Index of Biotic Integrity (IBI). The Index of Biotic Integrity (IBI) was first developed by Karr (1981) for low gradient, small warm water streams affected by intense agricultural activity, but was designed so its metrics could be modified to reflect species differences in other stream types (Leonard and Orth 1986, Chovanec et al. 2003). When Karr proposed this, he had a long experience of working with fish and water quality and had the opinion that by carefully monitoring fishes, one can rapidly assess the ‘health’ (‘biotic integrity’) of a local water resource. The IBI was developed to assess the biological integrity of lotic systems effectively and directly (Karr 1981). The IBI applies features of indigenous fish communities to assess watershed and stream quality, and is based on the assumption that community features change with stream degradation.

Typical effects of environmental degradation on fish assemblage were compiled by Margalef (1963) and Fausch et al. (1990) and were developed by Hughes and Noss (1992) in a tabular form.

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Typical effects of environmental degradation on biotic assemblages

The number of native species, and of those in specialized taxa or guilds, declines The percentage of exotic or introduced species or stocks increases The number of generally intolerant or sensitive species declines The percent of the assemblage comprising generally tolerant or insensitive species increases The percentage of trophic and habitat specialists declines The percentage of trophic and habitat generalists increases The abundance of the total number of individuals declines The incidence of disease and anomalies increases The percentage of large, mature, or old-growth individuals declines Reproduction of generally sensitive species decreases The number of size and age class declines Spatial or temporal fluctuations are more pronounced

Table 3.2.1: Typical effects of environmental degradation on biotic assemblages

These knowledge of typical effects of environmental degradation on fish assemblage has tremendously helped in the origin of IBI by Karr (1981) and latter on in its modifications by different scientists. In addition, these effects have also allowed the proponents of IBI to select the suitable variable or the metrics for their formula. These attributes of stream fish communities are also relatively easy to measure and thus have helped in the development of IBI. In his original work Karr (1981) had designed to assess the status of the community using twelve fish community parameters, which could be roughly grouped into two sets – species composition and richness, and ecological factors. These parameters are listed in the following table.

Parameters used in assessment of fish communities Species Composition and Richness • Number of Species • Presence of Intolerant Species • Species Richness and Composition of Darters • Species Richness and Composition of Suckers • Species Richness and Composition of Sunfish (except Green Sunfish) • Proportion of Green Sunfish • Proportion of Hybrid Individuals

Ecological Factors • Number of Individuals in Sample • Proportion of Omnivores (Individuals) • Proportion of Insectivorous Cyprinids • Proportion of Top Carnivores • Proportion with Disease, Tumors, Fin Damage, and Other Anomalies

Table 3.2.2: Parameters used in assessment of fish communities. Source: Karr (1981)

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Karr (1981) argues that the choice of species richness and total number of individuals as primary criteria for assessment, as long as those metrics are weighted by biogeographic, season and stream-size considerations. This allows a freedom to modify the metrics according to region, season and stream-size. In the same time, dynamics of production and consumption of energy, reflected by the second set of parameters as it indicates the water quality through changes in food availabilities or trophic levels.

Karr initially started assigning three values, (-), (0) and (+) for each metrics according to their state but as a step forward to quantify the system, he replaced them with the values (1), (3) and (5). These values are summed over all criteria for each site to provide an Index of Biotic Integrity. Since there are twelve metrics, the highest possible score according to this system would be 60. Six biotic integrity classes, such as ‘Excellent’, ‘Good’, ‘Fair’, ‘Poor’, ‘Very Poor’ and ‘No Fish’ are assigned according to score with some intermediate classes as well. The table 3.2.3 illustrates the suggested boundaries for the classes.

Class Index Number Excellent (E) 57 – 60 E – G 53 – 56 Good (G) 48 – 52 G – F 45 – 47 Fair (F) 39 – 44 F – P 36 – 38 Poor (P) 28 – 35 P – VP 24 – 27 Very Poor (VP) ≤ 23

Table 3.2.3: Evaluation criteria for IBI (Karr 1981)

The class ‘Excellent’ relates to the best situations without influence of man with the presence of all regionally expected species, including the most intolerant forms, with full array of age and sex classes. The class ‘Good’ is characterized by somewhat less species richness, mainly due to the loss of most intolerant forms. Here some species are represented with less than optimal abundances or size distribution and trophic structure is in stress. Similarly, the class ‘Fair’ indicates a further deterioration with fewer intolerant forms and more abnormal trophic structure.

-33- 3 Fish as an indicator of ecological integrity

The class ‘Poor’ is generally dominated by omnivores, pollution-tolerant forms and habitat generalists with depressed growth rates increased frequency of hybrids and diseased fish. ‘Very Poor’ class on the other hand is characterized by the presence of few fish, that too mostly introduced or tolerant species. Hybrids are common here, together with the fish with disease, parasites, damaged fins and other anomalies. The last class, ‘No Fish’ perhaps is the worst situation where a repetitive sampling fails to turn up any fish.

3.2.4 Modification of the Index of Biotic Integrity (IBI): One of the important aspects of IBI is its flexibility for modification, an attribute on which Karr himself is very proud of. The IBI is a multimetric indices that rates the existing structure, composition and functional organization of the fish assemblage with regional and habitat specific expectations derived from comparable high quality ecosystems (Lyons and Wang 1996). Simon (1999) also considered IBI as a member of multimetric indices that change structural characteristics depending on the geographic area. Thus, as the region of application of IBI changes, its metrics also changes.

There are numerous modifications of IBI, particularly in North America for the use in different regions (Fausch et al. 1984; Leonard and Orth 1986; Karr et al. 1987; Steedman 1988; Goldstein et al. 1994; Lyons et al. 1995; Lyons et al. 1996; Paller et al. 1996. Due to its popularity, the application of IBI spread to all the continents with different versions for different regions and different types of ecosystems. In Europe the IBI was modified and used by Oberdorff and Hughes 1992; Oberdorff and Porcher 1994; Oberdorff 1996; Didier et al. 1996, in Africa by Hugueny 1995, in Guinea; Hocutt et al. 1994 in Namibia, in Asia by Ganasan and Hughes, 1998, in South America by Gutierrez, 1994, in Australia by Harris, 1995, and in North America by Lyons et al. 1995, in Mexico. These new versions have the same multimetric structure, but they differ from the original IBI in number, identity and scoring of metrics.

In most of the new versions of IBI, the number of metrics called community metrics are selected, which fall broadly into three categories: species richness and composition, trophic composition and fish abundance and condition. Each metrics are adjusted to reflect changes in fish communities with the region and stream size. It is established that the natural variation in species richness of fish communities is determined by two factors: zoogeography and stream size. The prior knowledge of the natural condition and

-34- 3 Fish as an indicator of ecological integrity composition of the species of the streams under investigation is a must to choose the metrics and to put numerical values in it. When human activities degrade the rivers and streams, the aquatic communities they support are modified accordingly to various degrees. The IBI is designed to assess and evaluate the differences between natural or reference condition and the degree of disturbances. The following table lists metrics used in original IBI as well as the areas that could be modified to suit the stream size and the region.

IBI Modified from Karr (1981). IBI = sum of the scores of metrics Category Metric Scoring criteria 5 (best) 3 1 (worst) Species richness Total number of species and composition Number and identity of darter species Number and identity of sunfish species Varies with stream size and region Number and identity of sucker species } Number and identity of intolerant species <5% 5 – 20% >20% Proportion of individuals as green sunfish <20% 20 – 45% >45% Trophic Proportion of individuals as omnivores composition Proportion of individuals as insectivorous >45% 20 – 45% <20%

cyprinids >5% 1 – 5% <1% Proportion of individuals as top carnivores Varies with stream size and region Fish abundance Number of individuals in sample 0 0 – 1% >1% and condition Proportion of individuals as hybrids 0 0 – 1% >1% Proportion of individuals with disease, tumors, fin damage, and other anomalies Table 3.2.4.: IBI Modified from Karr (1981) IBI = sum of the scores of metrics Table source: Fausch et al. (1984)

Despite some examples of the application of traditional IBI for water quality monitoring, the fish base assessment of ecological integrity in Europe at present is more guided by Water Framework Directive (WFD) of European Union (EU). The main principle regarding bioindication approach to assess the ecological status of surface waters mentioned in WFD, EU (2000) calls for the assessment based on the investigation of the aquatic communities, algae, macrophytes, benthic macroinvertebrates, and fish (Chovanec et al. 2003). Subsequently, the ecological status of the water body is classified into five classes; high, good, moderate, poor and bad. For example the classification scheme for fish-based assessment of ecological integrity as developed by Schmutz et al. (2000) is given in the following table.

-35- 3 Fish as an indicator of ecological integrity

Criteria Levels of ecological integrity High Good Moderate Poor Bad Type-specific None or nearly Some species Several species Many species Most species species none missing missing missing missing missing

Self- None or some Several species Many species Most species Nearly all sustaining missing missing missing missing species missing species

Fish region No shift No shift Shift Shift Shift

Number of No guild No guild Single guild Many guilds Most guilds guilds missing missing missing missing missing

Guild No alteration Slight Substantial Complete Complete composition alteration alteration alteration alteration

Biomass and No or nearly Slight Substantial Heavy Extremely density no changes changes changes changes changed

Population No or nearly Slight Substantial Heavy Extremely age structure no changes changes changes changes changed Table 3.2.5: Fish-based assessment of ecological integrity (after Schmutz et al. 2000)

It is possible to modify the above metrics as well as the classifying system of the status of ecological integrity and apply to the Nepalese conditions once there is baseline information regarding the composition of fish in the region. The easiest way is to find the key indicator groups to substitute the metrics in the first category of the IBI. The second and third category of the metrics simply requires the number and proportion or ratio of the sampled fish.

However, the application of IBI in totality in Nepalese waters is not possible at present due to the lack of adequate information regarding fish fauna. Only a very few rivers in Nepal have been studied thoroughly in terms of biotic community. In addition, Nepal being one of the most heterogeneous countries in terms of geography, it is very difficult to generalize the information. Nevertheless, this study analyses and evaluates some of the metrics from the first and third categories to assess the impacts of some important human-induced disturbances in different rivers in Nepal. This study, with huge pool of data also opens the study and research on the fish-based assessment of surface waters in Nepal.

-36- 4 Electrofishing

CHAPTER IV: ELECTROFISHING

4.1 Definition and history:

Electro-fishing is a contracted form of electric fishing, which simply means fishing with electricity. In more technical definition, electro-fishing is the science of utilizing an electrical current to stun fish momentarily or force them to swim involuntarily towards an electrical field for collection. In this method, an electric current result in fish orienting themselves to the anode and swimming towards it involuntarily thus facilitate the capture. In this method, fish within the electric field are temporarily stunned and after a quick examination they are returned to the water without any harm.

Electric fishing probably started after the discovery of electricity and man’s ability to exploit this physical principal. Further evolution and development of this method of fishing is rather confusing. Hartley (1990) writes that the electric fishing developed from different origins in different environments and thus has a confusing history. Many of the events described below are documented by Hartley (1990). There are enough stories in different parts of the world about the use of electricity for fishing, even though it must have been in crude form with uncontrolled amount of current and lack of precautions. The first evidence or record of the electric fishing is the patent granted to Isham Baggs from London in 1863. However, this patent must have been the result of a long practical approach and the subsequent experience, indicating that the method is much older than that.

After Baggs’ work, there were a number of studies, mainly in Germany, regarding orientation and movement of fish when exposed to the direct current, as is shown by the work of Mach (1875) and Herman (1885). In England, in 1896, Loeb and Maxwell demonstrated that the sensory reaction of fish were forced and not voluntary. Just before that, Blasius and Schweitzer (1893) discovered the state called galvanonarcosis, in which the fish seemed to sleep with a relaxed body if it faced the anode. Practical aspects of electric fishing developed further in Germany as could be evident from the work of Holzer (1932) and Scheminsky (1924).

-37- 4 Electrofishing

There are also records that the Japanese fishermen were using electricity to drive out eels from their burrow into a net in the earlier part of the twentieth century. There was another patent in 1912, claimed by Larssen that allowed him to use electricity to catch a variety of aquatic creatures, which clearly indicates that he knew the potential of the method. The earliest record of an electric fish screen is from United States when Burkey had the first of his many patents in 1917. The work on the screens was later refined by MacMillan (1928) and Tauti (1931). The use of electricity for capturing fish in production studies dates from 1920’s (Lagler 1978).

After the II World War, development of electric fishing continued, mainly in Germany and US. Commercial production of electric fishing engines started at this time, which opened up a new dimension in the field of fishery science. In US, initially there were construction of small portable devices and the use of alternating current but later it was shifted towards construction of larger fishing devices such as fish screens using more advanced pulse direct current. With this, the days of experimental devices had passed and a whole lot of formalities, especially in terms of precautions against fatal accidents emerged.

Development of electric fishing in UK after the war followed the pattern of both Germany and US, but there were instances of some independent research elsewhere too. In the former Soviet Union, Strakhov and Nusenbaum (1959) were developing electric screens and Schentiakov (1960) electric trawling in lakes. In New Zealand, Burnet (1959) was testing electric fishing. Among the congresses and conferences, 1957 FAO International Fishing Gear Congress in Hamburg discussed the problems of electro-fishing, which was followed by the second congress in 1963. In 1965, the European Inland Fisheries Advisory Committee (EIFAC) arranged the meeting of various workers in the field and collected papers to form a book ‘Fishing with Electricity’ (Vibert 1967a).

The working party again gathered in 1973 in Poland to discuss and compare different aspects of fishing gear, which was compiled and published by Chmielewski (Hartley 1990 and the references therein). In the meantime, a book on general principles of electric fishing was published by Sternin et al. (1972), which was updated by Halsband and Halsband (1984). Lamarque, in collaboration with FAO did a study of electro-fishing in tropical water, which allowed the choice of best current for fishing either on seawater or low conductivity water. Two publications, Developments in Electric Fishing (Cowx 1990) and

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Fishing with Electricity (Cowx and Lamarque 1990), are among the most widely circulated books on electro-fishing so far. Now we are in the age, where due to advances in electronics, the construction of lightweight fishing gear with many designs and any type of current is possible.

Lamarque (1990) reported that between 1967 and 1987, there were 439 fishing operations in 15 countries in a range of biotopes including brooks, rivers, natural and fish farm ponds, fresh and brackish lagoons, lakes, estuaries, mangroves and the sea. During these, a great diversity of fish species (700) and crustacea (50) were caught at temperatures ranging between 5 and 33°C and conductivity between 7 and 40,000 mS cm–¹. Since then, the application of electric fishing is only increasing.

4.2 Fish response:

The reaction or the response of fish in the electric field is related with the nervous system, which is similar within themselves and also to those of other vertebrates. In a very simple term, the nervous system constitutes of brain and the spinal cord from where the myomeres come out and integrate the muscles. The objective in electrofishing is to interfere with this neurological pathway between the brain and muscles of the fish (Reynolds 2002). Thus, by disrupting the internal signal and overriding it with a signal from water, electric current redirects the neurological signal and muscular reaction.

Fish show certain characteristics when in the presence of electricity. The reaction of fish to electricity depends upon so many factors, such as, the type of current, field strength (power), the fish length, the fish species and the orientation of the fish in relation to the anode (www.fisheriesmanagement.co.uk/electrofishing.htm). There have been many researches on how and why fish shows a particular response in presence of electricity. Only the question of ‘how’ is established so far but there is not yet any established theory to answer ‘why’ the fish react in a particular way. Probably, it may be because the responses depend on so many things as mentioned before.

Response of fish to different current types is important things to know to select equipment and field situation during electrofishing. According to Lamarque ((1990), DC has good anodic galvanotaxis and induces tetanus only in the near vicinity of the electrode. Pulsed

-39- 4 Electrofishing

DC has poorer anodic electrotaxis and tetanizes further from the anode preventing some fishes from reaching the electrode. AC has no electrotaxis and fishes are tetanized at a greater distance from the electrode than pulsed DC or DC. In general, DC is the least and AC the most harmful electrical output with pulsed DC falling between the two. Thus, electrofishing for research purpose utilizes DC or pulsed DC in most of the cases.

The description of the reaction of fish in presence of electricity could be explained in the sequence of taxis, narcosis and tetanus (Lamarque 1990). The first reaction of the fish when electric field is applied is a quivering motion of the body or dorsal fin. After that, the fish move into the effective zone of the electrode and the responses correspond to increasing voltage or proximity to the anode and the direction the fish is facing with respect to the anode. The first thing that happens to the fish facing anode is the inhibited swimming, which means the normal swimming of fish is retarded. As the voltage gradient increases, the fish swims strongly towards the anode, which is also called as the first swimming towards the anode. This is a forced swimming and is a component of electrotaxis or more particularly, anodic galvanotaxis.

A further increase in voltage gradient results in galvanonarcosis where the fish become motionless and its muscles are relaxed. At another increase of voltage, the fish begin to swim again, this time in an unbalanced manner, called as second swimming to anode and is the main component of anodic galvanotaxis. Here the fish is obliged to go towards the anode. Above this voltage, anodic tetanus takes place, which is the state of muscular rigidity as a result of direct excitation of the muscles by the current.

For the fish facing the cathode, increasing voltage induces two reactions of the fish, cathodic galvanotaxis at a very low voltage followed by the turning of fish towards anode on little more voltage. This mechanism is called half-turn towards the anode. However, if fish fail to undergo the half-turn, cathodic tetanus of nervous origin takes place with rapid increase of voltage. This is followed by cathodic tetanus of muscular origin characterize by the absence of quivering in more voltage. And for the fish lying across the field, only one response, anodic curvature is observed.

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4.3 Factors affecting the efficiency of electric fishing:

Though electric fishing as a sampling technique has emerged as one of the most important tools in freshwater fisheries ecology and management, there are number of factors which influence the efficiency and hence produce a biased result. A sound knowledge of these factors help in obtaining a good data by applying optimal sampling strategy for a given conditions. These factors can be mainly divided into environmental, biological and technical according to origin (Zalewski and Cowx 1990). The table 4.3.1 lists all these factors.

Environmental Biological Technical Abiotic Community structure Personnel Conductivity Taxocene structure Size of crew Water clarity Species diversity Crew experience Species composition Motivation and ability

Habitat Population structure Equipment Habitat structure Density Equipment design Habitat dimensions Fish size Maintenance Substrate and cover Age structure Water velocity Species specific Organization behavior, physiology Site selection Seasonality color and morphology Standardization of effort Temperature Weather Table 4.3.1: Factors affecting electrofishing Source: Zalewski and Cowx (1990) modified

The factors mentioned in the above table are described briefly here.

4.3.1 Abiotic factors:

Conductivity: Conductivity of water is determined by the geology of the associated watershed, but is also influenced by human activities, such as mining, agriculture practice, soil erosion and effluent discharges. It is an important parameter that determines the efficiency of electric fishing with a particular capacity of fishing gear. As for instance, freshwater has a low conductivity; therefore a high field strength (Volts/cm) can be achieved due to the reduction created in current flow (amps) caused by the increased resistance (ohms). On the other hand, saline water is a better conductor of electricity, it has a lower resistance and hence a better current flow. Thus, with everything remaining the same, more power is required in salt water to achieve the same voltage as in freshwater. Measurement of conductivity before sampling allows the chances to select the gear with right electrical output.

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Water clarity: There is a clear relationship between the efficiency of electric fishing and water transparency, but is very complex. It seems the fishing is more efficient in clear water as the fish attracted and stunned are clearly seen so that they cannot escape the net. However, on the other hand the same property also allows fish to see the fishing team from distance and thus, they don’t come nearer into the electric field, especially in the water without cover. In the similar way, in turbid water, bottom dwelling, camouflaged and small fish are hard to see and catch even when immobilized.

Habitat structure and dimension: There are two basic freshwater habitat, fluvial and still water with many differences between them resulting in the differences of fish community and also the behavior of independent fish. Regarding the dimension, the most important factor affecting the fishing efficiency is the channel width. This is because if the electric field is inadequate to cover the whole width of the river fish are able to escape from the periphery. Thus, there is an inverse relationship between the electro-fishing and river width in general case. However, there are methods to increase the efficiency to a required level.

Substratum and cover: The bed or the bottom deposits also play a role in the fishing efficiencies. Normally fine particles such as mud and silts and organic debris are more conductive than coarse bottoms and thus cause problem by reduction in the current density of an electric field. The covers, that include floated and submerged plant as well as trees, have dual effect. These covers provide a shelter for many species and thus might increase the efficiency, but on the other hand, dense cover affect visibility making it difficult to catch the stunned fish. Thus, the purpose of the sampling has to be well defined to address the problem of efficiency.

Water velocity: If the velocity of water is very high, it affects the performance of the fishing team and there is also a chance of missing the stunned fish. On the contrary, in still waters, tetanized fishes are close to the electrode but drown quickly due to tiredness unless it is picked quickly. Thus, it is important to select suitable team and gear according to the condition.

Seasons: The hydrological and thermal regimes of freshwater ecosystems change with season and so do the behavior of fish. These changes are mainly guided by the purpose of nutrition and breeding. These facts increase or decrease the efficiency of electric fishing

-42- 4 Electrofishing even in the same stretch of sampling in different seasons. Thus to overcome the problem of seasonality as a factor for the efficiency of fishing, knowledge of autoecology of the species is important.

Temperature: The information on the impact of temperature on fishing efficiency is also full of contradictions. One study says that there is 40% reduction in conductivity when the temperature is reduced from 20°C to 0°C and concludes that the colder water increases the fishing efficiency (www.fisheriesmanagement.co.uk). While it has been shown that at temperatures below 4°C fish tend to pass more quickly in to a state of immobilization, which reduces the capture efficiency (Zalewski and Cowx, in Cowx and Lamarque 1990). In any case, there is an optimum temperature range for each species where the efficiency is highest.

4.3.2 Biotic factors:

Fish size: It is normally accepted that the fishing efficiency of electro-fishing increases exponentially with fish length. This means, longer the fish, bigger the effect of electric field and this makes electro-fishing a size selective method. Thus, if target is to fish smaller fish, an increase in the field strength decreases the selectivity. However, increase mortality will take place due to the higher voltage gradient.

Species composition: In diverse communities, the fishing efficiency is less compare to non- diverse community of one or two species. It is because, in diverse community all kind of fish, large and small, adapted for different microhabitats with many adaptive features, and also with variation in the internal conductivity may live together, which are not uniformly affected by one electric field. Thus, the efficiency of fishing largely depends upon the species composition of the fish community.

Fish density: The relationship of fish density and the fishing efficiency by electro-fishing is also not straightforward. In low density, the fish are less and are easily caught with the available effort. In high density, though the capture is more, efficiency declines because all the stunned fish cannot be recovered. Often in high density, the focus is mainly on large individuals and as the smaller ones are ignored, hence the lower efficiency.

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Age structure: Normally, the juveniles and small fishes due to their size have a lower probability of capture as discussed before regarding the fish size. However in lentic condition like ponds and lakes, the juveniles dominate the shallow littoral zone due to temperature preference and thus make them more vulnerable.

Behavior: Different life-style of the fish also influences the efficiency of sampling. For instance, benthic forms, though less likely to escape the electric field, are difficult to pick from betweens stones and roots, while nektonic may be able to escape the electric field, but are easier to collect. Likewise, the fish showing territorial behavior are vulnerable to catch while those showing schooling behavior, due to their fright response, escape the electric field. Also predators are more vulnerable to capture than the prey.

4.3.3 Technical factors:

Equipment: Efficiency of the fishing also depends upon the type of the fishing gear and its maintenance. Electro-fishing gear these days come in several designs and with variable output of electricity. Thus, efficiency can be vastly increased by choosing the specific design and output matching the objective of the fishing. Similarly, the gear in poor working condition can greatly reduce the efficiency and thus, a routine maintenance like cleaning the electrodes, changing the engine oils, changing filters, stitching the nets if it is damaged, etc. could help in the smooth running of machine during operation and hence increase the efficiency.

Personnel: Skill, experience and the number of crewmembers have a big influence on the efficiency of fishing. While the skill and experience always help in a good result, the number of members too helps until it is crowded and lowers the efficiency. In addition, the members should also be highly motivated to do the work to achieve best results.

Organization: Good organization and good planning always have a positive impact on the fishing operation. For, example, the sampling objectives should be clear and pre-survey of the sites must be done before the operation. Similarly, duration of the sampling, means of transportation, accommodation, safety measures, cost etc. should be made clear before going to the field. These things do have influence on the efficiency of fishing.

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4.4 The equipment:

The electro-fishing gears come in variety of types, designs and outputs and are commercially produced these days. The main types of the fishing equipments that utilize the electricity are:

1. Portable backpack shocking unit for classical wading 2. Boat mounted unit for classical boat fishing 3. Trawling, and 4. Screening/guiding

Regardless of type, an electrofishing system normally consists of following six sub-systems according to Novotny (1990). 1. Power supply that provides electrical energy to the system. 2. Power conditioner that modifies raw energy to meet the requirements of the specific application. 3. Instrumentation that provides knowledge of the electrical performance of the system. 4. Interconnection system that safely carry the suitable power to the electrodes. 5. Electrodes, which properly couple the right electrical power to the water. 6. Auxiliary equipment that are necessary for successful electric fishing (nets, lights etc)

The following is the complete list of electric fishing equipment that has been used in this research (Pictures 4.7.1 and 4.7.2).

• A petrol powered portable backpack shocking unit with safety kill switch, anode ring and rat tail cathode. • Chest waders, elbow length rubber gloves and polarized sunglasses • Dip nets of different sizes • Small and large holding buckets • Protocols and writing utensils

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4.5 Uses and significances of electric fishing:

Electro-fishing is one of the key tools available to fisheries management. This tool is already in extensive use in developed countries, while the developing countries are just beginning. The Environment Protection Agency (EPA 2004) of the United States puts electro-fishing as an invaluable tool for fisheries biologists and aquatic scientists, which if used properly can provide a wealth of information and insight for managing some of the nations most precious resources. The agency further adds that this method of collecting fish can be one of the best methods for non-lethal collections of resident fish species, allowing the scientist to temporarily collect organisms and retain them in an aerated holding tank until the right number, size, sex, or species have been collected.

Similarly, Burridge et al (1990) has reported that the electric fishing was established early in the last century and has acknowledged that it has continued to grow in popularity. It is used successfully in various habitats and environments, and is an accepted method for both commercial fishing and fisheries research worldwide. Allen-Gil (2002) also asserts that electrofishing is one of the most common techniques used in freshwater fisheries research. Similar remark was made by Hickley et al, Malvestuto et al, Amiro, Penczak et al, Eloranta, and Bird and Cowx (Cowx 1990 and the references therein). Lagler (1978) adds that this method is one of the least selective of all active fishing methods.

Lamarque (1990) has reported that between 1967 and 1987, 439 fishing operations were carried out in 15 countries in a range of biotopes including brooks, rivers, natural and fish farm ponds, fresh and brackish lagoons, lakes estuaries, mangroves and the sea. During these operations a great diversity of fish species (700) and crustacea (50) were encountered at temperature ranging between 5 and 33°C and conductivity between 7 and 40,000μS/cm. Such was his conclusion that with this the most efficient equipment and techniques for fishing in different waters and catching different species were determined. Since then the electro-fishing operations has been more intense, wide and more global, thus increasing the horizon and amount of results by many folds.

Regarding the type of electric fishing method, still classical wading outscores other methods. Steinmetz (1990) has also found that the classical wading is the most used method followed by classical boat fishing, trawling and screening or guiding. This also suggests that

-46- 4 Electrofishing streams, brooks and small rivers with suitable depth for wading are the sites where most of the electric fishing operation is carried out. Steinmetz (1990) too, in his survey found that the water types most frequently electric fished were brooks and rivers.

The main purposes for electro-fishing are stock assessment, sampling/health surveys, tag fish, catching spawners, anaesthetizing or eliminating species. In US, EPA and most of the other state agencies uses electrofishing as the primary methods for assessing fish communities in stream monitoring programs. In his study, Steinmetz (1990) found that the most important purpose of electric fishing is stock assessment followed by sampling/health survey, tagging fish, catching spawners, anaesthetize and least for eliminating species. It should be noted that all these activities could be needed to study the impacts of various disturbances on water bodies and thus it can be concluded that the electric fishing is a major operating method to evaluate biotic integrity or overall ecological integrity of the aquatic habitat.

4.6 Safety and precautions:

It is an age old saying, "never mix water with electricity". Obviously, electro-fishing can be dangerous and hazardous if certain precautions and safety measures are not taken. The electric fishing has evolved from homemade equipment, over 100 years back, primarily by fishery workers with little or no electrical experience. Accidents were frequent then and thus, the safety measures and precautions too have evolved to present state where the accidents during the operations are minimized. Due to the growing concern of safety, the equipment produced these days is designed to be accident free if handled according to the prescription.

Not only the equipment, due to the ever-present dangers and continual reports of accidents and close calls, many jurisdictions have started to police themselves (Goodchild 1990). As a result, United States and many European countries where the electric fishing has become indispensable, have formal policies, regulations and guidelines for the operation and equipment. Some of these countries also have formal training programs for electric fishing and associated first aid and some of them even have the provision of license for the operation.

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The main hazard during electric fishing is the electric shock that results in ventricular fibrillation (uncoordinated asynchronous contraction of the ventricular muscle fibers), respiratory arrest and asphyxia (chest muscles contracting and not releasing) in the descending order of severity. Besides the electric shock, another common risk is the drowning in water that is facilitated by electric current in water. The third category of risk are the secondary injury caused by the shock by making a person lose their footing and balance, by fire and heat from the engine, and a kind of noise fatigue.

However, the risks and hazards associated with electric fishing is highly reduced and minimized due to the advances in the equipment and policies as mentioned before. In fact there is a specified Code of Practice reviewed by the Safety Requirements panel that was presented in the 15th session of EIFAC in Gothenburg in 1988 (Cowx and Lamarque 1990). In any case, Goodchild (1990) has made recommendations in three parts. The first part concerns with the equipment and include designing and construction from qualified person, generators with sufficient capacity and readable meters and gauges, easy control systems, warning devices, specific plugs to avoid incorrect connection, right dip nets and hand-held anodes, and with color codes and labels.

The second part concerns with the personnel and demands that the all persons involved in electric fishing should be trained in the basic principles of electricity and operation of electric fishing equipment and basic first aid. The crew leader must accept the fact that the first important thing in an operation is the safety. The third part emphasizes the strict following of safe operation procedures and guidelines and that includes a routine inspection and maintenance of equipment, to keeping logbooks and instruction guides. If all these recommendations are followed, electric fishing would be the safest operation with minimum risk and hazards.

4.7 Electric fishing in Nepal:

In Nepal, there is a rampant use of electricity for fishing in many parts of the country, but is by a crude hand made gear utilizing the motorcar batteries. The efficiency of this kind of fishing is in doubt, though there is increasing trend indicating that it is working well. However, the electric fishing in Nepal so far is not for the studies and research, but for taking. There is some information that some of the recent hydropower projects might have

-48- 4 Electrofishing utilized electric fishing during the EIA period, but is not confirmed. Thus, this work could be the first systematic application of electro-fishing gear in Nepal for research and studies opening a new horizon for the studies of our streams, rivers, ponds and lakes.

The following is the description of electric fishing gear that has been used in this research.

Model GX50 Mechanic equipment description code GJAG Length 249 mm Wide 286 mm Height 225 mm Weight (dry) 5,2 Kg Engine type 4 stroke, valve on top, 1 cylinder Cubic capacity 49 cm³ Caliber x run 41.8 x 36.0 mm Maxim engine capacity (Power) 1.8 kW (2.5 PS)/ 7.000 rpm Maxim torsion “par” 3.04 N.m (0.31 kgf-m)/ 4.500 rpm Fuel consumption 340 g/kWh (250 g/PSh) Cooling system Forced air Ignition system Magnetic ignition Axle direction Left Fuel tank capacity 0.5 l Oil tank capacity 0.25 l Engine oil SF or SG; SAE 10W-30 Spark plug NGK: C5HSB, CR5HSB DENSO: U16FS-UB, U16FSR-UB Table 4.7.1: Specification of the fishing gear used in this work

This electro-fishing gear is a backpack unit and was used for classical wading. The operation was carried out in 23 sites of 9 rivers in all the seasons spanning from 2003 February to 2004 January, with altitude varying from 140 masl to 1621 masl and temperature from 8.9 to 31.9°C. During the entire sampling, 27,588 fishes of 47 species were captured. The main purpose of the sampling is to analyze composition and population dynamics of the fish to see whether they exhibit sensitivity to different disturbances. The following pictures (4.7.1 and 4.7.2) show the electric fishing gear and its operation in Nepalese water.

During all these sampling operations, the safety of the team member was the first priority. The safety concern was also extended to all the passersby and onlookers who came to see the sampling as well as the cattle in and around the sampling sites. This series of sampling has also developed and trained a core group of about 8 persons who are now capable of

-49- 4 Electrofishing using electric fishing gears independently, at least, a backpack unit and around 20 individuals who are exposed to this sampling procedure sufficiently and these together could be a valuable human resources to fisheries or any aquatic ecological studies and research in Nepal.

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Pic. 4.7.1: Electrofishing gear and its use in this research

Pic. 4.7.2: Electrofishing gear and its use in this research

-51- 5 Issues in context of Nepal

CHAPTER V: ISSUES IN CONTEXT OF NEPAL

5.1 Rivers and river system:

5.1.1 An Overview:

Being a landlocked country, Nepal consists of only freshwater or inland water resource. However, Nepal is extremely rich in water resource as could be evident from some of the forthcoming data. The inland water resource of Nepal includes natural waters such as rivers, lakes and reservoirs, and also village ponds, marginal swamps and irrigated paddy fields and equals 818500ha (Khanal 2001). Out of this, the network of rivers and streams, which are more than 6000 in number alone covers around 395000ha of surface. There are about 1000 of them which are more than 11 km in length and as many as 100 of them that are longer than 160 km. In total, the length of rivers and its tributaries in Nepal exceeds well past 45000 km mark. This statistic is unique and amazing when we consider the size of the country and by any standard, the drainage density of about 0.3 km/km², is very significant.

It is not only the number and area of the rivers and streams in Nepal that highlights the richness of water resource but also the quantity of water. The total annual runoff from Nepal including catchments in Tibet is about 222 billion m³/sec with a mean runoff coefficient of 0.777 (MOPE 2000) while the annual mean runoff of all rivers stands at 6,396 m³/sec. The country is traversed by four major river systems and around 90% of the surface water is concentrated in these basins. However, there is a big variation in flow as 70 –80% water is available only during the monsoon mainly between June and September. In any case with 2.27% of the worlds freshwater (CBS 2003), Nepal is regarded as the second richest country in the world in terms of water resource and the rivers play a significant role in it. The table 5.1.1 illustrates the runoff of the main rivers.

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Drainage Area (Km) Estimated Runoff (m³/sec) SN River Length Total In Nepal From All basins From Nepal 1 Mahakali 223 15260 5410 730 260 2 Karnali 507 44000 41550 1440 1360 3 Babai 190 3270 3270 95 95 4 West Rapti 257 6500 6500 160 160 5 Narayani 332 34960 30090 1820 1570 6 Bagmati 163 3610 3610 180 180 7 Sapta Koshi 513 60400 28140 1670 780 8 Kankai 108 1575 1575 83 83 9 Other Rivers 21432 21432 851 851 Total 1,91,007 1,41,577 7029 5339 Mean Specific Runoff (m³/sec/km²) 0,0368 0,0377 Annual Runoff (billion m³) 222 169 Converted Effective Precipitation (mm/year) 1160 1189 Average Annual precipitation in Nepal (mm/year) 1530 Mean Runoff Coefficient 0,777

5.1.1: Estimated Runoff of the Rivers (Source: JICA/DHM, 1993)

5.1.2 Geography and the Rivers:

Corresponding to the unique geographical position and geophysical system of Nepal, the rivers and streams here are diverse and dynamic. Geographically Nepal can be divided into three regions, running east to west; the Mountain, the Hill and the Terai (Plains). The mountains, which include high Himalayas with countless snowcapped peaks, constitute the northern part of the country and occupies about one third (35%) of the land area. Almost all big perennial rivers flowing through the country originate in this region. This region has a very tough terrain and difficult climatic condition and thus, has the lowest population of the entire region. According to the 2001 census, the region has only 7.3% population of the country (CBS 2003). As such, the rivers in this region have very little anthropogenic disturbances and appear as natural and pristine. However, natural disturbances cannot be ruled out as being the youngest mountain chain and still in the process of mountain formation, the region is very fragile due to the massive geological events.

Attractive peaks, fertile valleys and basins characterize the hill region or the middle mountain zone. This region takes the largest share (42%) of the land area of the country with about one tenth of its area being suitable for cultivation. This region being the center of tradition and culture is inhabited by 44.3% of the total population and is ever increasing. Even though the slopes of more than 30° are common in this area, people extensively use land here for agriculture. The results of which are apparent in terms of erosion, slope

-53- 5 Issues in context of Nepal failures, landslides, deforestation, etc. Also because of the easy availability of head due to steep gradient, this region is also ideal for the construction of hydropower dams and weirs. There are another sets of thousands of rivers originating from this region. Normally these rivers are perennial with the source in groundwater but commonly called rain fed rivers as they heavily depend on the precipitation for their average flow.

The narrow strip of flat alluvial plain, which is also the extension of Gangetic Plain, is the third geographical region of Nepal. Popularly called as the Terai, it comprises 23% of the land area of the country but accommodates the highest, 48.4% of the population. This is the bread zone of the country and is also characterized by dense sub-tropical forest. There are very few rivers originating here but every river of the country, perennial or seasonal has to pass from this area before they drain to Ganges on Indian side. The rivers here assume slow and meandering structure due to the negligible slope, which is less than 1%.

The three geographical division of Nepal appears very simple, but in reality it is much more complex with at least two prominent transitional zones, one between Himalayas and Midhills and the other between Midhills and Terai. They are respectively called as High Mountain Region and Siwalik region. Another series of highly seasonal rivers and streams originate from this Siwalik region also popularly called as the Churia range. These rivers are dry most of the times but during monsoon they are very strong and create havoc in lowland Terai.

In any case the morphology of Nepalese rivers is governed by the unique geo-physical system and extreme climatic variation. The combination of high altitude, steep gradient and the force of gravity are the factors for downward movement of materials on to the water body and the subsequence is the high sediment load in Nepalese rivers. The rivers here, particularly in hills and mountains are in high velocity cutting and eroding fragile and soft rocks of the youngest mountain chain forming deep gorges and sharp ‘V’ shaped valleys.

Though the climate of Nepal is diverse with the world’s entire major climatic zone within a small boundary, it is highly dominated by monsoon and this on its part controls the water regime. The rainfall in Nepal is condensed into a four months monsoon period between June to September, which accounts for about 80% of the annual rainfall. Though there are

-54- 5 Issues in context of Nepal pockets of arid and semiarid regions in Nepal, the average annual precipitation is quite high at 1530mm.

The rivers originating from glacier maintain a sound discharge all round the year because of the permanent source; on the other hand many mid-hill rivers have to depend upon the recharge by the rain to avoid drying. While the group of rivers originating from Churia is more or less seasonal, they have a very high flow during monsoon period and rest of the time they are dry. Thus these last two types of rivers are totally controlled by the monsoon climate.

5.1.3 Types of river:

The early systematic study on the type and classification of rivers in Nepal had been done in 1977 (Sharma 1977) and is further enhanced and documented by Shrestha (1990), Sharma (1996), Sharma (1997) and Khanal (2001). According to information based on these work, the rivers in Nepal can be classified on the basis of these criteria: i. Origin ii. Availability of water iii. Location i. Rivers according to origin: This type of classification is based on the age and different orogenies the Hindu-Kush Himalayan region underwent in the geological age. Being the youngest mountain chain, its formation can be traced back to a recent few geological ages with a complex method called plate tectonic. According to this theory, the Eurasian plate was pushed hard by the Indian plate along the prehistorical Tethys sea probably during late Cretaceous to Eocene period and the landmass at the point of contact was subsequently raised marking the beginning of Himalayan orogenies. There are geological evidences to show that some rivers were already there draining to Tethys sea during this period and quite a few of them survived the tectonic upheavals and are still continuing. While the other group of rivers originated immediately after the first tectonic upliftment.

By the further pushing of tectonic plate, the lesser Himalayas, like Mahabharat and Churia, were formed gradually in different geological ages at a place where the ancient sea was still persisting and the first groups of rivers were still draining. The first to come into existence

-55- 5 Issues in context of Nepal was the Mahabharat range during Oligocene to Miocene periods and that was the site for the origin of second categories of rivers. It should also be noted that the typical monsoon climate of the area was very much helpful in originating and shaping the structure of these rivers. By then, the first groups of rivers had to increase their length and drainage area. After this there was a formation of Churia hills during Pleistocene period, and along this there was the formation of next categories of river channels and the increment of length and drainage area of the first two. All these rivers from Himalayas in the North and Churia in south started depositing materials into the sea, which latter on became the Gangetic plane during the recent period. Thus, the rivers have originated and evolved at different time and space in this part of the world and could be easily classified according to this criteria into the following: a) Antecedent rivers: The rivers that were in existence before the Himalayas or originated during the beginning of its formation in Cretaceous to Eocene period form this group. These rivers are normally perennial with a long length, large drainage areas and a lot of tributaries. The main channels of rivers such as Kosi, Narayani, Karnali and Mahakali are the example of these rivers in Nepal. b) Young post-Mahabharat rivers: These rivers were formed along with the formation of Mahabharat range during Oligocene to Miocene period. Bagmati, Babai, Kamala, and Rapti are some example of this kind of rivers. c) Younger post-Churia rivers: These rivers are originated from the southern slope of Churia hills during Pleistocene period. Aruwa, Ratuwa, Bakra, Handiya, Rate, Hardinath, Amari, Lalbakaya, Mainaha, Pathraiya, Korah, Kateni etc. are all examples of this group. d) New rivers: This group includes rivers originating from Gangetic plain in recent times. They are relatively short rivers with only first or second order channel in Nepal.

-56- 5 Issues in context of Nepal ii. Rivers according to availability of water: The basis of this classification is the availability of water during dry season and accordingly following rivers are found in Nepal

a) The First Grade rivers: These are perennial snow-fed rivers with their source in glaciers in the Himalayan region. The big river system of the country, Kosi, Narayani, Karnali and Mahakali with their main tributaries fall in this group. Since these rivers maintain steady flow throughout the year, they have a high potential for hydropower and irrigation. b) The Second Grade rivers: These rivers are also perennial but originating below snowline with their source in spring or groundwater. They have a very high fluctuation of flow; in dry season mainly in summer, the flow is too low but soon in monsoon they swell into the highest level. These rivers too have a good potential for hydropower and irrigation. Bagmati, Rapti, Babai, Tinau are some examples of this group. c) The Third Grade rivers: These are intermittent and rain-fed rivers mostly originating from Churia range. Since they dry up during summer and create havoc during monsoon, they have less potential for hydropower and irrigation. Some examples of this group are Aruwa, Ratuwa, Bakra, Handiya, Rate, Hardinath, Amari, Lalbakaya, Mainaha, Pathraiya, Korah, and Kateni etc. iii. Rivers according to the location: The rivers in Nepal are normally oriented into north – south axis dividing the country into a number of zones. Broadly there are four major river systems at different places of Nepal from east to west and another one group in the south. From east to west they are as follows a) Koshi River System: Kosi river system, popularly called as Saptakosi is made by the extensive network of seven tributaries of which Arun, Sunkosi, Tamur, Dudhkosi and Tamakosi are the main elements. This is the largest river system of Nepal in terms of drainage area and covers a very large area in eastern Nepal through its tributaries and sub-tributaries. It is a transboundary river originating from Tibet and draining into Ganges before innervating the major part of eastern

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Nepal. Out of 534 km of total length of the river 35% lies in Nepal and similarly out of 604000 km² catchment area, about 46% lie within Nepal.

b) Narayani River System: Highly popular because of the social and religious region, the rivers in this system perforate Central region of Nepal. The main rivers in this system are Kali Gandaki, Trishuli, Budhi Gandaki, Marsyangdi, Seti and east Rapti. Some of the rivers in this system, like Trishuli and Budhi Gandaki originate from Tibet while others from high mountains and middle mountains. One of the main rivers, Kali Gandaki originates from cold and arid region of Mustang in high mountains and passes through the deepest gorge in the world. 89% of total catchment area of 34960 km² is in Nepal and almost entire of the 451 km length of the main channel is within Nepal. c) Karnali River System: This river system lies in the western region of Nepal with the main constituents Humla Karnali, Mugu Karnali, Bheri, Seti and Tila. With the exception of Humla Karnali, all other river originates within Nepal in the Greater Himalayas. Catchment area of this river system is 44000 km² and about 94% of this lie within Nepal. This is the longest rive system of all the river systems in Nepal with main river measuring 550 km and 79% of this is in Nepal. d) Mahakali River System: This is the system of Far Western region of Nepal and the river has a status of Boundary River as most part of it demarcates the western boundary of Nepal with India. The main rivers of this system are Mahakali, Gauriganga, and Chamelia. The catchment area of this system is spread into 15260 km² of which 34% lies within Nepal while the main channel is 223 km in length. e) Southern River System: This system normally includes all the rivers mainly originating from Mahabharat and Siwalik range, which are not the members, or tributaries of the major river systems of Nepal described above within the Nepalese territory. Some of the important southern rivers are, Babai, Bagmati, Kamala, Kankai and west Rapti etc. When combined all, the catchment area measures about 16000km².

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In addition to these three types of classification, there is couple of more types mainly depending upon the biology and its diversity. Shrestha (1990) has classified Nepalese rivers into the following, based on hydrobiology. a) Fast streams: These are torrential streams with high velocity (50cm/sec), rocky bottom with clear water, and with high oxygen and cool temperature. Biological community here includes Cladophora, Ulothrix, Caddis fly, snails, shrimps, larva of mayfly, stonefly and dragonfly, and fishes such as loaches, carp minnows, sucker head fish with adhesive organ and reduced air bladder. b) Slow streams: Deep with muddy, silt and sandy bottom, rate of flow and depth may vary; turbid water; rooted vegetation in shore and shallow; oxygen lower and temperature higher. The living world here includes snails and clams, bryzoans, crayfish, earthworms and fishes like catfishes, murrels, carp minnows, garfishes, feather back and perches. c) Intermittent streams: They have very low flow at dry season; almost dry up except in the pools. The life here includes crustaceans, Caddis fly, pupae and larvae of other insects and fishes like Channa, Heteropneustes, Mungri, Clarius, Puntius etc. which have efficient air breathing mechanisms. d) Springs: Chemical composition and water velocity constant, devoid of suspended matter and temperature constant. The life normally includes producer like algae and submerged aquatic plant, planktons etc.

Similarly, Nepal’s rivers could also be divided into number of zones according to the fish as an indicator (Shrestha 1990). However this is an arbitrary zonation with no exact demarcation between the zones with lot of overlapping. The different zones are:

-59- 5 Issues in context of Nepal a) Snow trout zone: This zone lies between 1800 – 3000 masl and the river is normally fast snow fed or glacier fed cold water. This zone is dominated by trout (Schizothorax sps.), sucker heads (Garra sps.) and loaches (Schistura sps.) b) Stone carp or mixed zone: This zone ranges between 1200 – 1800m and is truly a mixed zone with still fast flowing cold water hill stream consisting of the above fishes mixed with stone carp (Psilorhynchus sps.), catfish (Glyptothorax sps.) and trout (Schizothoraichthys sps.) c) Hill barble zone: This zone lies between 600 – 1200 m and the rivers here have slightly slow moving water with moderate temperature. This zone is famous for sportive fishes like Mahaseer (Tor sps.), and Katle (Neolissochilus sps.) d) Major carp zone: This zone ranges between 150 – 600 m mainly in the Terai characterize by slow and warm water with dominant fishes such as Rohu (Labeo sps.), Mrigal (Cirrhinus sps.) etc.

Thus, judging by any parameter, the origin, the number, the length, the discharge, the catchment area and the diversity, rivers are very prominent entity in Nepal. And to add that with its multiple utilities they become Nepal’s the most important natural resource. Nepal needs a lot of study and research in this field for its prosperity. The table 5.1.2 illustrates where each of the rivers (sites) studied in this work stands according to those classifications.

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Classification → Origin Availability Location Hydrobiology Fish as an Rivers name ↓ of Water indicator Aandhikhola Young, Second Narayani Fast Streams Hill barbed Post-Mahabharat Grade River zone System Arungkhola Young, Second Narayani Fast Streams Major carp Post-Mahabharat Grade River zone System Bagmati Young, Second Southern Fast Streams Mixed zone Post-Mahabharat Grade River System Jhikhukhola Young, Second Kosi Fast Streams Hill barbed Post-Mahabharat Grade River zone System Karrakhola Young, Second Narayani Fast Streams Major carp Post-Mahabharat Grade River zone System Narayani Antecedent First Grade Narayani Fast Streams Major carp River to Slow zone System Streams Rapti Young, Second Narayani Fast Streams Major carp Post-Mahabharat Grade River zone System Seti Antecedent First Grade Narayani Fast Streams Hill barbed River zone System Tinau Young, Second Southern Fast Streams Hill barbed Post-Mahabharat Grade River zone to System Major carp zone Table 5.1.2: Classification of the rivers studied in this work

5.2 Scientific studies on Nepalese water:

It would be a disregard to numerous scientists, researchers, academicians and explorers to say that there have been a very little studies on the various aspects of the Nepalese rivers and streams. With due recognition and appreciation to their contributions it would be appropriate to conclude that the studies are little and highly concentrated to a certain rivers or sections but also interesting and encouraging. Though Nepal is a small country, the diversity of the climatic condition overrules every natural entity to be as diverse as it is. It may be the physical features or it may be biological community, all are diverse making it difficult but very interesting study. Extensive as well as intensive studies and investigation of all the rivers and streams are still sought for but will occur in time with more people involved.

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The scientific studies mentioned above include all aspects of aquatic system such as hydrological features, fish and other aquatic lives, disturbances and pollutions, conservation and development of water resource etc. Some works like those of Swar (1980), Rajbanshi (1982), IUCN (1991), and Shrestha (1995) have comprehensively reviewed all available work done in Nepal concerning different aspects of aquatic ecosystem. Sharma (1996) has a list of biological expedition carried out in different time and places in Nepal and surrounding areas. From those sources and also from the references by many others, these studies can be broadly categorized into three phases belonging to different time frames.

5.2.1 Early phase:

Here it includes all the initial studies of Nepalese water before Nepal opened up to the outside world during 1950’s. Most of the work in this phase was restricted to historical, cultural and religious account of Nepalese rivers and lakes. However, a few scientific studies can still be traced back from this period. It is interesting to note that the initial scientific studies of Nepalese water were mainly focused in the studies of fishes. The first perhaps is the one by Hamilton (1822) where he studies the fishes found in river Ganges and its branches and some of the important tributaries of this river flow from Nepal.

This work is followed by a list of Gunthur (1861) that enlists the cold-blooded vertebrates from Nepal and includes large number of fishes. Then comes the works of Day (1878) titled, “The Fishes of India” and another (1889) titled, “The Fauna of British India including Ceylon and Burma”, which is a very comprehensive study of the number of fishes found in this region including Nepal, incorporating both, the description and the diagrammatic illustration. Such is the significance of this publication that even today all scientists involved in fisheries in this region crosscheck their sample with this one for initial taxonomic purpose. And also the present work has done so.

The other prominent works from this period are reports by Boulenger (1907) and Regan (1907). The former report has a collection of batrachians, reptiles and fishes from Nepal and the western Himalayas while the latter is concentrated on the fish but of the same geographical region. Both of these reports are in records in Indian Museum. Perhaps, the last work that could be mentioned from this phase is that of Menon (1949) in his study called, “Notes on Fishes in India” where he has given account of the fishes from Kosi Himalayas too.

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One thing interesting to note here is that Nepal first saw its hydroelectric plant during this period. The first one with a small 500 kilowatt (KW) capacity was commissioned in 1911 at Pharping in Kathmandu valley and the second one with similar capacity in 1936 at Sundarijal again in the valley. There are no details of the study of hydrology and environment prior to these setups except for some figures such as dates of commission, dam’s length and height and the capacity of production. Since the ruler of Nepal at that time had a good relationship with British India, it could be anticipated that these plants were installed with British technical assistance. In any case, the main purpose of these plants at that time was to light the palaces of the rulers, thus, as an element of luxury rather than that of production.

Apart from those mentioned above not many literatures related with hydrobiology and aquatic ecology regarding Nepal have been mentioned by authors from this time. In addition, the work done on those subjects by Nepalese is not documented at all. This indicates the overall academic and scientific scenario of the country at that time, which was very poor. The entire country was a closed system with ruler suppressing the people and with a very few educational institutions, that too only for ruling class and elites.

5.2.2 Middle phase:

The middle phase of the studies on the Nepalese waters started from 1952, when the country opened itself to the outside world following the downfall of a very long family governance of Ranas. Until then the country was almost virgin and thus in the beginning there were a series of scientific expeditions led by the foreign nationals. Sharma (1996) has a table listing at least 17 large scales scientific expeditions carried out by the experts from different countries during this phase. This was also the time when the government allowed and initiated widespread studies on geography, population and some of its natural resources like water and forest, as it was needed for planning and implementing developmental works.

This phase began with one of the all time most important studies of fishes in Nepal by Hora (1952) in his work called “The Himalayan Fishes”. Taft (1955) had a survey of the fisheries of Nepal through Nepal American Agriculture Co-operative Service. In the same year Hirono (1955) had the result of the Japanese Expedition to Nepal Himalayas for Freshwater Algae, Fauna and Flora. Another major contribution to the Ichthyology of Nepal comes from De Witt (1960). The year 1961 is marked by two expeditions, Expedition of the

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Research Scheme Nepal Himalaya in the Khumbu Himal and German and Austrian Expeditions to Nepal. Also Datta (1961) came up with the zoological results of the Indian Cho-yu expedition.

Menon (1962) continued to his earlier work and published ‘A Distributional List of Fishes of the Himalayas’. Meanwhile Zwelling (1962) sent a report to the Government of Nepal on fish culture development. There was another Japanese expedition, Himalayan Expedition of Chiba University, in the year 1963. Once again, Menon (1964) spotted Psilorhynchus pseudecheneis, as a new cyprinid fish from Nepal. Then there were a couple of notable expeditions till 1970, the one being the Canadian Expedition to Nepal (1967) while the other, German and Austrian Expeditions to Nepal (1970).

Till this time there was hardly any contribution from Nepali scholar and scientists in this field as could be evident from the works mentioned above. In fact, Nepalese scientists were on making during this phase. However, the government was doing tremendous effort to gather all possible information in these fields with collaborative works with foreign nationals and organizations. Several new departments such as Department of Hydrology and Meteorology, Department of Fisheries etc. were created. These departments on their part started working by establishing the working stations at different places. Another major achievement of this time was the documentation and quantification of rivers in Nepal and their potentials for hydropower and irrigation. Thus, a number of studies on the major river basins started in this time.

As hinted before, there is a solid emergence of Nepalese scholars and scientists in the field of hydrology, fishery and aquatic ecosystem especially from the second half of the decade of 70’s. But to begin with, Menon (1971) had the taxonomy of fishes of the genus Schizothorax, which is a dominant fish of cold waters in Himalayas. The next year Banarescu (1972) published, “A Contribution to the Knowledge of Cyprinoidei from Nepal, Khumbu Himal. In the same time Majumdar (1972) together with Majupuria T.C. and Shrestha J. had the New Records of Fish from Nepal. This could be perhaps the first entry of Nepalese scientist in the literature list of fishery biology and could also be one of the most dominant one. There were also two consecutive expeditions, “The Netherlands Center for Alpine Biological Research” in the years 1972 and 1973 respectively that too contributed in this field.

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The next year, Atkinson (1974) described the fish fauna of Nepal in his work titled, “Fauna of the Himalayas containing species of Kumaon, Garhwal, Nepal and Tibet”. Then came the work of Shrestha (1975) with his doctoral thesis, “Studies on the Structure and Seasonal changes in the Gonads of Two fishes of Nepal”. Those two works, Shrestha (1972) and Shrestha (1975) marked the beginning and dominance of Nepalese scientist in the field of Fishery biology in Nepal. While the former focused herself on fish and has contributed substantially in this field in Nepal, the latter has ventured to a wider area.

From production side, Woynarovich (1975) published an elementary guide to fish culture in Nepal. One of the well-known fishery scientists of Nepal, Rajbanshi (1976) came up with the work at species level in his work, “Looping of Snow Trout, Asala”. Next year Sharma (1977) published the first comprehensive work on the River Systems of Nepal. This book, probably the first one in its category is still a very handy one for a variety of information regarding rivers in Nepal. This work has also opened the path for many scholars and scientist to diversify their studies on water resource rather than limiting themselves to fish.

Sharma (1978) studied the quality of drinking water in Kathmandu. The same year Prosser (1978) prepared an environmental report in Gandaki River Basin, Power Study. The study on fish also went side by side with Shrestha (1978) continuing with seasonal changes in the testes of Garra gotyla gotyla and Pradhan (1979) submitting report on cage fish culture in Nepal to the Department of Fisheries. Finally there was another report by Shrestha (1979) on aquatic ecology and the potential of fisheries development in Bagmati River for GTZ.

In short, the middle phase of the study on Nepalese water and aquatic ecosystem was very important in many ways. There was a gathering of a lot of primary and baseline data on the above field, emergence of Nepalese scholars and specialists on the field and the diversification of the theme from mere fishery studies to geology, morphology, pollution, and the conservation and development of the resources.

5.2.3 Modern Phase:

All the work, research and publication, done in the field from 1980 onwards, could be put together in this modern phase. The phase starts with Swar (1980) presenting the status of limnological studies and research in Nepal at the conference in Kyoto. It is followed by some monumental works on fisheries. Shrestha (1981) published Fishes of Nepal, a long

-65- 5 Issues in context of Nepal wanted publication. Jayaram (1981) had the Freshwater Fishes of India, which is a good taxonomical work where the species of Nepal too were included. The same year Shrestha (1981) studied the pollution in river Bagmati with biological indicators, probably a first of its kind in Nepal.

Then, Rajbanshi (1982) had another contribution to the nation on fisheries science with his ‘General Bibliography of Fish and Fisheries of Nepal. Another general but very useful contribution regarding rivers of Nepal came from Shrestha (1983) published in Nepal Digest. Terashima (1984) worked in a remote lake named Rara in Nepal and came up with three new species of the Cyprinoid’s Genus Schizothorax, which were found to be indigenous to Nepal and enriched the diversity of fishes in Nepal.

There was an ecological survey of the Narayani River within the Royal Chitwan National Park by Edinburgh University Expedition to Nepal during 1984-1985 and the report was submitted to the King Mahendra Trust for Nature Conservation. The new records of fishes in Nepal continued with Edds (1985) and he also had the list of “The Fishes of Royal Chitwan National Park (1986)”. The same year he also had ‘Fisheries of Kali Gandaki/Narayani Rivers published. Shrestha (1988) worked on the important game fish of Nepal, Tor sps. (Mahaseer) and published ‘Ranching Mahaseer in the Himalayan Water of Nepal’, which includes important ecological and biological aspects of the fish.

Meanwhile, one of the great ichthyologists, Menon (1987) of the region was still contributing to our knowledge about the fish with ‘The Fauna of India and Adjacent Countries’, which is very helpful for taxonomy and quick information. Shrestha (1988) came up with yet another diverse study, environment of Gangetic Dolphin in Kosi River. Rai and Swar (1989) worked on a single species, Acrossocheilus hexagonolepis now modified as Neolissochilus hexagonolepis and is published in FAO Fisheries Report. In the similar way Sharma (1989) checked the status of Schizothorax sps. in Indian-Chinese Subcontinent and is also published in FAO Fishery Report. The same year there was a feasibility study of Karnali-Chisapani Multipurpose Project for Ministry of Water Resources by Himalayan Power Consultants.

Shrestha (1990) came up with another couple of works, the first being the ‘Resources Ecology of the Himalayan Waters’ and the next, ‘Rare fishes of Himalayan Waters of

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Nepal’. Shrestha (1991) submitted a report on cold water fish and fisheries of Nepal to FAO. Talwar and Jhingran (1991) came up with their comprehensive taxonomic work, Inland Fishes of India and Adjacent Countries in two volumes. This is one of the publications most extensively used by the scientists in this region for the purpose of identification of fishes. There are series of reports or papers by Shrestha for the next few years - The role, scope and importance of natural Water Resources for increased fish production in Nepal in 1992, Fisheries studies in Karnali River for Himalayan Power Consultants in 1992 and Fish Biodiversity of Wetland System of Kosi Tappu Wildlife reserve and Adjacent Areas for Department of National Park and Wildlife Conservation in 1993. In the meantime, Shrestha (1992) also contributed with his ‘Fishery Biology Study of Melamchi River’.

Shrestha (1994) published ‘Fishes, Fishing Implements and Methods of Nepal’. This book lists most of the species of fishes discovered so far in Nepal with diagrams and some color photos and thus is handy to carry to the field for quick taxonomic purpose. The next year, 1995, she enumerated the fishes of Nepal for HMG/N and Govt. of Netherlands. During the same period Subba (1995 and 1996) found the new record of hill stream fish, Olyra longicaudata and pygmy barb, Puntius phuntunio from Nepal while Swar (1996) made a taxonomic review of Katle, Neolissochilus hexagonolepis.

Sharma (1996) gave a new dimension to the studies of aquatic systems in Nepal. He was the first to use macrozoobenthos to determine the water quality. He came up with NEPBIOS, the first scientific water quality index applicable to Nepalese water and opened up a new area of study. Swar and Shrestha (1997) had a paper on human impacts on aquatic ecosystems and native fishes of Nepal, linking disturbances and biotic community of aquatic systems. Pradhan (1998) picked the line of benthos and modified the NEPBIOS into NEPBIO-brs while working on Bagmati River System. Meanwhile Sharma (1998) published a list of aquatic insects of Nepal that could be used as bio-indicators of water pollution.

Jayaram (1999) then published his latest book, ‘The Fresh Water Fishes of Indian Region’ that could be taken as the final work till now for the taxonomy of the fishes found in this region. That is the reason Shrestha (2001) had a taxonomic revision of fishes of Nepal based on the above publication and summed up with 182 species belonging to 93 genera under 31

-67- 5 Issues in context of Nepal families and 11 orders respectively. With the advent of the new century Rajbanshi (2001) published zoogeographical distribution and the status of coldwater fish in Nepal at river system level. Likewise Khanal (2001) introduced disturbance ecology to Nepal and studied different types of disturbances prevalent in Nepalese water by taking benthos as indicators.

Besides all these studies, there is a big series of literature on water resources regarding its social, economical and political dimensions. These literatures emerged from middle phase where messages mostly given were optimistic, like water is our wealth, our water is pure and virgin, our water has a potential to rescue us from poverty as could be evident from potential for energy and irrigation etc. But during the modern phase a lot of critical and sensitizing thought also made appearance. Some important names expressing such thoughts regarding water resources are Ajay Dixit, Dipak Gyawali, Bikash Thapa and A.B.Thapa The reasons behind are acute water shortages at different parts of the country, pollution, inability to generate the electricity demands of the country, people forced to pay one of the highest tariff for electricity in the region, commissions and lack of far sightedness shown by the planners and politicians in the treaties and contracts with other parties and, in general, our inability to harness our vast water resource.

In short, there are a number of scientific studies and research done in Nepalese water, but due to its volume and potential these studies look scant and with gaps. There should be some authority responsible for gathering and building up of information and primary data. They can start with collecting works from hundreds of graduate dissertations, which go unnoticed after its defense. This will certainly bridge the gaps on information regarding our resource. Likewise, the government or any competent authorities have to establish as many monitoring center as possible so that there is uninterrupted supply of sufficient data. One good trend is the increasing number of Nepalese scholars in this field and it should continue.

5.3 Fishes of Nepal:

Nepal is exceptionally rich in biodiversity and the diversity in fish is no exception. There are many reasons for this. First, Nepal is very rich in water resource with more than 6000 rivers and streams together with numerous lakes and ponds. Second, Nepal has a very large range of climatic zones, from subtropical to alpine, corresponding to its range of altitude

-68- 5 Issues in context of Nepal that scales from about 50 masl to the worlds highest point. Third, Nepal is a meeting point of two large biogeographical realms, Indo-Malayan and Palaearctic, and thus the species from both converge here. Therefore, it is only natural that a large number of fish species are found in Nepal. However, the only limitation is that being landlocked, the species occurring here are freshwater type and not marine.

It is evident from the previous heading that fairly a good number of studies and research have been carried out in the area of fish and fisheries in Nepal compare to the other fields of hydrology and aquatic ecosystem. The fishes of Nepal have been recorded as early as in 1822 by Hamilton and have been included in the work of many scientists such as Gunther (1861), Day (1889), Regan (1907), Menon (1949, 1987), Hora (1952), Jayaram (1981, 1999), Shrestha (1981, 1994, 1995, 1998, 2001), Shrestha (1994), Subba (1995), Talwar and Jhingran (1991) and Rajbanshi (1982, 2001). However, the total number of fish reported from Nepal varies in their works. Even the most reliable site on the internet (www.fishbase.org) counts it to be 155 species, which is different from many authors. In addition, there are some confusion also in the systematic position of some species, like the orders, families and genera.

This situation has been improved mainly by the effort of Shrestha (2001) who did a thorough taxonomic revision of her own earlier work (1995) where she had reported 185 species from Nepal. She has based her classification after the latest work of Jayaram (1999) and came up with a total of 182 species belonging to 93 genera under 31 families and 11 orders. The list of fishes from Nepal appended (appendix IV) is mainly taken from this work but are verified also with Day (1878), Talwar and Jhingran (1991), Rajbanshi (2001) and the website, www.fishbase.org. Since, this work is not purely a taxonomic work and also to make it simple, only the order, family and a genus is given to each species without going into intermediate positions such as suborder and subfamily. The species, which were caught during this research, is marked by the symbol *.

5.4 River disturbances in Nepal:

In general, the rivers and streams in Nepal are so numerous that till now the disturbances on them is not sufficiently documented. In fact, many rivers and streams and their sections are still assumed to be pure, virgin and without any anthropological disturbances. This could be

-69- 5 Issues in context of Nepal the reason that the rivers and streams are religiously referred to as a sacred place and also worshipped as a mother Goddess. The predominant Hindu religion of the country observes the rivers and streams as a symbol of freshness, continuity and eternity. It is believed that a dip in the river, specially the one that has the established cultural and religious value, has a potential to wash away all the dirts, sins and curses of a person.

From historical times, the rivers here are in multiple uses such as irrigation, water supply for drinking and washing, recreation, subsistence fishing and transportation. In addition, they have been used as a dumping site for industrial and household wastes probably because the people had the crude knowledge about the carrying capacity and self-purification ability of rivers. Despite all those uses from ancient time, the disturbances on Nepalese rivers with some adverse effects are recent phenomena. This could be mainly attributed to a huge population growth with increasing urban center, large-scale construction of dams and weirs for electricity and irrigation, commencement of large and medium scale industries and the evolution of chemical intensive modern agricultural practices.

Khanal (2001) distinguishes the river disturbances in Nepal into two types, Natural and Anthropological. As mentioned before, Nepal is situated in a geologically active area where the making of Himalayas is still on the process and thus it is natural that the rivers are not sparred of the natural disturbances and disasters. This has also been confirmed by many reports and studies regarding natural disasters in Nepal.

Some of the important natural events that lead to disaster are earthquakes, glacial lakes outburst floods (GLOFs) and bursting of artificial landslide dam. The frequency of earthquake is common with highly destructive one in about 50 years while the frequencies of latter two are one in ten years. Likewise there are some annual events such as cloud burst, heavy rainfall, landslides (rockslides, soil creep and debris flow), soil erosion, flood and drought. All these are natural events in the country and they disturb the rivers and streams.

While a little could be done to prevent these natural events except to take some precautions, there is another type of disturbance, human disturbance, which is on the rise and a lot can be done here to prevent massive disturbances. There is a wide list of human disturbances in Nepalese rivers and streams identified by Khanal (2001). Hydraulic and hydrological

-70- 5 Issues in context of Nepal disturbances include the construction of dams and impoundments, levees, canals, roads, bridges, culverts and embankments for various purposes such as hydropower generation, irrigation, water supply and transportation. Physical disturbances include substrate removal from river bed, river bank and floodplain while chemical disturbances come from washing (clothes, vehicles, carpets), mining practices, industrial waste, solid waste from municipalities, modern agricultural practices (fertilizers and pesticides), and the banks used in lieu of the public toilets.

There are even some disturbances coming from cultural/religious practice such as cremation, and feast involving mass bathing and religious offerings on one hand and on the other by the recreational activities such as picnic, fishing and rafting. But these disturbances are highly localized to certain sections of certain rivers. At the catchment level, haphazard settlements, overgrazing, intensive agriculture, deforestation and road constructions add to the river disturbances. This work would focus on the following four types of human disturbances on Nepalese rivers and streams.

5.4.1 Agriculture:

Agriculture is the most important and dominant economic activity in Nepal. It contributes to about 42% of the GDP and usually about one quarter of the country’s development budget is allocated to this sector (MOPE 2001). Though, the land use pattern of the country shows just 20.2% land under cultivation, over 80% of the total population still depends on agriculture for subsistence of living. The paradox is that about 1.7 million ha. of agriculture land, which accounts for almost 65% of the total cultivated land is still rainfed indicating the general lack of irrigation facility and dependency on the monsoon.

The engagement of such a large chunk of Nepalese in agriculture is perhaps because Nepalese society is predominantly a rural society with about 88% of them living in the rural areas without industries, offices and business opportunities. Based on the estimated population of 2001 (CBS 2003), Nepal has one of the highest population densities in the world with respect to cultivable land at nearly eight persons per hectare. However, all this population is not engaged in crop production. The people are also engaged in some of the other agriculture sector such as livestock and fisheries. In any case, sometimes the three sub sectors and most of the time at least two, go together.

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Out of total agricultural GDP, livestock contributes 31% and is thus very significant. In addition to the production of milk and meat, it also provides animal power and manure to farmland for maintenance of soil fertility. The country is also experiencing the increasing trend of number of livestock. Between 1984 to 1998 there was an increment of 15% in their number. This does not match with the area of pastureland, which remains more or less constant at 1.7 million hectare and is thus, putting pressure to pastures and forests.

Likewise, the fish, which forms the major source of protein to the rural Nepalese, is too in the increasing trend. The total production of fish in 1999/2000 was 31.7 thousand metric tones compared to mere 4.3 thousand metric tones in 1982/83. About 55% of the total fish is produced in rivers, lakes, paddy field, cage culture and reservoirs while the remaining is produced in ponds. There are at present 22 thousand fish raising ponds in the country, mostly in Terai and its total area has reached 8,840 ha.

Some of the important disturbances to the rivers and streams from agriculture come from the landslides and soil erosion due to faulty agricultural practices on steep slopes, runoff of chemicals such as fertilizers and pesticides and introduction of new and exotic species. Of these, the second one is strictly man made disturbance, which is more harmful to Nepalese rivers than the third, which too is a man made disturbance. The disturbance caused by the new intensive agricultural practice has proliferated into our rural areas and is now a serious threat to our once pure and virgin water. Some of the studies of selected areas in our region show that deterioration of water quality is quite alarming, particularly in small rivers, streams and shallow groundwater.

The main reason behind this is the chemical intensive so-called "Modern Agriculture" that encourages the blind and indiscriminate use of chemical fertilizers, pesticides and broad- spectrum antibiotics. The first introduction of mineral fertilizers in Nepal was in 1952 and in 1954 the consumption was 10 tons. It was in 1965/66, with the establishment of Agricultural Inputs Corporation (AIC), that organized supply of fertilizers, actually, began in the kingdom. There is no domestic production of synthetic fertilizer in Nepal and thus, all requirements are met through imports.

The use of chemical fertilizers (NPK) per hectare alone has increased tremendously from 7.6 kg in 1975 to 26.6 kg in1998 (MOPE 2001). However, after that it is in a decreasing

-72- 5 Issues in context of Nepal trend. This could be evident from the other set of data that says the consumption of chemical fertilizer was 2069 metric tonnes in 1965/66 and went up to 185,797 metric tonnes in 1994/95 before declining to 148,187 metric tones. The forthcoming table illustrates the import and consumption of chemical fertilizers in Nepal by type from 1997 to 2002 in metric tonnes:

Year N (Nitrogen) P (Phosphorus) K (Potassium) Total Import Consumption Import Consumption Import Consumption Import Consumption 1997/98 51429 32629 5222 13124 - 1442 56651 47195 1998/99 28440 32314 17800 12097 - 1258 46240 45669 1999/2000 13800 25034 - 12031 - 185 13800 71460 2000/01 - 16397 - 7191 - 35 - 23623 2001/02 2250 11857 5750 9597 - 610 8000 21964 Table 5.4.1: Consumption of chemical fertilizers in Nepal by type Source: CBS 2003

Fertilizer usage in Nepal was very low at 35kg/ha/annum in 1997/1998 as maximum national average consumption, which is the lowest after Bhutan in the South Asian region. However, it increased remarkably to 57.9 Kg/ha/annum in 2000/2001 (ANZDEC 2001) and the government plan is there to raise the overall average fertilizer use to 150 kg/ha/annum by the year 2015. Thus, so far the amount of fertilizer use is not a problem in Nepal, but its inappropriate use coupled with steep slope and torrential monsoon rain resulting in heavy runoff, land slides and soil erosion has some effect on the rivers and streams as these chemicals finally make their way into it.

Another group of agro-chemical that finds its usage in agriculture is the pesticides that are generally poisonous substances for preventing, controlling, destroying, repelling or mitigating pests. Pesticide use in Nepal has increased significantly in recent times due to the access to the market and the farmer’s desire for high productivity. The national average consumption of pesticide is estimated to be 650 g/ha (MOPE 1998) in commercial farming, which is very high compare to the other countries in the region. According to the Directorate of Plant Protection (DOPP), the country imported 33356 kg of insecticides, 15577 kg of fungicides/bactericides, 6748 kg of herbicides and 400 kg of rodenticides in the year 1997. The total consumption of pesticides in the country is approximately 55 tonnes of active ingredients per year (MOPE 2001). These figures could have been much more if there were monitoring of trade between Nepal and India, which share an open border.

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At present, there is only one pesticides/insecticides factory in the country and is unable to fulfill the country’s demand. AIC and other private dealers import and sell the items for agricultural use. Nepal, also receives a large quantity of these toxic chemicals through donation and international aid mechanisms in order to open markets. HMG of Nepal adopted the Pesticides Act in 1991 and Pesticides regulation in 1993. In accordance of these laws, Nepal has established the Nepal Pesticide Board (NPB) that will assist the government in formulating pesticides policies and adopting regulatory measures for the safe use of these. Among actions against toxic chemicals in the agriculture sector, Nepal has banned the use of 12 of them including DDT, BHC and Aldrin through the Pesticides Act but practical implementation is still questionable.

The pesticides, mostly insecticides, used in Nepal belong to highly persistent (Organo- Chlorine) group. The commonly used insecticides in the country continue to include DDT, BHC-dust, Aldrin and Endosulphers. Frequently these pesticides are either misused or overused mainly due to the lack of knowledge. Rice being a traditional and an economically important crop, farmers use the largest quantity of pesticides on it, but the number of applications is more on vegetables. The residues of pesticides have been detected in various crops such as rice, wheat, and pulse grains, and even in the milk.

These toxic chemicals, often called as the ‘chemicals of imperialism’ are produced in the western market and are dumped in the developing countries when they realize the chemicals are highly toxic and threat to health and environment. Some of these dangerous substances like chlorinated organomercury compounds are found just on the outskirts of Kathmandu, densely populated capital of Nepal, originate from German chemical company, Bayer and is already banned for use in the European Union since 1988. This highlights how Nepal has become a victim by becoming a dumping site of date expired, outdated and highly toxic chemicals coming from multinational companies of developed countries.

Date-expired chemical pesticides are a serious problem in Nepal as it lacks the means of disposal of these. A New Zealand based consulting company, ANZDEC Ltd. was contracted to carry out the task of disposing 137 MT of pesticides and also to prepare pesticides regulations for Nepal (NCS 1994). From AIC’s inventory of 137 MT of date- expired pesticides, about 70 MT were buried or spread in Amlekhgunj, Siddarthnagar, Nepalgunj and Biratnagar under the supervision of foreign consultants. But when a review

-74- 5 Issues in context of Nepal of burial sites by another foreign consultants were done, it was revealed that the Amlekhgunj burial was a public health hazard. In addition, there could be more than 20 MT of chemical pesticides still in the godown at Amlekhgunj and another 67 tonnes are stockpiled in unsafe conditions at various locations in the country (MOPE 2001)

While, there are agriculturists who relate the decreasing fertility of Nepalese soil with the overuse of pesticides, the consequences of it on the water and aquatic lives are very little studied and discussed. The water regime is the potential final place where these toxic chemicals find their way. The most important way through which these chemicals are transferred to water is by runoff. Washing vegetables in open water such as ponds and rivers is also very common and through this also these pesticides find water. In addition, using toxic chemicals directly in water for fishing by poisoning is also increasing. Just like in soil, in water too, the bioaccumulation and biomagnifications of these chemicals take place and affect the entire food chain. The following figure illustrates this process.

DDT accumulation in food chain

DDT in water DDT in Zooplankton DDT in small fish DDT in large fish DDT in fish-eating birds 0.000003 ppm 0.04 ppm 0.5 ppm 2 ppm 25 ppm

Fig. 5.4.1: Bioaccumulation and Biomagnifications Source: Cunningham and Saigo (1999)

Thus, two important agricultural inputs, fertilizers and the pesticides together with the weirs constructed for irrigation, collectively, affect the rivers and its ecology. The most affected aquatic life with these factors is obviously the fish. There has been very little study on this area. As such, this field is a very important field and this study intends to facilitate the further research in the field.

5.4.2 City (Urbanization):

Urbanization generally refers to the process of growth in the proportion of population living in the urban areas. Some characteristics of urbanization are the distinctive division of labor,

-75- 5 Issues in context of Nepal technology based production of goods, trade of goods and services, high level of spatial and economic interaction and relatively high density and diversity of population. There is a big problem of definition in the study of Nepal’s urbanization as there is no consistency of it on the areas designated as ‘urban’. This situation is more or less addressed by the Municipality Act of 1992, and the Local Self Governance Act of 1999, which redefine and classify the urban areas into three municipal areas, Metropolitan city, Sub-Metropolitan city and Municipality (CBS 2003). Each category is classified by taking population size, annual revenue and basic services and facilities into consideration.

Nepal is basically a rural society with most of the population living in villages. It remains one of the least urbanized countries in the world and also in South Asia. According to the latest census, around 3.2 million people live in urban areas, which is 13.9% of the total population (CBS 2003). However, urban areas have increased and developed haphazardly without any plan and projections creating wide range of problems that touch all sectors such as, environment, economy and society. In 1952/54, when there was the first census in Nepal, number of municipal areas in the country was just 10, which increased to 23 in 1981 and 58 in 2001. Similarly in the first census, urban population, as percent of rural population, was 3 that jumped to 6.8 in 1981 and to 16.2 in 2001. The table next shows the growth in urban population and urban places in Nepal from 1952 to 2001.

Census Year Urban Number of Percent of Intercensal Population Urban Places Population Increase (in ‘000) Urban (Percent) 1952/54 238.3 10 2.9 1961 336.2 16 3.6 41.1 1971 461.9 16 4.0 37.4 1981 956.7 23 6.4 107.1 1991 1695.7 33 9.2 77.2 2001 3227.9 58 13.9 90.4 Table 5.4.2: Growth of urban population and urban places in Nepal Source: Population Monograph of Nepal, Vol. 1, 2003

The pattern of urbanization in terms of three ecological regions (Mountains, Hills and Terai) suggests that it is increasing steadily in hills and Terai where the lust valleys and the plains constitute the landscape. The following table illustrates the percent distribution of urban population (and places) by ecological regions from 1952 to 2001.

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Ecological 1952/54 1961 1971 1981 1991 2001 regions ↓ Mountains ------1.3 (2) Hills 82.4 (5) 69.7 (8) 65 (7) 51.8 (9) 51.2 (13) 53.2 (27) Terai 17.6 (5) 30.3 (8) 35 (9) 48.2 (14) 48.8 (20) 45.5 (29) Total 100.0 (10) 100.0 (16) 100.0 (16) 100.0 (23) 100.0 (33) 100.0 (58) Table 5.4.3: Percent distribution of urban population Figures in parenthesis are number of urban places Source: Population Monograph of Nepal, Vol. 1, 2003

Very high percent of urban population seen in the previous table is by virtue of the population of Kathmandu valley, which has from historical time the largest share of Nepal’s urban population. In 1952/54 about 83% of the country’s urban population was in Kathmandu Valley. That has now declined but still 31% of urban population is in the valley. In fact, over 39% of Nepal’s urban population at present reside in just 5 urban areas with a population of over 100,000 and these include, Kathmandu and Lalitpur in Kathmandu valley, Biratnagar and Birgunj in Terai and Pokhara in the hills.

The overall population density in urban areas in the country is 985/km² but there are significant differences in terms of geographical regions. In general, the urban centers of inner Terai and hill/ mountain regions have lower densities compared to Kathmandu Valley and the Terai. The following table highlights the urban densities in different regions of the country compared to rural density.

Regions Population 2001 Area (sq. km) Density (per sq. km) Hills/Mountains 576,024 1047 550 Kathmandu Valley 995,966 97 10265 Inner Terai 392,108 975 402 Terai 1,263,781 1158 1092 Urban Total 3,227,879 3276 985 Rural Total 19,509,055 143905 136 Table 5.4.4: Urban densities in different regions of the country Source: Population Monograph of Nepal, Vol.1, 2003

Though, Nepal’s urban population is still low at less that 15% of the total population, what is alarming is the rate and the way it is growing despite the paucity of basic urban services in most of the urban centers. For example, about 71% of urban households in Kathmandu have water supply connection, which is the highest compare to 39% in Pokhara, 21% in Biratnagar and 10% in Bharatpur. Likewise, about 25% of households in Kathmandu are

-77- 5 Issues in context of Nepal connected to sewage facilities whereas in other municipal areas it is virtually lacking (MOPE 1998).

Another problem that has emerged as a consequence of rapid growth of urban population is that of solid wastes and garbage. Households are the main source of solid waste in Nepal and the per capita waste generation is estimated to be 0.48 kg/day (MOPE 2001). About three million urban residents in Nepal spread over 58 municipalities produced a total of 426,486 tonnes of waste in 1999 and of which the city of Kathmandu generated the highest of 29%. Solid waste constitutes 83% of total waste generated by country followed by agricultural waste at 11% and industrial waste at 6%.

Majority of the urban areas in Nepal, as is usual with other countries too, lie on the banks or nearby some rivers and streams and put impacts on it in variety of ways. Not only there is a massive encroachment of river banks due to unplanned and uncontrolled urban growth, but also the rivers acts as an easy site for dumping of the wastes including the direct drainage of the sewage if the city has any. Most of the cities, especially in the hills including Kathmandu valley suffer from acute shortage of water for daily needs. This further adds burden to the nearby rivers and streams, as people are forced to use it at least for cleaning, cleansing and washing their clothes and pots to the raw vegetables and cattle. All these facts lead to severe water pollution, which is a general sight around urban areas.

The polluted water has been the main source of many water borne diseases on one hand and on the other hand it is diminishing aesthetic value and depleting aquatic biodiversity of all water bodies around the cities. For example, there are virtually no fishes at all in river Bagmati that passes through the heart of Kathmandu and Lalitpur during its course in the cities. However there are some in headwater, before the river comes down to urbanized locality and again reappear once the river leaves the valley. This indicates that the fishes are sensitive to the various pressures put on the rivers by the process of urbanization and is an important field of study.

5.4.3 Dams and weirs:

The most important natural resource of Nepal is water resource. The prosperity of the country largely depends upon the wise and sustainable utilization of this resource. For this a wide varieties of hydraulic constructions mainly dams and weirs, impoundments, levees and

-78- 5 Issues in context of Nepal embankments, culverts and bridges have been made and inevitably will be in increase for variety of purposes such as hydropower generation, drinking water supply, irrigation, road construction, flood control, wastewater treatment, fisheries development, water transport and for many forms of recreation. Out of these, the dams and weirs particularly are more important as it is the basic structure in hydropower development, which is the most important source of energy for the country as well as well as in irrigation and water supply.

Nepal is a country of paradoxes. The country where a feasible hydropower potential amounts well over 40,000 MW, only a small fraction, 527.7 MW (CBS 2003) of it is produced so far. The statistics again say that only 15% population of the country has access to this energy source leaving the rest in darkness. In addition, the people in Nepal pay one of the highest electricity tariffs in the region. However, with ever-increasing energy demand from all sectors has put tremendous pressure to the government to harness more and more water resource for energy production. Consequently, numerous major and small hydropower projects are either under construction or planned and proposed for the approval. The following table lists the existing and upcoming hydropower projects from the country.

NO HYDRO PROJECT (EXISTING) CAPACITY (KW) 1 Trisuli 24,000 2 Sunkoshi 10,050 3 Gandak 15,000 4 Kulekhani I 60,000 5 Devighat 14,100 6 Kulekhani II 32,000 7 Marsyangdi 75,000 8 Puwa Khola 6,200 9 Modi Khola 14,800 10 Kali Gandaki A 144,000 11 Aandhi Khola (BPC)* 5,100 12 Jhimruk (BPC)* 12,300 13 Khimti Khola (HPL)* 60,000 14 Bhotekoshi (BKPC)* 36,000 15 Pharping 500 16 Panauti 2,400 17 Sundarijal 640 18 Phewa 1,088 19 Dhankuta 240 20 Tinau 1,024 21 Jhupra 345 22 Baglung 200 23 Doti 200 24 Phidim 240 25 Gorkhe 64 26 Jomsom 240 27 Jumla 200 28 Dhading 32 29 Syangja 80 30 Seti (Pokhara) 1,500 31 Helambu 50

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32 Salleri 400 33 Darchula I and II 300 34 Chame 45 35 Taplejung 125 36 Manang 80 NO HYDRO PROJECT (EXISTING) CAPACITY (KW) 37 Chaurjhari 150 38 Syarpudaha 200 39 Khandbari 250 40 Terhathum 100 41 Bhojpur 250 42 Ramechhap 150 43 Bajura 200 44 Bajhang 200 45 Arughat (Gorkha) 150 46 Tatopani I and II (Myagdi) 2,000 47 Okhaldhunga 125 48 Rupalgadh (dadeldhura) 100 49 Surnaiyagadh (Baitadi) 200 50 Namche 600 51 Achham 400 52 Dolpa 200 53 Chatara 3,200 54 Kalikot 500 55 Sange Khola (Sange HP) 183 56 Chilime (CPC) 20,000 NO HYDRO PROJECT UNDER CONSTRUCTION CAPACITY (KW) 1 Middle Marsyangdi 70,000 2 Gamgad 400 3 Heldung 500 4 Indrawati (NHPC) 7,500 5 Upper Modi 14,000 6 Piluwa Khola 3,000 NO PLANNED AND PROPOSED PROJECT CAPACITY (KW) 1 Seti (west) 750,000 2 Arun III 402,000 3 Budhi Gandaki 600,000 4 Kali Gandaki II 660,000 5 Lower Arun 308,000 6 Upper Arun 335,000 7 Karnali (Chisapani) 10,800,000 8 Upper Karnali 300,000 9 Chamelia 30,000 10 Pancheshwar 6,480,000 11 Thulodhunga 25,000 12 Tamur/Mewa 100,000 13 Dudh Koshi 300,000 14 Budhi Ganga 20,000 15 Rahughat Khola 27,000 16 Likhu 40,000 17 Kabeli A 30,000 NO PLANNED AND PROPOSED PROJECT CAPACITY (KW) 18 Upper Marsyangdi A 121,000 19 Kulekhani III 42,000 20 Aandhi Khola (storage) 180,000 21 Khimti II 27,000 22 Langtang Khola (storage) 218,000 23 Madi Ishaneshwar (storage) 86,000 24 Seti (storage) 122,000 25 Kankai (storage) 60,000 26 Upper Tama Koshi 250,000 27 Rawa Khola (Khotang) 2,300 28 Molung Khola (Okhaldhunga) 1,200 29 Naugargad (Darchula) 1,800

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30 Gandigad (Doti) 1,800 31 Phoigad (Dolpa) 150 32 Kolti (Bajura) 150 NO PRELIMINARY WORKS IN PROGRESS CAPACITY 1 Chaku Khola 910 2 Khudi 3,450 NO PRELIMINARY WORKS IN PROGRESS CAPACITY 3 Mailung 5,000 4 Daram Khola 5,000 5 Phema Khola 995 6 Sunkoshi Small 2,600 7 Langtang 10,000 8 Baramchi 999 Table 5.4.5: List of the hydropower projects Source: Nepal Electricity Authority, Fiscal Year 2001/02 – A Year in Review (Modified) The table 5.4.5 illustrates that there are 56 large and small-scale hydropower projects existing in Nepal and except for a few, all are in the operation. There are just six projects under construction now probably due to a difficult socioeconomic and political situation in the country. Once this phase of difficulty is over, many new projects would start simultaneously as could be seen from the above table, which lists 32 planned and proposed projects and at least 8 where the preliminary works are in the progress. Further, water being the most abundant resource of the country in one hand and on the other hand due to the demand of cheap, clean and renewable energy, Nepal Electricity Authority has a forecast of average growth of energy at more than 7%. This means hydropower projects that inevitably involve the construction of dams and weir will be a continuous process for the foreseeable future.

In addition, there are number of established irrigation projects and many more will come up in the future to reduce the dependency on monsoon as the country is predominantly agricultural. With very few industries and in absence of other job opportunities more than 80 % of population still depend upon agriculture for subsistence living. The irony is, only 21% of the total land is under cultivation and out of these about 1.7 million ha. that amounts to about 65% of the total cultivated land is still rainfed (MOPE 2000). This means, a massive network of irrigation especially in midhills and Terai is sure to come in future and these irrigation projects too involve the construction of some kind of dams and weirs.

There are multitudes of utilities of damming rivers but we must not forget that many times it changes, the river ecology, forever. The same is pointed out by Jungwirth (1998) when he says, ‘One of the central ecological problem of running water systems, which are subject to multiple uses and therefore suffer disproportionate damage worldwide in comparison to

-81- 5 Issues in context of Nepal other ecosystems, is the fragmentation of the longitudinal corridor by weirs of hydroelectric power plants and other water engineering measures’. Further, current ecological theories and concepts describe running waters as four-dimensional systems, their longitudinal, lateral and vertical linkages, interactions and exchange processes varying over time and over different scales (Jungwirth et al 2000).

The relative importance of all these dimensions vary according to the terrain the river is passing through but all are critical on themselves at their places. Thus, the building of dams and weirs has a potential to affect the ecological integrity of the river system and is therefore, an important field of research especially in the country like Nepal.

5.4.4 Industries:

Another possible threat to the rivers and streams comes from the industries. It may be true that the all round development in general and economic development in particular is associated with industrialization. The affluent western societies achieved this through industrial revolution a few centuries ago. However, their development had a cost. History is full of evidence that there were rampant air, water and soil pollution in Europe and America. The present day clean environment in these regions is only due to a very high price spent for cleaning the environment through regeneration and sophisticated technology.

In comparison, developing counties like Nepal has not paid that price as it is not an industrialized nation now and never was in its history. There were around 4500 manufacturing units in different part of the country providing employment to over 0.2 million people (MOPE 1998). The Central Development Region has the highest number of manufacturing establishments occupying about 55% of the total industries. Kathmandu valley, which lies within this region, holds almost all of those units. However, the recent data suggest that there is a large slump in the number of industries and the jobs at 3213 units and 0.19 million jobs probably due to the current socio-political situation of the country (CBS 2003).

Still, the total number of manufacturing units may look bigger without the knowledge of type of industries operating in Nepal. Industries in Nepal are categorized into four types – cottage industries, small industries with fixed capital up to Rs. 30 million, medium industries with fixed capital from Rs. 30 to 100 million and large industries with fixed

-82- 5 Issues in context of Nepal capital of above Rs. 100 million. Most of the industries in Nepal fall into the first two categories with a very few in medium industries category and even less in large industries category.

In the past, much of the industries in Nepal were established within a certain fixed area commonly called as industrial districts IDs or industrial estates (IEs). It could be because the basic infrastructure facilities, such as fence or boundary wall, industrial sheds, ware houses, roads, drainage/culverts, electricity/water supply, bank, clinic, post office, child care center, canteen and other required services for smooth operation of industries are easier to provide in a specific area designated as IDs and IEs. Further, this concept has been utilized by the government for regional economic development through establishment of such units at 11 different parts of the country under the assistance from various donor countries (Industrial Districts Management Limited, 2003).

The first industrial district to get established is Balaju Industrial District in Kathmandu way back in 1960 under U.S. assistance. The following table highlights the characteristics of all the industrial districts of the country.

IDs Establishe Sponsor Area Investment No. of No. Power Water Road ↓ d (Ropani) Rs.In million industrie of capacit suppl s * HM Private s Jobs y y (Km) G (KVA) Kl/hr Balaju 1960 USA 696 13.2 2000.0 92 4000 4000 20 5.2 0 Patan 1963 India 293 14.3 408.1 106 1472 1100 1 5 Hetauda 1963 USU 2829 25.5 3124.7 54 4844 5000 92 11 2 Dharan 1973 India 202 7.7 162.9 25 566 750 1 2.3 Nepalgunj 1973 India 233 9.6 28 635 500 7.57 2.34 125.00 Pokhara 1974 HMG/N 501 14.7 73 1400 700 20 2.54 500.00 Butwal 1976 HMG/N 434 11.0 987.3 56 1300 1350 6 2.14 Bhaktapur 1979 Germany 71 13.5 246.2 29 625 900 20 0.69 Birendranag 1981 Netherland 90 7.4 19 70 50 4.1 0.91 ar s 5.00 Dhankuta** 1984 HMG/N 63 5.6 - 1 - - - Rajbiraj 1986 India 294 35.5 7 27 100 8 2 25.00 TOTAL 5706 158 7584.0 489 1498 14450 179.6 34.12 0 5 7 * 1 hectare = 19.65 Ropani ** Construction held up Table 5.4.6: Details of the Industrial Districts Source: Industrial Districts Management Limited in Profile, 2003.

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Comparing the figures and the table above it is easy to make out that there is significant number of industries established outside the industrial districts. Bulk of these industries is in Kathmandu valley with a few scattered at different part of the country. Thus, except for the valley there seems an insignificant environmental problem coming out of these units, but the true pictures are different. Forty per cent of Nepal's total industrial units are related to water pollution (MOPE 2001). All industrial wastes in most cases are directly discharged into local water bodies, most commonly the lotic one, without any treatment.

The common type of wastes coming from the industrial effluent of Nepal include high load of oxygen demanding wastes, disease causing agents, synthetic organic compounds, plant nutrients, inorganic chemicals and minerals, and sediments (MOPE 1998). The following table highlights not only the industrial pollution load but also their occurrence in different development regions of the country.

Development Parameters Regions ↓ TSP (ton) Waste Water BOD (ton) TSS (ton) Solid Waste Volume (m³) (ton) Kathmandu 37857 2100000 1150 1417 1421 valley Central 19950 2160000 1284 2317 8622 excluding valley Eastern 6626 3450000 1424 3614 9560

Western 5505 699000 1050 1350 1615

Mid Western 2610 43000 336 300 287

Far Western 3835 105000 493 593 378

Total 76,383 8,556,997 5,741 9,591 21,883

Table 5.4.7: Industrial pollution load in Development Regions Source: MOPE, 2000

The main problem of industrial pollution in Nepal lies not with the number of industries but with the lack of environmental concerns and initiatives with them. However this is not to blame the industrial sector alone as the environmental awareness and most of the related legislations evolved much latter than their establishment in most of the cases. In addition, to boost the country’s economic status, many more industries are sure to come with liberal government policy. Thus, water pollution from industries would remain one of the important environmental problems in Nepal for some time.

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CHAPTER VI: MATERIALS AND METHODS

6.1 Strategy:

The study of disturbances in streams and rivers in this work uses the comparative studies of streams that have contrasting disturbance regimes. First the type of disturbances was finalized and accordingly the rivers and streams were selected to represent those disturbances. To give the study a temporal dimension, four replica of data set were collected corresponding to different seasons. Finally a comparison of disturbed site with undisturbed site was made for all the disturbances identified in different seasons to draw a conclusion. The information regarding fish population and physico-chemical parameters collected during the sampling were utilized for evaluating the magnetude of impairment. The same information was also utilized for various related purposes.

6.2 Type of disturbances:

Rivers in Nepal are subjected to different disturbances because of their varied uses. The scale of impairment to the rivers and aquatic life done by these disturbances are ever- growing. The type of disturbances this work wanted to focus was something that has to be common or sure to increase in future, bigger in magnitude and of general interest. With that view the following four types of disturbances were taken into consideration in this work.

• Agriculture • Urbanization • Dams and weirs • Industries

6.3 Site selection:

Selection of sites was done with main objective of including rivers and streams that are a good representative of the disturbances mentioned above. However, as there are several suitable sites to choose from, there were a number of factors considered.

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• Similarity in origin of the rivers: Almost all the rivers chosen were perennial having water all the year round. This will allow a good comparison.

• Accessibility: Almost all the rivers were accessible by road. This was necessary in order to carry the equipment.

• Socio-political situation: 2003 – 2004 was truly a difficult period in Nepal in terms of political upheaval with almost no guarantee of safety. However, politically sensitive localities were generally avoided. The permission letters for sampling are included in the appendix.

• Public demand: At least the study on one disturbance in river Narayani that of a paper mill was included as a part of this work as per the popular interest and demand.

So with the main objective and the factors described above the following rivers were selected for the study at the specified locations.

no river location 1 Aandhikhola Bayatari and Galyang (Shyangja) 2 Arungkhola Kusunde (Nawalparasi) 3 Bagmati Sundarijal (Kathmandu) 4 Jhikhukhola Paanchkhal (Kavre) 5 Karrakhola Hetauda (Makawanpur) 6 Narayani Narayanghat (Chitwan and Nawalparasi) 7 East Rapti Hetauda and Bhandara (Makawanpur and Chitwan) 8 Seti Pokhara (Kaski) 9 Tinau Maniphaant, Koldanda and Butwal (Palpa and Rupandehi)

Table 6.1: Rivers and the locations of the sampling sites with districts in parenthesis.

Among these rivers Aandhikhola, Bagmati and Tinau have been selected to study the impact of hydropower dam while Arungkhola, Karrakhola and Narayani have been selected to study the impact of industries. Similarly Jhikhukhola, East Rapti and Tinau are for agricultural impacts as Narayani, Seti and Tinau are for the disturbance caused by urbanization. The table 6.2 illustrates the rivers with respective disturbances identified.

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DISTURBANCESÆ Dams/weirs Urbanization Industry Agriculture RIVERS ↓ Aandhikhola X Arungkhola X Bagmati X Jhikhukhola X Karrakhola X Narayani X X East Rapti X Seti X Tinau X X X

Table 6.2: Rivers and the disturbances identified for the study shown by ‘X’

For each disturbance in each river two sites were selected, one representing the reference or upstream site while the other being the disturbed or downstream site. Thus, altogether 23 sampling sites were selected with the one in Narayani served as a reference site for both industrial and urban disturbances. The table 6.3 highlights the geographical position of all the sites.

The details of all the rivers studied and the corresponding sampling sites are described in the next chapter.

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SITES DESCRIPTION

Rivers Sites - Upstream Sites – Downstream Sites - Downstream Aandhikhola Bayatari Galyang 27° 58' 29.6" lat. 27° 56' 55.2" lat. 83° 43' 1.6" long. 83° 40' 33.1" long. 681 masl 670 masl Arungkhola Kusunde Kusunde 27° 37' 7.5" lat. 27° 36' 30.7" lat. 83° 57' 20" long. 83° 57' 20.5" long. 148 masl 140 masl Bagmati Sundarijal Sundarijal 27° 46' 24.9" lat. 27° 46' 18.4" lat. 85° 25' 33.8" long. 85° 25' 34.5" long. 1621 masl 1610 masl Jhikhukhola Paanchkhal Paanchkhal 27° 38' 55.3" lat. 27° 36' 24.4" lat. 85° 35' 28.5" long. 85° 39' 33.4" long. 936 masl 898 masl. Karrakhola Hetauda Hetauda 27° 24' 30.8" lat. 27° 24' 53.7" lat. 85° 03' 09.6" long. 85° 01' 09" long. 450 masl 450 masl Narayani Narayanghat Narayanghat – city Narayanghat -industry 27° 42 '16.1" lat. 27° 41' 51.1" lat. 27° 41' 40.8" lat. 84° 24' 50” long. 84° 24' 50" long. 84° 24' 7.3" long. 165 masl. 165 masl 162 masl Rapti Hetauda Bhandara 27° 27' 10.9" lat. 27° 34' 14" lat. 85° 02' 19.5" long. 84° 38' 54.8" long. 451 masl 202 masl Seti Pokhara Pokhara 28° 15' 12.8" lat. 28° 9' 39.4" lat. 83° 58' 4.5" long. 84° 0' 56.1" long 927 masl 630 masl Tinau Maniphant - Agriculture Koldanda - Agriculture 27° 49' 22.3" lat. 27° 47' 52.2" lat. 83° 36' 9.6" long. 83° 31' 37.6" long. 680 masl 616 masl Tinau Butwal – Dam Butwal - Dam 27° 44' 11.6" lat. 27° 43' 32.8" lat. 83° 27' 52.9" long. 83° 28' 6.3" long. 282 masl 207 masl Tinau Butwal – city Butwal – city 27° 43' 18.7" lat. 27° 41' 37.5" lat. 83° 28' 5.6" long. 83° 27' 38.3" long. 171 masl 152 masl Table 6.3: Rivers and exact coordinates of the sampling sites.

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6.4 Sampling:

6.4.1 Time and duration:

The first set of field sampling of this study in selected river sections of Nepal began on the third week of February 2003. Prior to that selection of appropriate sampling sites and testing of some of the equipments were carried out since October 2002. After the first real sampling, replicate of it were taken corresponding to all major seasons. Finally, four sets of data representing each season, spring, summer/premonsoon, autumn/postmonsoon and winter were collected spanning until the beginning of 2004. With 23 sites and four replicate of these, there are altogether 92 samplings that constitute this work.

6.4.2 Fish collection and measurements:

Fish sampling was done using electro fishing gear and this could be the first application of electro fishing gear for fish sampling in Nepal, as the previous records could not be traced. Fishing with electricity is a standard method of sampling all over the world at present (Cowx 1990 and the references therein). The method followed here was a simple but standard wading type where a person carries the generator fitted with motor on his back and an anode fitted with net in the hands. He was assisted by two persons each carrying a long dip nets to collect the shocked fish and a third person carrying a bucket to empty the nets. For the safety all the persons involved in fishing were insulated by a long wading boots. In addition, for the safety reason again, the local people and the onlookers around were well informed about the electricity hazard and were requested not to enter the river section when the sampling was in progress. Even the animals and cattle were guarded carefully from entering the water body during this period (the detail of the gear is described in chapter iv).

In each site, the fish sampling was done in two runs, 1 and 2 respectively. The stretch of the each sampling site was mostly between 50 to 100 meters but depending upon the conditions sometimes it was less than that and a few times exceeded. The time span for each run were taken separately and is even more important as it is a factor to calculate the catch per unit effort (CPUE) which in turn is important tool to see other population dynamics of the fish. CPUE in this work is defined as the number of fish captured in 10 minutes of electrofishing. The time for each run were tried to be around 20 minutes and was never less than 30 minutes for the total of run 1 and 2 in any of the sample in all seasons. Different types of readings were taken after the sampling and they included:

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i) Identification: The fishes were identified up to the species level as far as possible in the field itself with the help of keys in the Nepalese context (Day 1878, Shrestha 1984, Talwar and Jhingran 1991, and Jayaram 1999). The information given by the locals were also very valuable regarding the identification. Those unidentified were preserved in 10% formalin solution and were latter identified with the contribution from Central Department of Zoology (TU), Dept. of Fisheries (HMG/Nepal), academicians and experts.

ii) Length measurement: The total length (TL) of all fishes was measured up to the last 5 mm with the help of a specially constructed simple mechanical devise. The measuring range of this tool is 0 – 1000 mm (Picture 6.4.1).

iii) Weight measurement: Several representative weights of the each length group were also measured during the sampling using a standard weighing machine with the range of 2 grams to 5 kilograms and not with decimals (Picture 6.4.2).

6.4.3 Physico-chemical parameters:

Several physico-chemical parameters like temperature, Ph, dissolved oxygen, conductivity, stretch length, area, and water discharge of the rivers were noted down either before or after the fishing in another protocol. Standard portable devices (from WTW, Germany) and measuring tapes were used to collect this information and noted down in a separate protocol. Also the data from Department of Hydrology and Metrology (DHM) were obtained for comparison and correction.

6.4.4 Geo-morphology of the sampling sites:

The information of this nature was mostly observatory. The riverbanks and substrates were carefully observed and many times sketched in the protocol. The major substrate of each river, mainly rock, boulder, cobbles, pebbles, gravel, sand and silt were taken account in percentage. Number of digital photographs of each site highlighting its geology and morphology were also taken in the spot. Altitude, latitude and longitude of each sampling site were also measured by portable GPS (Global Positioning System) device.

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6.5 Data processing and analysis:

Processing and analysis of data was done at Universität für Bodenkultur (BOKU), Austria using standard software and statistical tools that are in use in modern research. All the data regarding fish, physico-chemical parameters and geomorphology were initially recorded in respective Excel spread sheets. The parameters analyzed included species diversity and richness, leading species, density and abundance, and productivity. Correlations between different parameters were examined and also some multivariate analysis was performed. The main program used for the analysis was SPSS. The data obtained from electro fishing are very much relevant and acceptable for all these tests and analysis (Cowx and Lamarque 1990).

Various kinds of books, journals and other information related with this work were studied, reviewed and compared with the results. The main sources for these materials were the number of libraries in the two universities involved, Kathmandu University (KU) and Universität für Bodenkultur (BOKU). Besides, number of external sources such as Ministries and Departments, private and public libraries and, NGO’s and INGO’s were also consulted.

6.6 Results and interpretation:

Results are produced in a numerical and graphical form to have better understanding. Numbers of statistical analysis and tests such as cluster analysis, canonical discrimination analysis, non parametric Kruskal–Wallis test, Mann-Whitney test and parametric one way ANOVA were used to produce results. All the statictical analysis and tests were done using SPSS version 11.0 software. Detail interpretation of these values and graphs has been done in the chapter discussion.

Pic.6.4.1: Length measuring instrument Pic.6.4.2: Digital weighing machine

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CHAPTER VII: DESCRIPTION OF THE SITES

Nepal is more or less rectangular in shape with an average length of 885 km east to west and non-uniform width of 193 km north to south. It covers an area of 147, 181 km² and lies from sub-tropical to the alpine region at 26°22’ to 30°27’ N latitude and 80°4’ to 88°12’ E longitude. It is a landlocked country between India and China and thus, rivers and the lakes constitute the important water bodies. Politically, it is divided into 75 Districts within 14 Zones and 5 Developmental Regions. The sites of the present study lie in the Districts, Kavrepalanchowk, Kathmandu, Makawanpur, Chitwan, Nawalparasi, Rupandehi, Palpa, Shyangja and Kaski of Bagmati, Narayani, Lumbini and Gandaki Zone, which in turn are part of Central and Western Development Regions.

This research involves the study of nine rivers from different parts of Nepal. The rivers that were studied, in alphabetical order, are Aandhikhola, Arungkhola, Bagmati, Jhikhukhola, Karrakhola, Narayani, East Rapti, Seti and Tinau. Among these rivers, Aandhikhola, Arungkhola, Karrakhola, Narayani, East Rapti and Seti belong to Gandaki River System, Jhikhukhola is a tributary of Koshi River System, and Tinau and Bagmati are river systems draining to Ganges in India (Sharma 1977). A brief description of each river and sites are given here.

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Map 7.1: Country map with sampling sites shown in square

Map 7.2: Part of the country map enlarged with sampling sites

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7.1 Aandhikhola:

It is an important river of Shyangja district and originates from Dahare hill, southeast from Karkineta (MOIC 1974). The district belongs to Gandaki Zone of Western Development Region. It is a rainfed midhills river estimated to be 96 km long with catchment area of 195 km², which finally drain to Kali Gandaki just before the country’s largest hydropower dam. The mean daily discharge of the river according to the latest record by Department of Hydrology and Meteorology (DHM) varies from minimum of 8.58 m³/s in a day in May to maximum of 696 m³/s in one day in August. The average annual flow of the river is 14.5 m³/s (DHM 2002).

Not only does this river fulfills the demand of water for agriculture and household activities in the district, a power plant too is set up to generate 5 Megawatts (MW) of electric power from this river. There is a provision of fish- pass in this hydropower project but its utility is in question. Since the impact of hydropower dam on the fish population is studied from this river, the details of this plant are also provided (table 7.1.1).

Two sampling sites were selected from this river. The upstream sampling site, also called as the reference site is placed some kilometer before the dam in Bayatari. The downstream sampling site lies immediately after the dam in the place called Galyang. The temperature of water in upstream site varied from 14.7 to 25.4° C and the measure of dissolved oxygen (DO) conductivity and pH reached up to 10 ppm, 51 µS/cm and 8.0 respectively. Similarly the substrate in this site was observed to possess 20% rock, 20% boulder, 30% cobbles, 25% pebbles, 4% gravels and 1% each of sand and silt.

The temperature of water in downstream site varied from 14.9 to 23.5° C and the measure of dissolved oxygen (DO) conductivity and pH reached up to 7.2 ppm, 52.2 µS/cm and 8.1 respectively. Similarly the substrate in this site was observed to possess 10% rock, 15% boulder, 30% cobbles, 30% pebbles, and 15% gravels.

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Aandhikhola Hydel and Rural Electrification Project (AHREP): Basic Project Data Design output 5 MW Project Site South Syangja District River Diverted Aandhikhola Catchment Area 444 km² Minimum River Flow 1.4 m³/s Design Flood for Plant Operations 1000 m³/s Diversion Weir Type Concrete Gravity Weir Height 6 m Weir Length 65 m Daily Pondage with Flashboards 43,000 m³ Particles Removed by Silting Basin 0.3 mm and larger Headrace Tunnel Length 1340 m Headrace Tunnel Section 4 m² Surge Tank 12 m² Surface Area Vertical Entrance Shaft Depth 240 m Penstock Diameter 1.1 – 0.9 m Gross Head 246 m Design Head 238 m Design Flow 2.7 m³/s Power House Cavern Floor Area 250 m² Turbines 3 X 1.7 MW Pelton Alternators 3 X 2.2 MVA/5.3 KV Tailrace Tunnel Length 1040 m Tailrace Tunnel Section 5.2 m² High Tension Transmission Lines Approximately 80 km Access Road 1.6 km Total Project Cost Rs 51 million Table 7.1.1: Details of Aandhikhola Hydel and Rural Electrification Project (AHREP) Source: Butwal Power Company Pvt. Ltd. (1982)

7.2 Arungkhola:

It is an important river of Nawalparasi district, which originates from midhills in Palpa district and drains to Narayani. The district belongs to Lumbini Zone of Western Development Region. The catchment area of this river is 215 km² and has annual flow of 12.3 m³/s (DHM 2002). The river has one of the country’s important industries, Shree Distillery (P) Ltd. along its bank. Established in 1985, the distillery has been producing rectified spirit and blending and bottling different brands of high quality liquors.

The factory is situated in Kusunde, Nawalparasi at the bank of Arungkhola and occupies about 65 ropanies of land. The company has sophisticated plants with capacity of 15,00,000 liter spirit per year and about 250 people work at the factory. The company has shown the

-95- 7 Description of the sites environmental concern too. To ensure that the factory would not pollute the Arungkhola and the surrounding areas, the company has fixed an effluent treatment plant. However, if it is operational and efficient are yet to know. The pictures and the information from local people indicate that the effluent from the distillery might be polluting the adjoining river if not the entire area.

This work has studied the impacts of the factory on the river taking fish as an indicator. There are two sampling sites for this purpose each before and after the industry on either side of the East-West Highway. The site before the industry is called as upstream or reference site and the one after is called as the downstream or disturbed site. The temperature of water in upstream site varied from 17.4 to 28.5° C and the measure of dissolved oxygen (DO) conductivity and pH reached up to 8.67 ppm, 72.5 µS/cm and 8.6 respectively. Similarly the substrate in this site was observed to possess 5% boulder, 25% cobbles, 25% pebbles, 30% gravels, 10% sand and 5% silt.

The temperature of water in downstream site varied from 17 to 26° C and the measure of dissolved oxygen (DO) conductivity and pH reached up to 7.7 ppm, 72.2 µS/cm and 8.3 respectively. Similarly the substrate in this site was observed to possess 15% boulder, 30% cobbles, 30% pebbles, 20% gravels, 3% sand and 2% silt.

7.3 Bagmati:

This is the most important river of Kathmandu Valley, which originates from Baghdwar at Shivapuri Hill as high as 2650 masl. It is a rainfed midhills river, which belongs to an independent system and holds great religious and cultural value. The total length of the river is 163 km with catchment area of 3610 km². The river flows around 30 km within Kathmandu Valley. The mean daily discharge of the river at Sundarijal according to the latest record by the Department of Hydrology and Meteorology (DHM) varies from 0.24 m³/s in April to 10 m³/s in someday in July with yearly mean of 1.37 m³/s. This river has one of the country’s oldest hydropower plants at Sundarijal. The amount of power produced by this plant is very insignificant, however, the diversion made by the dam is more important in terms of drinking water supply to the huge population of the valley. The impact of the dam in this river is studied in this work. The details of the studied hydropower plant

-96- 7 Description of the sites are summarized in the following table. Since it is one of the oldest projects in Nepal, the units are not consistent.

Project Site Kathmandu District River Diverted Bagmati Design Output 600 kW Minimum River Flow 1.2 m.l./h Design Flood for Plant Operation 2.4 m.l./h Diversion Weir Type Carbon Concrete Gravity Pipeline Weir Height 24 m Weir Length 6 m Headrace Tunnel Section 18 inch Surge Tank 1.5 m² Penstock Diameter 18 inch Design Head 950 feet Design Flow 2.6 m.l./h Power House Cavern Flow Area 1500 m² Turbines 2 X 300 kW Tailrace Tunnel Length 50 m Project Duration 1982 BS – 1991 BS Financed British Government Table 7.3.1: Details of Sundarijal Hydropower Plant

The impact of this dam in Bagmati River is studied in this work. Two sampling site were fixed in this river. The upstream or the reference site was just before the impoundment and the disturbed or the downstream site was immediately after the dam. Unlike Aandhikhola, there is no provision of fish pass between upstream and downstream of this dam and thus, the longitudinal corridor is completely disrupted. Both the reference and disturbed sites were inside Shivapuri National Park and prior permissions were taken before each sampling from the concerned authorities (see appendix for the permission letters).

The temperature of water in upstream site varied from 9.7 to 18.8° C and the measure of dissolved oxygen (DO) conductivity and pH reached up to 8.5 ppm, 23.6 µS/cm and 7.5 respectively. Similarly the substrate in this site was observed to possess 5% rock, 20% boulder, 25% cobbles, 25% pebbles, 20% gravels, 3% sand and 2% silt. The temperature of water in downstream site varied from 8.9 to 15.9° C and the measure of dissolved oxygen (DO) conductivity and pH reached up to 8.7 ppm, 24.3 µS/cm and 6.9 respectively. Similarly the substrate in this site was observed to possess 20% rock, 40% boulder, 20% cobbles, 10% pebbles, 5% gravels, 3% sand and 2% silt.

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7.4 Jhikhukhola:

This river is small in comparison with the other rivers of Kavrepalanchowk District, but is famous for creating a very fertile agricultural valley in the district. The district belongs to Bagmati Zone in the Central Development Region of the country. The river originates from midhills bordering Bhakatapur and Kavrepalanchowk Districts and finally drains to Sunkoshi River, which is an important tributary of the Koshi River System. The river covers an area of 111.4 km². The water discharge was found to be fluctuating between minimums of 9.0 m³/s to maximum of 93.6 m³/s (Gautam 1997).

The impact of agriculture on the river is studied in this river as it flows through a very fertile valley, where people are engaged in intensive agricultural practice and the use of fertilizers and pesticides are very high. According to the last census in 2001/02, there were 64570 holdings of land in Kavrepalanchowk district with an area of 44218.6 ha. Out of these, total area of arable land amounts to 37404.7 ha of which 11406.1 ha are irrigated by some means (CBS 2001). The quantity of mineral/chemical fertilizer used in the district was found to be 10512953 kg with highest consumption of 4173168 kg only for maize. The amount of this chemical input is in addition to the organic manure coming from a huge stock of cattle, which numbers 88751 heads excluding buffaloes and goats which count 87389 and 224434 respectively. The number of holdings using pesticide is highest for potato, which stands at 10363.

As usual, there are two sampling sites on this river around 12 km apart. The upstream, also called as reference, is in the confluence of Jhikhukhola and Dhulikhelkhola at Dovan Pati and the downstream or the disturbed site is at Baluwa. The temperature of water in upstream site varied from 15.4 to 29° C and the measure of dissolved oxygen (DO) conductivity and pH reached up to 6.9 ppm, 83.3 µS/cm and 7.5 respectively. The substrate in this site was observed to possess 30% rock, 20% boulder, 20% cobbles, 15% pebbles, 10% gravels, 3% sand and 2% silt. Similarly the temperature of water in downstream site varied from 14.6 to 29.3° C and the measure of dissolved oxygen (DO) conductivity and pH reached up to 10.9 ppm, 118.9 µS/cm and 8.6 respectively. The substrate in this site was observed to possess 1% rock, 20% boulder, 20% cobbles, 30% pebbles, 25% gravels, 3% sand and 1% silt.

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7.5 Karrakhola:

The river originates from the northeast of Siwalik range in Makawanpur District, which belongs to Narayani Zone of Central Development Region. From its origin the river flows toward west, passes through Hetauda city and drains in East Rapti River. The total length of the river was reported to be around 19.25 km with catchment area of 96 km² (Singh 1995). The river flows nearby the country’s biggest industrial district called Hetauda Industrial District (HID).

Established in 1963, with the help of United States of America, HID covers around 144 hectares of land with an investment of 25.5 million Rupees from the Government sector and 3124.72 million Rupees from the private sector (IDM 2003). The industrial district directly employs 4844 person in 54 industries of which 44 are in operation. The power capacity of the industrial district is 5000 KVA and has water supply of 92 kl/hr. There are varieties of industries inside HID and the products include paints, plastic corks, electricity poles, biscuits, tin containers, processed meats, carton boxes, ghee, toothpastes and soaps, plastic pipes, processed foods, ball-point pen, stone powder and livestock feeds.

Similarly, other products include construction materials, vegetable oil, cigarette, furniture, marble slab, leather, bone materials, plastic drums, dairy, beer, cotton fabrics, polyester, tea packaging, tiles, hollow concrete, zippers and drugs. In addition, there are some laboratories for quality control (IDM 2002). The effluents from all the industries inside the district are collected together and are drained to the nearby Karrakhola. However, a new construction for the effluent treatment is going on.

The impact of industries on this river was studied in this work. There were two sampling sites for this purpose in this river. The upstream or the reference site was selected a few kilometers before the industrial district and the downstream or disturbed site was about 1 km after the discharge of effluents from the industries. The temperature of water in upstream site varied from 14 to 25.1° C and the measure of dissolved oxygen (DO) conductivity and pH reached up to 8.4 ppm, 68 µS/cm and 7.33 respectively. The substrate in this site was observed to possess 20% cobbles, 30% pebbles, 30% gravels, 10% sand and 10% silt. Similarly the temperature of water in downstream site varied from 17.2 to 27.4° C and the measure of dissolved oxygen (DO) conductivity and pH reached up to 7.6 ppm, 115

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µS/cm and 7.28 respectively. The substrate in this site was observed to possess 10% rock, 30% boulder, 20% cobbles, 20% pebbles, 15% gravels, 3% sand and 2% silt.

7.6 Narayani:

This river also called as Sapta Gandaki is the main channel of Gandaki River System, which is one of the largest river systems of Nepal. The longest channel, Kali Gandaki of this river system is antecedent (see chapter river and river system) and is drained by several glacial rivers. Kali Gandaki originates from the other side of the Himalayas in Mustang area from Photu pass where it is called Mustangkhola and (Sharma 1997). After reaching the plain in Nepal, the system is popularly called as Narayani, which take southwestern direction from Narayanghat and finally becomes confluent with the Ganges in India. The total length of the river is 332 km with catchment area of 34960 km² of which 30090 km² lies within Nepal. The average annual discharge of this river at Narayanghat is mentioned as 1576 m³/s (DHM).

According to the last complete data of discharge of this river at Narayanghat, the minimum daily discharge was measured as 212 m³/s and the maximum as 10900 m³/s (DHM). This river is important for Nepal not only because of the size but also because of religious and cultural attachment. This particular river has been selected for this study mainly due to the popular demand. The impacts of both Bhrikuti Paper Mill and Narayanghat city, which lie on the two different banks of the river, have been studied in this work.

Bhrikuti Pulp and Paper Mill, now a private company, situated on the bank of Narayani River at Gaindakot, Nawalparasi was founded in 1982 by a mutual cooperation between HMG of Nepal and the Government of the People’s Republic of China with a design output of 10 tonnes/day of paper production. The first batch of paper was produced in 1986 and in 1989 the capacity of production was raised to 13 tonnes/day (Upadhaya 1994). The mill was privatized in 1990 and as a result the capacity of production was massively raised to 128 tonnes/day within six years (Upadhaya 1996). In addition to the raw materials such as wheat/rice straw and Sabai grass, the company uses large amounts of chemicals like caustic soda (NaOH), talcum powder, resin, bleaching powder (CaOCl2, alum, soda ash (Na2CO3), hydrochloric acid (HCl), CaO, Cl2 and the dyes for the production and maintenance (Kharel and Thapa 2003). For every ton of the finished product, the plant needs 300 tonnes of water.

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The following table shows the input of different materials required to produce one ton of paper in this mill.

One ton of paper Sabai Wheat Talcum Bleaching Soda grass straw powder Resin Powder Alum Soda ash Caustic 1465 Kg 1562 Kg 150 Kg 15 Kg 222 Kg 60 Kg 1.8 Kg 411 Kg Table 7.6.1: Materials for production of one ton of paper Source: Bhrikuti Paper Mills Ltd. (Brochure 1982)

There are two kinds of interactions of this factory with Narayani River. First, the river is the main source of huge volume of water the factory requires and second, the effluent from the industry is directly discharged into the river without treatment. Considering the discharge rate of the river, the impacts from first interaction might not be so significant. However, the impacts from the second interaction are physically visible and chemically established through various studies. This work studies these impacts by taking fish as an indicator.

Narayanghat city, which lies within Bharatpur Municipality of Chitwan district, is one of the fastest growing urban centers of Nepal because of its strategic position. The city holds a criss-cross of the longest highway of Nepal, the East-West Highway and the Highways leading to the Capital, Kathmandu and the most important touristic city, Pokhara. In fact, the major growth of the city started only after the construction of these highways. Bharatpur was gazetted as municipal area just in 1981 with the population 27602, but by 2001, the population had reached 89323 a three times growth (CBS 2003). Narayanghat is named after the river Narayani on the bank of which the city is situated. The study of the impacts of this rapid urbanization on Narayani River is also included in this work.

There were three sampling sites in this river for the study of impacts of two disturbances as the reference site or the upstream site serves the purpose for both. The reference site was fixed just before the section of the river from where the core urban area starts. The disturbed site for the study of the impact of city was fixed on the left bank of the river immediately after the city. As the city expands across the river and not along the river, the influence area of the city on the river is very less. The disturb site for the impact of industry was fixed about 100 m downstream from the place of effluent discharge on the right bank of the river. Due to the large size, the river is unwadeable and thus, the sampling was restricted to the banks of the river.

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The temperature of water in upstream site varied from 14 to 23.9° C and the measure of dissolved oxygen (DO) conductivity and pH reached up to 8.8 ppm, 283 µS/cm and 8.2 respectively. The substrate in this site was observed to possess 20% boulder, 30% cobbles, 25% pebbles, 10% gravels, 10% sand and 5% silt. The temperature of water in downstream site of the city varied from 16.2 to 28.3° C and the measure of dissolved oxygen (DO) conductivity and pH reached up to 9.8 ppm, 273 µS/cm and 8.8 respectively. The substrate in this site was observed to possess 25% boulder, 25% cobbles, 25% pebbles, 20% gravels, 3% sand and 2% silt. Similarly, the temperature of water in downstream site for the impact of industry varied from 16.4 to 26° C and the measure of dissolved oxygen (DO) conductivity and pH reached up to 7.4 ppm, 490 µS/cm and 8.3 respectively. The substrate in this site was observed to possess 30% boulder, 30% cobbles, 25% pebbles, 5% gravels, 5% sand and 5% silt.

7.7 East Rapti:

This is an important river of Makawanpur and Chitwan districts. The river originates from midhills in Makawanpur district at a place called Chisapani Garhi and flows south up to Hetauda and then takes westerly course and through a fertile valley of Makawanpur and Chitwan districts before joining with Narayani River. The river has a catchment area of about 3110 km² and runs for around 122 km (Sharma 1997). The average annual discharge of the river measured at Bhandara in Chitwan is 61 m³/s. According to the last complete data from DHM measured in this river at Rajaiya, the minimum daily discharge was 3.08 m³/s and the maximum 141 m³/s.

After a quick fall from its origin, the river meanders extensively in the low and fertile land of the two districts and plays important role in the agriculture. According to the last census in 2001/02, there were 59071 holdings of land in Makawanpur district with an area of 34256.1 ha. Out of these, total area of arable land amounts to 31740.3 ha of which 9130.7 ha are irrigated by some means (CBS 2001). The quantity of mineral/chemical fertilizer used in the district was found to be 3663451 kg with highest consumption of 1789186 kg only for maize. The amount of this chemical input is in addition to the organic manure coming from a huge stock of cattle, which numbers 149712 heads excluding buffaloes and goats which count 47440 and 243507 respectively. The number of holdings using pesticide in paddy alone stands highest at 9325.

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Similarly, according to the last census in 2001/02, there were 71429 holdings of land in Chitwan district with an area of 42113.2 ha. Out of these, total area of arable land amounts to 38348.9 ha of which 28442.0 ha are irrigated by some means (CBS 2001). The quantity of mineral/chemical fertilizer used in the district was found to be 4203056 kg with consumption of 2856863 kg only for paddy. The amount of this chemical input is in addition to the organic manure coming from a huge stock of cattle, which numbers 89333 heads excluding buffaloes and goats which count 91970 and 160873 respectively. The numbers of holdings using pesticides are 7341 in the district. The number of holdings using pesticide in paddy alone stands at 22287.

There were two sampling sites for the study of the impacts of agriculture on this river. The upstream or the reference site was fixed in the river in Makawanpur district few kilometers before Hetauda immediately after the river comes down from the midhills. The downstream or the disturbed site was set up in Bhandara, Chitwan district some 50 km away from the reference site. The site was just on the boundary of Royal Chitwan National Park and the special permissions were taken from the concerned authorities before each sampling (see appendix for permission letters).

The temperature of water in upstream site varied from 17.8 to 24.1° C and the measure of dissolved oxygen (DO) conductivity and pH reached up to 8.2 ppm, 174 µS/cm and 8.3 respectively. The substrate in this site was observed to possess 2% rock, 10% boulder, 30% cobbles, 30% pebbles, 20% gravels, 3% sand and 5% silt. Similarly the temperature of water in downstream site varied from 16.4 to 30° C and the measure of dissolved oxygen (DO) conductivity and pH reached up to 9.4 ppm, 420 µS/cm and 8 respectively. The substrate in this site was observed to possess 5% boulder, 40% cobbles, 30% pebbles, 20% gravels, 2% sand and 3% silt.

7.8 Seti:

This river is glacial in origin and comes from Annapurna range. This is the most important river of Kaski district and flows through the heart of Pokhara city where it cuts the ground deep and appears almost underground for some distance. It is a tributary of Gandaki River System with a catchment area of 3000 km², length 125 km and annual average discharge of

-103- 7 Description of the sites

52 m³/sec (Sharma 1997). According to the last complete yearly data of this river by DHM, the minimum flow was recorded as 11.5 m³/s and the maximum as 169 m³/s.

As the river passes through Pokhara, one of the most important urban center of the country, the impacts of urbanization on this river is studied in this work. Pokhara is a beautiful touristic city in the midhills of Kaski district of Western Development Region of Nepal, which is very close to very high Annapurna ranges of Himalayas. The rank of the city as an urban center of Nepal has improved tremendously from 13th in 1961 to 4th in 2001 (CBS 2003). The population of this city has grown at steady rate from 5413 in 1961 to 156312 in 2001. The strategic position and the touristic value of this city are the main reason of its growth and are expected to continue like this in future as well. It is natural to expect some disturbances of this growth on the river, which flows, through the center of the city.

Two sampling sites, upstream and downstream or the reference and disturbed were fixed on this river to study the impacts of urbanization. The reference site was fixed on the river along the Pokhara – Baglung Highway some distances before it enters the city. While, the disturbed site was fixed after the river emerges out of the city near Phulbari area. The temperature of water in upstream site varied from 12.8 to 21° C and the measure of dissolved oxygen (DO) conductivity and pH reached up to 9.5 ppm, 54.2 µS/cm and 8.5 respectively. The substrate in this site was observed to possess 20% rock, 30% boulder, 25% cobbles, 15% pebbles, 8% gravels, 1% sand and 1% silt. Similarly the temperature of water in downstream site varied from 14.3 to 20.5° C and the measure of dissolved oxygen (DO) conductivity and pH reached up to 9.4 ppm, 63.7 µS/cm and 7.9 respectively. The substrate in this site was observed to possess 10% rock, 30% boulder, 30% cobbles, 10% pebbles, 10% gravels, 5% sand and 5% silt.

7.9 Tinau:

Tinau River is one of the most important rivers of Palpa and Rupandehi districts of Lumbini Zone in Western Development Region of Nepal. The river originates from midhills above Maniphant in Palpa district and flows south to Rupandehi district. It is interesting to note that except during the flood period, the river goes underground just near Butwal city and emerges out only after about 10 km in the south (MOIC 1974). The river does not belong to any of the three major river systems of Nepal and runs about 95 km between an altitude of

-104- 7 Description of the sites

100 – 800 masl (Sharma and Shrestha 2001). The drainage area of the river is estimated to be 544 km² (Sharma 1977). According to the last complete annual data of the mean daily discharge of the river by DHM, the minimum was 2.58 m³/s and the maximum was 92.8 m³/s.

This river is the most important river in this work as the impacts of three different disturbances; agriculture, dam and the urbanization were studied here. The river after origination flows through a highly fertile valley called Maniphant (sometimes also called as Mariphant). The valley, which is irrigated naturally by Tinau River is suitable for the cultivation of varieties of crops, pulses and vegetables and as such is under intensive agricultural practices. This makes it an ideal site for the investigation of the impacts of agricultural practices on the river by taking fish as an indicator.

According to the last census in 2001/02, there were 44406 holdings of land in Palpa district with an area of 31623.5 ha. Out of these, total area of arable land amounts to 22734.9 ha of which 8372.0 ha are irrigated by some means (CBS 2001). The quantity of mineral/chemical fertilizer used in the district was found to be 759442 kg with highest consumption of 302627 kg only for paddy. The amount of this chemical input is in addition to the organic manure coming from a huge stock of cattle, which numbers 86660 heads excluding buffaloes and goats which count 77868 and 126657 respectively. The number of holdings using pesticide in paddy alone stands highest at 3123.

The same river has a hydropower project called Tinau Hydropower Project which was constructed by Butwal Power Company at about 3 km north of Butwal on the right bank in Palpa district (WECS 1997). Construction started in 2023 B.S. and completed in 2034, this is among the oldest hydropower projects of the country with mere 1 MW of installed capacity, but the dam constructed across this river for power generation completely disrupts the longitudinal corridor of the river. In addition, unlike Aandhikhola, there is no provision of fish pass either. This makes this river ideal for the study of the impact of dams on the river and thus it is a part of the study in this work.

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The details of Tinau Hydropower Project are summarized in the following table.

1 Minimum Flow in Tinau River 2.4 m³/s 2 Average Discharge 54 m³/s 3 Design Discharge 2.4 m³/s 4 Gross Head 50 m 5 Size of Powerhouse Cavern L: 88 m, H: 6 m Engine Hall L: 32 m, B: 4.5 m Corridor L: 56 m, B: 3 m 6 X – Section of Main Tunnel 2.1 m² 7 X – Section of Tailrace Tunnel 3.85 m² 8 Dam Length 65 m 9 Dam Height 8 m 10 Dam Type R.C.C. and Stone Masonry 11 Length of Tunnel 2462 m 12 Construction Period 11 Years 13 Turbines 2 X 250 kW and 1 X 500kW 14 Cost of Project Rs 102,00,000 Table 7.9.1: Details of Tinau Hydropower Project Source: WECS (1997) modified

Downstream from the hydropower plant the river also supports one of the important urban centers of the country called Butwal. The city is strategically placed in Bhanwar region as a door to the people of the hills of all Western Development Regions for their business and other interactions with Terai as well as with India. The city is also head quarter of Lumbini Zone and its importance is enhanced by the country’s longest highway, East-West Highway, which passes through the middle of the city and also by the link with another, Siddhartha Highway. Butwal Industrial District, a prestigious name in the commerce and industrial sector, is also situated in this urban center.

Butwal was gazetted as urban center in 1959, is not and was not a very crowded area in comparison with some other major municipal areas of the country. The census of 1971 recorded the population of the city as 12, 815. The population increased to 22,583 in 1981, 44,272 in 1991 and 75,384 in 2001 (CBS 2003). However, it is not the population as such, but its growth is simply alarming as could be seen from the above figure. The impact of this urbanization is ever increasing on the nearby Tinau River and is thus included in this study.

There were six sampling sites in Tinau river, two each for the three disturbances, agriculture, dam and urbanization. To study the agricultural impact, the upstream or the reference site was fixed just near the beginning of the valley, Maniphant in Palpa district.

-106- 7 Description of the sites

The downstream or the disturbed site for this purpose was selected in the place called Koldanda also in Palpa. Similarly, for the impact of dam, the upstream or the reference site was made about 100 m before the dam and the disturbed or downstream was about 500 m after the dam, both in Palpa district. The sampling sites for the study of the impact of urbanization however were in Rupandehi district. The upstream or the reference site was about 1 km before the city and the downstream was just before the river disappears underground.

The temperature of water in reference site for agriculture varied from 17 to 31.9° C and the measure of dissolved oxygen (DO) conductivity and pH reached up to 9.2 ppm, 25.6 µS/cm and 7.2 respectively. The substrate in this site was observed to 30% cobbles, 40% pebbles, 25% gravels, 3% sand and 2% silt. Similarly the temperature of water in downstream site for agriculture varied from 12.2 to 22.5° C and the measure of dissolved oxygen (DO) conductivity and pH reached up to 8.15 ppm, 72.3 µS/cm and 8.24 respectively. The substrate in this site was observed to possess 30% rock, 25% boulder, 20% cobbles, 20% pebbles, 3% gravels, 1% sand and 1%.

The temperature of water in reference site for city varied from 16 to 24.5° C and the measure of dissolved oxygen (DO), conductivity and pH reached up to 8.8 ppm, 70 µS/cm and 8.4 respectively. The substrate in this site was observed to 20% rock, 30% boulder, 20% cobbles, 20% pebbles, 8% gravels, 1% sand and 1% silt. Similarly the temperature of water in downstream site for city varied from 14.2 to 23.8° C and the measure of dissolved oxygen (DO) conductivity and pH reached up to 7.5 ppm, 68 µS/cm and 8.5 respectively. The substrate in this site was observed to possess 10% boulder, 10% cobbles, 30% pebbles, 30% gravels, and 20% sand.

The temperature of water in reference site for dam varied from 15 to 28.8° C and the measure of dissolved oxygen (DO), conductivity and pH reached up to 8 ppm, 68 µS/cm and 8.2 respectively. The substrate in this site was observed to possess 10% rock, 10% boulder, 10% cobbles, 10% pebbles, 30% gravels, 25% sand and 5% silt. Similarly the temperature of water in downstream site for dam varied from 15.4 to 26.4° C and the measure of dissolved oxygen (DO) conductivity and pH reached up to 7.6 ppm, 68.8 µS/cm and 8.2 respectively. The substrate in this site was observed to possess 15% rock, 15% boulder, 20% cobbles, 30% pebbles, 10% gravels, 5% sand and 5% silt.

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Map 7.3: Showing Sampling Sites in Aandhikhola

Map 7.4: Showing Sampling Sites in Karrakhola, East Rapti, Narayani and Arungkhola

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Map 7.5: Showing Sampling Sites in Bagmati River

Map 7.6: Showing Sampling Sites in Jhikhukhola

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Map 7.7: Showing Sampling Sites in Seti River

Map 7.8: Showing Sampling Sites in Tinau River

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CHAPTER VIII: RESULTS

8.1: Distribution, abundance and density of fish:

The following are the details of the fishes captured and studied in this research, which are presented systematically, according to Shrestha (2001) who in turn had followed Jayaram (1999). In addition, Day (1889), Rajbanshi (1982), Rahman (1989), Shrestha (1990), Talwar and Jhingran (1991), Shrestha (1994), Shrestha (1994) and Shrestha (1995) have also been consulted to work out this part of the result.

NO ORDER FAMILY GENUS SPECIES 1 Clupeiformes Clupeidae Gudusia Gudusia chapra Hamilton-Buchanan 1822 2 Cypriniformes Cyprinidae Neolissochilus Neolissochilus hexagonolepis McClelland 1839 3 Cirrhinus Cirrhinus reba Hamilton-Buchanan 1822 4 Labeo Labeo dero Hamilton-Buchanan 1822 5 Puntius Puntius chola Hamilton-Buchanan 1822 6 Puntius Puntius conchonius Hamilton-Buchanan 1822 7 Puntius Puntius sophore Hamilton-Buchanan 1822 8 Semiplotus Semiplotus semiplotus McClelland 1839 9 Tor Tor putitora Hamilton-Buchanan 1822 10 Tor Tor tor Hamilton-Buchanan 1822 11 Naziritor Naziritor chelynoides McClelland 1839 12 Aspidoparia Aspidoparia morar Hamilton-Buchanan 1822 13 Barilius Barilius barila Hamilton-Buchanan 1822 14 Barilius Barilius barna Hamilton-Buchanan 1822 15 Barilius Barilius bendelisis Hamilton-Buchanan 1822 16 Barilius Barilius shacra Hamilton-Buchanan 1822 17 Barilius Barilius vagra Hamilton-Buchanan 1822 18 Brachydanio Brachydanio rerio Hamilton-Buchanan 1822 19 Danio Danio aequipinnatus McClelland 1839 20 Danio Danio dangila Hamilton-Buchanan 1822 21 Esomus Esomus danricus Hamilton-Buchanan 1822 22 Crossocheilus Crossocheilus latius Hamilton-Buchanan 1822 23 Garra Garra annandalei Hora 1921

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NO ORDER FAMILY GENUS SPECIES 24 Garra Garra gotyla gotyla Gray 1830 25 Schizothorax Schizothorax richardsonii Gray 1832 26 Cypriniformes Cyprinidae Schizothoraichthys Schizothoraichthys progastus McClelland 1839 27 Psilorhynchidae Psilorhynchus Psilorhynchus pseudecheneis Menon and Datta 1961 28 Balitoridae Nemacheilus Nemacheilus corica Hamilton-Buchanan 1822 29 Acanthocobitis Acanthocobitis botia Hamilton-Buchanan 1822 30 Schistura Schistura beavani Günther 1868 31 Schistura Schistura rupecula McClelland 1839 32 Cobitidae Botia Botia almorhae Gray 1831 33 Botia Botia lohachata Chaudhuri 1912 34 Lepidocephalus Lepidocephalus guntea Hamilton-Buchanan 1822 35 Siluriformes Amblycipitidae Amblyceps Amblyceps mangois Hamilton-Buchanan 1822 36 Schilbeidae Clupisoma Clupisoma garua Hamilton-Buchanan 1822 37 Sisoridae Myersglanis Myersglanis blythii Day 1870 38 Glyptothorax Glyptothorax pectinopterus McClelland 1842 39 Glyptothorax Glyptothorax telchitta Hamilton-Buchanan 1822 40 Glyptothorax Glyptothorax trilineatus Blyth 1860 41 Pseudecheneis Pseudecheneis sulcatus McClelland 1842 42 Heteropneustidae Heteropneustes Heteropneustes fossilis Bloch 1794 43 Perciformes Channidae Channa Channa orientalis Bloch & Schneider 1801 44 Channa Channa punctatus Bloch 1793 45 Gobiidae Glossogobius Glossogobius giuris Hamilton-Buchanan 1822 46 Synbranchiformes Mastacembelidae Macrognathus Macrognathus pancalus Hamilton-Buchanan 1822 47 Mastacembelus Mastacembelus armatus Lacepede 1800 Table 8.1.1 : List of fish species recorded in this study

1. Gudusia chapra: This fish, commonly known as river shad or Suiya in Nepal has been listed by Day (1889), Chaudhuri (1912), Taft (1955), DeWitt (1960), Menon (1962), Shrestha (1978), Rajbanshi (1982), Rahman (1989), Shrestha (1990), Talwar and Jhingran (1991) and Shrestha (2001) under the same name or different synonyms. It is reported from India, Pakistan, Bangladesh, Burma, Malaya and Nepal. In Nepal, it has been reported from up to 373 masl altitudes and measures up to 200 mm total length (TL). The fish is not included in IUCN red list and the status is described as common. The present study has

-112- 8 Results found this fish only once in Karra Khola at 450 masl (new record) during spring and, thus, it could be a threatened species, at least, at this altitude. (Picture:8.1.1)

2. Neolissochilus hexagonolepis: This fish, commonly known as Katle in Nepal, has been listed by McClelland (1839), Day (1889), Hora (1937), Taft (1955), Mishra (1959), DeWitt (1960), Menon (1962), Shrestha (1978), Rajbanshi (1982), Shrestha (1990), Talwar and Jhingran (1991) and Shrestha (2001) under the same name or different synonyms. It is distributed in India, Nepal, Bangladesh, Burma, China, Thailand, Malaysia and Indonesia. In Nepal, this fish has been recorded from up to the altitude of 1700 masl with maximum size recorded is 610 mm. The fish is not included in IUCN red list though it is described as ‘vulnerable’ in the country may be because of its great commercial importance. This study finds the species occurring from the altitude 162 masl to 927 masl with some sections of river Aandhikhola, Tinau, Seti and East Rapti still holding a good number. (Picture: 8.1.2)

3. Cirrhinus reba: This fish, commonly known as Rewa in Nepal, has been listed by Hamilton-Buchanan (1822), Günther (1861), Day (1889), Taft (1955), DeWitt (1960), Menon (1962), Shrestha (1978), Rajbanshi (1982), Rahman (1989), Shrestha (1990), Talwar and Jhingran (1991) and Shrestha (2001) under the same name or different synonyms. It is reported from Pakistan, India, Nepal, Bangladesh and Burma. In Nepal it has been found up to 373 masl with maximum size of 305 mm. It is not included in IUCN red list and in Nepal its status is reported to be ‘common’. This study finds the species occurring in Karrakhola at 450 masl (new record) and it could be a threatened species at this altitude. (Picture: 8.1.3)

4. Labeo dero: Commonly known as Gardi, Rohu or Shahi in Nepal, this fish has been mentioned by Hamilton-Buchanan (1822), Day (1889), Chaudhuri (1912), Hora (1937), Taft (1955), DeWitt (1960), Menon (1962), Shrestha (1978), Rajbanshi (1982), Rahman (1989), Shrestha (1990), Talwar and Jhingran (1991), and Shrestha (2001) under the same name or different synonyms. It is reported from Iran, Afghanistan, Pakistan, India, Nepal, Bhutan Bangladesh, Burma, China and Sri Lanka. In Nepal it has been found up to 1424 masl with maximum size of 300 mm. It is not included in IUCN red list and in Nepal its status is reported to be ‘common’. This study finds the species occurring in rivers Narayani, East Rapti, Arungkhola and Tinau at the altitude ranging from 148 to 207 masl with maximum total length of 320 mm (new record). Its distribution seems much more limited than reported in the past. It has a significant commercial value. (Picture: 8.1.4)

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5. Puntius chola: This fish, commonly known as Sidre or Pothi in Nepal has been listed by Hamilton-Buchanan (1822), Day (1889), Taft (1955), DeWitt (1960), Menon (1962), Shrestha (1978), Rajbanshi (1982), Rahman (1989), Shrestha (1990), Talwar and Jhingran (1991) and Shrestha (2001) under the same name or different synonyms. This fish is reported from Pakistan, India, Nepal, Bangladesh, Sri Lanka, Burma and Bhutan. In Nepal it has been reported from up to 300 masl with maximum size of 80 mm. It is not included in IUCN red list though in Nepal it is mentioned as ‘rare’. This study finds this fish in rivers Aandhikhola and Karrakhola, and also confirms it to be rare but the distribution is wider up to 670 masl (new record). (Picture. 8.1.5)

6. Puntius conchonius: Commonly known as Sidre or Pothi again, this fish has been listed by Hamilton-Buchanan (1822), Day (1889), Taft (1955), DeWitt (1960), Menon (1962), Shrestha (1978), Jayaram (1982), Rajbanshi (1982), Rahman (1989), Shrestha (1990), Talwar and Jhingran (1991) and Shrestha (2001) under the same name or different synonyms. This fish is reported from Afghanistan, Pakistan, India, Nepal and Bangladesh. In Nepal it has been reported from up to 1800 masl with maximum size of 80 mm. It is not included in IUCN red list and the status is described as ‘common’. The present study finds this fish in rivers Arungkhola, Karrakhola, Narayani, East Rapti, Seti and Tinau and confirms it as common at least in the altitude 140 to 927masl with the maximum size reaching up to 85 mm (new record). (Picture: 8.1.6)

7. Puntius sophore: Commonly known as Sidre or Chandanpothi, this fish has been listed by Hamilton-Buchanan (1822), Day (1889), Fowler (1924), Taft (1955), DeWitt (1960), Menon (1962), Tilak (1970), Shrestha (1978), Rajbanshi (1982), Rahman (1989), Shrestha (1990), Talwar and Jhingran (1991) and Shrestha (2001) under the same name or different synonyms. It is reported from Afghanistan, Pakistan, India, Nepal, Bangladesh, Bhutan, Burma and China. In Nepal it has been reported from up to 1460 masl with maximum size of 100 mm. It is not included in IUCN red list and the status is described as ‘common’. The present study finds this fish in rivers Arungkhola, Karrakhola, Narayani, East Rapti, Seti and Tinau and confirms it as common. (Picture: 8.1.7)

8. Semiplotus semiplotus: This fish, commonly known as Chepti in Nepal has been listed by McClelland (1839), Day (1889), Hora (1939), Chaudhuri (1919), Hora (1937), Taft (1955), DeWitt (1960), Menon (1962), Shrestha (1978), Rajbanshi (1982), Shrestha (1990),

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Talwar and Jhingran (1991) and Shrestha (2001) under the same name or different synonyms. It is reported from India, Nepal, Burma, and Bhutan. In Nepal it has been reported from up to 463 masl with maximum size of 300 mm. It is not included in IUCN red list and the status is described as ‘common’ in the country. This study finds this fish from the rivers Aandhikhola, Arungkhola and Narayani up to 670 masl (new record), but seems threatened unlike previously reported. (Picture: 8.1.8)

9. Tor putitora: This fish, commonly known as Sahar or Mahseer in Nepal has been listed by Hamilton-Buchanan (1822), Day (1889), Hora (1939), Taft (1955), Mishra (1959), DeWitt (1960), Menon (1962), Shrestha (1978), Rajbanshi (1982), Rahman (1989), Shrestha (1990), Talwar and Jhingran (1991) and Shrestha (2001) under the same name or different synonyms. It is reported from Afghanistan, Pakistan, India, Nepal, Bangladesh and Bhutan. In Nepal it has been reported from up to 1891 masl with maximum size of 1800 mm. Though it is not included in IUCN red list, it is reported ‘vulnerable’ in the country. It is a big commercial game fish. The present study finds this fish in rivers Aandhikhola, Arungkhola, Narayani, East Rapti and Tinau up to 681 masl and confirms that it is vulnerable. (Picture: 8.1.9)

10. Tor tor: This fish, commonly known as Sahar in Nepal has been listed by Hamilton- Buchanan (1822), Day (1889), Mirza (1967) Shrestha (1978), Rajbanshi (1982), Rahman (1989), Shrestha (1990), Talwar and Jhingran (1991) and Shrestha (2001) under the same name or different synonyms. It is reported from Pakistan, India, Nepal, Bangladesh, Bhutan and Burma. In Nepal it has been reported from up to 1891 masl with maximum size of 1200 mm. Though it is not included in IUCN red list, it is reported as ‘endangered’ in the country. It is a big game fish with high commercial value. The present study finds this fish in rivers Narayani and Tinau up to 282 masl and confirms that it is endangered. (Picture: 8.1.10)

11. Naziritor chelynoides: This fish, commonly known as Karange in Nepal, has been listed by McClelland (1839), Day (1889), Shrestha (1990), Talwar and Jhingran (1991) and Shrestha (2001) under the same name or different synonyms. It is reported from Pakistan, India and Nepal. In Nepal it has been reported from up to 1700 masl with maximum size of 250 mm. It is not included in IUCN red list and reported as ‘fairly common’ in the country. The present study however finds this fish only in river Aandhikhola at 681 masl with

-115- 8 Results maximum size of 210 mm and thus fish seems less than common than reported earlier. (Picture: 8.1.11)

12. Aspidoparia morar: This fish, commonly known as Harda, Bhegna or Chepwa in Nepal, has been listed by Hamilton-Buchanan (1822), Day (1889), Hora (1937), Taft (1955), DeWitt (1960), Menon (1962), Shrestha (1978), Rajbanshi (1982), Rahman (1989), Shrestha (1990), Talwar and Jhingran (1991) and Shrestha (2001) under the same name or different synonyms. It is reported from Iran, Afghanistan, Pakistan, India, Nepal, Bangladesh, Burma and Thailand. In Nepal it has been reported from up to 850 masl with maximum size of 145 mm. It is not included in IUCN red list and reported as ‘common’ in the country. The present study however finds this fish only in rivers Narayani and East Rapti, that too less in number and with restricted altitudinal range up to 202 masl. (Picture: 8.1.12)

13. Barilius barila: This fish, commonly known as Fageta or Khasre in Nepal, has been listed by Hamilton-Buchanan (1822), Day (1889), Chaudhuri (1912), Taft (1955), DeWitt (1960), Menon (1962), Shrestha (1978), Rajbanshi (1982), Rahman (1989), Shrestha (1990), Talwar and Jhingran (1991) and Shrestha (2001) under the same name or different synonyms. It is reported from India, Nepal, Bangladesh and Burma. In Nepal it has been reported from up to 1424 masl with maximum size of 125 mm. It is not included in IUCN red list and reported as ‘common’ in the country. The present study also finds this fish as very common and is caught in all the rivers studied except Bagmati, up to 936 masl with maximum size of 130 mm (new record). (Picture:8.1.13)

14. Barilius barna: This fish, commonly known as Fageta in Nepal, has been listed by Hamilton-Buchanan (1822), Day (1889), Taft (1955), DeWitt (1960), Menon (1962), Shrestha (1978), Rajbanshi (1982), Rahman (1989), Shrestha (1990), Talwar and Jhingran (1991) and Shrestha (2001) under the same name or different synonyms. It is reported from India, Nepal, Bangladesh and Burma. In Nepal it has been reported from up to 1891 masl with maximum size of 150 mm. It is not included in IUCN red list and reported as ‘common’ in the country. However, the present study found only one of these specimens at the altitude of 452 masl in Karrakhola indicating that this species might be highly threatened. (Picture: 8.1.14)

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15. Barilius bendelisis: This fish, commonly known as Fageta in Nepal, has been listed by Hamilton-Buchanan (1822), Day (1889), Hora (1937), Taft (1955), DeWitt (1960), Menon (1962), Shrestha (1978), Rajbanshi (1982), Rahman (1989), Shrestha (1990), Talwar and Jhingran (1991) and Shrestha (2001) under the same name or different synonyms. It is reported from Pakistan, India, Nepal, Bangladesh, Bhutan and Sri Lanka. In Nepal it has been reported from up to 1891 masl with maximum size of 180 mm. It is not included in IUCN red list and reported as ‘common’ in the country. The present study also finds this species as quite common and is recorded from all the rivers studied except Bagmati up to the altitude 936 masl. (Picture: 8.1.15)

16. Barilius shacra: This fish, commonly known as Fageta in Nepal, has been listed by Hamilton-Buchanan (1822), Day (1889), Hora (1937), Taft (1955), DeWitt (1960), Menon (1962), Tilak (1971), Shrestha (1978), Rajbanshi (1982), Rahman (1989), Shrestha (1990), Talwar and Jhingran (1991) and Shrestha (2001) under the same name or different synonyms. It is reported from India, Nepal, and Bangladesh. In Nepal it has been reported from up to 850 masl with maximum size of 130 mm. It is not included in IUCN red list and reported as ‘common’ in the country. However, the present study finds the species only in rivers Arungkhola, Narayani and East Rapti, and is not so common as reported though the same altitudinal range has been explored. (Picture: 8.1.16)

17. Barilius vagra: This fish, commonly known as Fageta or Khasre in Nepal, has been listed by Hamilton-Buchanan (1822), Day (1889), Hora (1937), Taft (1955), Mishra (1959), DeWitt (1960), Menon (1962), Mirza and Sadiq (1978), Shrestha (1978), Rajbanshi (1982), Rahman (1989), Shrestha (1990), Talwar and Jhingran (1991) and Shrestha (2001) under the same name or different synonyms. It is reported from Afghanistan, Pakistan, India, Nepal, Bangladesh and Sri Lanka. In Nepal it has been reported from up to 1500 masl with maximum size of 150 mm. It is not included in IUCN red list and reported as ‘common’ in the country. The present study too finds it common and it is caught in all rivers except Bagmati among the rivers studied. (Picture: 8.1.17)

18. Brachydanio rerio: This fish, commonly known as Zebra in Nepal, has been listed by Hamilton-Buchanan (1822), Day (1889), Taft (1955), DeWitt (1960), Menon (1962), Shrestha (1978), Rajbanshi (1982), Rahman (1989), Shrestha (1990), Talwar and Jhingran (1991) and Shrestha (2001) under the same name or different synonyms. It is reported from

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Pakistan, India, Nepal, Bangladesh, Bhutan and Burma. In Nepal it has been reported from up to 1350 masl with maximum size of 25 mm. It is not included in IUCN red list but reported as ‘vulnerable’ in the country. The present study finds this fish up to the height of 898 masl with maximum size of 50 mm (new record), and though reported vulnerable, there are certain sections of river like Tinau where they are found in abundance. (Picture: 8.1.18)

19. Danio aequipinnatus: This fish, commonly known as Bhitti or Patale Sidre in Nepal, has been listed by McClelland (1839), Day (1889), Regan (1907), Taft (1955), DeWitt (1960), Menon (1962), Shrestha (1978), Rajbanshi (1982), Rahman (1989), Shrestha (1990), Talwar and Jhingran (1991) and Shrestha (2001) under the same name or different synonyms. It is reported from India and Nepal. In Nepal it has been reported from up to 1460 masl. It is included in IUCN red list as the species with Data Deficient (DD) and reported as ‘insufficiently known’ in the country. The present study finds this species from Arungkhola and Jhikhukhola from up to 936 masl with the maximum size of 85 mm, and the exact status has to be studied further as it is not so common. (Picture: 8.1.19)

20. Danio dangila: This fish, commonly known as Nepti in Nepal, has been listed by Hamilton-Buchanan (1822), Day (1889), Hora (1937), Taft (1955), DeWitt (1960), Menon (1962), Rajbanshi (1982), Rahman (1989), Talwar and Jhingran (1991) and Shrestha (2001) under the same name or different synonyms. It is reported from India, Nepal, Bangladesh, Bhutan and Burma. In Nepal it has been reported from up to 300 masl. It is not included in IUCN red list but reported as ‘occasional’ in the country. The present study finds this species only in Seti river at 630 masl with maximum size of 75 mm (new records) and seems to be a highly threatened species. (Picture: 8.1.20)

21. Esomus danricus: This fish, commonly known as Dhedawa or Darai in Nepal, has been listed by Hamilton-Buchanan (1822), Day (1889), Chaudhuri (1912), Taft (1955), DeWitt (1960), Menon (1962), Rao and Sharma (1972), Shrestha (1978), Rajbanshi (1982), Rahman (1989), Shrestha (1990), Talwar and Jhingran (1991) and Shrestha (2001) under the same name or different synonyms. It is reported from Afghanistan, Pakistan, India, Nepal, Bangladesh, Sri Lanka and Burma. In Nepal it has been reported from up to 1460 masl with maximum size of 75 mm. It is not included in IUCN red list and reported as ‘common’ in the country. The present study finds it only in the river Tinau, Karrakhola and Arungkhola up to 680 masl and also not so common. (Picture: 8.1.21)

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22. Crossocheilus latius: This fish, commonly known as Lohari, Petfora, Besuro or Kaundi in Nepal, has been listed by Hamilton-Buchanan (1822), Day (1889), Hora (1937), Taft (1955), DeWitt (1960), Menon (1962), Rao and Sharma (1972), Shrestha (1978), Rajbanshi (1982), Rahman (1989), Shrestha (1990), Talwar and Jhingran (1991) and Shrestha (2001) under the same name or different synonyms. It is reported from India, Nepal and Bangladesh. In Nepal it has been reported from up to 850 masl with maximum size of 220 mm. It is not included in IUCN red list and reported as ‘common’ in the country. The present study finds its distribution limited to within 202 masl and was caught in river Narayani, Arungkhola, Rapti and Tinau. (Picture: 8.1.22)

23. Garra annandalei: This fish, commonly known as Buduna in Nepal, has been listed by Hamilton-Buchanan (1822), Day (1889), Hora (1921), Taft (1955), DeWitt (1960), Menon (1962), Ganguly and Dutta (1973), Shrestha (1978), Rajbanshi (1982), Rahman (1989), Shrestha (1990), Talwar and Jhingran (1991) and Shrestha (2001) under the same name or different synonyms. It is reported from India, Nepal, Bangladesh and Bhutan. In Nepal it has been reported from up to 1891 masl with maximum size of 150 mm. It is not included in IUCN red list and reported as ‘common’ in the country. The present work finds it in all the rivers studied except Bagmati and Narayani (but found in the tributaries), up to 936 masl with maximum size of 165 mm (new record) and is quite common. (Picture: 8.1.23)

24. Garra gotyla gotyla: This fish, commonly known as Buduna in Nepal, has been listed by Gray (1832), Day (1889), Prashad (1912), Hora (1921), Taft (1955), DeWitt (1960), Menon (1962), Ganguly and Dutta (1973), Shrestha (1978), Rajbanshi (1982), Rahman (1989), Shrestha (1990), Talwar and Jhingran (1991) and Shrestha (2001) under the same name or different synonyms. It is reported from Afghanistan, Pakistan, India, Nepal, Bangladesh, Bhutan and Burma. In Nepal it has been reported from up to 1560 masl with maximum size of 150 mm. It is not included in IUCN red list and reported as ‘fairly common’ in the country. The present work finds it in all the rivers studied except river Bagmati with maximum size of 180 mm (new record) and is perhaps the most common species. (Picture: 8.1.24)

25. Schizothorax richardsonii: This fish, commonly known as Buchhe Asla in Nepal, has been listed by Gray (1832), Günther (1861), Heckel (1877), Day (1889), Regan (1907), Chaudhuri (1913), Hora (1921), Taft (1955), DeWitt (1960), Menon (1962), Mirza and

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Awan (1978), Shrestha (1978), Rajbanshi (1982), Terashima (1984), Shrestha (1990), Talwar and Jhingran (1991) and Shrestha (2001) under the same name or different synonyms. It is reported from Afghanistan, Pakistan, India, Nepal and Bhutan. In Nepal it has been reported from up to 2810 masl 600 mm. It is not included in IUCN red list but reported as ‘vulnerable’ in the country. The present study finds it in river Bagmati, Narayani, East Rapti and Aandhikhola up to 1621 masl. It is an important game fish with high commercial value and is found sufficiently only in river Bagmati during this research. (Picture: 8.1.25)

26. Schizothoraichthys progastus: This fish, commonly known as Chuche Asla in Nepal, has been listed by McClelland (1839), Günther (1861), Day (1889), Shrestha (1978), Rajbanshi (1982), Tilak and Sharma (1982), Shrestha (1990), Talwar and Jhingran (1991) and Shrestha (2001) under the same name or different synonyms. It is reported from India, Nepal and Bhutan. In Nepal it has been reported from up to 1820 masl with maximum size of 300 mm. It is not included in IUCN red list but reported as ‘vulnerable’ in the country. The present study finds this commercially valuable game fish in only river Seti up to 927 masl, thus, indicating a very restricted distribution. (Picture: 8.1.26)

27. Psilorhynchus pseudecheneis: This fish, commonly known as Tite Machha in Nepal, has been listed by Menon and Datta (1962), Shrestha (1978), Rajbanshi (1982), Shrestha (1990), Talwar and Jhingran (1991) and Shrestha (2001). This species is endemic to Nepal and has been reported from up to 2950 masl with maximum size of 200 mm. It is not included in IUCN red list but reported as ‘vulnerable’ in the country. The present study finds this species only in rivers Narayani and East Rapti, up to 202 masl and that too in very limited number. (Picture: 8.1.27)

28. Nemacheilus corica: This fish, commonly known as Gadela in Nepal, has been listed by Hamilton-Buchanan (1822), Day (1889), Taft (1955), DeWitt (1960), Menon (1962), Shrestha (1978), Rajbanshi (1982), Rahman (1989), Shrestha (1990), Talwar and Jhingran (1991) and Shrestha (2001) under the same name or different synonyms. It is reported from Afghanistan, Pakistan, India, Nepal and Bangladesh. In Nepal, it has been reported from up to 1460 masl with maximum size of 75 mm. It is not included in IUCN red list but reported as ‘insufficiently known’ in the country. The present study finds it in rivers Aandhikhola,

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Jhikhukhola, Karrakhola, Narayani, East Rapti and Tinau, though not in good number. (Picture: 8.1.28)

29. Acanthocobitis botia: This fish, commonly known as Dhade Goira in Nepal, has been listed by Hamilton-Buchanan (1822), Blyth (1861), Day (1889), Chaudhuri (1910), Taft (1955), DeWitt (1960), Menon (1962), Shrestha (1978), Rajbanshi (1982), Rahman (1989), Shrestha (1990), Talwar and Jhingran (1991) and Shrestha (2001) under the same name or different synonyms. It is reported from Pakistan, India, Nepal, Bangladesh, China, Burma and Thailand. In Nepal, it has been reported from up to 1380 masl with maximum size of 100 mm. It is not included in IUCN red list and is reported as ‘common’ in the country. The present study finds it in rivers Arungkhola, Karrakhola, Narayani, East Rapti, Seti and Tinau, up to 680 masl and in good number. (Picture: 8.1.29)

30. Schistura beavani: This fish, commonly known as Pate Goira or Gadela in Nepal, has been listed by Günther (1868) Taft (1955), DeWitt (1960), Menon (1962), Shrestha (1978), Rajbanshi (1982), Rahman (1989), Shrestha (1990), Talwar and Jhingran (1991) and Shrestha (2001) under the same name or different synonyms. It is reported from India, Nepal and Bangladesh. In Nepal, it has been reported from up to 1560 masl with maximum size of 75 mm. It is not included in IUCN red list and is reported as ‘common’ in the country. The present study finds it in all rivers that is studied, up to 1610 masl with maximum size of 100 mm (new records), and is very common. (Picture: 8.1.30)

31. Schistura rupecula: This fish, commonly known as Tele Goira or Gadela in Nepal, has been listed by McClelland (1838), Day (1889), DeWitt (1960), Shrestha (1978), Rajbanshi (1982), Shrestha (1990), Talwar and Jhingran (1991) and Shrestha (2001) under the same name or different synonyms. It is reported from India, Nepal and Bangladesh. In Nepal, it has been reported from up to 2810 masl with maximum size of 100 mm. It is not included in IUCN red list and is reported as ‘common’ in the country. The present study finds it in all the rivers that are studied, up to 1621 masl and is very common. (Picture: 8.1.31)

32. Botia almorhae: This fish, commonly known as Baghi in Nepal, has been listed by Gray (1831), Day (1889), Taft (1955), DeWitt (1960), Menon (1962), Shrestha (1978), Rajbanshi (1982), Rahman (1989), Shrestha (1990), Talwar and Jhingran (1991) and Shrestha (2001) under the same name or different synonyms. It is reported from India and

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Nepal. In Nepal, it has been reported from up to 300 masl with maximum size of 150 mm. It is not included in IUCN red list and is reported as ‘insufficiently known’ in the country. The present study finds it in Narayani and Rapti rivers, up to 202 masl with maximum size of 170 mm (new record) and recommends a further study for its exact status. (Picture: 8.1.32)

33. Botia lohachata: This fish, commonly known as Baghi in Nepal, has been listed by Chaudhuri (1912), Taft (1955), DeWitt (1960), Menon (1962), Shrestha (1978), Rajbanshi (1982), Rahman (1989), Shrestha (1990), Talwar and Jhingran (1991) and Shrestha (2001) under the same name or different synonyms. It is reported from Pakistan, India, Nepal and Bangladesh. In Nepal, it has been reported from up to 850 masl with maximum size of 100 mm. It is not included in IUCN red list and is reported as ‘common’ in the country. The present study finds it in rivers Arungkhola, Narayani, East Rapti and Tinau, up to 207 masl with maximum size of 140 mm (new record) and in fair number. (Picture: 8.1.33)

34. Lepidocephalus guntea: This fish, commonly known as Chuinke or Goira in Nepal, has been listed by Hamilton-Buchanan (1822), Day (1889), Smith (1945), Rendahl (1948), Taft (1955), DeWitt (1960), Menon (1962), Shrestha (1978), Rajbanshi (1982), Rahman (1989), Shrestha (1990), Talwar and Jhingran (1991) and Shrestha (2001) under the same name or different synonyms. It is reported from Pakistan, India, Nepal, Bangladesh, Burma and Thailand. In Nepal, it has been reported from up to 76 masl with maximum size of 85 mm. It is not included in IUCN red list and is reported as ‘common’ in the country. The present study finds it in Arungkhola, Karrakhola, Narayani, East Rapti and Tinau rivers, up to 452 masl with maximum size of 95 mm (new records), and is quite common in some of these rivers. (Picture: 8.1.34)

35. Amblyceps mangois: This fish, commonly known as Chilwai, Pichhi or Bindhar in Nepal, has been listed by Hamilton-Buchanan (1822), Day (1889), Chaudhuri (1919), Taft (1955), DeWitt (1960), Menon (1962), Shrestha (1978), Rajbanshi (1982), Rahman (1989), Shrestha (1990), Talwar and Jhingran (1991) and Shrestha (2001) under the same name or different synonyms. It is reported from Pakistan, India, Nepal, Bangladesh, Burma and Thailand. In Nepal, it has been reported from up to1372 masl with maximum size of 150 mm. It is not included in IUCN red list and is reported as ‘rare’ in the country. The present study finds it in Arungkhola, Karrakhola, Narayani, East Rapti and Tinau rivers, up to 616 masl, and is still fairly common in some of those rivers. (Picture: 8.1.35)

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36. Clupisoma garua: This fish, commonly known as Jalkapur or Bainkhe in Nepal, has been listed by Hamilton-Buchanan (1822), Day (1889), Hora (1937), Taft (1955), Mishra (1959), DeWitt (1960), Menon (1962), Shrestha (1978), Rajbanshi (1982), Rahman (1989), Shrestha (1990), Talwar and Jhingran (1991) and Shrestha (2001) under the same name or different synonyms. It is reported from Pakistan, India, Nepal and Bangladesh. In Nepal, it has been reported from up to 570 masl with maximum size of 609 mm. It is not included in IUCN red list and is reported as ‘fairly common’ in the country. A good commercial fish, this study finds it in only river Narayani up to 165 masl and in very low number, thus, seems to be threatened. (Picture: 8.1.36)

37. Myersglanis blythii: This fish, commonly known as Tilkabre in Nepal, has been listed by Day (1869), Regan (1907), Hora (1952), Menon (1962), Shrestha (1978), Rajbanshi (1982), Shrestha (1990), Talwar and Jhingran (1991) and Shrestha (2001) under the same name or different synonyms. It is an endemic fish to Nepal and has been reported up to 2960 masl with maximum size of 100 mm. It is not included in IUCN red list and is reported as ‘rare’ in the country. This study finds it in Arungkhola and Seti rivers, up to 927 masl and in very little number indicating that it should be rare. (Picture: 8.1.37)

38. Glyptothorax pectinopterus: This fish, commonly known as Karasingha in Nepal, has been listed by McClelland (1842), Hora (1923), Taft (1955), DeWitt (1960), Menon (1962), Shrestha (1978), Rajbanshi (1982), Shrestha (1990), Talwar and Jhingran (1991) and Shrestha (2001) under the same name or different synonyms. It is reported from Pakistan, India and Nepal. In Nepal, it has been reported from up to 1820 masl with maximum size of 150 mm. It is not included in IUCN red list and is reported as ‘fairly common’ in the country. This study finds it in East Rapti and Tinau rivers, up to 616 masl and in very little number indicating that it should be highly threatened or rare. (Picture: 8.1.38)

39. Glyptothorax telchitta: This fish, commonly known as Kotel or Kavre in Nepal, has been listed by Hamilton-Buchanan (1822), Day (1889), Hora (1949), Taft (1955), DeWitt (1960), Menon (1962), Bashir and Mirza (1975), Shrestha (1978), Rajbanshi (1982), Rahman (1989), Shrestha (1990), Talwar and Jhingran (1991) and Shrestha (2001) under the same name or different synonyms. It is reported from Pakistan, India, Nepal and Bangladesh. In Nepal, it has been reported from up to 1424 masl with maximum size of 125 mm. It is not included in IUCN red list and is reported as ‘rare’ in the country. This study

-123- 8 Results finds it in Narayani, East Rapti and Tinau rivers, up to 616 masl with the maximum size of 130 mm (new record) and in not very high number indicating that it should be highly threatened or rare. (Picture: 8.1.39)

40. Glyptothorax trilineatus: This fish, commonly known as Kavre in Nepal, has been listed by Blyth (1861), Day (1889), Regan (1907), Shrestha (1978), Rajbanshi (1982), Shrestha (1990), Talwar and Jhingran (1991) and Shrestha (2001) under the same name or different synonyms. It is reported from India, Nepal, Burma and Thailand. In Nepal, it has been reported from up to 1820 masl with maximum size of 150 mm. It is not included in IUCN red list and is reported as ‘rare’ in the country. This study finds it in Narayani, East Rapti and Tinau rivers, up to 282 masl and in very low number indicating that it should be highly threatened or rare. (Picture: 8.1.40)

41. Pseudecheneis sulcatus: This fish, commonly known as Kabre in Nepal has been listed by McClelland (1842), Taft (1955), DeWitt (1960), Menon (1962), Tilak and Husain (1973), Shrestha (1978), Rajbanshi (1982), Rahman (1989), Shrestha (1990), Talwar and Jhingran (1991) and Shrestha (2001) under the same name or different synonyms. It is reported from India, Nepal, Bangladesh and Tibet. In Nepal, it has been reported from up to 1891 masl with maximum size of 175 mm. It is not included in IUCN red list and is reported as ‘occasional’ in the country. This study finds it in Arungkhola, Karrakhola, Seti and Tinau rivers, up to 927 masl and in very low number indicating that it should be highly threatened or rare or could be occasional as reported before. (Picture: 8.1.41)

42. Heteropneustes fossilis: This fish, commonly known as Singhe in Nepal, has been listed by Bloch (1794), Günther (1861), Day (1889), Regan (1907), Taft (1955), DeWitt (1960), Menon (1962), Mishra (1976), Shrestha (1978), Rajbanshi (1982), Rahman (1989), Shrestha (1990), Talwar and Jhingran (1991) and Shrestha (2001) under the same name or different synonyms. It is reported from Pakistan, India, Nepal, Bangladesh, Burma and Sri Lanka. In Nepal, it has been reported from up to 1400 masl with maximum size of 175 mm. This stinging fish is not included in IUCN red list and is reported as ‘common’ in the country. This study finds it in Aandhikhola, Karrakhola, East Rapti, Jhikhukhola, Seti and Tinau rivers, up to 898 masl with maximum size of 205 mm (new record) and in very low number indicating that it should be a highly threatened species if not rare. (Picture: 8.1.42)

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43. Channa orientalis: This fish, commonly known as Bhoti or Hile in Nepal, has been listed by Bloch and Schneider (1801), Hamilton-Buchanan (1822), Day (1889), Chaudhuri (1919), DeWitt (1960), Menon (1962), Rajbanshi (1982), Rahman (1989), Shrestha (1990), Talwar and Jhingran (1991) and Shrestha (2001) under the same name or different synonyms. It is reported from Iran, Afghanistan, Pakistan, India, Nepal, Bangladesh, Burma and Sri Lanka up to Indonesia. In Nepal, it has been reported from up to 1400 masl with maximum size of 180 mm. This fish is not included in IUCN red list and is reported as ‘common’ in the country. This study finds it in Arungkhola, Karrakhola, Narayani, East Rapti, Seti and Tinau rivers, up to 680 masl with maximum size of 220 mm (new record), and is fairly common. (Picture:8.1.43)

44. Channa punctatus: This fish, commonly known as Bhoti or Hile in Nepal, has been listed by Bloch (1793), Günther (1861), Day (1889), Regan (1907), Taft (1955), Mishra (1959), DeWitt (1960), Menon (1962), Shrestha (1978), Rajbanshi (1982), Rahman (1989), Shrestha (1990), Talwar and Jhingran (1991) and Shrestha (2001) under the same name or different synonyms. It is reported from Afghanistan, Pakistan, India, Nepal, Bangladesh, Burma and China. In Nepal, it has been reported from up to 1350 masl with maximum size of 304 mm. This fish is not included in IUCN red list and is reported as ‘common’ in the country. This study finds it in Aandhikhola, Arungkhola, Jhikhukhola, Karrakhola, Narayani and Tinau rivers, up to 936 masl and is quite common. (Picture: 8.1.44)

45. Glossogobius giuris: This fish, commonly known as Bulla in Nepal, has been listed by Hamilton-Buchanan (1822), Day (1889), Koumans (1941), Taft (1955), DeWitt (1960), Menon (1962), Shrestha (1978), Rajbanshi (1982), Rahman (1989), Shrestha (1990), Talwar and Jhingran (1991) and Shrestha (2001) under the same name or different synonyms. It is reported from Africa to Oceania encompassing Indian sub continent and South of China. In Nepal, it has been reported from up to 300 masl with maximum size of 175 mm. This fish is not included in IUCN red list and is reported as ‘common’ in the country. This study finds it in Narayani and East Rapti rivers, up to 202 masl and its number indicates that it is a highly threatened species in Nepal. (Picture: 8.1.45)

46. Macrognathus pancalus: This fish, commonly known as Kath Gainchi or Malanga Bam in Nepal, has been listed by Hamilton-Buchanan (1822), Day (1889), Menon (1962), Shrestha (1978), Rajbanshi (1982), Rahman (1989), Shrestha (1990), Talwar and Jhingran

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(1991) and Shrestha (2001) under the same name or different synonyms. It is reported from Pakistan, India, Nepal and Bangladesh. In Nepal, it has been reported from up to 300 masl with maximum size of 250 mm. This fish is not included in IUCN red list and is reported as ‘common’ in the country. This study finds it only in Arungkhola at 202 masl and its number indicates that it is not as common as reported earlier. (Picture: 8.1.46)

47. Mastacembelus armatus: This fish, commonly known as Bam in Nepal, has been listed by Lacepede (1800), Günther (1861), Day (1889), Hora (1921), Taft (1955), DeWitt (1960), Menon (1962), Shrestha (1978), Rajbanshi (1982), Rahman (1989), Shrestha (1990), Talwar and Jhingran (1991) and Shrestha (2001) under the same name or different synonyms. It is reported from Pakistan, India, Nepal, Bangladesh up to Vietnam and Indonesia. In Nepal, it has been reported from up to 784 masl with the maximum size of 300 mm. This fish is not included in IUCN red list and is reported as ‘common’ in the country. This study finds it in Aandhikhola, Arungkhola, Karrakhola, Narayani, East Rapti and Tinau rivers, up to 681 masl with maximum size of 675 mm (new record) and is fairly common. (Picture: 8.1.47)

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Pic.8.1.1: Gudusia chapra (Hamilton-Buchanan Pic.8.1.2: Neolissochilus hexagonolepis (McClelland 1822) 1839) Source: www.fishbase.org

Pic.8.1.3: Cirrhinus reba (Hamilton-Buchanan 1822) Pic.8.1.4: Labeo dero (Hamilton-Buchanan 1822) Source: www.fishbase.org

Pic.8.1.5: Puntius chola (Hamilton-Buchanan 1822) Pic.8.1.6: Puntius conchonius (Hamilton-Buchanan Source: Talwar and Jhingran (1991) 1822)

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Pic.8.1.7: Puntius sophore (Hamilton-Buchanan 1822) Pic.8.1.8: Semiplotus semiplotus (McClelland 1839)

Pic.8.1.9: Tor putitora (Hamilton-Buchanan 1822) Pic.8.1.10: Tor tor (Hamilton-Buchanan 1822)

Pic.8.1.11: Naziritor chelynoides (McClelland 1839) Pic.8.1.12. Aspidoparia morar (Hamilton-Buchanan 1822) Source: www.images.google.com

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Pic.8.1.13: Barilius barila (Hamilton-Buchanan 1822) Pic.8.1.14: Barilius barna (Hamilton-Buchanan 1822) Source: Talwar and Jhingran (1991)

Pic.8.1.15: Barilius bendelisis (Hamilton-Buchanan 1822) Pic.8.1.16: Barilius shacra (Hamilton-Buchanan 1822)

Pic.8.1.17: Barilius vagra (Hamilton-Buchanan 1822) Pic.8.1.18: Brachydanio rerio (Hamilton-Buchanan 1822)

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Pic.8.1.19: Danio aequipinnatus (McClelland 1839) Pic.8.1.20: Danio dangila (Hamilton-Buchanan 1822)

Pic.8.1.21: Esomus danricus (Hamilton-Buchanan 1822) Pic.8.1.22: Crossocheilus latius (Hamilton-Buchanan 1822)

Pic.8.1.23: Garra annandalei (Hora 1921) Pic.8.1.24: Garra gotyla gotyla (Gray 1830)

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Pic.8.1.25: Schizothorax richardsonii (Gray 1832) Pic.8.1.26:Schizothoraichthys progastus (McClelland 1839)

Pic.8.1.27:Psilorhynchus pseudecheneis (Menon and Datta 1961) Pic.8.1.28: Nemacheilus corica (Hamilton-Buchanan Source: www.fishbase.org 1822) Source: www.fishbase.org

Pic.8.1.29: Acanthocobitis botia (Hamilton-Buchanan Pic.8.1.30: Schistura beavani (Günther 1868) 1822)

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Pic.8.1.31: Schistura rupecula (McClelland 1839) Pic.8.1.32: Botia almorhae (Gray 1831)

Pic.8.1.33: Botia lohachata (Chaudhuri 1912) Pic.8.1.34: Lepidocephalus guntea (Hamilton-Buchanan 1822)

Pic.8.1.35 : Amblyceps mangois (Hamilton-Buchanan 1822) Pic.8.1.36: Clupisoma garua (Hamilton-Buchanan 1822) Source: Shrestha (1995)

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Pic.8.1.37: Myersglanis blythii (Day 1870) Pic.8.1.38: Glyptothorax pectinopterus (McClelland Source: Shrestha (1994) 1842) Source: Shrestha (1994)

Pic.8.1.39: Glyptothorax telchitta (Hamilton-Buchanan 1822) Pic.8.1.40: Glyptothorax trilineatus (Blyth 1860)

Pic.8.1.41: Pseudecheneis sulcatus (McClelland 1842) Pic.8.1.42: Heteropneustes fossilis (Bloch 1794)

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Pic.8.1.43: Channa orientalis (Bloch & Schneider 1801) Pic.8.1.44. Channa punctatus (Bloch 1793)

Pic.8.1.45: Glossogobius giuris (Hamilton-Buchanan Pic.8.1.46: Macrognathus pancalus (Hamilton- 1822) Buchanan1822) Source: www.fishbase.org

Pic.8.1.47: Mastacembelus armatus (Lacepede 1800)

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Altogether 27588 fishes were captured during the entire sampling period lasting one complete year and encompassing nine rivers in Central and Western Developmental Region of Nepal. The captured fish represented 5 orders, 12 families, 33 genus and 47 species. Table 8.1.2, below not just only shows the different species captured in the different rivers that were sampled but also the seasons in which they were captured. The mark ‘S’, ‘P’, ‘A’ and ‘W’ mentioned in the table denotes the four seasons – spring, premonsoon or summer, postmonsoon or autumn and winter respectively. While, the table 8.1.3 shows the yearly average of the abundance in catch per unit effort (CPUE) of fish species in the sampled rivers. CPUE in this study is defined as the number of species captured in 10 minutes of electrofishing.

Rivers→ Aandhi Arung Bagmati Jhikhu Karra Narayani East Seti Tinau species↓ Rapti Gudusia chapra Hamilton- S Buchanan 1822 Neolissochilus hexagonolepis S P A W S A W S P W S P A W S P AW S P A W McClelland 1839 Cirrhinus reba Hamilton- A Buchanan 1822 Labeo dero Hamilton- A W P A P A A W Buchanan 1822 Puntius chola Hamilton- P S Buchanan 1822 Puntius conchonius S P A W P A W S P A W S P A S W S P A W Hamilton- Buchanan 1822 Puntius sophore Hamilton- S P A W S P A W S P A S P A S A S P A W Buchanan 1822 Semiplotus semiplotus S A W A McClelland 1839 Tor putitora Hamilton- S P W S A W S P S W S P A W Buchanan 1822 Tor tor Hamilton- A S Buchanan 1822 Naziritor chelynoides S McClelland 1839 Aspidoparia morar P P A Hamilton- Buchanan 1822

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Rivers→ Aandhi Arung Bagmati Jhikhu Karra Narayani East Seti Tinau species↓ Rapti Barilius barila Hamilton- S P A S P A W S P A W S P A W P A W S P A W P A W S P A W Buchanan 1822 Barilius barna Hamilton- W Buchanan 1822 Barilius bendelisis Hamilton- S P W S P A W S P A W S P A W S P A W S P A W S S A W Buchanan 1822 Barilius shacra Hamilton- S S P S P W Buchanan 1822 Barilius vagra Hamilton- S P A W S A W S S P A W S P A W S P A W S P W S A W Buchanan 1822 Brachydanio rerio Hamilton- S P A W A S P A W S P A S P S P A W Buchanan 1822 Danio aequipinnatus W S P A W McClelland 1839 Danio dangila Hamilton- S P Buchanan 1822 Esomus danricus Hamilton- S W A S P A W Buchanan 1822 Crossocheilus latius A P A A A W Hamilton- Buchanan 1822 Garra annandalei Hora 1921 S P A W P S P S P S P S P AW S P

Garra gotyla Gray 1830 S P A W S P A W S P A W S P A W S P A W S P A W S A W S P A W Schizothorax richardsonii S P A W S P A W S W P A W Gray 1832 Schizothoraichthys progastus S P AW McClelland 1839 Psilorhynchus pseudecheneis W W Menon and Datta 1961 Nemacheilus corica P A A P A W P A Hamilton- Buchanan 1822 Acanthocobitis botia S P A W S P A W S P W S P A W S P A S Hamilton- Buchanan 1822

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Rivers→ Aandhi Arung Bagmati Jhikhu Karra Narayani East Seti Tinau species↓ Rapti Schistura beavani Günther 1868 S P A W S P A W P S P W S P A W S P A W S P A W S P A S P A W Schistura rupecula McClelland 1839 S P A W S P A W A S P A W S P A W S P A W S P A W S P AW S P A W Botia almorhae Gray 1831 P A W A Botia lohachata Chaudhuri 1912 A W S P A W A W S A W Lepidocephalus guntea S P A W S P A W S P A W S P A W Hamilton- Buchanan 1822 Amblyceps mangois S P A W S P A W P W S P A W S A W Hamilton- Buchanan 1822 Clupisoma garua Hamilton- S Buchanan 1822 Myersglanis blythii A S P A Day 1870 Glyptothorax pectinopterus W S McClelland 1842 Glyptothorax telchitta S P A S A A W Hamilton- Buchanan 1822 Glyptothorax trilineatus A A S A Blyth 1860 Pseudecheneis sulcatus W P A W A McClelland 1842 Heteropneustes fossilis S S P W S S S S A W Bloch 1794 Channa orientalis Bloch & Schneider S P A W S P A P A S P S P A W 1801 Channa punctatus Bloch 1793 A S P A W S P A W S A W P A W S P A W Glossogobius giuris A S Hamilton- Buchanan 1822 Macrognathus pancalus P A W Hamilton- Buchanan 1822 Mastacembelus armatus S P A W P A W S P A W S P A W S P A W S P A W Lacepede 1800

TOTAL SPECIES 18 27 3 12 25 32 30 18 29 Table 8.1.2: Distribution of fish species in sampled rivers and seasons

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River Aandhikhola accounted for 18 different species in total with only 9 of them in all seasons, 3 of them in three seasons and 6 of them showed up only in one season. Out of these six species of single season, Naziritor chelynoides was not found in any other rivers sampled in any seasons. Garra gotyla gotyla and Neolissochilus hexagonolepis had a good abundance, while Barilius vagra, Garra annandalei, Schistura beavani and Schistura rupecula had a fair abundance. Another thing to note in this river is the highest abundance of Mastacembelus armatus among the rivers sampled. The average abundance of fish in this river was found to be 71.89 / 10 mins.

Arungkhola showed a good diversity of fish with 27 species. Among them 12 species were present in all the seasons, 5 species were present in three seasons, 4 of them showed up in only two seasons and 6 of them sneaked in only one season. Schistura beavani had the highest CPUE in this river followed by Garra gotyla gotyla. Acanthocobitis botia, Barilius barila, Lepidocephalus guntea, Puntius conchonius and Puntius sophore had a fair abundance. Macrognathus pancalus was recorded only from here among the sampled rivers. The average abundance of fish in this river was found to be 96.10 / 10 mins.

Only 3 species were found in Bagmati River during the sampling time of which Schizothorax richardsonii was the only species found in all the seasons. Schistura beavani and Schistura rupecula were recorded only once and that too in the separate seasons. However, the abundance of S. richardsonii was found to be good at over 30/10mins. The average abundance of fish in this river was found to be 30.61 / 10 mins, lowest among the rivers sampled. Jhikhukhola on the other hand was relatively richer than Bagmati with 12 species and half of them were present in all seasons. 2 species were recorded from here in three seasons and another 1 from two seasons. Still, 3 species showed up just in one season. The river was characterized by high abundance of Barilius barila, while the abundance of B. vagra, Channa punctatus, G. gotyla and S. rupecula were fair and sufficient. The average abundance of fish in this river was found to be 79.17 / 10 mins.

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Fish species Aandhikhola Arungkhola Bagmati Jhikhukhola Karrakhola Narayani East Rapti Seti Tinau Average Acanthocobitis botia 0.00 3.31 0.00 0.00 22.81 1.23 12.24 0.801.24 4.63 Amblyceps mangois 0.00 2.76 0.00 0.00 6.66 0.10 1.25 0.000.04 1.20 Aspidoparia morar 0.00 0.00 0.00 0.00 0.00 1.06 1.19 0.000.00 0.25 Barilius barila 1.32 3.59 0.00 41.77 2.42 2.24 10.16 1.344.71 7.51 Barilius barna 0.00 0.00 0.00 0.00 0.03 0.00 0.00 0.000.00 0.00 Barilius bendelisis 0.30 1.10 0.00 2.75 1.88 0.18 3.06 0.050.60 1.10 Barilius shacra 0.00 0.04 0.00 0.00 0.00 0.12 0.34 0.000.00 0.06 Barilius vagra 4.94 2.53 0.00 6.71 2.17 0.51 9.83 1.192.14 3.33 Botia almorhae 0.00 0.00 0.00 0.00 0.00 1.05 0.09 0.000.00 0.13 Botia lohachata 0.00 0.78 0.00 0.00 0.00 5.03 0.57 0.000.16 0.73 Brachydanio rerio 0.13 0.31 0.00 0.09 5.32 0.13 0.00 0.106.65 1.42 Channa orientalis 0.00 1.18 0.00 0.00 0.39 0.08 0.08 0.060.39 0.24 Channa punctatus 0.03 1.77 0.00 3.13 0.66 0.15 0.00 0.001.80 0.84 Cirrhinus reba 0.00 0.00 0.00 0.00 0.03 0.00 0.00 0.000.00 0.00 Clupisoma garua 0.00 0.00 0.00 0.00 0.00 0.47 0.00 0.000.00 0.05 Crossocheilus latius 0.00 0.03 0.00 0.00 0.00 1.81 0.06 0.000.02 0.21 Danio aequipinnatus 0.00 0.09 0.00 1.26 0.00 0.00 0.00 0.000.00 0.15 Danio dangila 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.060.00 0.01 Esomus danricus 0.00 0.19 0.00 0.00 0.79 0.00 0.00 0.000.44 0.16 Garra annandalei 4.27 0.44 0.00 1.31 0.38 0.00 1.13 16.030.54 2.68 Garra gotyla 23.82 14.71 0.00 7.13 5.47 8.63 20.22 2.8222.12 11.66 Glossogobius giuris 0.00 0.00 0.00 0.00 0.00 0.03 0.04 0.000.00 0.01 Glyptothorax pectinopterus 0.00 0.00 0.00 0.00 0.00 0.00 0.03 0.000.03 0.01 Glyptothorax telchitta 0.00 0.00 0.00 0.00 0.00 0.47 0.14 0.000.22 0.09 Glyptothorax trilineatus 0.00 0.00 0.00 0.00 0.00 0.02 0.28 0.000.06 0.04 Gudusia chapra 0.00 0.00 0.00 0.00 0.03 0.00 0.00 0.000.00 0.00 Heteropneustes fossilis 0.06 0.00 0.00 0.56 0.14 0.00 0.03 0.070.09 0.11 Labeo dero 0.00 0.34 0.00 0.00 0.00 0.88 0.94 0.000.08 0.25 Lepidocephalus guntea 0.00 6.33 0.00 0.00 19.91 0.80 0.04 0.000.08 3.02 Macrognathus pancalus 0.00 0.16 0.00 0.00 0.00 0.00 0.00 0.000.00 0.02 Mastacembelus armatus 2.08 0.94 0.00 0.00 0.66 0.60 0.63 0.000.50 0.60 Myersglanis blythii 0.00 0.03 0.00 0.00 0.00 0.00 0.00 0.210.00 0.03 Naziritor chelynoides 0.16 0.00 0.00 0.00 0.00 0.00 0.00 0.000.00 0.02 Nemacheilus corica 0.10 0.00 0.00 0.03 0.09 1.72 0.13 0.000.01 0.23 Neolissochilus hexagonolepis 17.88 0.00 0.00 0.00 0.32 0.29 1.56 4.690.85 2.84 Pseudecheneis sulcatus 0.00 0.03 0.00 0.00 0.03 0.00 0.00 0.310.06 0.05 Psilorhynchus pseudecheneis 0.00 0.00 0.00 0.00 0.00 0.08 0.14 0.000.00 0.02 Puntius chola 0.03 0.00 0.00 0.00 0.16 0.00 0.00 0.000.00 0.02 Puntius conchonius 0.00 3.56 0.00 0.00 10.15 3.78 2.88 0.143.71 2.69 Puntius sophore 0.00 7.15 0.00 0.00 5.22 3.00 2.38 0.2121.09 4.34 Schistura beavani 7.72 41.70 0.06 0.43 19.97 6.54 30.46 2.2120.24 14.37 Schistura rupecula 6.33 2.48 0.03 13.99 4.47 5.95 19.59 11.797.75 8.04 Schizothoraichthys progastus 0.00 0.00 0.00 0.00 0.00 0.00 0.00 18.340.00 2.04 Schizothorax richardsonii 1.09 0.00 30.51 0.00 0.00 0.21 1.53 0.000.00 3.71 Semiplotus semiplotus 0.06 0.13 0.00 0.00 0.00 0.02 0.00 0.000.00 0.02 Tor putitora 1.55 0.41 0.00 0.00 0.00 0.15 0.41 0.000.30 0.31 Tor tor 0.00 0.00 0.00 0.00 0.00 0.02 0.00 0.000.02 0.00 Grand Total 71.89 96.10 30.61 79.17 110.16 47.35 121.44 60.41 95.95 79.23 Table 8.1.3: Abundance of fish in different rivers (number/10 minutes of fishing)

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Quite a high number of fish species were recorded from Karrakhola. Out of 25 species recorded 12 of them were found in all the seasons, 4 in three seasons, 1 in two seasons and the rest accounted for only one season. The river was characterized by the good abundance of A. botia, Lepidocephalus guntea, Puntius conchonius, and S. beavani. The abundance of Amblyceps mangois, Brachydanio rerio, G. gotyla, Puntius sophore and S. rupecula were also found to be in fair condition. The species Cirrhinus reba and Gudusia chapra were recorded only from this river during the sampling. The average abundance of fish in this river was found to be 110.16 / 10 mins.

Narayani, the biggest river sampled for this study was found to be harboring of the highest number of fish species. Altogether 32 fish species were recorded from this river in this study, which is still less than recorded by many authors. Among the species recorded 9 were found in all seasons, 9 were present in three seasons, 6 were in two seasons and 8 of them in at least one season. The river was found to hold a good number of G. gotyla gotyla, while Botia lohachata, P. conchonius, S. beavani and S. rupecula were found to be in fair number. One of the most highly threatened species, Tor tor was also recorded from this river. The total abundance of fish in this river was calculated to be 47.35 / 10 mins.

East Rapti was another river studied for this purpose and 30 fish species were recorded from here. Out of them, 10 species were present in all seasons, 4 species were recorded from three seasons, 6 were accounted from two seasons, and remaining 10 were present at least in one of the seasons. The river showed a high abundance of Acanthocobitis botia, B. barila, B. vagra, G. gotyla, S. beavani and S. rupecula. The species with fair abundance in this river were found to be P. conchonius and P. sophore. Among some of the least common species identified during this sampling schedule, Glossogobius giuris, Glyptothorax pectinopterus and Psilorhynchus pseudecheneis were also recorded from this river. The total fish abundance in this river was found to be highest among the river studied at 121.44 /10 mins.

Seti River accounted for 18 species in this study. Among them only 4 species were recorded throughout the year while, 6 species each were present in three seasons and two seasons, and only 2 species were present only in one season. Two fishes, Danio dangila and Schizothoraichthys progastus were recorded only from this river during the entire sampling period. The river showed a high abundance of Garra annandalei, S. rupecula and S.

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Tinau is perhaps the most important river in this study. The total number of species recovered from this river was also quite high with 29 species. Out of these, 13 species were recorded from all seasons, 6 species from three seasons, 5 species from two seasons and another 5 species were present only once. Some of the least common species according to this study recorded from this river includes Esomus danricus, G. pectinopterus and T. tor. The species with a good abundance in this river identified were G. gotyla, P. sophore and S. beavani while, B. barila, Brachydanio rerio, P. conchonius and S. rupecula were also found to be in fair numbers. The total abundance of fishes in this river was also found to be quite high at 95.95 / 10 mins.

The Fig.8.1.1 shows the total average abundance of each fish calculated during this study.

Average abundance of fish

16,00 Total abundance: 79.23 14,00 Number of species: 47

12,00

10,00

8,00

6,00

4,00 CPUE (catch /10 min) CPUE

2,00

0,00 Tor tor Tor Labeo dero Tor putitora Garra gotyla Garra Barilius barila Barilius vagra Puntius chola Danio dangila Barilius barna Cirrhinus reba Barilius shacra Botia almorhae Botia lohachata Gudusia chapra Puntius sophore Clupisoma garua Garra annandalei Channa orientalis Brachydanio rerio Esomus danricus Schistura beavani Barilius bendelisis Aspidoparia morar Myersglanis blythii Channa punctatus Schistura rupecula Nemacheilus corica Nemacheilus Puntius conchonius Glossogobius giuris Acanthocobitis botia Amblyceps mangois Crossocheilus latius Crossocheilus Danio aequipinnatus Naziritor chelynoides Glyptothorax telchitta Semiplotus semiplotus Glyptothorax trilineatus Lepidocephalus guntea Heteropneustes fossilis Macrognathus pancalus Pseudecheneis sulcatus Mastacembelus armatus Schizothorax richardsonii Glyptothorax pectinopterus Neolissochilus hexagonolepis Schizothoraichthys progastus Psilorhynchus pseudecheneis fish name Fig. 8.1.1: Abundance of different fish species during one year of sampling

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This figure illustrates the average abundance (CPUE) of all the fish species recorded during this work in all the rivers studied and in all the seasons. The total average abundance for all fish was found to be 79.23 and among these the abundance of S. beavani, G. gotyla gotyla, S. rupecula and B. barila was found to be fairly good. On the other hand the species such as B. barna, C. reba, D. dangila, G. giuris, G. chapra, M. pancalus, M. blythii, N. chelynoides, P. pseudecheneis, P. chola, S. semiplotus and T. tor were found to have very low abundance.

Table 8.1.4, shows the density of the fish in different rivers, which were studied in this work. It was calculated as the number of fish in 100 m² areas. It was found that Jhikhukhola had the highest density of fish at 24.11/100m² and Narayani had the lowest at less than one in the same area. However, Narayani is one of the biggest river of the country and the fishing was possible only on the shoreline of the river. Tinau was found to have a good density of fish at 23.51/100m² followed by Arungkhola, Karrakhola, East Rapti, Aandhikhola, Bagmati and Seti in the decreasing order of the density.

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Fish species Aandhi Arung Bagmati Jhikhu Karra Narayani Rapti Seti Tinau average Acanthocobitis botia 0,00 0,45 0,00 0,00 2,84 0,03 0,96 0,04 0,25 0,51 Amblyceps mangois 0,00 0,49 0,00 0,00 0,93 0,00 0,08 0,00 0,02 0,17 Aspidoparia morar 0,00 0,00 0,00 0,00 0,00 0,02 0,06 0,00 0,00 0,01 Barilius barila 0,14 0,79 0,00 11,05 0,30 0,03 0,80 0,10 1,18 1,60 Barilius barna 0,00 0,00 0,00 0,00 0,00 0,00 0,00 0,00 0,00 0,00 Barilius bendelisis 0,03 0,17 0,00 1,04 0,29 0,00 0,26 0,01 0,22 0,22 Barilius shacra 0,00 0,01 0,00 0,00 0,00 0,00 0,03 0,00 0,00 0,00 Barilius vagra 0,50 0,35 0,00 1,65 0,24 0,01 0,84 0,05 0,37 0,45 Botia almorhae 0,00 0,00 0,00 0,00 0,00 0,02 0,00 0,00 0,00 0,00 Botia lohachata 0,00 0,10 0,00 0,00 0,00 0,08 0,03 0,00 0,02 0,03 Brachydanio rerio 0,01 0,06 0,00 0,01 0,47 0,00 0,00 0,00 1,88 0,27 Channa punctatus 0,00 0,00 0,00 0,20 0,00 0,00 0,00 0,00 0,00 0,02 Channa gachua 0,00 0,15 0,00 0,00 0,04 0,00 0,01 0,00 0,11 0,03 Channa punctatus 0,00 0,28 0,00 0,46 0,04 0,00 0,00 0,00 0,54 0,15 Cirrhinus reba 0,00 0,00 0,00 0,00 0,00 0,00 0,00 0,00 0,00 0,00 Clupisoma garua 0,00 0,00 0,00 0,00 0,00 0,01 0,00 0,00 0,00 0,00 Crossocheilus latius 0,00 0,00 0,00 0,00 0,00 0,03 0,00 0,00 0,00 0,00 Danio aequipinnatus 0,00 0,01 0,00 0,32 0,00 0,00 0,00 0,00 0,00 0,04 Danio dangila 0,00 0,00 0,00 0,00 0,00 0,00 0,00 0,00 0,00 0,00 Esomus dandricus 0,00 0,05 0,00 0,00 0,03 0,00 0,00 0,00 0,14 0,02 Garra annandalie 0,43 0,05 0,00 0,44 0,05 0,00 0,11 1,43 0,23 0,30 Garra gotyla 2,70 1,92 0,00 2,61 0,72 0,15 1,70 0,16 4,25 1,58 Glossogobius giuris 0,00 0,00 0,00 0,00 0,00 0,00 0,00 0,00 0,00 0,00 Glyptothorax pectinopterus 0,00 0,00 0,00 0,00 0,00 0,00 0,00 0,00 0,01 0,00 Glyptothorax telchitta 0,00 0,00 0,00 0,00 0,00 0,01 0,01 0,00 0,03 0,01 Glyptothorax trilineatus 0,00 0,00 0,00 0,00 0,00 0,00 0,02 0,00 0,01 0,00 Gudusia chapra 0,00 0,00 0,00 0,00 0,01 0,00 0,00 0,00 0,00 0,00 Heteropneustes fossilis 0,00 0,00 0,00 0,08 0,03 0,00 0,00 0,00 0,03 0,02 Labeo dero 0,00 0,03 0,00 0,00 0,00 0,02 0,05 0,00 0,01 0,01 Lepidocephalus guntea 0,00 0,87 0,00 0,00 2,14 0,01 0,00 0,00 0,01 0,34 Macrognathus pancalus 0,00 0,02 0,00 0,00 0,00 0,00 0,00 0,00 0,00 0,00 Mastacembelus armatus 0,21 0,11 0,00 0,00 0,08 0,01 0,04 0,00 0,13 0,07 Myersglanis blythii 0,00 0,00 0,00 0,00 0,00 0,00 0,00 0,02 0,00 0,00 Naziritor chelynoides 0,02 0,00 0,00 0,00 0,00 0,00 0,00 0,00 0,00 0,00 Nemacheilus corica 0,01 0,00 0,00 0,01 0,01 0,03 0,01 0,00 0,00 0,01 Neolissochilus hexagonolepis 2,15 0,00 0,00 0,00 0,05 0,00 0,16 0,30 0,24 0,32 Pseudecheneis sulcatus 0,00 0,01 0,00 0,00 0,00 0,00 0,00 0,03 0,01 0,01 Psilorhynchoides pseudecheneis 0,00 0,00 0,00 0,00 0,00 0,00 0,01 0,00 0,00 0,00 Puntius chola 0,00 0,00 0,00 0,00 0,03 0,00 0,00 0,00 0,00 0,00 Puntius conchonius 0,00 0,50 0,00 0,00 1,48 0,06 0,23 0,01 0,94 0,36 Puntius sophore 0,00 0,99 0,00 0,00 0,58 0,05 0,17 0,01 5,73 0,84 Schistura beavani 0,87 7,08 0,02 0,16 2,88 0,11 2,27 0,14 4,67 2,02 Schistura rupecula 0,74 0,41 0,01 6,08 0,72 0,09 1,45 0,86 2,45 1,42 Schizothoraichthys progastus 0,00 0,00 0,00 0,00 0,00 0,00 0,00 1,86 0,00 0,21 Schizothorax richardsonii 0,10 0,00 7,71 0,00 0,00 0,00 0,20 0,00 0,00 0,89 Semiplotus semiplotus 0,01 0,01 0,00 0,00 0,00 0,00 0,00 0,00 0,00 0,00 Tor putitora 0,15 0,07 0,00 0,00 0,00 0,00 0,04 0,00 0,03 0,03 Tor tor 0,00 0,00 0,00 0,00 0,00 0,00 0,00 0,00 0,00 0,00 Grand Total 8,07 14,98 7,74 24,11 13,98 0,79 9,55 5,05 23,51 11,98 Table 8.1.4: Density of fish in different rivers (number/100m²)

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8.2 River classification based on biotic and abiotic factors:

A) Cluster analysis (CA): Classification can be defined as a process where a set of objects, systems or entities are divided into a number of discrete groups on the basis of some measure of their similarities or differences with respect to one or more pre-defined criteria. But classification of ecological systems like rivers is difficult due to complexities because the systems are generally characterized by indistinct boundaries and their characteristics vary continuously rather than discretely. However there are numbers of precise statistical tools such as cluster analysis (CA) and discriminant analysis (DA), which process varieties of variables to give a meaningful classifications of the system.

This study has tried to classify the different rivers and river systems that were sampled by using both biotic and abiotic factors. CA was performed to classify the rivers by using some fish attributes such as the number of species and their abundance, whereas several abiotic factors such as altitude, temperature, dissolved oxygen and the substrates were included in discriminant analysis.

In this work, hierarchical cluster analysis has been applied by using Ward’s method for river classification. This method was used because it processes a small space distorting effect, uses more information on cluster contents than other methods, and has been proved to be an extremely powerful grouping mechanism (Lambrakis et al. 2004). In the basis of total number of species and their abundance a cluster analysis to group and classify the different rivers that were sampled was also done. The table 8.2.1 shows the details of this analysis, while Fig.8.2.1 shows the relationships among the rivers and rivers systems that were studied in this work. The relative similarities between the rivers in the group or the cluster could be seen by the values of coefficients in the table or by the distance at which the cluster combined.

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Agglomeration Schedule Stage Cluster First Cluster Combined Appears Next Stage Cluster 1 Cluster 2 Coefficients Cluster 1 Cluster 2 Stage 1 1 6 682.300 0 0 3 2 2 7 1373.232 0 0 4 3 1 8 2417.669 1 0 5 4 2 5 4026.153 2 0 5 5 1 2 6671.631 3 4 6 6 1 9 10409.027 5 0 7 7 1 3 15311.099 6 0 8 8 1 4 24188.286 7 0 0 Table 8.2.1: Statistical details of the cluster analysis

This analysis has put Aandhikhola and Narayani rivers in one group with Seti River joining them to form a first cluster indicating that the three share some common features. Similarly, Arungkhola and Rapti formed another group with Karrakhola joining them to form a second cluster. Here too, the result indicated that there exist some common features between them. These two clusters joined before any other rivers join them, indicating further that the two clusters belonged to one larger group or system. Tinau was found to be quite far from this group though Bagmati and Jhikhukhola were found to be at more and most distant from the group.

Fig. 8.2.1: Clusters of river

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B) Canonical Discrimination Analysis (CDA): After looking at the remarkable results of cluster analysis to group different rivers and river systems in the basis of the abundance and number of fish species, it was felt that whether the series of abiotic factors, which were recorded during this study, have the same potential. For this ‘ canonical discriminant analysis’ was done. In another words, the cluster analysis was done in the basis of biotic factors, whereas the discriminant analysis was done in the basis of abiotic factors. The data of abiotic factors utilized in this analysis were altitude, temperature, dissolved oxygen, pH, conductivity, and the substrates such as rock, boulder, cobbles, pebbles, gravels, silt and sand. All these abiotic factors were used as independent variables in this analysis. As each run of sampling was referred as one case, there were 184 cases altogether in this work. The table below shows the details of valid and missing variables.

Analysis Case Processing Summary

Unweighted Cases N Percent Valid 184 100.0 Excluded Missing or out-of- range group codes 0 .0 At least one missing 0 .0 discriminating variable Both missing or out-of-range group codes and at least 0 .0 one missing discriminating variable Total 0 .0 Total 184 100.0

Table 8.2.2: Valid and missing variables in CDA

The discriminant analysis uses the function, f(x) = a.X + b.Y + c.Z + ------where a, b and c’s are the coefficients and X, Y and Z’s are the variables. Each variable get their own coefficients and the value of each of them are pooled together to form group matrices. The values of each variable are weighted against each other and are correlated. Three such functions are initially used but the analysis chooses the best two functions in the basis of canonical correlation to produce results. The table 8.2.3 summarizes the canonical discriminant functions and also illustrates why the first two functions were chosen particularly based on canonical correlation.

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Eigenvalues

Canonical Function Eigenvalue % of Variance Cumulative % Correlation 1 6.563(a) 77.7 77.7 .932 2 1.608(a) 19.0 96.7 .785 3 .277(a) 3.3 100.0 .466 a First 3 canonical discriminant functions were used in the analysis. Table 8.2.3: Summary of Canonical Discriminant Functions

The standardized canonical discriminant function coefficients for each variable in all three functions are illustrated in the forthcoming table.

Function 1 2 3 altitude -1.287 .320 -.110 boulder -.458 -.002 .951 pebbles 1.053 .765 1.177 cobbles -.271 -.749 .588 rock 1.548 .769 .659 silt -.341 -.267 .181 oxygen .169 -.054 -.226 conductivity .006 .114 -.315 temperature .194 .107 -.709 sand .352 .450 1.458 Ph .167 .110 -.560 Table 8.2.4: Standardized Canonical Discriminant Function Coefficients

When all these standardized canonical discriminant functions pooled together within the groups to derive correlations between discriminating variables, it gave an interesting result (Table 8.2.5). In function 1, the variables having largest absolute correlation were found to be altitude and two morphological features, boulders and pebbles. The same in function 2 were found to be some additional morphological features such as cobbles, rock and silt, and two physico-chemical parameters, dissolved oxygen (DO) and conductivity. The function 3 had temperature, sand, pH and gravels having some correlation, though the last variable is not used in the further analysis.

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Structure Matrix

Function 1 2 3 altitude -.583(*) .556 -.178 boulder -.155(*) .016 .016 pebbles .104(*) -.072 -.021 cobbles -.060 -.651(*) -.129 rock -.014 .326(*) -.109 silt .027 -.259(*) .121 oxygen .015 -.149(*) -.122 conductivity .048 -.118(*) -.061 temperature .160 -.038 -.476(*) sand .113 .173 .390(*) Ph .060 .008 -.292(*) gravels(a) .058 .050 -.081(*) Pooled within-groups correlations between discriminating variables and standardized canonical discriminant functions Variables ordered by absolute size of correlation within function. * Largest absolute correlation between each variable and any discriminant function a This variable not used in the analysis. Table 8.2.5: Correlation details of the discriminant variables

Processed 184 Excluded Missing or out-of- range group codes 0 At least one missing discriminating 0 variable Used in Output 184 Table 8.2.6: Classification Processing Summary

cd_riversystem Prior Cases Used in Analysis

Unweighted Weighted Bagmati .087 16 16.000 Gandaki .565 104 104.000 Koshi .087 16 16.000 Tinau .261 48 48.000 Total 1.000 184 184.000 Table 8.2.7: Prior Probabilities for Groups

With these functions and correlations of the variables, the classification of the river systems were done using all 184 cases and all the cases were used in both the ways, weighted and unweighted in the analysis. Among the cases used, Bagmati had 16 cases, Gandaki had 104 cases, Koshi had 16 cases and Tinau had 48 cases (Table 8.2.6). The results of the classification of the rivers system were amazing, perfectly matching the regional differences of the country. This indicated that the group of abiotic factors such as morphological and

-148- 8 Results physico-chemical features was able to discriminate among themselves to represent regional and physico-geographic group of the rivers and river systems of Nepal.

The figure 8.2.2 showed how the different variables in each rivers and river systems discriminated each other and how close they were to their group centroids, which were remarkably apart from each other and distinct. In Bagmati, the variables were found to be 100% distinct and totally discriminated the variables of other rivers (Table 8.2.8). Similarly in Gandaki system, the variables were 98.1% distinct whereas only 1.9 % of them were not distinct and that too from only one river system, Koshi. The Koshi system on the other hand showed 100% distinct variables completely discriminating the group of variables from other systems. Finally Tinau River showed 83.3% distinct variables and all those variables, which were not able to discriminate the system, were found to be mixed with the variables of Gandaki system only.

Thus, the morphological features and the physico-chemical parameters of different rivers and river system studied in this work were found to be very good variables, which were able to classify the rivers and river system of Nepal. The result of the classification showed that it is very much in terms with the age-old classification of the Nepalese rivers (Sharma 1977 and 1997) in terms of region, origin and geology.

Predicted Group Membership cd_river system Bagmati Gandaki Koshi Tinau Total Original Count Bagmati 16 0 0 0 16 Gandaki 0 102 2 0 104 Koshi 0 0 16 0 16 Tinau 0 8 0 40 48 % Bagmati 100.0 .0 .0 .0 100.0 Gandaki .0 98.1 1.9 .0 100.0 Koshi .0 .0 100.0 .0 100.0 Tinau .0 16.7 .0 83.3 100.0 Cross- Count Bagmati 16 0 0 0 16 validated(a) Gandaki 0 100 4 0 104 Koshi 0 0 16 0 16 Tinau 0 8 0 40 48 % Bagmati 100.0 .0 .0 .0 100.0 Gandaki .0 96.2 3.8 .0 100.0 Koshi .0 .0 100.0 .0 100.0 Tinau .0 16.7 .0 83.3 100.0 Table 8.2.8: Classification results

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In the cross validation of above grouping where each case was classified by the functions derived all cases other than that case, the group variable for Bagmati River and Koshi system were again found to be 100% distinct. While 96.2% in Gandaki system and 83.3% in Tinau were able to discriminate the respective river and system. Here too even when they were not discriminate cent percent, the group variables were mixed with only one other river or system. The classification system was found to be so accurate that 94.6% originally grouped cases and 93.5% of cross-validated grouped cases were classified correctly.

Canonical Discriminant Functions

4 cd_riversystem Bagmati Gandaki Koshi Tinau 2 Group Centroid Koshi Tinau Bagmati

0 Function 2 Function Gandaki

-2

-4

-8 -6 -4 -2 0 2 4 Function 1

Fig. 8.2.2: Classification of the river system by CDA

Thus, the morphological features and the physico-chemical parameters of different rivers and river system studied in this work were found to be very good variables, which were able to classify the rivers and river system of Nepal. The result of the classification showed that it is very much in terms with the age-old classification of the Nepalese rivers (Sharma 1977 and 1997) in terms of region, origin and geology.

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8.3: STUDY OF THE SIZE STRUCTURE OF SUCKER HEAD, Garra gotyla gotyla (Gray, 1830)

Length and weight data are useful and standard results of fish sampling programs (Morato et al. 2001). Such data are essential for a wide number of studies, for example estimating growth rates, age structure and other aspects of fish population dynamics. Study of the size structure (length frequency) in riverine fish reveals many ecological and life-history traits such as the river health, stock conditions and breeding period of the fish. The size structure of a fish population at any point in time can be considered a ‘snapshot’ that reflects the interactions of the dynamic rates of recruitment, growth and mortality (Neumann 2001).

From length frequency distributions of fish there are methods to determine the ages (Bagenal and Tesch 1978), which together with the weight and abundance (catch per unit effort) give details of the different disturbance regime of the rivers, breeding ground and breeding seasons, the general health of the stock, density and biomass, and the status of the species. Length-weight regressions have been extensively used to estimate weight from length because of technical difficulties and the amount of time required to record weight in the field (Morato et al. 2001). Therefore, the size structure analysis is one of the most commonly used fisheries assessment tools.

Although size structure analysis is a standard and regular method to evaluate the conditions of both rivers and stocks in developed countries of North America and Europe, it has just started in the developing countries. Nepal, with a huge amount of water resource, has a tremendous potential for fisheries development. Some information on ecological and population characteristics of the fish, such as region and altitude of occurrence, habitat preference, temperature range, maximum length, feeding habit, life history and a crude status of many of the fish species are available. However, the size structure analysis, which is so important in fisheries management is clearly lacking in the Nepalese fish species. This could be the first work of its kind in Nepal.

This work analyzed the size structure and length-weight relationship of sucker head, Garra gotyla gotyla (Gray 1830), a widely distributed and important fish species of the region. This fish, commonly known as Buduna in Nepal, has been listed by Gray (1832), Day (1889), Prashad (1912), Hora (1921), Taft (1955), DeWitt (1960), Menon (1962), Ganguly

-151- 8 Results and Dutta (1973), Shrestha (1978), Rajbanshi (1982), Rahman (1989), Shrestha (1990), Talwar and Jhingran (1991), Shrestha (1994) and Shrestha (2001) under the same name or different synonyms. It is reported from Afghanistan, Pakistan, India, Nepal, Bangladesh, Bhutan and Burma. In Nepal the species has been reported from up to 1560 masl with maximum size of 150 mm. It has been included as coldwater fish of Nepal by Shrestha (1999) and Swar (2001). It is not included in IUCN red list and reported as ‘fairly common’ in the country. The present work finds it in all the rivers studied except river Bagmati and is perhaps one of the most common species. It is a harmless fish feeding on algae, plants and detritus (www.fishbase.org).

The importance of the fish has been mentioned as minor commercial by Talwar and Jhingran (1991). However, due to high value as a food fish as well as its distribution, this species has a potential to become important protein source to the poverty-ridden population of Nepal. But there is hardly any method developed to assess the population dynamic of the species nor is there any example of using it as an indicator for the impact of various disturbances. This is the first description of length frequency distribution and length-weight relationship of Garra gotyla gotyla. In Nepalese context, even a basic work regarding size structure description and distribution is of great value for reference as well as for comparison for future studies.

A. Length frequency distribution:

Out of nine river sampled in this study, the species Garra gotyla gotyla was recorded from all except Bagmati river at Sundarijal in Kathmandu. There were altogether 4567 numbers of the species captured from eight of the remaining rivers from all seasons. The total length of the species varied from minimum of 20 mm to the maximum of 180 mm, and there were all the length groups in between. The length of 180 mm of the species is perhaps the new record. Similarly the weight of the fish varied from minimum of 2 gm to maximum of 73 gm. The mean length of the fish species in each case is rounded to a whole number. The result of the length frequency distribution in each river, that is the spatial variation of length frequency, is shown in the following figures (note the scale).

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Fig. 8.3.1: Length frequency of Garra sps. Fig. 8.3.2: Length frequency of Garra sps.

Fig. 8.3.3: Length frequency of Garra sps. Fig. 8.3.4: Length frequency of Garra sps.

Aandhikhola: This river has one of the best length frequency distribution (Fig.8.3.1). Altogether 711 number of the fish species were captured in all season in this river with minimum total length of 30 mm and the maximum of 180 mm. Looking at the length frequency distribution in this river, it can be said that it holds a very healthy population of the species. There are sizable numbers of the species with the length 50 mm and under, while the largest numbers are with the length category of 80 to 100 mm, the size already capable of breeding. There are also abundant of the species with length category 105 – 150 mm indicating the favorable habitat condition for the mature adults. In addition, the presence of the species even longer than that and up to 180 mm just indicates the river

-153- 8 Results provides the optimum suitable conditions for all the stages in the life cycle of the species. The mean length of the species in this river was found to be 85 mm, highest of the entire river studied.

Arungkhola: Total number of this species caught in Arungkhola was 458 with minimum total length of 20 mm to the maximum of 115 mm from all seasons (Fig.8.3.2). The length frequency distribution of the species in this river shows a different picture than that of Aandhikhola. In this river too, there are abundant of number of the length category 20 – 50 mm, suggesting that it provides a good spawning ground for the species. However, the peak of the number was in the length category 55 – 80 mm, which is less than before. There were some number with the length category of 85 – 115 mm, but longer than that were absolutely missing. The mean length of the species was also clearly less than before at 58 mm.

Jhikhukhola: Total number of this species captured in Jhikhukhola was 214 with the minimum total length of 30 mm to the maximum of 120 mm (Fig.8.3.3). There were few numbers of the fish with less than 50 mm of total length suggesting the decline of the breeding ground. However, there were large numbers of this fish in the length category of 50 – 90 mm suggesting a similar situation as in Arungkhola. There were some numbers of the fish of total length category 95 mm up to 120, which is also similar to Arungkhola. The large matured fishes were missing here too, though the mean total length of the species was little higher than before at 68 mm.

Karrakhola: The number of this species caught in Karrakhola was 172. Among the captured, the minimum total length was 20 mm and the maximum was 120 mm (Fig.8.3.4). The highest numbers of fish in this river were of the length category 20 – 50 mm indicating the condition of breeding ground to be normal. There were slump of numbers of the length categories between 55 –100 mm. There were very few numbers of the length categories 105 –120 mm and after that all large adult fishes were missing. The mean total length of the species here was 53 mm.

Narayani: It is one of the biggest rivers of Nepal, but the total number of the sucker head captured in this river was moderate at 415 (Fig.8.3.5). The total length of the species in this river varied from 40 mm minimum to the maximum of 175 mm. The distribution of length frequency of the species here gives a very different picture. The total length category, 50

-154- 8 Results mm or less of this species was almost missing in this river indicating that it is not suitable for spawning. However, there were abundant of length categories from 55 mm to 100 mm suggesting a suitable habitat for fresh adults. There were also many fishes of length group 105 mm – 150 mm and a few even up to 175 mm suggesting that the conditions are suitable for very large adults. The mean of the total length was also relatively higher at 81 mm.

East Rapti: The total number of this fish species caught here were 636. Among the captured, the minimum total length was 30 mm whereas the maximum was 140 mm (Fig.8.3.6). Compare to Narayani, there were more number of fish with length categories less than 50 mm indicating a good conditions for the fries. However, the bulk of the number of this fish here was made up of the length categories between 50 mm to 95 mm. There were relatively few numbers of the fish higher than those length categories, but available length group was moderately longer up to 140 mm. The mean of the total length of the species in this river was 67 mm.

Seti: The lowest numbers of this species were caught from Seti River. Out of 84 number of sucker head captured from here, the minimum total length of the fish was 40 mm and the maximum was 130 mm (Fig.8.3.7). There were very few numbers of lesser length categories and also many of these categories missing. It indicates that the conditions for spawning are not favorable. However, there were steady numbers of them in the categories from 55 mm to 100 mm suggesting that the conditions are not so bad for fresh adults. There were some fishes longer than those categories up to 130 mm, but some groups are missing indicating the population may not be healthy. Nevertheless, the mean total length of the species in this river stands at 74 mm.

Tinau: In terms of abundance as well as the distribution of length frequency, the population of sucker heads was the healthiest in this river. The total number of the fish accounted here were 1877, and that with a very unpleasant situation during premonsoon when a massive poisoning of the river was reported just a few days before the sampling. The total length of the species varied from minimum of 20 mm to the maximum of 145 mm (Fig.8.3.8). There were a good number of the fish of the length categories 20 mm to 50 mm suggesting good conditions for spawning and initial growth. The majority of the population was composed of the length categories 55 mm to 100 mm indicating a right habitat conditions for the growth and maturation of the species. The numbers of fish more than 100 mm in total length were

-155- 8 Results few but there were a presence of continuous length categories up to 145 mm. The mean of total length of the population of sucker heads in Tinau River was found to be 62 mm.

Fig. 8.3.5: Length frequency of Garra sps. Fig. 8.3.6: Length frequency of Garra sps.

Fig. 8.3.7: Length frequency of Garra sps. Fig. 8.3.8: Length frequency of Garra sps.

The length frequencies of the sucker head were also found to vary in temporal basis. There are different pictures and the mean total length of the species in the four seasons, when they were sampled. The temporal variation of the length frequency normally gives insight to the attributes such as the time of spawning, migration if any, and the growth status of the stock. Here are the findings of all year around divided into four seasons in a clockwise series.

Spring: The total number of sucker head captured in this season was 1326 with the total length varying from 30 mm to 180 mm (Fig.8.3.9). The absence of the fish of 20 mm length categories indicates that this season might not be the spawning season. There were some

-156- 8 Results fish of the length categories 30 mm to 45 mm and these could be the fish hatched in the last breeding season. There are large numbers of fish of length categories 50 mm – 100 mm. Though the numbers slump above this length categories, there abundance were consistent till length category 150 mm and there were some even longer than that up to 180 mm. Presence of all ranges of fish suggest that they are resident fish. Also the highest mean of the total lengths, 72 mm was due to the less number of fries indicating spring is not a breeding season.

Premonsoon: The total number of the fish caught in this season was remarkably low because of the poisoning of Tinau River just before the sampling as mentioned before. In addition no fish were recorded from Seti River as well. 608 sucker heads were captured in this season ranging from 20 mm to 140 mm (Fig.8.3.10). Presence of some numbers of 20 mm category indicated that the season should be the starting point of spawning. There were many fishes up to 45 mm length group. The peak of the numbers however were of the length categories 50 mm to 90 mm. Above those length groups the numbers slumped till the 140 mm length groups and there were even some groups entirely missing. The mean total length of the assemblage was lowest at 61 mm. The absence of some higher length groups and large mature adults indicate there might be some migration after spawning.

Autumn: The numbers of fish captured in this season were the highest at 1371 with lot of juveniles, which indicate that it followed the breeding time (Fig.8.3.11). Also important was the remarkable recovery of the numbers of sucker heads in Tinau River. The lengths of the captured fishes varied almost a full range from 20 mm to 175 mm indicating a good and healthy assemblage. There were many fishes of the length groups 20 mm to 35 mm indicating the time of breeding. However, the peaks of the numbers were of the length groups 40 mm to 95 mm. There was a gradual slump of numbers from 100 mm to 150 mm length categories, which is a characteristic of a normal healthy population. There were even some numbers of sucker heads above 150 mm up to 175 mm. The mean of the total length in this season was found to be 66 mm.

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→

Fig. 8.3.9: Length frequency of Garra sps. Fig. 8.3.10: Length frequency of Garra sps.

↑ ↓ ←

Fig. 8.3.12: Length frequency of Garra sps. Fig. 8.3.11: Length frequency of Garra sps.

Winter: The numbers of sucker heads captured in this season were 1262 ranging from 30 mm to 170 mm length groups (Fig.8.3.12). The distribution of length frequencies was almost continuous except for some very large mature adults. There were less fishes with the length group 30 mm to 45 mm compared to autumn may be because of the mortality or other factors. However, there were steady numbers of them from 50 mm to 95 mm length

-158- 8 Results class. The number declines gradually from 100 mm to 160 mm and there was fish even up to 170 mm an indication of a normal healthy population. There was no indication of migration as well in this season. The mean total length of the species in this season stands at 69 mm.

B. Length – weight relationship:

The length-weight relationship, which is an important attribute in assessing the health of the fish, to calculate the biomass and to manage the stock was also formulated for the Garra species using nonlinear regression and was compared for the seasons and river systems. Among the eight rivers from Nepal where the species was recorded, Aandhikhola, Arungkhola, Karrakhola, East Rapti, Narayani and Seti rivers constitute the Gandaki system; Jhikhukhola belongs to the Koshi system, whereas Tinau is taken as an independent system. The details of the regression of seasonal variations of length-weight relationship are shown in the table 8.3.1.

Seasons▬► Spring Premonsoon or Postmonsoon or Winter Details summer Autumn Regression Nonlinear Nonlinear Nonlinear Nonlinear Equation f = exp(a*x) f = exp(a*x) f = exp(a*x) f = exp(a*x) R 0.94697814 0.92296271 0.89885934 0.94971944 R² 0.89676761 0.85186016 0.80794811 0.90196702 Tolerance 0.000100 0.000100 0.000100 0.000100 Stepsize 100 100 100 100 ‘‘Iterations 1000 1000 1000 1000 Coefficient (a) 0.0241 0.0260 0.0227 0.0245 Std. Error 0.0002 0.0002 0.0001 0.0001

Table 8.3.1: The Details of the Statistics for Each Season for length-weight relationship

Seasonal variation of length-weight relationship of this species gives very interesting picture corresponding to its life history as well as physiological stress (Fig.8.3.13). Looking at the regression, the healthiest fish or the highest biomass was found in premonsoon or summer season while the least biomass was in autumn. The details of the statistics for each season are given in table 8.3.1.

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120 autumn premonsoon 100 winter spring 80

60

weight [gm] 40

20

0 0 20 40 60 80 100 120 140 160 180 200 total length [mm] Fig. 8.3.13 Length-Weight Relationship of Garra gotyla gotyla in Different Seasons

The relationship has the highest coefficient in premonsoon or summer (0.0260) and lowest in postmonsoon or autumn (0.0227). Thus, the curve is sharpest or steepest in premonsoon while opposite in postmonsoon or autumn. Between these seasons there is an interval of just about 3 or 4 months, but perhaps the event monsoon in this interval time seems a very big factor in determining the health and biomass of the fish. For example, according to this regression, a sucker head measuring 180 mm in length measured 60 gm in autumn whereas the same size weighed as much as 110 gm in summer or premonsoon. The coefficients were intermediate in spring and in winter, and hence the curves too were moderate and lied between the curves of premonsoon and postmonsoon.

The relationship of length and weight of sucker heads also varied between different river systems of Nepal. Since the coefficient of the curve was found to be highest in premonsoon and lowest in autumn, the length-weight relationship of the species in these two seasons are compared here. The details of the statistics for all three river systems are given in table 8.3.2. Another reason to compare the length-weight relationship between these seasons is because the number of sucker heads collected was highest in autumn/postmonsoon and lowest in summer/premonsoon. In premonsoon, the coefficient of curve was highest in Gandaki System at 0.0261 whereas both the Koshi and Tinau System had a same lower value of 0.0241. The regression showed that until the length 95 mm the sucker heads in all

-160- 8 Results the river systems had the same growth and biomass as they measured same around 10 gm. However the growth seemed to differ from that point in this season and in Gandaki System it is more rapid. For example, the sucker head measuring 180 mm in this season was found to measure as much as 110 gm, while in the other systems it was lowly 76 gm (Fig. 8.3.14).

River Koshi Tinau Gandaki Systems▬► premonsoon postmonsoon premonsoon postmonsoon premonsoon postmonsoon Details Regression Nonlinear Nonlinear Nonlinear Nonlinear Nonlinear Nonlinear Equation f = exp(a*x) f = exp(a*x) f = exp(a*x) f = exp(a*x) f = exp(a*x) f = exp(a*x) R 0.89734577 0.95172228 0.82110163 0.85992448 0.92624661 0.90389843 R² 0.80522944 0.90577530 0.67420788 0.73947011 0.85793277 0.81703237 Tolerance 0.000100 0.000100 0.000100 0.000100 0.000100 0.000100 Stepsize 100 100 100 100 100 100 ‘‘Iterations 1000 1000 1000 1000 1000 1000 Coefficient (a) 0.0241 0.0257 0.0241 0.0240 0.0261 0.0226 Std. Error 0.0004 0.0002 0.0010 0.0003 0.0002 0.0001 Table 8.3.2: Summary of the statistics of three river systems in premonsoon and postmonsoon seasons.

Interestingly, the coefficient of the curve was found to be highest in Koshi River System at 0.0257, while it was lowest in Gandaki system at 0.0226 in postmonsoon season. The value was intermediate in Tinau System where it was found to be 0.0240. Thus, the curve is highest in Koshi System and lowest in Gandaki System with Tinau fitting in between the two. Until the length 80 mm, the corresponding weights were found to be more or less same in all the river systems at around 7 gm, but after that the weight gradually fell apart. For example, the sucker head measuring 180 mm in Koshi System was calculated to be 102 gm while the same total length in Gandaki System was around 58 gm. The weight for the same length in Tinau however was found to be intermediate between those two at around 75 gm. Thus, the length-weight relationship of the species in three river systems was found to be significantly different (Fig. 8.3.15).

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Premonsoon/summer

120 Gandaki Koshi 100 Tinau

80

60

40 weight [gm]

20

0 0 20 40 60 80 100 120 140 160 180 200 total length [mm] Fig. 8.3.14 : Length-weight Relationship of Garra gotyla gotyla in Different River Systems

Postmonsoon/autumn

120 Gandaki Koshi 100 Tinau

80

60

40 weight [gm]

20

0 0 20 40 60 80 100 120 140 160 180 200 total length [mm] Fig. 8.3.15 : Length-weight Relationship of Garra gotyla gotyla in Different River Systems

The length-weight relationship of the same river system in these two seasons also showed interesting trends. The Koshi System was found to have higher coefficient of the curve in postmonsoon season (0.0257) in comparison with premonsoon (0.0241). On the other hand, the Gandaki System has higher coefficient in premonsoon (0.0261) compared to

-162- 8 Results postmonsoon (0.0226). The growth in Tinau System was found to be more or less consistence in the two seasons.

The regression showed that a sucker head with total length of 180 mm measured around 76 gm in premonsoon in contrast to 102 gm in postmonsoon in Koshi System. Similarly the species with the same length measured around 110 gm in premonsoon and around 58 gm in postmonsoon, a remarkable difference. The sucker heads of Tinau System for the same length, however, measured around 75 gm in both the seasons.

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Jhikhukhola upstream in spring (Agriculture) Jhikhukhola downstream in spring (Agriculture)

180 180 Total abundance:32 160 160 Total abundance:134.33 Number of species:7 140 140 Number of species:7 120 120 100 100 80 80 60 60 40 40 20 Abundance (CPUE)

Abundance (CPUE) 20 0 0 a s s i a s il u u li ni a i i r yl a l s le s n a at ssi u tyla ili ula ct ndale got av elisis da o s c s vagra fo bari d natus n os us b u ra s be s vagra in f i r u p na beava rili anna a ilius ben punctat n a rupe aril G ste ura r r ra B a Garra g tu Ba aequipinnat rra st B Barili na s tu neu n aequi i o h Barilius bendelisis Ga op Schi ha i Garra a chis Channa pun anio Schistura rupecula Barilius C ropneustes Sc S D er e Dan et Het H Fish species Fish species

Fig.8.4.1 Impact of agriculture Fig.8.4.2 Impact of agriculture

Jhikhukhola upstream in Premonsoon/summer (Agriculture) Jhikhukhola downstream in Premonsoon/summer (Agriculture)

180 180 160 Total abundance:48.33 160 Total abundance:71.67 Number of species:6 140 Number of species:7 140 120 120 100 100 80 80 60 60 40 40 20 Abundance (CPUE)

Abundance (CPUE) 20 0 0 i ila a lis ni r tus yl a i i a atus la s e n ssi av u an ula cta ndale fo tus tyla v c a a got bari elisis tat a dal a ius b un ipin n r s be d c n go ossilis p u n r a f a ste lius un na rr be rupe aril G u ura ri ben p n ra a B e st a r nna na Ga tu tu a n B n is Barilius bendelisis Garra a Schi h Ch rop Schistura rupecula ha Garra a chis Danio aeq e Barilius C ropneustes Sc S anio aequipinn e Het D et H Fish species Fish species

Fig.8.4.3 Impact of agriculture Fig.8.4.4 Impact of agriculture

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Jhikhukhola upstream in autumn (Agriculture) Jhikhukhola downstream in autumn (Agriculture)

180 180 Total abundance:39.5 160 Total abundance:45.5 160 Number of species:6 Number of species:8 140 140 120 120 100 100 80 80 60 60 40 40

20 Abundance (CPUE) Abundance (CPUE) 20 0 0

a a rio l s s a tus rio ca l re a oty orica cul lisi tus tyla ri g c e arila atu io nct de an u a go d uipinnatus arra lius b anio re uncta r lus co rupecu y a p q eilus i d i h n G h ar Barilius barila c n c B equipinn Gar a a ae istura rup nna p r o ma h Barilius bendelisis B Ch Barilius ben Brachy nio a mache Ne Sc Cha a e Schistura Dani D N Fish species Fish species

Fig.8.4.5 Impact of agriculture Fig.8.4.6 Impact of agriculture

Jhikhukhola upstream in winter (Agriculture) Jhikhukhola downstream in winter (Agriculture)

180 180 Total abundance:202.72 160 Total abundance:59.28 160 Number of species:7 140 Number of species:7 140 120 120 100 100 80 80 60 60 40 40 Abundance (CPUE) Abundance (CPUE) 20 20 0 0

la s s is ni s s ri us u yla isis tu a at ot va arila l vani n g a e natu ndelisi e s b in ea ius b e unctat ipin rra b rupecula liu ip p u a ra b aril Ga stes fossil ur a puncta B ius b u t Bari Garra gotyla nna aeq nn aequ istu aril a chis ch B Ch ropne S Schistura Barilius bend Cha S Schistura rupecula Danio te Danio He Heteropneustes fossilis Fish species Fish species

Fig.8.4.7 Impact of agriculture Fig.8.4.8 Impact of agriculture

-165- 8 Results

East Rapti upstream in spring (Agriculture) East Rapti downstream in spring (Agriculture)

100 100 90 90 Total abundance:179.80 Total abundance:187.17 80 80 Number of species:16 Number of species:15 70 70 60 60 50 50 40 40 30 30 20 20 10 10 Abundance (CPUE) 0 Abundance (CPUE) 0

i ia la is ra a e la is ta a e ni ra ia is ra ra la is is a s s re ni a i l y it te tus ius or s y r e tu pi ius o or ot agr n a va ito ot li iu sil nt a e it b ngois elis v ot ch t b ngois hac ot g l ava ecula a d g l fossilis gu m hon oph a de s g os gu p ut tis s Bar s anda a te s pu tis s Barila s vag s arm chon be p iu n rr nc u iu rra u ono n bi il tes ra bea bi ili us bi a a ru o an a ax us Tor o ili ril a alus ag r Tor G gobius giuror tu G ustes f tur Bar ius ben Bariliu ra o exagonolepis s Bar ius ben Ba ogo ex s tu yceps m l Barilius shac r h h ius co i l Bar s h i s l s Punti h ne eph s tius coPuntius soph anthoc b Ga embelus ar nt anthoc Garra annandaleios n Bari ptot ropneus u Sc Schistura rupecula Bari rop oc ilu Sch Schi Gloss ly e ac Pu Gl e d Pu Ac Am t chil Ac Amblyceps m pi ch G o Glyptothorax telchitta Het LepidocephalusMas Het Le Mastacembelusso liss lis o Ne Neo Fish species Fish species

Fig.8.4.9 Impact of agriculture Fig.8.4.10 Impact of agriculture

East Rapti upstream in Premonsoon/summer (Agriculture) East Rapti downstream in Premonsoon/summer (Agriculture)

10 0 100 90 Total abundance:151.5 90 Total abundance:77.25 80 Number of species:13 80 Number of species:16 70 70 60 60 50 50 40 30 40 20 30 10 20 0 10 Abundance (CPUE) 0

i is a is ra a is s i o ril is c iu ani l ac n v ng e h dero hore ecula a s ba d s op ea p u onolep s u ardson ben g s h aria morar ilius ic ps m p r Garra gotylaLabeo xa iu tura b r e Barili ius Barilius vagra e s tura r x il Ba h i is a r Punt h h blyc Garra annandalei s ntius concho or m Aspido Ba emacheilusu cori u Sc Sc N hil P AcanthocobitisA botia c o s Mastacembelus larmatusis Schizoth o Ne Fish species Fish species

Fig.8.4.11 Impact of agriculture Fig.8.4.12 Impact of agriculture

-166- 8 Results

East Rapti upstream in autumn (Agriculture) East Rapti downstream in autumn (Agriculture)

100 100 90 Total abundance:71 90 Total abundance:78.25 80 80 Number of species:13 Number of species:17 70 70 60 60 50 50 40 40 30 30 20 20 10 10

Abundance (CPUE) 0 0 Abundance (CPUE)

r s s s s s i s i i a a e li a ta ro re n tia ar a s ra la il si gr a yl it tu tu pi ius o onii r si g tiu tyla ius u gois ora li ha de e n gois a dero n bar or chata ot lch ol ava ds bo n baril eli v orhae chata la olepis o an m a s latius o n e go neatus nde a g e e soph ar lm ha i n ardsoni m ilu r ilinea go a o ril nch lius be ilius vaalm loh e r x t ab ra b bend l eilus t abeo a rupecch ps a a ra L rich ps ma paria morilius rilius h L lus armatus r i ari ar ti G o ax tr tius o a c Garra s co tura beavan B lius B h r hexa ce d Ba lius B o u s x r yce ri Botia un rax i ri Botia Botia hexagoi l Bo tot tho P chistu s Puntius sophore Ba Channa orient S Ba Channa orientalis tothorax lu Schi Aspidoparia acembelus armaPuntius concho Schistura rupecula Asp p Punt Schistu AcanthocobitisAmb botia Crossoch chilus zotho AcanthocobitisAmbly Cross zothora Glyp lypto st i Glyptothorax telchitta i G Gly Ma isso Sch Mastacembe Sch eolissochi Neol N Fish species Fish species

Fig.8.4.13 Impact of agriculture Fig.8.4.14 Impact of agriculture

East Rapti upstream in winter (Agriculture) East Rapti downstream in winter (Agriculture)

100 100 90 Total abundance:138.75 90 Total abundance:87.78 80 Number of species:13 80 Number of species:10 70 70 60 60 50 50 40 40 30 30 20 20 10 10 Abundance (CPUE) Abundance 0 Abundance (CPUE) 0 s i ii ia is la i a a ta la s s . . n la ra t i s r r y u u . . n s s i i o o r li c g a t r t l. . a u o o ia i a is a a a la s . n la i a g a a a h e a e v c it t o il r r t u u .. . n r b n b e o t o e s t r is c g a ty r t . . a u o d h v c g p m n h a d u o g l a l v c o t is a s a r c e p r b a e a a h o te o e s ti t s n s h a o o e b u a p n b h v c g m h a e d i m iu e s u r n a g r r s a d s a p r n c e p r u b il b u li lo r ti s a d a h ti s n s a o o p o s r li i a u r a ic o i m u s u h r a g e b ru a p s i r a c lu x r r T i e i o r in d h r c a r a i G e e e tu u b s il b iu il l t s a a c o o e B iu a t e s t x o r l r a c u x u r a i c l B o p b h p is s c p s ri a l e u r r T th y ri B s i a e a a ti G e e e s t u l B x m s h h r o c B iu a B p h s t x n b a a lu c o h il B o b p i s a a B r e i u S c h t ly r B x s h i r c m o c h h S t n b a m u s c h h a c c o a r e l u c o A A t t n a B c i S h o s o iz c m o h h S t t s y h A h a c c o p a s h A t t n z li r c o s o i ly M o S t a s y h o il s h G e p M i r c s ly l o S N P o il G e s Fish species N P Fish species

Fig.8.4.15 Impact of agriculture Fig.8.4.16 Impact of agriculture

-167- 8 Results

Tinau upstream in spring (Agriculture) Tinau downstream in spring (Agriculture)

160 160 140 Total abundance:225.94 140 Total abundance:198.25 Number of species:14 Number of species:16 120 120 100 100 80 80 60 60 40 40 20 20 Abundance (CPUE) Abundance 0 (CPUE) Abundance 0

i i ia is a is ra ta o s e s s lis s is s re n la ra a s a s a a o s s s i a s s s s s e i a a r t o a tus l ru u i tu p iu a u ti i il i r t ri li u u le l u u ili u .. u r n l r o o g lis g tali a a tyla at e n o v c o o r lis g a a t c a ty r t t l. i o a u o t b e a reri n t d o te o h a e g a a h re t a ri d o e a s a o n h v c it r baril d v o c n p e oss h p b n b e v c n t t e s o p a e t o tis n s i o lin f rma c o e p Tor tor s a d a io ie c n n g p n fo rm n h o e p u T i e u n s a s b ti s n s h n r n a a a o li a o c s b u p li lohach orie danricus ti ri s n s ru r putito i m iu e iu o o u d n r in ri s g n r r s manrilius ri dan a pun s c t u ra o b s il b il l a p s n r t t te s a o s a o cob p a s b a a y n a x lu co i ra T o r r d a u a a c x s u x c u r ra o e ti h Garrae g uste e s tu c p a s a ia y n a G e l e ti tu u T c B B o c n ra e b u nt istu s o e B iu B t h n n m ra p ra u e h s n s t ly riliu B o n i u h i h c il o c a n o r o e b iu u i is a ra ha th p m nt P c h t ly r B a h a s a x h n m s t h h B B C EsomuGarra annarax po lus hexagonolu S c n b a r h a t p lu n P c c Chann o ro ce i S a B B C C E G r o o e i u S AcanthAmb h e ta h P c m o t r c h S t lypt s A A th p te ta c P to o ly e s o p G Het t G a s y Ma issoc p H lis ly M o Gl G e Neol N Fish species Fish species

Fig.8.4.17 Impact of agriculture Fig.8.4.18 Impact of agriculture

Tinau upstream in Premonsoon/summer (Agriculture) Tinau downstream in Premonsoon/summer (Agriculture)

160 160 Total abundance:250.36 140 140 Number of species:11 Total abundance:23.75 120 120 Number of species:5 100 100 80 60 80 40 60 20 40

Abundance (CPUE) 0 20 Abundance (CPUE) Abundance i i 0 la o la a s n la ri ri lis le y re a a epis va re nt d ot nte l s s o ctatus n g u oniu a ecu ila e a a s ba e n anricus h p alis cus tea ul or u d na c sopho be ar t i atu epi hor c t li ori pu n rra gono n s a ru m ol ti ri a a r a or putitora io rerio ien anr gotyla na a G alus g x co tiu tu T us b a ar upe Ba n h elus armatuse s s tur li or punctatus r rra b iu un i s us us sop ra beavania somus a m t P h us d Garr i u ur Tor pu Cha E G e us h Bari nna Brachydani Channa ocep c l un Sc Schi hexagon st id a P rachydan Punt p Esom Garra annandalei embel B Cha Channa c lus Schist Schi Le idocephalus gun Puntius conchonius Mast Lep asta M Neolissochi eolissochi Fish species N Fish species

Fig.8.4.19 Impact of agriculture Fig.8.4.20 Impact of agriculture

-168- 8 Results

Tinau upstream in autumn (Agriculture) Tinau downstream in autumn (Agriculture)

160 160 Total abundance:310.39 140 140 Total abundance:55.9 Number of species:12 Number of species:10 120 120 100 100 80 80 60 60 40 40 20 20 Abundance (CPUE) Abundance (CPUE) 0 0

i is a s a a o s s s s a a s s o a s a s s s e i a a is la is a ta io is s s s o s is s la il i r t ri li u u u l t u li r e u c i u u r n l r o s r r l tu iu tta u ilis r tu ica iu ra o r is g a a t ti c ty it t i e t t ri p t i o a u o ta t icus i t e a n ore van o g a l a h re t a ri o h a s d n a o le a n h v c it ng ari eli ag ha a otyla h a ss d ntea or atus h cu tit n b e v c n t la n c e s u c o p a e t b v c nr g lc o u c olep lc e a d a io e c g l n fo o g rm c o l h o e p u s d s s l a e ine g n u ho op ea s n s h ri n s a a te li e a s n u c s b u p ma ha nio re u d a t l s f eo s s c s b up pu m iu e iu n o u lu d r ri s b s u o s n r r iu en iu o a orien il x tri b s armlu a r r s il b il lo a p i s r x t e a u s il g s o s a o s ril b ril punctae te i go is on s r a p r r d a e u a a x t L l lu e a i c u r ra s yd a a x s La alus lu a c iu u r To e a s a ia y n a h G r s a h x e ti tu u T ep u tia l h ch Garr h e he ne s t t tu c B iu B t h n n c m o ra u h e c e n s n s t c Ba i Ba nn nn o mus hora eu c ex e u n is s y il o c a n o o th o e p b a h e u u i is ly ril Bo a a o t n a h ti h i l r B a h a s s o h n e m h ti h h ss to thora s ch Pu h b a r h s t t p c e m s c n P c c Brac Ch o Es emb m u n B B C C o E p o o o c e lu e u S Ba Ch to rop c il e Sc Sc m r y t r d i d S Amb e idocepta Ne h Pu A C l p te i ta N h u P Cr Glyp t p ud G ly e p s c e oc e G e a o s Glyp He Le s H L M s P Mas is Ps lis l o o e N Ne Fish species Fish species

Fig.8.4.21 Impact of agriculture Fig.8.4.22 Impact of agriculture

Tinau upstream in winter (Agriculture) Tinau downstream in winter (Agriculture)

160 160 Total abundance:200.5 Total abundance:55.43 140 140 Number of species:14 Number of species:11 120 120 100 100 80 80 60 60 40 40 20

Abundance (CPUE) 20

0 Abundance (CPUE) 0 s i a is ra ta io lis s us ta lis is ra ois il s a r a tu u c i ero p an o g ar ag re t ta hit s d le v it is a s a a o s s s s a a s o a s s s e i a a b eli v ch n lati lc t o il si r t ri li u u u yl tt ili r e tu i iu r n l r s d s a io ie nc e fos o no ea g r li g a e ta t ti ic t i s e t a p n o va cu to man r u o b upecula pu n a e a ch r n ta la r o ch s d n le o h a e ti liu en liu loh an o p rra gotylax t be r r a b d v a o e c n g l fo o u rm o h p e p u s ri b ri d a eilus a a ag a s n s h ni ri n s a a te e g a n c so b u p s ia n a h r stes L x To m liu e iu o a o u ilu d rr x s b s o n r r ep u t hy n Ga o u s ri b ril l d p e s a a te a lu us g o s ra a o c Ba ili Ba c an oc omus danri belus armatus p a s a ia y na a h u r s L a l xa c tiu u r T ly r Bo a an s s ne ephalusm guntea e u t h n n c m G o u h e e s n st tu p c s he Puntius sophore yc B ili B o c a n o o th e p b h iu u i is Ba Br Ch Ch os E ce u Schistura l r B ra h a s s o n e m t P h h r a Puntius conchonius Schistur b a B C h s E t p c e us n c c Amb C pido t m B C ro yp ro o c il u S S Glyptoth e s A C l e id ta h P Hetero L G et p s c Ma H Le a so M lis eo Neolissochil N Fish species Fish species

Fig.8.4.23 Impact of agriculture Fig.8.4.24 Impact of agriculture

-169- 8 Results

Narayani upstream in spring (City and Industry) Narayani downstream in spring (City)

40 40 Total abundance:47.90 35 Total abundance:37.31 35 Number of species:10 30 Number of species:14 30 25 25 20 20 15 15 10 10 5 5 Abundance (CPUE) Abundance (CPUE) 0 0

i i s a s s i ii a is a a a o a a a a s s e a i a ia i a a io a la a a . e n la a i r r t i l t . r n l r t r r t r t u . u r n r t s r u y it e u . u n s c g y it e t . i a u o i c g a r t t t . i o a u o o o li a e ru t t o o t o l e h a n v c t a a h r a h n a o n h v c i b e a a h r a o n o h s i b e o s t h c c g o a e t h v c g g lc u g o p a e d d v g g l u m p d u s d s o m h e p r u s s a io r a h e p r i n s a i e g r a o p i n s te g o p t h n a a t a x c b u a it h n a a a x c s b u a i e s u r s r r e s u r s r r i o a m r s e n h b i o a m r x e n h b b iu il l x u s s o b iu il l u s s a c o o l r d o a a l h o ra a ic o l r d o a a l h o r a i i r u c u r r T i r u c u r r T c s r a ia y s a l s ti u c s r a ia y s a l s i u u t h i G o e t u u t i G o e t t u o i a B p h u s n s t x o i a h h u s n s t x h l o c h p b l i s l B o c p h p b l i s t i B u t i iu u i th i B u t i iu u i a r B a l e h t h ra r B a l o e h t h r n a r to m P c h o n a r t m P c h o C c e c n c C c e c n c a B B p o o u S h a B B p o S h c y c S t c c o u t l d a s P ly d s S A i t s o A i a P o G p i z t is z s l i G p s l i e a o h e a o h L e c L e c M M N S N S Fish species Fish species

Fig.8.4.25 Impact of city Fig.8.4.26 Impact of city

Narayani upstream in Premonsoon/summer (City and Industry) Narayani downstream in Premonsoon/summer (City)

40 40 35 Total abundance:83.11 35 Total abundance:79.25 Number of species:20 30 Number of species:20 30 25 25 20 20 15 15 10 10 5 5 Abundance (CPUE) Abundance (CPUE) 0 0

i s r a s a a e o s s s a o s a s a r s a a s s s a i ia i l i r r ta i i l a a . e n la ia is la i e a io i s la a a . s e n la a t a i a r l u u tt r u c . u r r t a r r a t r l u u t ro u c . u r r o r r is c g a t i y i e e t i . i a u o o r ri s c g t i y it e t i . i a u o o l e a t t t r o t o li h a e a t t e t r o t g o a a a rh h r t a h d n a o n h v c i g o a a a r h r t a h d a o n v c i b e n t la o o t b e t a o n o h t n m b h v o c g lc u c g o p a e n m b h v o c n l c u g o p a e a d o e c o m u d o e c g l o m c u is s s s a i i n s e g r a h o e p is a s s a i i s g r a h o e p t a n m r a t e s x c b u p t a n s m r n te e s c p i m i u s u l h n u u r a s i m i u s u l h n u a x s b u r i e i a o a o il b s u e n r r r i e i o u il ra b s u e n r r b il b u il l p r x s il s a b il u l a lo a p r x s l a s a r li d e a a lu h o r a o s a b i i e a u i h o s r a o o i r a a a u e u r o r il r a d a a l u e u c p p a s r a i a y a h r L a l c i u T p p a s r i a y a h ra L a l c i u r T t i n G h s t t u c a t i n G h s t t u o e o u a t h n c o h e s t o e o u a t h n c o h e s t c d B li B o n c lu n s c B i B o n c u n s h i i B o c a n o h p b i u i s h id il o c n o h p b il u i s t y r B a s t a i u h i t y r B B a s t a i u i l p B h a o e m h t h l p B a h a e h t h n a r h s t c m P c n a r s to m P c h b s e c n c b s h c e m c n c a B B C o p o e o u S a B B C o p o e S c m A C r c S c m A C r c o u ly d s y d s S A C i a N P C l i a N P A t is A A t s G p s l G p s li e a o e a o L e L e M M N N Fish species Fish species

Fig.8.4.27 Impact of city Fig.8.4.28 Impact of city

-170- 8 Results

Narayani upstream in autumn (City / Industry) Narayani downstream in autumn (City)

40 40 35 Total abundance:97.75 35 Total abundance:58.25 Number of species:17 Number of species:14 30 30 25 25 20 20 15 15 10 10 5 5

Abundance (CPUE) Abundance 0 Abundance (CPUE) Abundance 0 i s s s s s s s s r la i a e ta io la i ta o a a e n la s s s a s s i s r i r a r u u r t u r e u c u r u o la i a e a io s la i t o a a s e la r s a t i y i t t t i i a u t t i r t r u r t u r u c u r n u o li g h e t t u e r o r s a u i y i t e t i i a u t t a h a i h a n a n v c o r li g h a e t t t u e t r o e a r r t a o d o h l a h a i h a a n v c o r b v c l g c e u o a e o e a r r t a o d n o h l d o c g l o m c p p b v o c l g lc e u o p a e o a io s n g r h o e p i T d o c g o m c ip s n s m n s te i e c s a i s s e in g r h o e p T l h n u a u il a s s b u m n s m n a t l e s c b u iu e u u l r i r b s u n r u l h n u r u i a s m l li a o a i r x t l e i e iu o u il i r b s u n r i b i l p b a u s i o s a il b l a l a p r x t u s l s a e r r d e a a l r a s i d e a b a a l i o r a a o r x L u e c u r r r a x u e u r s a s a i ia y a h a l i u a s i a y a h o r L a l c i u t t G g o a h t t u s a t i G o a h t t u s u h n c r h e s t u t h n c g r h e s t B li B o o o h c n is u B li B o o h c n s u i c n o t o p b u s t i o c n o t o p b u i s t r B a a s s e a i u h i r B a s s a i u h i B o h m t h o B a o h e m t h o a r h s s t t c n P c l a r h s s t t c P c l e m c p o e m n c p B B o lo p o o e u S i B B o l p o o e u S i C r t c S C r y t c S ly d l p d P C G p i a N P m C G i ta N m t y p e G ly p s e G l s e e a S G a S G L L M M Fish species Fish species

Fig.8.4.29 Impact of city Fig.8.4.30 Impact of city

Narayani upstream in winter (City / Industry) Narayani downstream in winter (City)

40 40 35 Total abundance:38.83 35 Total abundance:31.5 Number of species:10 30 30 Number of species:8 25 25 20 20 15 15 10 10 5 5 Abundance (CPUE) Abundance Abundance (CPUE) Abundance 0 0

i i a is a is a e a s a a s a s a a is a is a e a s a a s a s a i il r t l n l . ti il r t l n l . t o s a u y e u ic . . iu . o r s a u y e tu ic . . iu a . o r i g a t t t t . . a u . o i g a t t t r . .. u . g a l h a a r . . n v c s g a l h a a . n v c s b e a r h t o n o d b e a r h t o n o g d n b c g o a e d n b v c u o a e d d v o c g u m c a u r d o c g m c a u r is a a g r h e p is a s a g r h e p t s n s m n s x e c a t n s m n a s x e c b u a i u l h a a b u i m u l h u a s m i e iu u r s u e s n r h i e iu r s u e n r h b l l a lo p r l p a c b l l a lo p r l h p a c s i b i lu s i h o i s i b i lu s i o r a i o r r a u r a r o r r a u r p s ia a a a l e s s c u r c p s ia a a a l e s s c u r c a a t i G t a a t i G h t o e u t n h e h u u s u x o e u t n h e u u s tu x B i B o c l s t c B i B o c il s h c il o n p b i h u i s a h il o n p b h u i s a t y r B a h c i h i r t y r B a e a h c i h i r l B a e m t h o l B m t h o n b a h c m c n n c n b a h c m c n n c a e o y c h a o e o y c h B C o c e u S t B C c e u S t c m d s h S c m d s h S o i a N s r P o i a N s r P A A t i z A A t li z p l lo i p lo i s o i e s o i h e a h a L e s c L e s c M N P S M N P S Fish species Fish species

Fig.8.4.31 Impact of city Fig.8.4.32 Impact of city

-171- 8 Results

Seti upstream in spring (City) Seti downstream in spring (City)

45 45 40 Total abundance:50.16 40 Total abundance:62.73 Number of species:10 35 35 Number of species:13 30 30 25 25 20 20 15 10 15 5 10 5 Abundance (CPUE) 0

Abundance (CPUE) 0 i ii i a is a o is a e la is s e a ti r i l il l l h u r n l . i s r y i t . i a u . s s i s i i o i g a g a t . o . ia i a io i la e la i . s e n la . l e t s y . n v c t r r l i l l h . u r . b e a r n d o s l h s is y i t . i a u . v n a o a e o l g e a g a t s y o d a n g o b x p y a r t l n n h v c g s io ie f h e p b e n n d o s i n s d a s e o h v g b o o p a e o it n r a i c s b u t s d o e a n o p r e u n r s h r i i i d f s g h o e b i a o io r n n h t n s r a a i c b u p b il n e o s a i e u n n r s a s r o r d a n a t a s r a ic i a o o r n x n s a s l c u r b b l i n e s a c s a y n a g lu ti u a o i d a t la e o r a y u a G u i t u r r a n a s c u r o i B h n r s s n s t c s a y n a g h i u th l c D e r h i o u G u t t u h i a r iu u is o i h n a s s s n s t h t r a n e c t h h l B c D r e r i s n r h a o P h t th i a r u iu u i c a p y n c r a a n e il t h i a B C G o s c o n a r h p y P c h a B M u S z h n c r c r is S i a B B C G o e l P c r M c u S o A t h o S o c A e P th e e t s S e s o H li N H iz o h e c Fish species N S Fish species

Fig.8.4.33 Impact of city Fig.8.4.34 Impact of city

Seti upstream in Premonsoon/summer (City) Seti downstream in Premonsoon/summer (City)

45 45 40 Total abundance:79 40 Total abundance:51.67 35 Number of species:7 35 Number of species:11 30 30 25 25 20 20 15 15 10 10 5 5 Abundance (CPUE) Abundance

Abundance (CPUE) 0 0

i i i i i i a a a o s a i a a a a o s a i a i l i i l e n l i l r i li l e n l . t i r r l i l h . .. t i r i l h . . r g a t . a u . r g a g t . a u . o e t g a y . o e t a y . v c a a r n d l v c p b a a r n d l b n g a e b n a a e s b v a n b v a n b x y s o e a e p s s io ie e p i s s i i d a s x y i s s d a s e h t n r i b u it n r i b u t i u u n e r h iu u o n h r b li i a o io n t b l li a io n h i il n h a i i n s a c o r r d a n a la r a h o r r d a n a la r a i s r c c y u u r c a a y n a g u i a a n a g l t u a h a u t u o h a i t r o B B n D r s l s t a B B n D r s h s h c r r i i s r h c a r r i s o t a h i t c h i a a e h o a h a e th n r h y c c h n r y o c h c h G s c o a B C G o S t a B C S c M s S o c M s S z li i A is iz A h l o c h e o c S e S N N Fish species Fish species

Fig.8.4.35 Impact of city Fig.8.4.36 Impact of city

-172- 8 Results

Seti upstream in autumn (City) Seti downstream in autumn (City)

45 45 40 Total abundance:38.25 40 Total abundance:64.25 35 Number of species:8 35 Number of species:9 30 30 25 25 20 20 15 15 10 10 5 5

Abundance (CPUE) Abundance 0 (CPUE) Abundance 0

i ii i i ii i ia la e la s e n la ia la e la s e n la t i l h . u r . t i l h . u r . r y t . t o a u .. r y t . t o a u .. o a t y . o a t y . a d o l a h v c p a d o l a h v c p b b g c a e b b g c a e n g b a l p s n g b a l p s is u o e p is u o e p t s a a s x y t s a a s x y i u n i s s b u i u n i s s b u i r n e r h i r n e r h b l n r h s a t b l n r h s a t i a a is r a h i a a is r a h o r a l u r o r a l u r c a g s e i u ic c a g s e i u ic a G u t t u a G u t t u o B r s l n n s t a o B r s l n n s t a r i e i s r r i e i s r th r u i th r u i a e h h h o a e h h h o n y c P c h n y c P c h c c h c c h a G o e S t a G o e S t c M s S o c M s S o s d z s d z A li u i A li u i e h e h o c o c e s e s S S N P N P Fish species Fish species

Fig.8.4.37 Impact of city Fig.8.4.38 Impact of city

Seti upstream in winter (City) Seti downstream in winter (City)

45 45 40 Total abundance:70.25 40 Total abundance:67 35 Number of species:6 35 Number of species:7 30 30 25 25 20 20 15 15 10 10 5 5

Abundance (CPUE) 0 Abundance (CPUE) 0

i a a a s s a i l r e l l . la a e la s s la i l y . u iu . i r l u u . r g a t . t u . r y .. t i u . a . a n c g a t . . a d o a p a a d o a n c p b v n g lc o e b g c o e x h p s v n g a l s s s a e u y u h p a s c u s s a a x c u y iu u n r h n r h u n r e s h l li n r t i iu n r t i i s s o il l n r h s r r a a i a h i a i o a h u e c r c r r a c r a a G il u i a a s e ic a n s t a a G u n u B B r h B B r l s t a r e u s r i e s r c i i o r iu i a h t h a h h t o o c n h c h G s c t c n c h e u G o e t is S o u o l d P z s d S u i s P z o li u i e e h e h s c o c N e s P S S N P Fish species Fish species

Fig.8.4.39 Impact of city Fig.8.4.40 Impact of city

-173- 8 Results

Tinau upstream in spring (City) Tinau downstream in spring (City)

150 150 Total abundance:54.1 Total abundance:184.54 125 125 Number of species:7 Number of species:14 100 100

75 75 50 50

25 25

Abundance (CPUE) 0 Abundance (CPUE) 0

i i r i i r a s a s a a o s s s a . s s s s e a a a s a is a a o s s s a s s s s e a a i i il i r t i li le l . li r n l r o i i il r t i li e l . u li . r n l r o t o s r u u y . u i u . iu t t o r s r u u l y . t i u . iu t r i g a a t c a t t t . o a u o o li g a a t c a t . t . o a u o o g a l e t i p s a . n v c t r g a e t i t a s a o n v c it r b a h r ta r d o a s h i b e a h r ta r d o s h t n b e c n o e g o a e t o n b v c n p e g o a e o d v c n n g o m p d o c n n g o o m p u s a a io e in n f r a h e p u T is a a i ie in f r a h o e p T i s n s i n a a t i x o p t s n s r n a a n l p t h n r a l a c s b u i u h n a i i a x c s b u i m u e u u d n r c i s e r m i e u o u d n r t r s n r r i i o a o r r n r b l li lo a r t e e b il b l l p n e t e s h s a s i b i p s n c t s h o s a o o s i d s a t o r a o o r r d a a a e r a r r a a p u c u r p s a y a u x s lu c iu r T c p a s a y a u x s l s i u T c a a i n G p s t tu a i n G t t u o e u t h n a a u e u o e u t h n a x a u e u s t B i B n m r r u s n s t c B li B o n m r r e il n is h c il o c n r x o e b il u i s h i c a n o r a o b u s t y r a o n i u i t y r r n h i u h i l B a h a s a a h h t h l B a h a s a h m t n a r r t p m P c h n a r h o t p c P c h b h E e c n c b E e n c a B B C G o o o S a B B C G h o o o u S c m C h t r c o u S c m C t t r c s S t p a s P o P A A te t s A A t p e ta is o ly i y t l t e s l p l e s p o y o G H a l G a ly e H e M G M G N N Fish species Fish species

Fig.8.4.41 Impact of city Fig.8.4.42 Impact of city

Tinau upstream in Premonsoon/summer (City) Tinau downstream in Premonsoon/summer (City)

150 150 Total abundance:18.75 Total abundance:39.75 125 125 Number of species:5 Number of species:5 100 100 75 75 50 50 25 25

Abundance (CPUE) 0 Abundance (CPUE) 0 i i a o s s s a s s a a l i i e l a . e n l r i i i r l u u l e u . u r a o s s s a s s e a a r t y t t . i o a u o l i i e l a . n l r e ta c a t t i r l u u l e u . u r a r a i o n a o n h v c i r a t y t t . i o a u o b n t r d e t e t ic a t t n g u g o p a a r a o n a o n h v c i o e c n m h e p u b n t r d e t s i i n a a g r a o n g u g o p a r a x c b u p o e c n m h e p u u n u d n r a s r s i i n a a g r a o i a o r s e n r r a x c b u p il p n u s s a u n u d n r a s r r d s a l h o r a o li a o r s e n r a a u c u r T i p n u s s a o a y n a u a l i u r d s a l h o r a G s t t u a a u c u r T B h n n m a h e u s t a y n a u a l i u c r b l n is G s t t u a n o r p i u is B h n n m a h e u s t a i u h c r b l n is r h a s a e m h t h a n o r p i u u is h c c n P c a a e i h C E G e c r h s a m h t h B o o u S h c c n P c C c S B C E G e c d a s P o o u S i t s C c S p i id a s P s l t s e a o p s li L e e a o M L e N M N Fish species Fish species

Fig.8.4.43 Impact of city Fig.8.4.44 Impact of city

-174- 8 Results

Tinau upstream in autumn (City) Tinau downstream in autumn (City)

150 150 Total abundance:107.5 Total abundance:40.5 125 125 Number of species:13 Number of species:12 100 100 75 75 50 50 25 25

Abundance (CPUE) 0 Abundance (CPUE) 0

i s i s a s a a o s s s s a a s s o a s a s s e a a i la is a a o is s s s la a s is o a a s s e n a a i l i t i i l t i n l i r t i l u u u t u l r . c u u r l r i r r l u u u t u il r e u c . u u r r o r s r t i y it t i e . i . t i a u o r is a t i y i t e t t i . t i a u i g a a t c t e t . r . o o l g e a t c t s r . o to g a l e t a i h a s . a n v c t g a a h r t a i h a d n a a n h v c i e a h r t a r o s d n m o a h ti e t a r o s o g t n b v c n l c e u c o a e n b v c n l lc e u lc o p a e d c n g l o r c x l p u d o e c n g o o m c a u a a io ie s n f o g h e p a a i i s e n f g r u h o e p s n s n a e i e a e u o p s n s r n a a t li e s x c u p h n r u a t il s s c s b u m u h n u u d i s a s s b m iu e u o u l d r s b s s h n r r i e iu o l r r b s u e n r r l li o a i r x r lu l l lo a p i r x t e l a s i b i l p s t e a u u i s o s a o s i b i e s t a lu s i h is o s r o r r d a e a a t l l s i r a r r d a a a u u a p u r x s L e c u r T p s a y a h u r x s L a l e s e c i u r T a s a ia y n a h a e lu e ti u a a i n G h t t e u t n c G o a u h h i n t u e u t h n c o a u h e u n s tu B i B h n m r b c s n s t c B li B n m h r e c il n is c l o c n o h e p h e u i s i o c a n o o t p b e u s y i a o t o m a c i u i y r s o n a h i u h i l r B a a s s n e h t h l B a h a s o h e m h t r h s o h e o P c h a r h s t t p c c c P c h b a h t t p c m c n b E e m n c B C o E p o o o c s c B B C o p o o o e o e u S B C r t e e u S m C r t r c s S m y r d ta is d S ly d d l p e i N l P A C p e i a N s P A C t s u y t p t li u G ly p o G l e s e e e a e e e o s G a s G H L M H L e N P M N P Fish species Fish species

Fig.8.4.45 Impact of city Fig.8.4.46 Impact of city

Tinau upstream in winter (City) Tinau downstream in winter (City)

150 150 Total abundance:27.5 125 Total abundance:73 125 Number of species:12 Number of species:5 100 100 75 75 50 50 25 25 Abundance (CPUE) 0 Abundance (CPUE) 0

i i s a s a a o s s s s a a s o a s s e a a s a s a a o s s s s a a s s s a a i il i r t i li l t i r . r n l r i l i t i i l t i o a . e n l r s r u u u y t il e u . u i s r r l u u u t il r e u . u r o r i g a a t ti c t i e t t . i o a u o o r i g a t i y i t t . i o a u o g a l e t i h s a o n v c t l e ta t c t s e t e a h r ta a r o s d n h ti g a a h r a a i o h d n a o n h v c i n b v c n l c n o a e n b e n t l r c s e t d o c n g l o u m p u v c n g l u g o p a a s a i ie s e f o g r o h o e p a d a o e c fo o m h e p u n s r n a a t e c u p s n s i i n s a e g r a o p m u h n u d r s a g s b h n r a t e a x c b u i e iu o o u il b s a n r r m u e u u lu d r s s s r il b l l a p r x e u s s a o li i o a o i r x b e n r s r i d e s a a t a l x o r a s i b il l p e a u s s a o p r a r s L u c u r T r r d a e s a a t l h o r a a s a ia y n a h u a l e i u p s a u r s L lu c u r T e u t c G o u e h t t u a a i y n a h G a s ti u B i B h n n m h s n s t e u t h n c o u e t u c il o c n o th e p b u i s B i B n m h u s n s t y r a o s i u i c il o c n o th e p b il u i s l B a h a s s o n e t h y r a o i u i a r s t p m lu P c h l B a a s s o n e h t h b h E c e i n c a r h s t p m P c h B B C o p o o h u S b h E c e c n c m C r y r c S B B C o p o o o u S l e id a c P m C r y r c S A C t t o l id a s P G p A C e t s e s s G t p i e a s e s l H L li e a o M H L e o M e N N Fish species Fish species

Fig.8.4.47 Impact of city Fig.8.4.48 Impact of city

-175- 8 Results

Aandhikhola upstream in spring (Dam) Aandhikhola downstream in spring (Dam)

45 45 40 Total abundance:84.02 40 Total abundance:75.98 35 Number of species:11 35 Number of species:13 30 30 25 25 20 20 15 15 10 10 5 5

Abundance (CPUE) Abundance 0 0 Abundance (CPUE) Abundance

i i i i a s a o a s s a s a a s a o a s a a l i r i e l li . n l r l i r i e l n l i s r l y i . e . . u i r l ... e r r i g a t . d . a u .. t o r is g y s .. a u ...... o a l e s i . v c o t l e a t . d ... l t e a r d o s m a r l ti a a r i v c a b v r o a e a e d o e p ti d o n g o x p u b v fo a o a e h i i f a n e p h i d o n g n e p u s n s a a y e p s i a s s h ic m u n n s l b u ic m n s a y s u i e iu r s h r r u n n u l b e p l l a n r e e a r e i e iu r te l u r r i b i a t lu s r a o l l a n r e e l a r x r r d a h r x s i i s i r s o a s y s e c u u T r b r d a u b h a a a G u il t u a s s y a h u r r s T B iu h a b r t r a a G e c c t u l B c r e h is u u h a m r t o u i r m o is o t B i B r n o s t r a a n it c h h o il c r e i s o a r p e r o c h t l r a p c to s h i th l c i c a i s h B B G o s S o ip a r o r i c o p r a z s S z G r ta i l c z i t a li i B B z S i e s h m te s o S m t N o e a a e h e a e c e c e S S N N H M N H M S S Fish species Fish species

Fig.8.4.49 Impact of dam Fig.8.4.50 Impact of dam

Aandhikhola upstream in Premonsoon/summer (Dam) Aandhikhola downstream in Premonsoon/summer (Dam)

45 45 40 Total abundance: 47.39 40 Total abundance:123 35 Number of species:9 35 Number of species:12 30 30 25 25 20 20 15 15 10 10 5 5

Abundance (CPUE) 0 Abundance (CPUE) 0

i i i i a is a e la a a a a a s a a s a a a a il r l . l n l . r l i e l l n l . r s y . ic . o a u . i r l u c . . r li g a t . r . . o r is g y t i . o a u . o a . h v c it l a t r . t e a d o m o a d t a a d o a h v c s i b v r c a e r b e o g c a e d t d n g c x u d v n g m c r s a a s e p a a e p u n s a s e b u p s n s a r x s a p u e u n r h u r h a a s u b u i i r s u i c r iu e u n r u e i r h r il b l n u il t a i l li n r l t r i a l s n r a r o i b i s i h a ic o r a e r r r a a u n r a r a s a e lu u u T s l e s u r T a G h i t u x a a G h u t B iu b P s t a u a e u tu x l B r c h i B i B r c il P s i r m a is r il r b i s a r a c h o r a h h i r a e o c h a m c h o c m c h a m c B G e s S t G e o c h a s S o B c e S t t N li s S o s iz a N s o t li iz a e h s c o h M a N S e c M N S Fish species Fish species

Fig.8.4.51 Impact of dam Fig.8.4.52 Impact of dam

-176- 8 Results

Aandhikhola upstream in autumn (Dam) Aandhikhola downstream in autumn (Dam)

45 45 40 Total abundance:46.25 40 Total abundance:42 35 Number of species:9 35 Number of species:6 30 30 25 25 20 20 15 15 10 10 5 5

Abundance (CPUE) 0 Abundance (CPUE) 0 i i i i i a a s a a a a s a s a i il r le l . n l l r e l . n l u y . . . i u l u . n r g t a t . . a u . r g t y t . a u . v c . a t o a a a d o a a a o a o v c s t m a a e d b t d a e b v c n g r r v c n g m g d x e p a e p r s n a a a s s n a r s a e b u a a x b u a u u n h iu u u n r r i iu r s h r l i r e h l l p n r a ic i il p n s a c i i u s r r a h r a i r r a a l r a r a lu r r a u r a a a G s u a a e l u x a e t u n a G i t u B n u s t x B b s t a B n r b l i s B n r h i r i i a r is r a h h r a m c h a m h a h o h c c o h e o c G e c c c h C c o S th G s S t s S C a s S o a o t li t is z z s l i s o i a o h a e h e c c M M N N S S Fish species Fish species

Fig.8.4.53 Impact of dam Fig.8.4.54 Impact of dam

Aandhikhola upstream in winter (Dam) Aandhikhola downstream in winter (Dam)

45 45 40 Total abundance:71 40 Total abundance:85.5 Number of species:8 35 Number of species:9 35 30 30 25 25 20 20 15 15 10 10 5 5

Abundance (CPUE) 0 Abundance (CPUE) 0 i i is a a s n a a r le l u l .. r s i s i ii s y t . a u . i a la . n la a li g a t . o r le u . n r a . v c s it is y t . a u e a d o g t l g a t o to v a e d a o a o v c s i d n g m a r u e d a e t a r e p d v n g m g d n s a x b u a p a e p r u n a n s a r p e iu r e r h r a a x b u a l n r a c e u n r r r b i s h i o i r e h r a a u r a r b il n s a c o s l s u r T r a h r a i a G t s a lu r r T u a e u u x a G s u i B r l s t u a e t u il r b i i s a i B r u s t x h i r il r b il i s r a h r i a a m c c h o a h h r c a m c h o G e o S h e c c B c t B G S h s S o c o S t a s a s o t li iz t is z s o s l i a h a o h e c e c M S M N N S Fish species Fish species

Fig.8.4.55 Impact of dam Fig.8.4.56 Impact of dam

-177- 8 Results

Bagmati upstream in spring (Dam) Bagmati downstream in spring (Dam)

10 0 10 0 Tot al abundance:36.76 Tot al abundance:15.29 90 90 Number of species:1 Number of species:1 80 80

70 70

60 60

50 50

40 40

30 30

20 20

10 10

0 0 Schizot horax richard sonii Schizot horax richard sonii Fish species Fish species

Fig.8.4.57 Impact of dam Fig.8.4.58 Impact of dam

Bagmati upstream in Premonsoon/summer (Dam) Bagmati downstream in Premonsoon/summer (Dam)

100 10 0 Total abundance:21.8 Tot al abundance:20.95 90 90 Number of species:2 Number of species:2 80 80 70 60 70 50 60 40 50 30 40 20 Abundance (CPUE) 10 30

0 20

10

beavani 0 Schistura Schist ura b eavani Schizo t ho rax richardso nii richardsonii Schizothorax Fish species Fish species

Fig.8.4.59 Impact of dam Fig.8.4.60 Impact of dam

-178- 8 Results

Bagmati upstream in autumn (Dam) Bagmati downstream in autumn (Dam)

100 100 Total abundance:43.47 Total abundance:2.32 90 90 Number of species2: Number of species:1 80 80

70 70

60 60

50 50

40 40

30 30 Abundance (CPUE) Abundance (CPUE) 20 20

10 10

0 0 Schistura rupecula Schizothorax richardsonii Schistura rupecula Schizothorax richardsonii Fish species Fish species

Fig.8.4.61 Impact of dam Fig.8.4.62 Impact of dam

Bagmati upstream in winter (Dam) Bagmati downstream in winter (Dam)

100 100 Total abundance:6.5 90 Total abundance:97.75 90 Number of species:1 Number of species:1 80 80

70 70

60 60

50 50

40 40

30 30 Abundance (CPUE) Abundance (CPUE) 20 20

10 10

0 0 Schizothorax richardsonii Schizothorax richardsonii Fish species Fish species

Fig.8.4.63 Impact of dam Fig.8.4.64 Impact of dam

-179- 8 Results

Tinau upstream in spring (Dam) Tinau downstream in spring (Dam)

45 45 40 Total abundance:74.17 40 Total abundance:89.28 35 Number of species:12 35 Number of species:12 30 30 25 25 20 20 15 15 10 10 5 5

Abundance (CPUE) 0 Abundance (CPUE) 0

i i r i i r a is a is a a o is s s e la . s is s s e n a a a is a is a a o is s s e la . s is s s e n a a ti il r t i l u u l . l u r l r o ti il r t i l u u l . l u r l r o o r s r t y . tu i tu . i a u t o r s r t y . tu i tu . i a u t o li g a a c a t s . o o o li g a a c a t s . o o g a h e t a i p a a . n v c t r g a h e t a i p a a . n v c t r b e a r t r d o s g h ti b e a r t r d o s g h ti n b v c n o e o p a e o n b v c n o e o p a e o d o e c n n g n o m a u d o e c n n g n o m a u is a a i i a i n f r h o e p T is a a i i a i n f r h o e p T t s n s r n a a t li x c b u p t s n s r n a a t li x c b u p i m u h n u d n r i s a s i m u h n u d n r i s a s i e iu o o c r e n r r i e iu o o c r e n r r b il b l l a p n r e t e s h s a b il b l l a p n r e t e s h s a o s r i d s a t o r a o o s r i d s a t o r a o r a a p x s u c u r r a a p x s u c u r c p a s a ia y n a u l s i u T c p a s a ia y n a u l s i u T e t n a G x a u e u t t u e t n a G x a u e u t t u o B iu B h n m r r l s n s t o B iu B h n m r r l s n s t h c il o c n r a e b i u i s h c il o c n r a e b i u i s t y r a o r o n h i u i t y r a o r o n h i u i l B a h a s a t h l B a h a s a t h n a r o th p m c P c h n a r o th p m c P c h b h E e n c b h E e n c a B B C G h o o o S a B B C G h o o o S c m C t t r c s u c m C t t r c s u o S o S A A t p e a s P A A t p e a s P y t t li y t t li p l e s p l e s y o y o l G H a e l G H a e G M N G M N Fish species Fish species

Fig.8.4.65 Impact of dam Fig.8.4.66 Impact of dam

Tinau upstream in Premonsoon/summer (Dam) Tinau downstream in Premonsoon/summer (Dam)

45 45 40 Total abundance:13.32 40 Total abundance:38.5 Number of species:3 35 Number of species:6 35 30 30 25 25 20 20 15 15 10 10 5 5

Abundance (CPUE) 0 Abundance (CPUE) 0 i s s s i la io i e la a s s e n la a i i i r l u u l e u . u r r a o s s s a a s s e a a r a t c a ty t t . i o a u o il i li e l . r n l r e t i . n v c t r r u u l y e u . u a r a r d o n a h i a t c a t t t . i o a u o b n t g o a e t a e t a i a o n v c it c n n g u m a p u r t r d o n h t io e g r h e p b n u g o p a e s i n a a x o p o e c n n g m u n r a a c s b u s i i g r a h o e p u o u d n r s e r r r n a a a x c b u p li a r n u n u d n r a s r i p s n u s h o s a o li a o r s e n r r d a a a l r a i p n u s s a o a u a lu s c iu r T r d s a l h o r a a y n G t u a a u c u r T h n a h e u t u a y n a u a l s i u B n m r l s n s t G e t t u c n r p b i u i s B h n n m a h u s n s t a o i u i c n r p b l i s a a a e h t h a o r i iu u i r h s m c P c h a a s a e h t h h c n c r h m P c h B C E G o e o S h c e c n c C c u B C E G o S d s S C c o u S i a s P id a s P p t li t is s o p s l e a e a o L e L e M M N N Fish species Fish species

Fig.8.4.67 Impact of dam Fig.8.4.68 Impact of dam

-180- 8 Results

Tinau upstream in autumn (dam) Tinau downstream in autumn (dam)

45 45 40 Total abundance:61.91 40 Total abundance:54.23 35 Number of species:10 35 Number of species:9 30 30 25 25 20 20 15 15 10 10 5 5

Abundance (CPUE) 0 Abundance (CPUE) 0 s s s s s s s s s s s i i la i a ta io i la ta i o a a e n la a i i r r l u u u t u il r e u c . u u r r s a s a a o s s s s a a s s s a s s a a o r is a t i y i t e t t i . t i a u o i l i t i i l t i o a . e n l r l g e a t c t s r . o t i s r r l u u u t u il r e u c . u u r g a a h r t a i h a d n a a n h v c i o r i g a a t i y i t e t t i . t i o a u o e n t la r o s o g t l e t t ic t s r t n b v c lc e u lc o p a e g a a h r a a o h a d n a o a n h v c i d o e c n g o o m c a u n b e n t l r c e s o e t a a i i s e n f g r u h o e p v c n g l u c g lc o p a s n s r n a t li e s x c p a d o e c n o o m h e p u h n u a i a s s b u s a i i n s a e i f g r a u o m iu e u o u l d r r s b s u e n r r n s h r a t l e s x c b u p l li o a i r x t l m u e u n u lu d r i s a s s r s i b i l p s te a u s i h s o s a o li i o a o i r x r b s u e n r r r d a e a a l i r a i b l l p t e u s il s s a o p a a u r x s L a lu e s c iu r T s r i d e s a a t a l h i o r a a s a i y n h G e t u p r a r x s L u e c u r T e u t n c o a u h e h u n t u a s a ia y n a h u a l s e i u B i B h n m r c l s n s t e u t c G o a u e h t t u c l o c n o h e p b i e u i s B i h n n m r h u n s n s t y i a o t o a i u i c l B o c n o h e p b c l i s l r B a a s n e h h t h y i a o t o a i e iu u i r h s s o h m c P c h l r B a a s h n e h h t h b a h t t p c m c n a r h s s to t m P h B C o E e o c b h p c m c c n c B C r p o o o c e e u S B C o E p o o e c m y t r d s S B C r t r o c e o e u S l p e i a N s d P m ly d s d S A C t t i u C p e i a N P y p l A y t t s u G l e s e G l p s li e o e e e G H a e s G a o s L H L e M P M P N N Fish species Fish species

Fig.8.4.69 Impact of dam Fig.8.4.70 Impact of dam

Tinau upstream in winter (Dam) Tinau downstream in winter (Dam)

45 45 40 Total abundance:28.25 40 Total abundance:77.02 35 Number of species:7 35 Number of species:9 30 30 25 25 20 20 15 15 10 10 5 5 0 0 Abundance (CPUE) Abundance (CPUE)

i i is a s a a o s s s s a a s o a s s e a a is a s a a o s s s s a a s o a s s e a a l i r t i li l t li r u r n l r l i r t i li l t li r u r n l r o i s r u u u y t i e t . iu o i s r u u u y t i e t . iu r i g a a t ti c t i e t . o a u o r i g a a t ti c t i e t . o a u o g a l h e t a i h s a . n v c t g a l h e t a i h s a . n v c t a r t a r o s d n h ti a r t a r o s d n h ti n b e v c n l c u g o p a e n b e v c n l c u g o p a e a d o c n g l o o m a u a d o c n g l o o m a u a i ie n s a e f g r h o e p a i ie n s a e f g r h o e p s n s h r a t e a x c b u p s n s h r a t e a x c b u p m u u n u u d r s s e s r m u u n u u d r s s e s r i e i o a o il r b n r i e i o a o il r b n r s il il l p s x e a u s h s a o s il il l p s x e a u s h s a o b d e a a t l o r a b d e a a t l o r a p r r a u L lu c u r p r r a u L lu c u r a s a ia y a h r s a s i u T a s a ia y a h r s a s i u T e t n n G o u e t t u e t n n G o u e t t u u h n c m h lu s n s t u h n c m h lu s n s t c B li B o c n o h e p b i i s c B li B o c n o h e p b i i s y i a o t iu u i y i a o t iu u i l r B a a s s n e h t h l r B a a s s n e h t h r h o m c P c h r h o m c P c h b a h s E t p c e n c b a h s E t p c e n c B C o p o o o u S B C o p o o o u S m B C r r c s S m B C r r c s S ly d ly d A C e i ta s P A C e i ta s P t p li t p li G e s G e s e a o e a o H L e H L e M N M N Fish species Fish species

Fig.8.4.71 Impact of dam Fig.8.4.72 Impact of dam

-181- 8 Results

Arungkhola upstream in spring (Industry) Arungkhola downstream in spring (Industry)

110 110 100 Total abundance:129.85 100 Total abundance:39.93 90 Number of species:16 90 Number of species:13 80 80 70 70 60 60 50 40 50 30 40 20 30 10 20

Abundance (CPUE) 0 10 Abundance (CPUE) 0 i a is a is a a is s s a a s e a a ti il r r l l r n l r o r s tu u y e iu a u i o li c g a c t t o o a s a s a a s s s a a s e a a g a a t a i n n v c it i i il i r r li l r n l r b e a t r o h t t o r s u u y e iu n b h v n u o p a e o li c g a t c t t o a u o d c n g u g a a t i n v c it is a s ie g h o e p b e a ta r o n h t t s n s r n a c p n b h v n o a e i m u s d a s b u d c n g u p u i e iu o u r s n r r is a s s ie g h o e p b l u l p r u s a t n s r n a a c b u p s i b i i s l o r a o i m u e s u d r s r o r il r a a u i iu o r s n r c p s a u a c i u r T b il b u l p u s a a r a n G t t u o s r li i s a l o r a o o e u a n h s t i r a u r B i B n m n s c p a s r a u a c i u T h c il n p u i s e a n G t t u t y B a o i u i o B iu a n n m h s t l r h a s e t h c l B n is n a c P c h h i B a n o p u u is b h E n c t ly r a e ti h a B C o u S n a h s P c h c m C S b h c n c d a B C E o S A A i P c m C u p d S A A i P e p L e L Fish species Fish species

Fig.8.4.73 Impact of the industry Fig.8.4.74 Impact of the industry

Arungkhola upstream in Premonsoon/summer (industry) Arungkhola downstream in Premonsoon/summer (industry)

110 110 100 Total abundance: 82.25 100 90 Total abundance: 12.25 90 Number of species:15 80 80 Number of species:14 70 70 60 60 50 50 40 40 30 30 20 20 10

10 Abundance (CPUE) Abundance (CPUE) 0 0 i i a s a s o s s a a s s s e a i i i i il i i li e l r n l a s a is o s s a a s s s e a t s r u l e u u u i i il i li e l r n l o r i a t ty t l t i o a u t s r u l e u u u o g l e t a o r i a t ty t l t i o a u a r a o n a a n h v c o g a l e t a b n b e n t d c o a e r a o n a a n h v c c n g u m p b n b e n t d c o a e s a d o e n h e p d c n g u m p i s n i i n a g r o s a o e n h e p t n r a a a c b u i s n i i n a g r o i m u e u n r s s r it n r a a a c s b u b li a o r p n m iu e u n r s r s i b p n u s s a b l a o r p n o r d a a l s o r a s i b p n u s o s a p s a lu c u r o r d a a l s r a c a y n a G a u ti u p s y a lu c iu r e u h n a h e t u c a n a G a u t u o B i n r h s n s t e u h n a h e t u h c l c n p t b i s o B i n r h s n s t t y i a r iu u i h c il c n r p t b u i s l r a a a e a t h t y r a a i u i n a r h n m P c h l a h a a e t h b h c e n c n a r c n m P c h a B B C G o g S b h e n c c m C c u S a B B C G o g u S d o c m C c S A A i r a P d o P p c t A A i r ta s p c s e a a e a a L M L M M M Fish species Fish species

Fig.8.4.75 Impact of the industry Fig.8.4.76 Impact of the industry

-182- 8 Results

Arungkhola upstream in autumn (Industry) Arungkhola downstream in autumn (Industry)

110 110 100 100 Total abundance:32 Total abundance:50.5 90 90 Number of species:14 Number of species:21 80 80 70 70 60 60 50 50 40 40 30 20 30 10

20 Abundance (CPUE) 0 10 Abundance (CPUE) i i 0 a s a s a a o s s s a o a s i s e a s a i i il i r t i li l r . r n l r t o s r u iu y e lu . th iu u o r i g a a t t t e t . o a u t o g a l h e t a a y n v c o t ii i b e a r t a o d n m l h l ti a s a is a a o s s s a o a s s s e a s a n b v c n l u c o a e i i il r t i li l r h r n l r d o c g o r b p p u t o r s r u iu y e lu u t iu tu s a a i ie s g n a h o e p i o li g a a t t t e t t o a u o ti s n s n e s c p g a e t a a ly n v c o t i h n r u a a i s b u m b e a h r ta a o d n h l ti m iu e u o u l r b s s n r r n b v c n l c b o a e b l li o a i r p n e d o c g u m p p u s i b i l p a u u o s a o s a a i ie s o g n r h e p i o r r d a e a l s l a r a s ti s n s n s o p p a L l c u r T i u h n r u a e a a i c s b u m c a s a i y n a h a u e g ti u m i e u o u l r b s p n n r r e t n c G h t u s b l li lo a i r e o B iu h n h b s s n s t s i b i p e a u s a o s a o c l B o c n o p t r i u o r r d a a l s u l r a s h i a m iu u is t c p s a y a h L a l c iu u r T t ly r B a a s e a e t h a a i n G u g t t u s r h e h lo o e u t h n c h e s s t n b a h s c n y n P c c B li B n th r n s u a C o c c p h i o c a n o p b u i s t B B C o g u S i t y r a s a e i u h i c m r o a M S l B r h a e m t h lo id r t P n b a h s c n y n P c A A C s m a C e c p p c B B o o g M u S i a e c m C r o c S e a id r a P m S A A C t L M M p c s e e a a S L M M Fish species Fish species

Fig.8.4.77 Impact of the industry Fig.8.4.78 Impact of the industry

Arungkhola upstream in winter (Industry) Arungkhola downstream in winter (Industry)

110 110 100 100 90 Total abundance:128.25 90 Total abundance:179.75 80 Number of species:22 80 Number of species:19 70 70 60 60 50 50 40 40 30 30 20 20 10 10 Abundance (CPUE) Abundance (CPUE) 0 0

i i a s a s a o s s s s a o a s s s s e a s a s a is a a o s s s s a o a s s s s e a s a i i l i ra t i l r r n l ra i i il r t i li l r r n l r t i s ri l u u u e u u u u u t o r s r u u u y e u u u iu tu o r i g a a t t c y e t l t t i o a u t o i g a a t t c t e t l t t o a u o o g l e t i t a n v c t o g a l e t i a n v c o t a a h r a a r o d n a a h lo i b a h r a a r o d n a a h l i b n b e n t c c o a e t n b e n t c c o a e t v c c n n g u m l p p v c c n n g u l p p s a d o e n o n h e p i u s a d a o e o n m h e p i u i s n s a i n i a g r u o i s n i i n in a g r u o t h n ri a e a a c s b p t s h r a e a c b u p i m u e u u p d r s s ru m i m u e u n u p d r a s s r m b li i o a o i r b p n r i i o a o i r b s p n r i b il l p a u s s s a e o b il b l l p u s s a e o s r r d u s a l s i o r a s s r i d u s a a l is o r a s o p a u L u c u r T o r a s u u r c a s a ia y n a q a u l e i u c p a s a y a q u L a l e c i u T e t e G e t t u s a i n G u t t u s o B iu h n n m h h n s n t o e u t h n e h e n s t c l B o c n a p t b is u c B li B n m th n s u h i a o e iu u is t h i o c a n a o p b e u i s t t ly r B a a e a h t h o t y r a a i u h i n r h o s m P h l l B h a o s e m h t h o b a h i c n c n c n a r i c n P c l a B C n E g e c p b h E e c n c p B C o c e u S i a B B C n o g e S i c m a d o S c m C c u S i r a d P m a d o d P A A D t u A A i r ta m p c s e D p c u e e a e s e a s S e a a S L M L s M P M M P Fish species Fish species

Fig.8.4.79 Impact of the industry Fig.8.4.80 Impact of the industry

-183- 8 Results

Karrakhola upstream in spring (Industry) Karrakhola downstream in spring (Industry)

45 45 40 Total abundance:112.77 40 Total abundance: 65.25 35 Number of species:16 35 Number of species:17 30 30 25 25 20 20 15 15 10 5 10 5

Abundance (CPUE) 0 Abundance (CPUE) 0 i i a s a s a o s s a a s a s a e a i i l i r i i e l r i l r n l t i r l u l il e u . i i o r is g t y p t t . o o a u a s a s o s s a s s a a o l e ta a t s . i i l i a i i e l a i a . l e n l g a a r a a n a h h v c t i s r r l u l r il e u . r b e n t d o s g o r i g t y p t t . o o a u n b v h u c p a e o l e ta a t s d o e c n g o m a g a a r a o a n a o h h v c is a i i c f g r s o e p b n e n t d s t s n s r n a a x b v g h u g c p a e i m u n u n s a u s b u s a d o e c n o m e p i e iu o r a s e i r i s n s i i n a c f g r a s o b l l a p n r i e u s h t s a t n r a a x b u s i b i s t l r a i m u e u u n r a s s u s r o r r d a a a u n u b li i a o r i e ti c p s y a u s a l s i u r s i b il p n e u s s a a a n G u t t u o r r d a a s t l h n r a o e u h n a d u h e u t p s a s lu u r c B i B n r il P n s c a a y n a G u a s u ti u h il c n r u e p b i s e u h n a d u h e t u t y r a n h u h i o B i B n r u P n s t l a h a a G e h c il c n r u e p b il i s n a r p c m c P c h t y r a u i b h e c l a h a a n e h h a B B C G o o o S n a r G p m P c h c m C r c s b h c e c c d S a B B C G o o S e i a s c m C r c o S A A t t li d s p s A A e i a e e o t p t is a e s l H L e e a o M N H L e M N Fish species Fish species

Fig.8.4.81 Impact of the industry Fig.8.4.82 Impact of the industry

Karrakhola upstream in Premonsoon/summer (Industry) Karrakhola downstream in Premonsoon/summer (Industry)

45 45 40 Total abundance:82.25 40 Total abundance:128.75 35 Number of species:13 35 Number of species:15 30 30 25 25 20 20 15 15 10 10 5 5 Abundance (CPUE) Abundance (CPUE) 0 0

i i i i a s a is a o s a a s s s e a a s a is a o s a a s s s e a i i il r i li e l r n l i i il r i li e l r n l t o r s r l y e u u iu t o r s r l y e u u iu o li g a a t t t t o a u o li g a a t t t t o a u g a e t a a n v c g a e t a a n v c b e a r d o n h b e a r d o n h n b v n u c o p a e n b v n u c o p a e d o e n g m l d o e n g m l is a s i i g r u h o e p is a s i i g r u h o e p t n s r a a c b u t n s r a a c b u i m u e u n n r a s s r i m u e u n n r a s s r li i a o r s n li i a o r s n b i b l n u s s a b i b l n u s s a o s r i d a l is o r a o s r i d a l is o r a p r a a u c u r p r a a u c u r c a s a y n a l e i u c a s a y n a l e i u e u G e t t u e u G e t t u o B i h n a h n s n s t o B i h n a h n s n s t c l B c r p b i s c l B c r p b i s th y i a r e iu u i th y i a r e iu u i l r a a e h t h l r a a e h t h n a r h m P c h n a r h m P c h b c e c n c b c e c n c a B B C G o e S a B B C G o e S c m c u S c m c u S d d P d d P A A i ta A A i ta p u p u s e s e e a e a L s L s M P M P Fish species Fish species

Fig.8.4.83 Impact of the industry Fig.8.4.84 Impact of the industry

-184- 8 Results

Karrakhola upstream in autumn (Industry) Karrakhola downstream in autumn (Industry)

45 45 40 Total abundance:146.78 40 Total abundance:118 35 Number of species:17 35 Number of species:16 30 30 25 25 20 20 15 15 10 10 5 5

Abundance (CPUE) 0 Abundance (CPUE) 0

i i a is a is a o is s a s a a s a s e a a is a is a o is s a s a a s a s e a ti il r i l l r n l ti il r i l l r n l o r s r tu b u y e tu ic . iu a u o r s r tu b u y e tu ic . iu a u o li g e a e c t t r .. o o li g e a e c t t r .. o g a a r t a r i n a n h v c g a a r t a r i n a n h v c b e n t r o o g b e n t r o o g n b v c n g u o p a e n b v c n g u o p a e s a d o e s m c a h e p s a d o e s m c a h e p i s n s i i n a g r x o i s n s i i n a g r x o t r u a a s c b u t r u a a s c b u i m u e u n u n d r s e s r i m u e u n u n d r s e s r b li i a o i r lu n b li i a o i r lu n s i b il p u s i h o s a s i b il p u s i h o s a o r r d a h s a l r a o r r d a h s a l r a p r u lu e c u r p r u lu e c u r c a s a y n a r a s ti u c a s a y n a r a s ti u e n i G h e h u t u e n i G h e h u t u o B iu B h n m c l s n s t o B iu B h n m c l s n s t h c il c n C p b i u i s h c il c n C p b i u i s t y r a o a h i u h i t y r a o a h i u h i l a h a s e m t h l a h a s e m t h n b a r h c m c n P c n b a r h c m c n P c a B C E e o c a B C E e o c B C o c e u S B C o c e u S c m d s S c m d s S A A i a N s P A A i a N s P p t li p t li e s o e s o L a e L a e M N M N Fish species Fish species

Fig.8.4.85 Impact of the industry Fig.8.4.86 Impact of the industry

Karrakhola upstream in winter (Industry) Karrakhola downstream in winter (Industry)

45 45 40 Total abundance:139 40 Total abundance:88.5 35 Number of species:16 35 Number of species:13 30 30 25 25 20 20 15 15 10 10 5 5

Abundance (CPUE) 0 Abundance (CPUE) 0

i i a s a a s a o s a a s s e a a s a a s a o s a a s s e a i i il i r i l . r n l i i il i r i l . r n l t o r n s r u y e u . iu t o r n s r u y e u . iu o r i g t t t t . o a u o r i g t t t t . o a u g a l e a o n v c g a l e a o n v c b a e a r ta o n h b a e a r ta o n h n b v g o a e n b v g o a e b d o c g u m p b d o c g u m p is a s i g r a h o e p is a s i g r a h o e p t s n s n a x c b u t s n s n a x c b u i m u u e u n u r a s r i m u u e u n u r a s r li i i a r s e n li i i a r s e n b i l b l p u s s a b i l b l p u s s a o s r i i d a l h o r a o s r i i d a l h o r a p r r u c u r p r r u c u r c a a s a y a a l s i u c a a s a y a a l s i u e u G e t t u e u G e t t u o B i h n h u s n s t o B i h n h u s n s t c B l B c n p b l i s c B l B c n p b l i s th y i i iu u i th y i i iu u i l r a a e h t h l r a a e h t h n a r m P c h n a r m P c h b h c e c n c b h c e c n c a B B o S a B B o S c m C c o u S c m C c o u S id a s P id a s P A A t s A A t s p s li p s li e a o e a o L e L e M M N N Fish species Fish species

Fig.8.4.87 Impact of the industry Fig.8.4.88 Impact of the industry

-185- 8 Results

Narayani downstream in spring (industry) Narayani downstream in Premonsoon/summer (Industry)

40 40 Total abundance:18.33 35 35 Total abundance:35.33 Number of species:8 30 30 Number of species:8 25 25 20 20 15 15 10 10 5 5

Abundance (CPUE) 0 Abundance (CPUE) 0 i ia is a a a io a la a a s s e n la . a t r r t r tt u u r . r s c a u y i e t .. i a u . s r a s s s a a s i o li g e r t t . o o ia i l i a a e a io i s l t o a a . s e n la a a h h n a n v c s it t a i r r a t r l u t r u c . u r r b e a r a o g h t o r r is c a tu i y i e t i . i a u h v c c u o a e d o l g h e a t t e t r o to d o g g l m a p r u g o a a a r h r t a h n a o n h v c i s s a i g r h o e p b e n t la o c d o t i n s a e x a p n m b h v o c g l u g o p a e it h n a t a c s b u s a d o e c o m c p u e s u r s e n r h r i s s a i i s e g r a h o e b li o a m r x t a n s m h r n a t e s x c b u p b iu i l u s h o s a ic o i m i u e s u l n u lu r a s r o l r d o a a l r a r i i o o i r x b s u e n r i r u c u r r T b il b u l a l a p s il s a c s r a ia y s a l s i u s a r li i d e a a a lu h o r a o t i G o e u t t u x o i r a a r u e u r o iu a h h l s n s t c p p a s r i a y a h L a l c i u T l B o c p h p b i i a e a t i n G o h s t t u h i B t iu u is r o o B iu a t h n n c h e u s t t r B a lu e h t h c d l B o o c o h b c l n is r o m h o h i i B a n t p a i u u is n a t c c n P c t ly r B B a a s e i h a C e o c h n p r h o m h t h B B p o u S t b s a h s t c m c n P c c y d c s S a B C o p e c l i a s P o A B C r o c e o u S A t i z c m ly d s S G p l i A A C i a N P s o t is e a h G p s l L e c e a o M S L e N M N Fish species Fish species

Fig.8.4.89 Impact of industry Fig.8.4.90 Impact of industry

Narayani downstream in autumn (Industry) Narayani downstream in winter (industry)

40 40 35 Total abundance:20.83 35 Total abundance:19.75 Number of species:10 30 Number of species:11 30 25 25 20 20 15 15 10 10 5 5 Abundance (CPUE) Abundance 0 Abundance (CPUE) 0

i r i a s a e a o s s a s a s o a s a s e a s a s s s s l i r t i l i t r r n l o i i la i a e ta la a . a n la i s a r u u r t u e u c u u t t i r a u e . c . . u . r i g a t i ty i t e t t i i o a u t o r s a t y t . i . . i a u . l h e t iu r n v c r o li g h t r . . . a a r h r a a o h a d n a h lo g a a r h a n n v c b e c t l g c e o o a e o b e t o m o a u d d v o c g l u m c p p n b v o c u r o a e r a o n o g r h e p i T s d c g c x e h e s n s i n s s e i o i a s a n g a s p a lm h n u a t il e a s c s b u t n s m h a s e c b u u e u u l r iu b s r m i m u u l u r s h p r h li i a o a i r x r lu n e i e i o s u n c i b il l p b t a u s i o s a b il b l a l p r u l a i r r d e a a l r a s s i a l lu i s s o r a r a o r x L lu e c u r o r r a e r a s a i ia y a h a ti u c p a s i a a a e u u c u u t t n c G g o a h e h t u s a t i G h il t u x B i B o h r c s n s t o e u t n h b h s t l o c n o o h p b u i s tu c B li B o o c h c is a i s t o a i u i h i n p u s r r B B a a s e t h o t y r B a m a c n i h i r s s o h m P c h l l B e t h o a h t t c m n n b a h c e o y n c B o o e c p c m s c th B C r l p o o c e u S i a B o e h u S y t d S c m C a s r S o G l p i a N P m id t N li o P C t A A s l iz G ly p s e p o i e e a e s h G a S c L L M P M N S Fish species Fish species

Fig.8.4.91 Impact of industry Fig.8.4.92 Impact of industry

-186- 8 Results

8.4 Assessment of ecological integrity of the rivers:

There were four types of disturbances having potential to affect the integrity of the river system chosen for study in this work. The four types of disturbances include agricultural practices, urbanization, construction of dams and weirs, and industrialization. The extent and importance of these disturbances in river systems of Nepal have, already, been discussed in the chapter, “Issues in context of Nepal.” For each disturbance three rivers were considered as case studies. For each disturbances, two sampling sites, the upstream or the reference and the downstream or the disturbed sites indicating different disturbance regime has been compared in terms of assemblage and population dynamics of fish. The abundance of the fish in all cases was measured in CPUE, which is ‘catch per unit effort’ and the unit effort in this study is the 10 minutes of electrofishing by general wading method. Here are the results of these comparisons according to the disturbances.

8.4.1. Disturbances due to agriculture: The three rivers studied for agricultural disturbances, mainly, due to agricultural inputs such as fertilizers and pesticides include Jhikhukhola in Kavre district, East Rapti in Makawanpur and Chitwan districts, and Tinau in Palpa district. The details of the amount of these agricultural inputs have, already, been discussed in earlier chapters. To examine thoroughly the each case, seasonal variations in impacts have been studied. The results of the study in each river and in each season are directly presented here. The statistical significances of this disturbance in Nepalese river will be presented latter. a) Jhikhukhola: This river in a broad view showed some differences between two disturbances regime indicating the potential of this disturbance to affect the integrity of the river system. There were not much difference between upstream and downstream in terms of the number of the species, but the composition of the species showed some variations and the total abundance showed a huge variations. The number of species upstream in reference site was 7 in spring and the same number of species was present in the downstream or the disturbed site as well in this season (Fig. 8.4.1 and 8.4.2). Total abundance of fish (CPUE) in upstream was 32 whereas the same was as high as 134.33 in downstream, a big difference. The common species between the two sites in this season were B. barila, C. punctatus, G. annandalei, and S. beavani but the other three species varied between two sites. D. aequipinnatus, G.

-187- 8 Results gotyla gotyla and S. rupecula were found only in reference site while B. bendelisis, B. vagra and H. fossilis were present only in disturbed site.

Total numbers of species in both the sites were more or less similar in premonsoon or summer season as well at 7 and 6, respectively (Fig.8.4.3 and 8.4.4). During this season, the total abundance of fish increased in upstream to 48.33 while there was a big slump in downstream to 71.67, though the downstream abundance was still higher. B bendelisis, and S rupecula showed up in upstream this season but C. punctatus disappeared. Likewise, B. bendelisis, B. vagra and S. beavani were absent from downstream while G. gotyla gotyla and S. rupecula appeared.

The results in autumn season were found remarkably different compared to those two seasons. Though the total number of species in upstream and downstream remained more or less constant at 6 and 8, there was a big difference in the abundance of fish (Fig. 8.4.5 and 8.4.6). Surprisingly, the upstream abundance this time was higher than the downstream at 45.5 and 39.5 respectively. Interestingly, the species showed the similar composition in upstream, the downstream recorded two new species, B. rerio and N. corica. The disappearance of H. fossilis was another remarkable feature in this season.

The results for winter season in this river once again were similar to spring and premonsoon. The total number of species in both the sites remained same at 7 (Fig. 8.4.7 and 8.4.8). The abundance of fish is once again in favor of downstream at perhaps highest at 202.72 compared to upstream at 59.28. There is not much difference in the species composition though the absence of G. annandalei since autumn and reappearance of H. fossilis was noteworthy.

-188- 8 Results

Jhikhukhola upstream in all seasons

80 70 Total abundance: 46.28 60 Number of species: 8 50 40 30 20 Abundance (CPUE) 10 0 Garra rerio beavani Barilius Channa rupecula Schistura Schistura corica punctatus Danio bendelisis annandalei fossilis Garra gotylaGarra Brachydanio Nemacheilus Barilius barila Barilius vagra aequipinnatus Heteropneustes Fish species

Fig. 8.4.93: Impact of agriculture

Jhikhukhola downstream in all seasons

80 70 Total abundance:112.05 60 Number of species: 12 50 40 30 20

Abundance (CPUE) 10 0 Garra rerio beavani Barilius Channa rupecula Schistura Schistura corica punctatus Danio bendelisis annandalei fossilis Garra gotyla Brachydanio Nemacheilus Barilius barila Barilius vagra aequipinnatus Heteropneustes Fish species

Fig. 8.4.94: Impact of agriculture

The total yearly differences in the number, composition and abundance of fish species are shown in fig. 8.4.93 and 8.4.94 between the two sites. There were distinct differences between upstream and downstream sites in terms of the number of species and the total abundance in the yearly data. The number of species in upstream all round the year was 8 while in the disturbed site was 12. Similarly, the total yearly abundance of the fish in upstream was 46.28 while that in the downstream site were more than double at 112.05. In addition, the difference of the composition of fish species in the assemblage between two

-189- 8 Results sites were B. vagra, B. rerio, H. fossilis and N. corica, which were never found in the reference site throughout the year. b) East Rapti: Impact of agriculture in East Rapti River was found to be least in terms of fish species number and their abundance. In spring season, the total numbers of species present in upstream and downstream were 16 and 15, respectively (Fig. 8.4.9 and 8.4.10). The total abundance of fish in this season, too, showed a little difference at 179.80 and 187.17 in upstream and downstream respectively. However there were some differences in species composition. G. giuris, G. telchitta and L. guntea were absent in the reference site while B. shacra, H. fossilis, N. hexagonolepis and T. putitora were absent from the disturbed site. The remaining fish species were common in the two sites. About half of the total abundance of fish in downstream was made up of a single species, S. beavani.

The premonsoon season had the similar characteristic in both of the sites except that there was significant decline in the abundance in the disturbed site. The total numbers of species in upstream and downstream were found to be 13 and 16 respectively (Fig. 8.4.11 and 8.4.12). Similarly the total abundance was 151.5 and 77.25 on the two sites respectively. The species missing from the reference site in this season were A. morar, B. shacra, L. dero, M. armatus and P. conchonius, and those missing from the disturbed site were N. hexagonolepis and S. richardsonii.

The autumn season was marked by the big drop of fish abundance in upstream site. The total numbers of species in upstream and downstream site in this season were 13 and 17 respectively (Fig. 8.4.13 and 8.4.14). Similarly the total abundance was 71 and 78.25 on the two sites respectively. The species missing from the reference site in this season were A. morar, B. almorhae, B. lohachata, C. latius, G. telchitta, G. trilineatus and L. dero and those missing from the disturbed site were A. botia, C. orientalis, N. hexagonolepis and S. richardsonii. The number of species in downstream site in this season is the highest with some species specialized for low land water.

The winter season was again characterized by high abundance of fish in reference site and decrease in species number in disturbed site. The total numbers of species in upstream and downstream site in this season were 13 and 10 respectively (Fig. 8.4.15 and 8.4.16).

-190- 8 Results

Similarly the total abundance was 138.75 and 87.78 on the two sites respectively. The species missing from the reference site in this season were G. pectinopterus and P. pseudecheneis and those missing from the disturbed site were A. mangois, B. shacra, M. armatus, N. hexagonolepis, S. richardsonii and T. putitora. A big number of the species is missing from downstream site in this season though many of the missing species mentioned above were missing permanently.

East Rapti upstream in all seasons

35 30 Total abundance: 135.26 25 Number of species: 19 20 15 10 5

Abundance (CPUE) Abundance 0

s e n i l i i r i a s a s a a e a s s a s u a s s o a s a e s e a a i l i i l i i i a r r t e r t r o r n l r t i l l u l u n s a u r t i e u c h o r r i y i t i n i a i c g a a e e t t o u o o l h t a t u r c o o t t s t g a a h i h a n a o n v c i a r o d h s b e a d s o e t n l p c n h v c g e u g o a e m B o g l p d d n o m c d u e o o s a s a n f g a h e p r i i s a s e i r o s n s m n e u p t a h r a t l s x c b u a i i l u i i a s m s u n r u s s e u e o l i t r b r r r i i o i r u e n h b l l a x t l b u l n c e u s s s a s a i i i b a i o c o e a a t l h r a o r l r a a p i i a e x L u e c u r p p s i a o r s a i r T c r h l u a a i n G p s t t g a h t u e o u t c a o u h e s o a r s t x i B o n u n s c B r o h c l d l o o x e p b u i h i i r t o i u s a B a i u i t y r B s a r l B s a n e h t h p h a o h h n s r m P h a s t t p c c c o b s m c n G o o e c a C o p o o n h B l o e o u S A r t c t c m h y r y S t l d s G p i a N P o A C e h A t t s o y p i r z t G l l i e s e o p o l h G a H L i y e c l s M N S G P Fish species

Fig. 8.4.95: Impact of agriculture

East Rapti downstream in all seasons

35 30 Total abundance: 107.61 25 Number of species: 25 20 15 10 5

Abundance (CPUE) 0

s o r i i a s a s a a e a s s a s a s s o a u a n s e a a i i l i t i e l i . t i t n l a r r l l r r r t i a u l r . t u e c o . u . o r s y i r c a i . i t t a i . i a u . i g a a t e o o o l h t u s r g . . g o t i h a n v c t a a r h o d n r i a a d o h b e s m o a u t n c n l g c e o a e B h v n l u r p a m n g i c x e d e o o u s a s a t n f g h e p i i s e a o h s a s i e s t a s n mo r c t l e s c p l h a i b u c i i u n u s m u e s u r s s s h p r i r o l i e r b u n r i i a o i r x r b l l n t l l b u e u u i s a s a i i i b p a l s o o e a a t l s r a o r l r a a x i a o r x L e c u r p p i a s a e u u i T c s h x u a r a t i n l t a G g o a h i t u e o u t c a u h b h r o a n a r s t i B o r c n s c d B l o o r h e p h c i h i o r u s o i a t o u i t y B B s m a c n i l r B s o n e h p a o h t h s e h t n a s h t t c o y P c b s p m n G t c s c o a Ch o o p o o h B l o u S A t r c m r o r a s S z t y d t i i l i l o G p e Ne P A A C p s l h y t p i G o l c y e a s l e e G S H L P G M N Fish species

Fig. 8.4.96: Impact of agriculture

-191- 8 Results

The total yearly difference in the number, composition and abundance of fish species in this river is shown in fig. 8.4.95 and 8.4.96. There were some minor differences between upstream and downstream sites in terms of the number of species and the total abundance in the yearly data. The number of species in upstream at least once in the year was 19 while in the disturbed site was more at 25. Similarly, the total yearly abundance of the fish in upstream was 135.26 while that in the downstream site were slightly less at 107.61. Among the differences between composition includes species such as A. morar, B. almorhae, B. lohachata, C. latius, G. giuris, G. pectinopterus, G. telchitta, G. trilineatus, L. dero, L. guntea, P. pseudecheneis, C. orientalis, H. fossilis, N. hexagonolepis, S. richardsonii and T. Putitora where the first eleven species were found completely missing from the upstream while the remaining five were missing from the disturbed site. c) Tinau: Tinau River is the last example of the agricultural impact in this study. The number of species was found to be more or less same in two different sites though the abundance was quite high in the reference site unlike the agricultural impact on the rivers mentioned above. In spring the total numbers of the species present in upstream and downstream sites were 14 and 16, respectively (Fig. 8.4.17 and 8.4.18). The total abundance of fish in this season, too, showed a little difference at 225.94 and 198.25 in upstream and downstream, respectively. However there were some differences in species composition as A. mangois, G. pectinopterus, H. fossilis, N. hexagonolepis, P. conchonius and T. putitora were absent in the reference site while, B. rerio, E. danricus, M. armatus and P. sophore, were absent from the disturbed site.

The premonsoon season was characterized by a big drop in both the number of species and the abundance in the downstream site. In this season, the numbers of species present in upstream and downstream were 11 and 5, respectively (Fig. 8.4.19 and 8.4.20). The total abundance of fish in this season was found to be 250.36 and just 23.75, respectively. The species missing from downstream site compared to the reference were B. rerio, C. punctatus, E. danricus, G. annandalei, M. armatus, P. conchonius and P. sophore. However, S. rupecula was found in downstream site and not in reference site.

The autumn season marked some recovery in downstream site. The number of species in this season at reference and disturbed sites were 12 and 10 respectively (Fig. 8.4.21 and

-192- 8 Results

8.4.22). Similarly the total abundance of fish in those sites was found to be 310.39 and 55.9 respectively. The differences in the composition of the species were brought about by A. mangois, B. vagra, B. rerio, C. punctatus, E. danricus, H. fossilis, M. armatus, N. hexagonolepis, P. sophore, and T. putitora.

Tinau upstream in all seasons

120

100 Total abundance: 246.8

80 Number of species: 16

60

40

20 Abundance (CPUE) 0

r i s i s s s s a s a a o i e s e a i i a i n l a i l r i l e a t . . u r i u l l l i r t s r tu tt i . o r i a u g c a p i .. . o o l e ta s n g a i ty v c a a t o h a h to e r d s o r n m a b n o c e ti v c n n r x p b d e n i l o h s a o i g e p u i n t f a e o s n s a a e c ti r b u u c s p i n d n a m u e u t s s h n i i r r b l a o p e r b l n x e s o s a i i s r u s p t l r a o o r d a c r a a a u u r p s a u s l i u c y n r e T x i t t n s u e u a G o u t o h n m b h s Ba i Ba r a n c l n e u i i c a r r h i s o c u i th y r a t m t h l a o n h a o h n r h o e n P c b h t p Es s c a C G t c Ba B C p o s S m o r a i S t y t l Pu l Ac A p te s o G y e a e l N H M G Fish species

Fig. 8.4.97: Impact of agriculture

Tinau downstream in all seasons

120 100 Total abundance: 83.33 Number of species: 18 80 60 40 20

Abundance (CPUE) 0

o s m i i r . a s a o s s s a n . s s e a a . l i i i e l i . n l . r a r r . . i l u l t . . u s r u o . r t y . i a u i g a f o o b l e c a t c c . t i l s v t n a a n c i a r d o e h e t r s u t s n e s o a e a b v l p i c n n g p t e t d o e u i t e u h e p i s i n a l o m n s a x p r a x s i c b u b n b s u u u d n r r i e o a a h n r s i a r u o l l p n r r a i b i m c s o p s e o r a c r r d a a o a o e u o c r T o e s y a u n i u a a n h h G c s t t u c t t p h u h n a s t B i B n m r a s n s t y o l c n o o t i i s l i a r t l u n o t r i u i r a s h b a a t h s p p o h a r e P c a h t a n y y e c c m B C E G l l B e u S C M A N S A G G H P Fish species

Fig. 8.4.98: Impact of agriculture

The winter season was marked by some slump in the abundance of fish in the reference site. The number of species in this season at reference and disturbed sites were 14 and 11

-193- 8 Results respectively (Fig. 8.4.23 and 8.4.24). Likewise, the total abundance of fish in those sites in this season was found to be 200.5 and 55.43 respectively. The differences in composition in those sites in this season were A. mangois, C. punctatus, E. danricus, G. telchitta, H. fossilis, M. armatus, N. hexagonolepis, P. conchonius and P. sophore.

The total yearly difference in the number, composition and abundance of fish species in this river is shown in fig. 8.4.97 and 8.4.98. There were some marked differences between upstream and downstream sites not in terms of the number of species but in the total abundance in the yearly data. The number of species in upstream at least once in the year was 16 while in the disturbed site was more at 18. Similarly, the total yearly abundance of the fish in upstream was 246.8 while that in the downstream site were much less at 83.33. Among the differences between compositions includes species such as A. mangois, G. pectinopterus, G. telchitta, N. hexagonolepis, T. putitora, E. danricus, M. armatus, and P. sophore, where the first five species were found completely missing from the upstream while the remaining three were missing from the disturbed site.

8.4.2 Disturbances due to urbanization: The three rivers studied for disturbances due to urbanization, mainly, due to the haphazard growth of the cities or the urban centers, include Narayani in Chitwan district, Seti in Kaski district and Tinau in Butwal district. The three cities, of which the impacts were studied here, are Narayanghat, Pokhara and Butwal, respectively. The details of the extent of urban growth and populations of these cities have been already discussed in earlier chapters. To examine thoroughly the each case, seasonal variations in impacts have been studied. The results of the study in each river and in each season are directly presented here. The statistical significances of this disturbance in Nepalese river will be presented latter. a) Narayani: Narayani River is one of the largest rivers of Nepal and two types of disturbances, urbanization and industrialization, were studied in this river. First, the impacts due to the city are described here. The spring season showed a little difference between the reference site and the downstream disturbed site in terms of the number of species and the abundance of the fish. The total numbers of species in upstream and downstream in this season were 14 and 10 respectively (Fig. 8.4.25 and 8.4.26). Similarly the total abundance of fish in these sites in spring was 37.31 and 47.90 respectively. The differences in the composition

-194- 8 Results between two sites in this season were the species, B. bendelisis, B. shacra, B. vagra, C. garua, G. telchitta, M. armatus, P. conchonius and S. richardsonii, which were present in only one of the either sites.

The premonsoon season showed increase of both the number of species and the abundance in both of the site with even less differences between the two. The numbers of species in upstream and downstream site in this season were 20 each in both (Fig. 8.4.27 and 8.4.28). Similarly, the total abundance of fish in these two sites was 83.11 and 79.25 respectively. There was a very minute difference in the composition of the species. The upstream site was lacking A. botia, L. guntea and N. hexagonolepis while the downstream was found missing of B. rerio, G. telchitta and T. putitora.

The autumn season marked a decrease in the number of fish species and the abundance in disturbed site. The number of species in reference and the disturbed sites in this season were 17 and 14 respectively (Fig. 8.4.29 and 8.4.30). Similarly, the total abundance of fish in these two sites was 97.75 and 58.25 respectively in this season. There were few variations in the species composition. The upstream site was found missing of G. trilineatus only while the downstream was found missing of B. bendelisis, P. sophore, S. semiplotus and T. tor.

The winter season showed a substantial decrease in the number of species and the abundance of fish in both the sites. The numbers of species in the two sites were 10 and 8 respectively in this season (Fig. 8.4.31 and 8.4.32). Similarly, the total abundance of fish in these two sites was 38.83 and 31.5 respectively. There were some variations in the composition of the species in two sites. The upstream was found missing of B. bendelisis and L. guntea compared to downstream while the downstream was found missing of A. botia, B. vagra, B. almorhae and P. pseudecheneis compared to upstream.

The total yearly difference in the number, composition and abundance of fish species in this river is shown in fig. 8.4.99 and 8.4.100. There were some small differences between upstream and downstream sites in terms of the number of species and the total abundance in the yearly data. The number of species in upstream at least once in the year was as high as 28 while in the disturbed site was little less at 23. Similarly, the total yearly abundance of the fish in upstream was 64.25 while that in the downstream site were again a little less at

-195- 8 Results

54.22. The fish species missing in the reference site compared to disturbed site included G. trilineatus only while the species missing in disturbed site compared to reference site included, B. rerio, C. garua, P. pseudecheneis, S. richardsonii, S. semiplotus and T. tor.

Narayani upstream in all seasons

20 18 Total abundance: 64.25 16 14 Number of species: 28 12 10 8 6 4 2

Abundance (CPUE) 0

s o r i r a s a s a a e a o a s a a u o a s e a s a i i l a l r r t i t t r . r n l . r ti i r u t c . u d r s a u . . . to o r c a i i a i . i a u r i g r ty e .. . . o . o o l h e t . r . . l t g o n v c r a a a r h r h e g h a a a o b e d a o e s p ti o n l c o a e i h o c g n p h m g l i c b d v o o s u s a a l h p h e p c T i s e i s o i s s s u i m p t a n m a a t e c l h n r l u s s s s u r i i u s u t b m e u l r b l r e r r i i o a u u u n b l a a m i r x u l l e l l s a x s s a i i i x a i i o d e a h h o r a o r b l r o a a i a L b e h u r p p a y r a p c i r s T c s r s h c ti i G r t tu o h c e o u ti h c e m n o o o s tu tu Ba i Ba p c o n s c d l c h c y i h o e u s h i i Ba t h o t y u a s i i t l r Bo a l s t o c h h l p Bo t o s r h o n s t Pu p b o d a m i n i C t i t l o c z a Br o p l i Ba e u Sc As r p p s o i c m y S h m s y e a N e P A A C c e L P Gl N M S Gl S Fish species

Fig. 8.4.99: Impact of city

Narayani downstream in all seasons

20 18 Total abundance: 54.22 16 14 Number os species: 23 12 10 8 6 4 2

Abundance (CPUE) 0 s o h a u n c r t i r a s a s a a e a o a s a a o e a o e s e a a i i l i a l r r t i t . r t a r n l . . r o t i u t . c u . r a r u g d t o r s i y i . i i a u . i c g a r t e n o .. o o l h e t m r a u l t g o n v c r a a a r h h e d u h a i a a o r e r o x e p t o n l c o a e i b b h v o c g n g a p h g l i c d o o e s u s a m a l h e p c T i s e i o i s s s s p i m p t a n m a a t e s l h n r s h c s u r i i u t m u e s u l r u u b r e r r i i b u s n a o a i r x l l s b l u l l m l a x i b i a i s o s a i x a u u o s o r l d o e a a e r a r l u a i a r L e i c r s T p p i a y a h h i u r c s r s h b t i i G r t t t o h h u u e o u h c p c o o o s t t Ba i Ba p m c c n s c d l c h n i h o e u s h i i Ba t h u i o t y u e a o i t l r Bo a l s t c y h l p Bo t r c s P h o n a s to o o h c p b s m n i C t s r c z a B o p i i B d ta e u S A i l c m r p o S m y s l h l y p N o i P A A C l a e G e Sc Se G L Ps M N Fish species

Fig. 8.4.100: Impact of city b) Seti: The river Seti flows through the heart of the city called Pokhara and thus is taken as a good site for the study of the impacts of urbanization on the river. The spring season is

-196- 8 Results characterized by a relatively better condition in downstream site rather than upstream. The total numbers of species in upstream and downstream in this season were 10 and 13 respectively (Fig. 8.4.33 and 8.4.34). Similarly the total abundance of fish in these sites in spring was 50.16 and 62.73 respectively. The species missing in downstream in this season compared to reference site were B. bendelisis, B. vagra and M. blythii while the missing ones in the reference site were A. botia, B. rerio, C. orientalis, D. dangila, H. fossilis and P. conchonius.

The premonsoon season marked the increase of abundance in the reference section though the number of species declined. The total numbers of species in upstream and downstream in this season were 7 and 11 respectively (Fig. 8.4.35 and 8.4.36). Similarly the total abundance of fish in these sites in premonsoon was 79 and 51.67 respectively. The species missing in downstream in this season compared to reference site was only M. blythii while the missing ones in the reference site were A. botia, B. rerio, C. orientalis, D. dangila and N. hexagonolepis.

The autumn season was characterized by the decline in the abundance of fish in upstream and little increase in downstream with almost the same number of the species. The total numbers of species in upstream and downstream in this season were 8 and 9 respectively (Fig. 8.4.37 and 8.4.38). Similarly the total abundance of fish in these sites in autumn was 38.25 and 64.25 respectively. The species missing in downstream in this season compared to reference site were M. blythii and P. sophore while the missing ones in the reference site were A. botia, G. gotyla gotyla and S. beavani.

The winter season showed almost similar conditions in both reference and disturbed site with only minor differences in all fish based parameters. The total numbers of species in upstream and downstream in this season were 6 and 7 respectively (Fig. 8.4.39 and 8.4.40). Similarly the total abundance of fish in these sites in winter was 70.25 and 67 respectively. The species missing this time in downstream compared to reference site were B. barila, and P. conchonius while the missing ones in the reference site were B. vagra, G. gotyla gotyla and P. sulcatus.

The total yearly difference in the number, composition and abundance of fish species in this river is shown in fig. 8.4.101 and 8.4.102. There were some small differences between

-197- 8 Results

Seti upstream in all seasons

30 otal abundance: 59.41 25 T 20 Number of species: 13 15 10 5

Abundance (CPUE) 0 o s

s n u i i i i i t a a s a o s a a l o s e a i i . i l i r i l e l a n l i l i l h r . t r s g u . r s y t c i a u i g a g a t o o l e s a l s t y n v c a a l h n d o x u y e r n o b b v o a e a n g f b s p d o e h s e h e p i i o t i s s d a s s t n r a s n i h c s u h i n i u e u r e b r i i o o n c a r t n s e b l l i n a i i b i s s a u o o r d a n r a r a n a l l u a i c r s y u i u r c n a g e G t t u a h o o u h e h s t Ba i Ba n r s n s D c i l c n r c s h h i a r u i u i t t o h r a p e e t r h s h o n y P c a o d n c z a C Ga r s B i S i B M l u u c e S h t o e P A e e Sc Ps H N Fish species

Fig. 8.4.101: Impact of the city

Seti downstream in all seasons

30 25 Total abundance: 61.41

20 Number of species: 16 15 10 5

Abundance (CPUE) 0 g

o i i i . i r a a s a o s a a s e a i i l i r i l e l . n l i l i l .. r p t r . . u r s y th . i a u i g a g a t s o o l e y .. s a t u n v c a r n d o o l h b e e y n f s o a e b v b p a n g h h d o e s i s h e p t i s i a s o n s s i t r d a i s c b u i n e s h u u n r r i e o t e i a o r n u n c b l l i l i i n s s a b i i n o d a a r a o r r a n a l a u u r h e c r c s y i u n a g t G e c h t u u h a o o n s s t Ba i Ba r n c n s l D o i c r r s h i a u p s e i i t th r h a a e t h s h o n o y d Pu i n r l z a C G u Br Sc i Ba e M o t e Sc h e Pu Ac e N Ps H Sc Fish species

Fig. 8.4.102: Impact of the city

upstream and downstream sites in terms of the number of species and the total abundance in the yearly data. The number of species in upstream that showed up at least once in the year was 13 while in the disturbed site was little higher at 16. Similarly, the total yearly abundance of the fish in upstream was 59.41 while that in the downstream site were a little higher at 61.41. The fish species missing in the disturbed site compared to the reference site included B. bendelisis and M. blythii only while the species missing in reference site

-198- 8 Results compared to the disturbed site included A. botia, B. rerio, C. orientalis, D. dangila and H. fossilis. c) Tinau: Impact of Butwal city in Tinau River was studied in this work. Spring season showed tremendous differences between the reference and the disturbed site in this river in terms of both the number of species and the total abundance. The total numbers of species in upstream and downstream in this season were 14 and 7 respectively (Fig. 8.4.41 and 8.4.42). Similarly the total abundance of fish in these sites in spring was 184.54 and 54.1 respectively. The species missing in downstream in this season compared to reference site were B. barila, B. lohachata, B. rerio, G. gotyla gotyla, G. pectinopterus, N. hexagonolepis and T. putitora while the missing ones in the reference site were none.

The premonsoon season was marked by a huge decrease in both the number of species and the total abundance particularly in the upstream site. The total numbers of species in upstream and downstream in this season were 5 in each respectively (Fig. 8.4.43 and 8.4.44). Similarly the total abundance of fish in these sites in premonsoon was 18.75 and 39.75 respectively. The species missing in downstream in this season compared to reference site included just one species, S. rupecula; likewise, the missing one in the reference site too was just a one species L. guntea.

The autumn season showed a good recovery both in terms of the number of species and the total abundance particularly in the upstream site. The total numbers of species in upstream and downstream in this season were 13 and 12 respectively (Fig. 8.4.45 and 8.4.46). Similarly the total abundance of fish in these sites in autumn was 107.5 and 40.5 respectively. The species missing in downstream in this season compared to reference site were C. latius, G. telchitta, N. corica, N. hexagonolepis, and P. sulcatus while the missing ones in the reference site were B. barila, B. bendelisis, C. punctatus and M. armatus.

The winter season again marked the decline of the abundance and to some extent the species as well. The total numbers of species in upstream and downstream in this season were 12 and 5 respectively (Fig. 8.4.47 and 8.4.48). Similarly the total abundance of fish in these sites in winter was 73 and 27.5 respectively. The species missing in downstream in this season compared to reference site were B. vagra, B. rerio, C. latius, L. dero, M.

-199- 8 Results armatus, L. guntea, N. hexagonolepis and P. sophore, while the missing one in the reference site was a single species, B. barila.

Tinau upstream in all seasons

55 50 45 Total abundance: 95.95 40 35 Number of species: 21 30 25 20 15 10 5 Abundance (CPUE) 0

s o i a a s a a o s s a a o a u a n s e a a i i l i l r t . t r t . r n l r t i r u u . t e c o . u r s t i y . i t i i a u i g a t e a . o o o l e t r g t a h n v c a a h r o d n c h i b t a o o a l t e l m b v c n c u o a e c g l r p d o i o c x u u s a i t g h e p s e a s o i s s n e p t n a c t e s c h n s b u i u u u u r s h r i e i l e b s u s n r o a i r i b l l l p x l a i b i a u u i s o p l s o r a o r d e a a l e r u r L e c r T s a y a h a e u i u c a a i x l n G t t u t n o h h i u h c b e s t o B a s i B c h n l o c n o r h p i s h i t h u m a i u i t c h r B a a s o e c t r o h n s t c e o P c a h h m e n t c s c a B o p o S B C e d u c r o a s S t y d i l t u i N l P A C p s p o e G y a l e e s

L P G M N Fish species

Fig. 8.4.103. Impact of the city

Tinau downstream in all seasons

55 50 Total abundance: 40.46 45 40 35 Number of species: 13 30 25 20 15 10 5 Abundance (CPUE) 0

s o i a a s a a o s s a a o a u a n s e a a i i l i l r t . t r t . r n l r t i r u u . t e c o . u r s t i y . i t i i a u i g a t e a . o o o l e t r g t a h n v c a a h r o d n c h i b t a o o a l t e l m b v c n c u o a e c g l r p d o i o c x u u s a i t g h e p s e a s o i s s n e p t n a c t e s c h n s b u i u u u u r s h r i e i l e b s u s n r o a i r i b l l l p x l a i b i a u u i s o p l s o r a o r d e a a l e r u r L e c r T s a y a h a e u i u c a a i x l n G t t u t n o h h i u h c b e s t o B a s i B c h n l o c n o r h p i s h i t h u m a i u i t c h r B a a s o e c t r o h n s t c e o P c a h h m e n t c s c a B o p o S B C e d u c r o a s S t y d i l t u i N l P A C p s p o e G y a l e e s

L P G M N Fish species

Fig. 8.4.104 Impact of the city

The total yearly difference in the number, composition and abundance of fish species in this river is shown in fig. 8.4.103 and 8.4.104. There were considerable differences between upstream and downstream sites in terms of the number of species and the total abundance in the yearly data. The number of species in upstream that showed up at least once in the year

-200- 8 Results was 21 while in the disturbed site was comparably low at 13. Similarly, the total yearly abundance of the fish in upstream was 95.96 while that in the downstream site was less than half at 40.46. The composition of the assemblage too showed some differences in the two sites. The fish species missing in the disturbed site compared to the reference site included B. rerio, C. latius, G. pectinopterus, G. telchitta, L. dero, N. corica, N. hexagonolepis, P. sulcatus and T. putitora, while the species missing in reference site compared to the disturbed site included a single species, C. punctatus.

8.4.3 Disturbances due to dams: The three rivers studied for disturbances due to the construction of dams and weirs include Aandhikhola in Syangja district, Bagmati in Kathmandu district and Tinau in Palpa district. The technical and other details of the dams constructed on these rivers have been already discussed in earlier chapters. To examine thoroughly the each case, here too, seasonal variations, in impacts, have been studied. The results of the study in each river and in each season are directly presented here. The statistical significances of this disturbance in Nepalese river will also be presented latter. a) Aandhikhola: Impact of the dam constructed for the 5 MW Aandhikhola Hydro Electricity Project on the river Aandhikhola was studied in this work. In spring season there were very few differences in the number of species and the total abundance of the fish in upstream reference site and the downstream disturbed site. The total numbers of species in upstream and downstream in this season were 11 and 13 respectively (Fig. 8.4.49 and 8.4.50). Similarly the total abundance of fish in these sites in spring was 84.02 and 75.98 respectively. However, there were some differences in the species composition. The fish species missing in the disturbed site compared to the reference site included B. vagra and N. chelynoides while the species missing in reference site compared to the disturbed site included B. rerio, H. fossilis, S. semiplotus and T. putitora.

Premonsoon season marked the decrease in the both number of species and the abundance in the reference site but the downstream rather improved. The total numbers of species in upstream and downstream in this season were 9 and 12 respectively (Fig. 8.4.51 and 8.4.52). Similarly the total abundance of fish in these sites in premonsoon was 47.39 and 123 respectively. The fish species missing in the disturbed site compared to the reference

-201- 8 Results site included just a single species, T. putitora, while the species missing in reference site compared to the disturbed site included B. bendelisis, N. corica, P. chola and S. richardsonii.

The autumn characterized the unfavorable condition particularly in the downstream as shown by the abundance and the number of species. The total numbers of species in upstream and downstream in this season were 9 and 6 respectively (Fig. 8.4.53 and 8.4.54). Similarly the total abundance of fish in these sites in autumn was 46.25 and 42 respectively. The fish species missing in the disturbed site compared to the reference site included B. barila, C. punctatus, G. annandalei and N. hexagonolepis, while the species missing in reference site compared to the disturbed site included just a single species, S. richardsonii.

The winter season showed an improvement in both the site particularly in terms of the abundance of fish. The total numbers of species in upstream and downstream in this season were 9 and 8 respectively (Fig. 8.4.55 and 8.4.56). Similarly the total abundance of fish in these sites in winter was 71 and 85.5 respectively. The fish species missing in the disturbed site compared to the reference site included B. bendelisis and S. richardsonii, while the species missing in reference site compared to the disturbed site included just a single species and this time, T. putitora.

The total yearly difference in the number, composition and abundance of fish species in this river is shown in fig. 8.4.105 and 8.4.106. There were some differences between upstream and downstream sites in terms of the number of species and the total abundance in the yearly data and was in favor of downstream. The number of species in upstream that showed up at least once in the year was 12 while in the disturbed site was comparably high at 16. Similarly, the total yearly abundance of the fish in upstream was 62.16 while that in the downstream site was more than that at 81.62. The composition of the assemblage too showed some differences in the two sites. The fish species missing in the disturbed site compared to the reference site included C. punctatus and N. chelynoides, while the species missing in reference site compared to the disturbed site included B. rerio, H. fossilis, N. corica, P. conchonius and S. semiplotus.

-202- 8 Results

Aandhikhola upstream in all seasons

30 25 Total abundance: 62.16 20 Number of species: 12 15 10 5

Abundance (CPUE) 0 n n i s i i o s a s s l s a o a a l i a o e a i l a s i l l . n l u r i r u e c s . g t r r t s i o d i a y . a u o l g t d r a r o e s r i t a a h v c l i e a r d o x a t o o t b a o c a p v n f c e i d c g e h u o n e p s i n a s s c n s s h p y s i m n n a u l u b u u e u r i u r e l u s i r e r l i n r t e l t b l a p i e i a x s o i s u r d a a h l n r a r e b i r a T s a u c a y u u r s a G h h u n a t u h e m r u B i r c P t o l B c s t i c n r n i e o s h r t a o i o a a a p c i h t l s a r r h h o a i m c o p G s r t c i B B z e i z C l S i e s S m t a o h a N e e N e c M S H N S Fish species

Fig. 8.4.105 Impact of dam

Aandhikhola downstream in all seasons

30 25 Total abundance: 81.62 20 Number of species: 16 15 10 5 Abundance (CPUE) 0

i i a s a o s a s s a a a s a i i e i l r l . l n l r i u l l e . r i . c . u r s t y i . o a u . i g a t . t o l e s d r . . t a a i h v c i a r d o o e t s m o a d l t b v o c a e r c n g r d o o c x p u i f n e p a i n a a s s n s e p a y s b u n l h u u n r s u m e u s h r r i i u i c l a r e l p n e l t a i e i b i u i o t s r r d a l h r a r a n s e r T s y a s e c u u a a l u x G t u n a u h i s u h b r t B i r P s a B c h l c n e i r u i r o s t m a c i r t h a a a n i o r h o e r o c l a h p m h i c B G c s t p o S B C z e i r a s S o i t a l e N z m t s i N o e a h e e c S H M N S Fish species

Fig. 8.4.106 Impact of dam

b) Bagmati: The study made in this river was at Sundarijal in Kathmandu where the river is disrupted by one of the oldest dam construction in the country. There was just one dominating species in both upstream and a downstream site in this river and thus, the differences between the sites is in just the abundance of that species. In spring, just 1 species, S. richardsonii was recorded on the either side of the dam. The abundance of the species in upstream was 36.76 while that in the disturbed site was just 15.29 (Fig.8.4.57 and 8.4.58). In premonsoon, 1

-203- 8 Results more species S. beavani was recorded on both the site, but the abundance of fish in upstream declined considerably. Thus, there were 2 species on both the sites in this season with the total abundance of 21.8 and 20.95 in upstream and downstream respectively (Fig.8.4.59 and 8.4.60).

Bagmati upstream in all seasons

60 Total abundance: 49.95

50 Number of species: 3

40

30

20 Abundance (CPUE)

10

0 Schistura beavani Schistura rupecula Schizothorax richardsonii Fish species

Fig. 8.4.107 Impact of dam

Bagmati downstream in all seasons

60 Total abundance: 11.26

50 Number of species: 2

40

30

20 Abundance (CPUE)

10

0 Schistura beavani Schistura rupecula Schizothorax richardsonii Fish species

Fig. 8.4.108 Impact of dam

In autumn 1 different species, S. rupecula showed up in the reference site whereas the downstream site was left with just the same dominant species, S. richardsonii (Fig.8.4.61

-204- 8 Results and 8.4.62). The total abundance of fish in this season in upstream too increased to 43. 47, but the abundance in the disturbed site was one of the lowest of the entire study at 2.32. In winter season, both the upstream and downstream site was with only the same single dominant species but the abundance particularly in the upstream was highest of all the season (Fig.8.4.63 and 8.4.64). The abundance of fish in this season was 97.75 and 6.5 in upstream and downstream respectively.

The total yearly difference in the number, composition and abundance of fish species in this river is shown in fig. 8.4.107 and 8.4.108. There were not many differences between upstream and downstream sites in terms of the number of species but the total abundance in the yearly data showed significant differences and was in favor of upstream. The number of species in upstream that showed up at least once in the year was 3 while in the disturbed site was 2. Similarly, the total yearly abundance of the fish in upstream was 49.95 while that in the downstream site were much less at 11.26. The composition of the assemblage did not show much difference in the two sites. The fish species missing in the disturbed site compared to the reference site was just a single species S. rupecula. c) Tinau: This river too holds one of the very old dams under Tinau Small Hydropower Project and the impact of this dam is studied in this work. In spring season there were no differences in the number of species and few in the total abundance of the fish in upstream reference site and the downstream disturbed site. The total numbers of species in upstream and downstream in this season were 12 each (Fig. 8.4.65 and 8.4.66). Similarly the total abundance of fish in these sites in spring was 74.17 and 89.28 respectively. However, there were some differences in the species composition. The fish species missing in the disturbed site compared to the reference site included N. hexagonolepis and T. putitora while the species missing in reference site compared to the disturbed site included B. barila, B. rerio and M. armatus.

The premonsoon characterized a huge drop in both the species number and the abundance of fish on either side of the dam. The total numbers of species in upstream and downstream in this season were 6 and 3 respectively (Fig.8.4.67 and 8.4.68). Similarly the total abundance of fish in these sites in premonsoon was 13.32 and 38.5 respectively. There were minor differences in the species composition. The fish species missing in the disturbed site

-205- 8 Results compared to the reference site included G. gotyla gotyla, N. hexagonolepis, S. rupecula and T putitora, while the species missing in reference site compared to the disturbed site included P. sophore only.

The autumn season marked a good recovery in both the number of species and the abundance of fish on either side of the dam. The total numbers of species in upstream and downstream in this season were 10 and 9 respectively (Fig.8.4.69 and 8.4.70). Similarly the total abundance of fish in these sites in autumn was 61.91 and 54.23 respectively. There were some differences in the species composition. The fish species missing in the disturbed site compared to the reference site included B. barila, N. hexagonolepis and T. putitora, while the species missing in reference site compared to the disturbed site included G. trilineatus and L. dero.

The winter season showed difficult conditions for the fish particularly in the upstream of the dam as was shown by their abundance and composition. The total numbers of species in upstream and downstream in this season were 7 and 9 respectively (Fig.8.4.71 and 8.4.72). Similarly the total abundance of fish in these sites in winter was 28.25 and 77.02 respectively. There were some differences in the species composition as well. The fish species missing in the disturbed site compared to the reference site included P. conchonius and T. putitora, while the species missing in reference site compared to the disturbed site included B. vagra, B. lohachata, L. dero and P. sophore.

The total yearly difference in the number, composition and abundance of fish species in this river is shown in fig. 8.4.109 and 8.4.110. There were some differences between upstream and downstream sites in terms of the number of species and the total abundance in the yearly data and was in slightly favor of downstream. The number of species in upstream that showed up at least once in the year was 15 while in the disturbed site was comparably high at 17. Similarly, the total yearly abundance of the fish in upstream was 44.41 while that in the downstream site was more than that at 64.76. The composition of the assemblage too showed some differences in the two sites. The fish species missing in the disturbed site compared to the reference site included T. putitora and T. tor, while the species missing in reference site compared to the disturbed site included B. lohachata, B. rerio, L. dero, and M. armatus.

-206- 8 Results

Tinau upstream in all seasons

35 30 Total abundance: 44.41

25 Number of species: 15 20 15 10 5

Abundance (CPUE) 0 s o s

u n u t t i r a a s a a o a a o o s e a a i l i l r t i t . r a a r n l r o t i r t . g u t r s y i . c i a u i g a t e o o o l e m a l t n v c r a a h h e d h i o r u e r x t o b c c o a e b v l n a p g i e s u d o o T s a i l h e p i e i o s s s p t n a t r e s c h n h i s u i u t b e u r b u r r i i s n o a r x l e b l l l a i b i s o x a u o o r d a a e n r a r l u L i c r T a y r a i c s b e u i G r t t o h u u t h o o h s t Ba i Ba m c n s l c h i h i t c u s h e i u i t o h r Bo a t e t r c s h n to P c a o d n t c a s B p ta i S B l u u c p S y s l y o e P A l a e G G Ps M N Fish species

Fig. 8.4.109 Impact of dam

Tinau downstream in all seasons

35 30 Total abundance: 64.76 25 Number of species: 17 20 15 10 5

Abundance (CPUE) 0

s i r a a s a a o a a o s e a a i l i r t i l t tu n l r o i r r t r t . . .. u t r s y i a . i a u i g a t e o o o l e .. .. t r a h h e u n v c i a o d h b e r a e t o b c c s o a e v l n p g i h u d o o T s a i l s h e p i s e i s o n s e i p t h a t s c b u i n u s u u r tr l i e b e n r i o a r u r b l l l x l a i b e s o i x a i n o o r d a a r a r b u L h e c r T a y r a i c s u i G r t t t o c h u o u h m s t Ba i Ba o n s h o c l c e i s i t h u th s e i i r Bo a t c t h o s h n t d Pu o a i n t t l a Br p u Ba Sc p s o y e Sc l y a e Pu Ac l G N M Ps G Fish species

Fig.8.4.110 Impact of dam

-207- 8 Results

8.4.4 Disturbances due to industries: The three rivers studied for disturbances due to the industries include Arungkhola in Nawalparasi district, Karrakhola in Makawanpur district and Narayani in Chitwan and Nawalparasi districts. The technical and other details of the industries on the bank of these rivers have been already discussed in earlier chapters. To examine thoroughly the each case, here too, seasonal variations in impacts, have been studied. The results of the study in each river and in each season are directly presented here. The statistical significances of this disturbance in Nepalese rivers will also be presented latter. a) Arungkhola: This river holds one of the important distilleries called ‘Shree Distillery’ on its bank and the present work studied the impact of this industry on this river. The spring season showed big differences between reference and disturbed site particularly in terms of the abundance of fish. The total numbers of species in upstream and downstream in this season were 16 and 13 respectively (Fig.8.4.73 and 8.4.74). Similarly, the total abundance of fish in these sites in spring was 129.85 and 39.93 respectively. There were some minor differences in the species composition as well. The fish species missing in the disturbed site compared to the reference site included A. mangois, B. shacra and E danricus, while the species missing in reference site compared to the disturbed site were none.

The premonsoon season was characterized by a big jump in the abundance of fish in downstream site particularly by a single species, S. beavani. The total numbers of species in upstream and downstream in this season were 15 and 14 respectively (Fig.8.4.75 and 8.4.76). Similarly, the total abundance of fish in these sites in premonsoon was 82.25 and 126.25 respectively. There were some minor differences in the species composition as well. The fish species missing in the disturbed site compared to the reference site included B. rerio and M. pancalus, while the species missing in reference site compared to the disturbed site was just one, B. bendelisis.

The autumn marked the decline in the abundance of fish in both the site, however there was a considerable increase in the number of species in the reference site. The total numbers of species in upstream and downstream in this season were 21 and 14, respectively (Fig.8.4.77 and 8.4.78). Similarly, the total abundance of fish in these sites in autumn was 50.5 and 32 respectively. There were considerable differences in the species composition in this season.

-208- 8 Results

The fish species missing in the disturbed site compared to the reference site included B. rerio, C. latius, L. dero, L. guntea, M. pancalus, M. blythii, S. semiplotus and T. putitora, while the species missing in reference site compared to the disturbed site was just one S. rupecula.

The winter season was characterized by the high abundance of fish in both the sites as well as by a highest number of species. The total numbers of species in upstream and downstream in this season were 22 and 19, respectively (Fig.8.4.79 and 8.4.80). Similarly, the total abundance of fish in these sites in winter was 128.25 and 179.75, respectively. There were some differences in the species composition in this season as well. The fish species missing in the disturbed site compared to the reference site included D. aequipinnatus, L. dero, M. pancalus and S. semiplotus, while the species missing in reference site compared to the disturbed site included P. sulcatus only.

The total yearly difference in the number, composition and abundance of fish species in this river is shown in fig. 8.4.111 and 8.4.112. There were not any substantial differences between upstream and downstream sites in terms of the number of species and the total abundance in the yearly data and was slightly in favor of upstream. The number of species in upstream that showed up at least once in the year was 26 while in the disturbed site was a little less at 20. Similarly, the total yearly abundance of the fish in upstream was 97.71 while that in the downstream site were marginally less at 94.48. The composition of the assemblage however, showed some differences in the two sites. The fish species missing in the disturbed site compared to the reference site included B. shacra, C. latius, D. aequipinnatus, L. dero, M. pancalus, M. blythii and S. semiplotus, while the species missing in reference site compared to the disturbed site included just a single species, P. sulcatus.

-209- 8 Results

Arungkhola upstream in all seasons

60 Total abundance: 97.71 50 Number of species: 26 40 30 20 10 Abundance (CPUE) 0

i i i i a s a s a a a o s s s s s a o a s s s s e a s a i i l i t i i e l n l r r l l r h r r t i r u u u u e u u u u u o r s t i t y l t i a u i c g a a e t t t o t o o e t c a t l t i y t g a h a a n a a a n v c o i a a r d o d l h b e t a r l t n c n l n c c o a e b h v u b p c n n g l p d o e o n m u s a s a i n g h e p i i s i n s i a r u o n s a e s p t h r a a i c b u i n a s s m u s u u u p d n r s r m e l b r i i o o i p n n b l l a i r u l p n u s a e i b i u a s s o s i d e s a l a i o r a o r l r a a s l s i L u u r p a y a q u a c i T c a s h u l e u r a i n G g t t u s e t h n c e a h e o u a h n s t B i B n m r s n s c a t u l o c n o r p b r i s h i a e u t B o i u i t y r a a s e a e h l B a h t o r h o s m h n s i c n y P c l b a h c n E G e c a B C o n o g p B e u S i C r c M c m a S d o d i r a P C m A A t u D p c e s e e a a s S L M P M Fish species

Fig.8.4.111 Impact of industry

Arungkhola downstream in all seasons

60 Total abundance: 94.48 50 Number of species: 20 40

30

20

10 Abundance (CPUE) 0

i i i i a s a s a a a o s s s s s a o a s s s s e a s a i i l i i i e l n l r r t l r h r r t i r u u u u l e u u u u u o r s t i t y t l t t t i t i c g a a e o a u o o l e t c a t g t i a y t a a h a a n a l a n v c o i a r d o d h l b e t a r t n n l c b h v c n u b c o a e c n g l p p d o n m u s a e o n h e i s a i i n g r p i s n s i a u o n s a e s p t h r a a i c b u i n u a s s m m u s u u p d n r s r e o l i b p r i i o n n b l a i r u l l p n u s s a e s i b i i u a l s o o d e s a a i r a o r l r a a s l s i u u r p q u L a c T c s a y a h l e i u a r a i n u g t e G t u s e u t h n c a h e n o a n h s s t B i B m r n s u c l o c a p t r i h n o r b e u s t i a o u i t y B a i r B a a s e e h l o a h t o r s m h l n s i c n y P c b a c n E G e c p a B Ch o n o g B e S i Ch c M u c m d o S i d r a P m A A Cr t Da p u c e s e e a S a s L M M P Fish species

Fig. 8.4.112 Impact of industry b) Karrakhola: The river receives all the effluent from the most important industrial district; ‘Hetauda Industrial District’ of the country in Hetauda and thus, the impacts of industries in this river were studied here. In spring season, there was a big difference in the abundance of fish between upstream and downstream sites but in terms of the number of species the two sites were almost same. The total numbers of species in upstream and downstream in this season

-210- 8 Results were 16 and 17, respectively (Fig.8.4.81 and 8.4.82). Similarly, the total abundance of fish in these sites in spring was 112.77 and 62.25, respectively. There were some minor differences in the species composition as well. The fish species missing in the disturbed site compared to the reference site included B. vagra and C. punctatus, while the species missing in reference site compared to the disturbed site were G. chapra, N. hexagonolepis and P. conchonius.

The season premonsoon was characterized by the reverse trend in the abundance of fish compared to spring between the two sites as well as the absence of few species. The total numbers of species in upstream and downstream in this season were 13 and 15 respectively (Fig.8.4.83 and 8.4.84). Similarly the total abundance of fish in these sites in premonsoon was 82.25 and 128.75, respectively. There were some minor differences in the species composition as well. The fish species missing in the disturbed site compared to the reference site included P. sulcatus only while the species missing in reference site compared to the disturbed site were B. rerio, C. orientalis and M. armatus.

The autumn season indicated favorable conditions in both the sites in terms of abundance as well as the number of species. The total numbers of species in upstream and downstream in this season were 17 and 16, respectively (Fig.8.4.85 and 8.4.86). Similarly the total abundance of fish in these sites in autumn was 146.78 and 118 respectively. There were some minor differences in the species composition as well. The fish species missing in the disturbed site compared to the reference site included B. bendelisis, C. punctatus and E. danricus, while the species missing in reference site compared to the disturbed site were C. reba and N. corica.

In winter, the abundance of fish in upstream remained more or less constant but in disturbed site there was a decreasing trend. The total numbers of species in upstream and downstream in this season were 16 and 13, respectively (Fig.8.4.87 and 8.4.88). Similarly the total abundance of fish in these sites in winter was 139 and 88.5, respectively. There were again some minor differences in the species composition. The fish species missing in the disturbed site compared to the reference site included B. barna, C. punctatus and M. armatus, while the species missing in reference site compared to the disturbed site were none.

-211- 8 Results

Karrakhola upstream in all seasons

30 Total abundance:120.2 25 Number of species: 21 20 15 10 5

Abundance (CPUE) 0

e i l i a s a a s a o s s a s a a s a s a s a s e a i i i i e i o i l r l r l r n l i l u l l u t n r b u i e u c u o r s t y t t i n t o i a u r i g a a t p o o l e e c s r g t a i o n v c a a a r r a n a a h h b t r d o e n s o n b u g c c o a e b v h l p c n n g o m c d o e s s a f g a h e p i i c r u o i s s n a a s t s n r u c n a s x b u i a s u s m u u u d n r a s s r i u e o n u e i n i i a i r i b l l l p n e u l t a i b i s i s s s i h s s t l h i o r a o r d a a n r r a u u p r u s a e c r c s y a u l e i u a a n r s u t a i G h t u e h n a d u h e n o u u s t B i B n m r P n s c B c l i l c n C u e p b i e s h i a r u o a i u i t y e h l r a a a n h h t h s G m h n r c P c b a h p m c c n E e c a B C G o o o e S B C e u c m r c S d s d i P e a N A A t s t p i u s l e e e o a s H L e M P N Fish species

Fig. 8.4.113 Impact of industry

Karrakhola downstream in all season

30 Total abundance:100.12 25 Number of species:21 20 15 10 5

Abundance (CPUE) 0

e i l i a s a a s a o s s a s a a s a s a s a s e a i i i i e l i o n i l r r l r l i l u l l u t n r b u i e u c u o r s t y t t i n t o i a u r i g a a t p o o l e e c s r g t a i o n v c a a a r r a n a a h h b t r d o e n s o n b u g c c o a e b v h l p c n n g o m c d o e s s a i c f g r a h e p i i n a u s o s s n s u a t r a s x c b u i n a s s m u u u d n r s s u r u e o n a i n i i i a i i u e b l l r l t l p n e u s s s a s i i b i s l i h o d h a s t i r a o r r a a n r r u u r p a u s a e c c s y u l e i u a a n r s u t a i G h t u e h n a d u h e n o u u s t B i B n m r P n s c B c l i l c n C u e p b i e s h i a r u o a i u i t y e h l r a a a n h h t h s G m h n r c P c b a h p m c c n c a C E G e B o o o e S B C e u c m r c S d s d i P e a N A A t s t p i u s l e e e o a s H L e M P N Fish species

Fig. 8.4.114 Impact of industry

The total yearly difference in the number, composition and abundance of fish species in this river is shown in fig. 8.4.113 and 8.4.114. There were not any substantial differences between upstream and downstream sites in terms of the number of species and the total abundance in the yearly data. The number of species in upstream that showed up at least

-212- 8 Results once in the year was 21 while in the disturbed site it was 21 too. Similarly, the total yearly abundance of the fish in upstream was 120.2 while that in the downstream site were marginally less at 100.12. The composition of the assemblage however, showed some differences in the two sites. The fish species missing in the disturbed site compared to the reference site included B. barna, C. punctatus, E. danricus and P. sulcatus while the species missing in reference site compared to the disturbed site included C. reba, G. chapra, N. corica and P. conchonius. c) Narayani: There is a big industry called Bhrikuti Pulp and Paper Mill on the bank of Narayani River at Gaindakot in Nawalparasi district. The factory not only depends on the river for its entire water requirement but also discharges its effluents in the same river. The impact of this industry in the river was studied here in this work. The impact of the industry was quite visible in spring season as there was a big difference in the abundance of fish and the species richness between upstream reference site and downstream disturbed sites. The total numbers of species in upstream and downstream in this season were 14 and 8, respectively (Fig.8.4.25 and 8.4.89). Similarly, the total abundance of fish in these sites in spring was 37.31 and 18.33 respectively. There were also considerable differences in the species composition as well. The fish species missing in the disturbed site compared to the reference site included B. bendelisis, B. shacra, B. vagra, B. lohachata, G. gotyla gotyla, G. telchitta, N. hexagonolepis, S. rupecula, S. richardsonii and T. putitora while the species missing in reference site compared to the disturbed site were B. rerio, M. armatus, P. conchonius and P. sophore.

The premonsoon season also showed a big difference between upstream and downstream site though there was a good increase in the abundance of fish in both the sites. The total numbers of species in upstream and downstream in this season were 20 and 8, respectively (Fig.8.4.27 and 8.4.90). Similarly, the total abundance of fish in these sites in premonsoon was 83.11 and 35.33, respectively. There were also tremendous differences in the species composition as well. The fish species missing in the disturbed site compared to the reference site included A. mangois, B. bendelisis, B. shacra, B. vagra, B. almorhae, B. lohachata, B. rerio, C. latius, G. gotyla gotyla, G. telchitta, L. dero, M. armatus, N. corica, S. beavani, S. rupecula and T. putitora while the species missing in reference site compared to the disturbed site were C. orientalis, C. punctatus, L. guntea and N. hexagonolepis.

-213- 8 Results

The autumn season marked some increase in the species number in the disturbed site but as before there were noticeable differences between the two sites yet again. The total numbers of species in upstream and downstream in this season were 17 and 11, respectively (Fig.8.4.29 and 8.4.91). Similarly the total abundance of fish in these sites in autumn was 97.75 and 20.83, respectively. There were good differences in the species composition as well. The fish species missing in the disturbed site compared to the reference site included B. bendelisis, B. vagra, C. latius, G. gotyla gotyla, G. telchitta, L. dero, L. guntea, S. beavani, S. semiplotus and T. tor while the species missing in reference site compared to the disturbed site were B. barila, B. rerio, C. punctatus and G. giuris.

The winter season was found to show the least impact of the industry mainly due to a huge drop in the abundance as well as in the number of species in the reference site and not because of the improvement in the disturbed site. The total numbers of species in upstream and downstream in this season were 10 each in both (Fig.8.4.31 and 8.4.92). Similarly, the total abundance of fish in these sites in winter was 38.83 and 19.75, respectively. However, there were some differences in the species composition. The fish species missing in the disturbed site compared to the reference site included A. botia, B. bendelisis, G. gotyla gotyla, M. armatus, N. corica, P. pseudecheneis, S. beavani and S. rupecula while the species missing in reference site compared to the disturbed site were A. mangois, B. barila, C. punctatus, L. guntea, N. hexagonolepis P. conchonius and S. richardsonii.

The total yearly difference in the number, composition and abundance of fish species in this river is shown in fig. 8.4.115 and 8.4.116. There were substantial differences between upstream and downstream sites in terms of the number of species and the total abundance in the yearly data. The number of species in upstream that showed up at least once in the year was 28 while in the disturbed site it was 21. Similarly, the total yearly abundance of the fish in upstream was 64.25 while that in the downstream site were much less at 23.56. The composition of the assemblage too showed some differences in the two sites. The fish species missing in the disturbed site compared to the reference site included B. bendelisis, B. shacra, C. latius, G. gotyla gotyla, G. telchitta, L. dero, P. pseudecheneis, S. semiplotus, T. putitora and T. tor while the species missing in reference site compared to the disturbed site included C. orientalis, C. punctatus and G. giuris.

-214- 8 Results

Narayani upstream in all seasons

20 18 Total abundance: 64.25 16 14 Number of species: 28 12 10 8 6 4 2 Abundance (CPUE) 0

e n l i i r i r a s a s a a e a o s s a s a s a o a s a e s e a s a i i l i t i i l i t o n l a i r r l r r n r o t a r u u u r t e u c h u u t o r r s t i y i i n i a u i c g a a r e t t o t o t t u c o o o l h e t r t r g a a i h n a o n v c o i a a r h r a o d h s b e t a o e l t n b c n l g c g o a e o h v o g u p d m c g l c d p d o e o m u s a s a i g a h e p r i T i s i n s s e r o n s u p t a m r a a t e s x c b u a i l h n a s i m u s u u u r u s m e l i b e r r r i i o o u e n h b l l a a m i r x l i u l p u s s s a e s a b i i b a l i h o c o d e a r a o r l r a o a p i s i a u e u r p p a a o r L a c i r T c a s i y s h l u r a i n G s t t i g h t u s e o t h n c o h e s o u a n u s t x B i B o p c n s c d l o c n o h p l u i u h o b i u s a i i a t u i t t y B u s a i r B a a l s e h h r l p B h t r h o h o n s m c P c l a h s t c c o b s C m n o e c a B C o p o n h p B l e o u S i A C r t c m c y S y d s l G i N P o a h m A A C t s p i r z G s l i e e o a o l h S L i e c s M N S P Fish species

Fig. 8.4.115 Impact of industry

Narayani downstream in all seasons

20 18 Total abundance: 23.56 16 14 Number of species: 21 12 10 8 6 4 2 Abundance (CPUE) 0

e n l i i r i r a s a s a a e a o s s a s a s a o a s a e s e a s a i i l i i i l i t o n l a r r t l r r r o t i r u u r t e u c u n u r s a u h t o r a t i y i t t i n i a u t i c g a r e o o o o l h e t t u r c g o t c t r a a h r a i h n a o n v o i a r a o d h s l b e t a o e t n n l c o b h v c g u g o a e m o c g g l p d p d o m c d u s a e o p r i s a i i g r a h e T i s n s s e o n s a u p t a m r a t e s x c b u a i l h n a s i m u s u u u s m e u l r i b e r r i i o o u e n h r b l a a m i r x l u l l p u s s a e i b i b a i s c o s a i l h o a o r l d a o e a a r i s r u p u p p i a o r L a e c r r s i a y a s h l i u T c a r a i n s t i G h t t u s e o t h n c g o h e s o u a s t x B i n p u n s c B o o h c l u d l o c n o p b u i s h i i a t i u a t t y B u s a i u i r B a a s e h h r l p B o h t o r s m h l n a s t c c P c o b s Cl m c n o e c p a B Ch o p o n h B l o u S i A Ch c t c m y S y d s l i G a Ne P o m A A Cr t s h p i z G r e s l i e o a o l h S L i c s M S Ne P Fish species

Fig. 8.4.116 Impact of industry

-215- 8 Results

8.5 Statistical verifications:

There were some differences in fish assemblage and abundance as was evident from broad and general overlook between upstream and downstream or the reference and disturbed sites indicating that the fish population dynamics could be a good indicator of the different disturbance regimes. However, the statistical backing is helpful and necessary to draw any conclusions regarding the impacts of different kinds of disturbances in rivers and streams. This study too was involved in an extensive statistical analysis to check which and where the impacts are significant to help draw the conclusions. Two variables, ‘sum of CPUE (abundance)’ and the ‘number of species’ were identified as the important variables. All statistical analysis was done using SPSS and MS EXCEL programs.

The first thing done in the statistical analysis of the data was to create ‘box plots’ of the data. The box plots not only gives the full dimension of all the data acquired in this work but also gives a good glimpse of variations of the data in terms of above mentioned variables to compare the conditions in each rivers studied for all the impacts and that too in all the seasons. It shows maximum, minimum and median values of the variable as well as 25 –75 percent values which are lodged in the box. In addition it also shows the extreme values of the variables as out-liers. First, two separate box plots were made one each of all the impacts in all seasons for sum of CPUE and the total number of species. Latter, they were splitted to represent the impacts for each season to see which season has the highest impacts of each disturbance, which were studied. In addition, separate tables were made for each box plots to describe the data.

The fig.8.5.1 describes the abundance of fish in both upstream and downstream sites for all the impacts studied in all the seasons (Table 8.5.1). The figure showed that there is a significant difference between upstream and downstream in industrially disturbed sites in terms of the abundance of fish. There were some differences in agricultural sites, whereas very little differences on the impacts of dam and city. Similarly, fig.8.5.2 describes the total number of fish species in both upstream and downstream sites for all the impacts studied in all the seasons (Table 8.5.2). This figure also showed some impacts due to industries and agriculture in the rivers studied, while very little differences were found between upstream and downstream for the impacts of city and dam.

-216- 8 Results

The fig.8.5.3 describes the abundance of fish in both upstream and downstream sites for the agricultural impacts in all the seasons studied in this work (Table 8.5.3). The figure showed a considerable difference in the total abundance and median between upstream and downstream particularly in autumn and premonsoon season, while in other seasons the differences were comparatively low. Similarly, fig.8.5.4 describes the total number of fish species in both upstream and downstream sites for the agricultural impacts in all the seasons studied in this work (Table 8.5.4). The figure showed a considerable difference in number of fish species between upstream and downstream in premonsoon and winter seasons.

The fig.8.5.5 describes the abundance of fish in both upstream and downstream sites for the impacts due to city in all the seasons studied in this work (Table 8.5.5). The figure showed some differences in median between upstream and downstream in all seasons except in spring where, though, there was a big difference in the maximum value. Similarly, fig.8.5.6 describes the total number of fish species in both upstream and downstream sites for the impacts due to city in all the seasons studied in this work (Table 8.5.6). The figure showed a considerable difference in number of fish species between upstream and downstream in spring and premonsoon seasons compare to others.

The fig.8.5.7 describes the abundance of fish in both upstream and downstream sites for the impacts due to dam in all the seasons studied in this work (Table 8.5.7). The figure showed considerable differences in median between upstream and downstream in premonsoon while the impacts on other seasons were less. Similarly, fig.8.5.8 describes the total number of fish species in both upstream and downstream sites for the impacts due to dam in all the seasons studied in this work (Table 8.5.8). The figure showed some differences in number of fish species between upstream and downstream in premonsoon and autumn seasons compared to others.

The fig.8.5.9 describes the abundance of fish in both upstream and downstream sites for the impacts due to industries in all the seasons studied in this work (Table 8.5.9). The figure showed considerable differences in median between upstream and downstream in all seasons indicating that the industries might be a big disturbance to the river ecology.

-217- 8 Results

cd_place upstream downstream

300,00

58 200,00

57 sumCPUE

100,00

0,00

agriculture city dam industry cd_impact

Fig. 8.5.1: Abundance of fish (CPUE) in all impacts in all seasons

cd_place 20 upstream 64 downstream

15

10 Numberfishspecies

5

0

agriculture city dam industry cd_impact

Fig. 8.5.2: Number of species in all impacts in all seasons

-218- 8 Results

impact: agriculture cd_place 350 upstream downstream

300

250

200

150 sumCPUE

100 31

50

0

spring premonsoon autumn winter cd_season

Fig. 8.5.3: Abundance of fish (CPUE) in agricultural impacts

cd_impact: agriculture cd_place 20 upstream downstream 18

16

14

12

10

8 Numberfishspecies 6

4

2

0

spring premonsoon autumn winter cd_season

Fig. 8.5.4: Number of species in agricultural impacts

-219- 8 Results

impact: city cd_place 350 upstream downstream

300

250

200

150 sumCPUE

100 56

50

0

spring premonsoon autumn winter cd_season

Fig. 8.5.5: Abundance of fish (CPUE) in impacts of city

cd_impact: city cd_place 20 upstream downstream 18

16 61

14

12

10

8 Numberfishspecies 6

4

2

0

spring premonsoon autumn winter cd_season

Fig. 8.5.6: Number of species in impacts of city

-220- 8 Results

impact: dam cd_place 350 upstream downstream

300

250

200

150 sumCPUE

100

50

0

spring premonsoon autumn winter cd_season

Fig. 8.5.7: Abundance of fish (CPUE) in impacts of dam

cd_impact: dam cd_place 20 upstream downstream 18

16

14

12

10

8 Numberfishspecies 6

4

2

0

spring premonsoon autumn winter cd_season

Fig. 8.5.8: Number of species in impacts of dam

-221- 8 Results

impact: industry cd_place 350 upstream downstream

300

250

200 174

150 sumCPUE

100

50

0

spring premonsoon autumn winter cd_season

Fig. 8.5.9: Abundance of fish (CPUE) in impacts of industry

cd_impact: industry cd_place 20 upstream downstream 18

16

14

12

10

8 Numberfishspecies 6

4

2

0

spring premonsoon autumn winter cd_season

Fig. 8.5.10: Number of species in impacts of industry

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Impacts N N median minimum maximum Percentiles (valid) (missing) 25% 75% Agriculture ups 24 0 122.5 26.0 319.44 49.9 234.3 down 24 0 82.2 15.0 256.0 42.4 146.9 City ups 24 0 72.5 16.5 207.5 39.6 85.4 down 24 0 51.25 20.0 97.22 38.4 68.4 Dam ups 24 0 51.25 8.64 101.5 28.12 69.7 down 24 0 50.7 2.0 125.0 12.4 80.4 Industry ups 24 0 88.83 27 181 69.87 124.8 down 24 0 41.46 16.67 187 23.5 128.87 Table 8.5.1: Abundance of fish (CPUE) in all impacts in all seasons Impacts N N median minimum maximum Percentiles (valid) (missing) 25% 75% Agriculture ups 24 0 10 4 15 6 12 down 24 0 7 3 16 5 11 City ups 24 0 8 3 16 6 11.75 down 24 0 7 4 19 5 10 Dam ups 24 0 6.5 1 10 1.25 8 down 24 0 5.5 1 12 1 9 Industry ups 24 0 12.5 9 18 10.25 14 down 24 0 11 2 17 8 13 Table 8.5.2: Number of species in all impacts in all seasons Impacts N N Median minimum Maximum Percentiles Agriculture (valid) (missing) 25% 75%

ups 6 0 107.02 26 301.33 35.0 297.42 Spring down 6 0 158.1 102.0 247.0 130.0 238.0 ups 6 0 151.5 44.0 257.65 50.5 246.72 Premonsoon down 6 0 44.5 15 124 18.25 104.5 ups 6 0 71 42 319.4 47.25 305.86 Autumn down 6 0 49.25 38.5 105.0 40.0 74.85 ups 6 0 138.75 45.56 208.0 66.2 196.75 Winter down 6 0 100.12 41.67 256.0 43.8 176.1 Table 8.5.3: Abundance of fish (CPUE) in agricultural impacts Impacts N N median minimum maximum Percentiles Agriculture (valid) (missing) 25% 75%

ups 6 0 9 4 15 5.5 12.75 Spring down 6 0 10 6 14 6 13.25 ups 6 0 10 6 13 6.75 11.5 Premonsoon down 6 0 4.5 3 15 3.75 13.5 ups 6 0 9.5 5 12 5.75 11.25 Autumn down 6 0 8 5 16 5 12.25 ups 6 0 11 5 13 5.75 12.25 Winter down 6 0 7 5 11 5.75 8.75 Table 8.5.4: Number of species in agricultural impacts

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Impacts N N median minimum maximum Percentiles city (valid) (missing) 25% 75%

ups 6 0 50.16 36.36 207.50 37.78 173.06 Spring down 6 0 53.2 28.24 97.22 38.56 66.1 ups 6 0 79 16.5 83.5 19.87 82.92 Premonsoon down 6 0 54.2 24.5 85.5 43.62 76.13 ups 6 0 82.75 29.5 135.5 42.62 116.0 Autumn down 6 0 46.75 39.5 79.0 41.0 74.13 ups 6 0 60 33 89 41.75 80.4 Winter down 6 0 36.5 20 78 23.75 61.5 Table 8.5.5: Abundance of fish (CPUE) in impacts of city Impacts N N median minimum maximum Percentiles city (valid) (missing) 25% 75%

ups 6 0 10 5 13 6.5 13 Spring down 6 0 6 5 13 5 10.75 ups 6 0 5.5 3 16 4.5 10.75 Premonsoon down 6 0 8.5 4 19 4.75 16.75 ups 6 0 9.5 6 15 6 12.75 Autumn down 6 0 8.5 7 13 7.75 12.25 ups 6 0 7.5 4 11 5.5 9.5 Winter down 6 0 5.5 4 8 4 6.5 Table 8.5.6: Number of species in impacts of city Impacts N N median minimum maximum Percentiles Dam (valid) (missing) 25% 75%

ups 6 0 67.67 23.53 99.4 43.4 86.1 Spring down 6 0 74.76 12.0 100 16.92 85.75 ups 6 0 21.8 8.64 47.5 15.7 47.32 Premonsoon down 6 0 48.95 7.5 125.0 12.0 122.0 ups 6 0 53.0 34.4 63.33 37.86 61.21 Autumn down 6 0 42.0 2.14 58.00 2.41 52.34 ups 6 0 71 28 101.5 28.37 95.87 Winter down 6 0 64.25 2 103.04 8.75 95.89 Table 8.5.7: Abundance of fish (CPUE) in impacts of dam Impacts N N median minimum maximum Percentiles Dam (valid) (missing) 25% 75%

ups 6 0 8 1 10 1 10 Spring down 6 0 8.5 1 12 1 10.5 ups 6 0 5 1 8 1.75 8 Premonsoon down 6 0 2.5 1 11 1 9.5 ups 6 0 8 1 10 1.75 8.5 Autumn down 6 0 5 1 9 1 6.75 ups 6 0 5 1 9 1 7.5 Winter down 6 0 6.5 1 9 1 8.25 Table 8.5.8: Number of species in impacts of dam

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Impacts N N median minimum maximum Percentiles Industry (valid) (missing) 25% 75%

ups 6 0 91.7 36.36 165.0 37.8 143.9 Spring down 6 0 39.9 16.7 66.0 19.2 64.9 ups 6 0 83.11 68.5 96.0 73.75 90.75 Premonsoon down 6 0 118.5 34.67 144.0 35.7 132.8 ups 6 0 97.75 27.0 181.33 62.25 129.50 Autumn down 6 0 32.0 20.67 131.00 20.9 111.5 ups 6 0 111.5 33 162.5 41.75 152.37 Winter down 6 0 88.5 19 187 20.12 176.12 Table 8.5.9: Abundance of fish (CPUE) in impacts of industry Impacts N N median minimum maximum Percentiles Industry (valid) (missing) 25% 75%

ups 6 0 12 10 14 10 14 Spring down 6 0 10 2 14 6.5 14 ups 6 0 12 9 16 10.5 14.5 Premonsoon down 6 0 9.5 5 13 7.25 12.25 ups 6 0 13.5 10 15 11.5 15 Autumn down 6 0 11.5 7 15 8.5 13.5 ups 6 0 12 9 18 9 15.75 Winter down 6 0 11.5 6 17 7.5 15.5 Table 8.5.10: Number of species in impacts of industry

Similarly, fig.8.5.10 describes the total number of fish species in both upstream and downstream sites for the impacts due to industries in all the seasons studied in this work (Table 8.5.10). The figure showed more or less consistent differences in number of fish species between upstream and downstream in all seasons.

The data were then subjected to the test of homogeneity of variance, where the same variables, the abundance and the number of species, as described before were tested. The details of the homogeneity test are shown in table 8.5.11. The result of this test showed that all the data of variables are homogenous and consistent, and thus was fit for further statistical analysis.

-225- 8 Results

Test of Homogeneity of Variance

Levene Statistic df1 df2 Sig. Sum of CPUE Based on Mean 2.105 1 188 .149 Based on Median 1.423 1 188 .234 Based on Median and with adjusted df 1.423 1 176.084 .235 Based on trimmed mean 1.487 1 188 .224 Number of fish Based on Mean .032 1 188 .859 species Based on Median .027 1 188 .870 Based on Median and with adjusted df .027 1 187.133 .870 Based on trimmed mean .028 1 188 .868 Table 8.5.11: Test of homogeneity of variance

The next statistical test done was the ‘tests of normality’ where the distribution of the data of the two variables, sum of CPUE (abundance) and number of fish species, in both reference and disturbed sites were tested for whether they are normally distributed. Two methods for tests of normality, Kolmogorov-Smirnov and Shapiro-Wilk were used here and both of them produced the same result (Table 8.5.12). The data of the sum of CPUE, that is abundance had no normal distribution whereas, that of number of fish species was found to possess normal distribution. Therefore, the two variables needed different tests and analysis.

Tests of Normality

cd_place Kolmogorov-Smirnov(a) Shapiro-Wilk Statistic df Sig. Statistic df Sig. Sum of CPUE upstream .188 94 .000 .833 94 .000 downstream .159 96 .000 .877 96 .000 Number fishspecies upstream .091 94 .052 .975 94 .070 downstream .080 96 .154 .975 96 .067 a Lilliefors Significance Correction Table 8.5.12: Tests of normality of variables

8.5.1 Nonparametric Kruskal-Wallis Test (for seasonal variations of impacts): Since the distribution of data of abundance was not found to be normal, nonparametric test, Kruskal-Wallis Test, was done for this variable. The test was performed for the seasonal variations of impact for all the seasons in each of the reference and disturbed sites called here after as upstream and downstream. The Kruskal-Wallis Test for the seasonal variations in impacts due to agriculture for upstream showed the asymptotic significance as 0.984, which is greater than 0.05 indicating that the impacts there were not significant (Table 8.5.13). However, the same test for agricultural impact in downstream produced the value

-226- 8 Results of 0.010, which is less than 0.05 indicating that the seasonal variations in impacts in downstream were significant.

Similarly, this nonparametric test for seasonal variations in the impact of city in upstream produced the value of asymptotic significance as 0.793 and that in downstream as 0.547. These values indicated that the disturbances due to urban growth did not produce significant variations both in upstream and downstream in the rivers studied for this purpose. The test for the impact of dam however produced a mixed result. The value for the upstream was found to be 0.026 and that for downstream was found to be 0.472. These values revealed that among the rivers studied, the seasonal variations in CPUE in upstream were statistically significant whereas in downstream, it was not. Likewise, the same test for the seasonal changes of industrial impact produced the value of 0.229 and 0.259 in upstream and downstream respectively. This means the seasonal variations in CPUE for industrial impacts in rivers were not significant among the cases studied in this work.

Impacts Place Asymp. Significance Agriculture Upstream 0.984 Downstream 0.010* City Upstream 0.793 Downstream 0.547 Dam Upstream 0.026* Downstream 0.472 Industry Upstream 0.229 Downstream 0.259 Table 8.5.13: Values of Asymptotic Significance from Kruskal-Wallis Test for sum of CPUE (for seasonal variations of impact)

8.5.2 Parametric One way ANOVA (for seasonal variations of impacts): As the distribution of data was normal for the second variable, the number of fish species, a parametric tests were done in this case for all the impacts in each site for seasonal variations as was done for the sum of CPUE in nonparametric test. The parametric test chosen here was ‘One way ANOVA’, which is normally done in these cases.

The value of significance for the changes due to the agriculture in all seasons in upstream was found to be 0.972 and in downstream it was 0.630 indicating that there were not significant seasonal variations in impacts in terms of number of species in the cases studied (Table 8.5.14). Similarly, the values of significance in upstream and downstream sites for the impacts of city were found to be 0.530 and 0.165 respectively. These values too

-227- 8 Results indicated that the city had no seasonal changes in impacts in rivers in terms of this second variable among the rivers studied for this purpose.

The values of significance for the impacts of dam in terms of number of species were found to be 0.786 and 0.717 in upstream and downstream respectively. This also meant the same story that there were no significant seasonal variations in impacts if we take the number of species as a variable among the rivers studied. Finally, for the disturbances due to the industries the value of significance were found to be 0.448 and 0.716 in upstream and downstream respectively, pointing towards the same facts as in the other disturbances.

Impacts Place Significance Agriculture Upstream 0.972 Downstream 0.630 City Upstream 0.530 Downstream 0.165 Dam Upstream 0.786 Downstream 0.717 Industry Upstream 0.448 Downstream 0.716 Table 8.5.14: Values of Significances in one-way ANOVA for number of fish species (for seasonal variations of impact )

8.5.3 Nonparametric Mann-Whitney Test (for impacts): After Kruskal-Wallis test another nonparametric, Mann-Whitney test for all the disturbances were also done to see if the impacts were significantly different between upstream and downstream in terms of sum of CPUE. Mann-Whitney Test for the agricultural disturbance in terms of abundance (CPUE) produced the value of 2-tailed asymptotic significance as 0.135 indicating that there were no significant impacts in the abundance of fish due to this disturbance among the river studied (Table 8.5.15).

Test results of this test for the impacts of city on the cases studied produced 2-tailed asymptotic significance as 0.103 also indicating that there were no significant impacts in terms of abundance of fish. Similarly, the test results of the same test for the impacts of dam gave the value of 2-tailed asymptotic significance as 0.853. This value also indicated that there were no significant impacts of dam on the rivers studied. However, Mann-Whitney Test for the disturbance of industries on the rivers studied produced a different result. The

-228- 8 Results

2-tailed asymptotic significance in this case was found to be 0.042 indicating that the impacts from the industries were significant in terms of the abundance of fish.

Impacts Asymptotic Significance (2-tailed) Agriculture 0.135 City 0.103 Dam 0.853 Industry 0.042* Table 8.5.15: Values of 2-tailed Asymptotic Significance from Mann-Whitney Test for sum of CPUE (for impacts)

8.5.4 Parametric One way ANOVA (for impacts): The second parametric one-way ANOVA test was performed to see the differences due to the disturbances in upstream and downstream of the rivers in terms of the number of species. In this second ANOVA, the value of significance for the impacts of agriculture was found to be 0.343, which means that the impacts were insignificant among the rivers studied for this purpose in terms of number of fish species (Table 8.5.16). Similarly, the value of significance for the impacts of city in this method was found to be 0.733, again indicating that the impacts were not significant among the rivers studied for this disturbance in terms of number of fish species.

The results of the analysis for the impacts of dam were found to be no different. The value of significance for the impacts of dam by this method was found to be 0.844 indicating that the impacts were not significant among the cases studied for this disturbance in terms of the second variable. However, the results of the analysis for the impacts of industries were found to be different than others. The value of significance here was found to be 0.011 indicating that the impacts were significant for this disturbance in terms of number of fish species.

Impacts Significance Agriculture 0.343 City 0.733 Dam 0.844 Industry 0.011* Table 8.5.16: Significances in one-way ANOVA for number of fish species (for impacts)

-229- 9 Discussion

CHAPTER IX: DISCUSSION

9.1 Distribution, abundance and density of fish:

Biota at any place is the product of evolutionary and biogeographic process (Karr 1991; Westra 1995). It means that the resident biota at any site varies according to the geographic region as well as in evolutionary time. Though biota at any place is a dynamic thing, biological integrity refers it as a balanced, integrated, adaptive system having its full range of elements (genes, species, assemblages) and processes (mutation, demography, biotic interactions, nutrient and energy dynamics, and metapopulation processes) expected in areas with minimal human influence (Karr 2000).

Management of water resource requires the analysis of physical, chemical and biological integrity. Monitoring of physical and chemical characteristics of water is quite common, but biological monitoring based on biological indicator is rare. However, the recently proposed index of biotic integrity (Karr 1981) that uses the attributes of fish communities to assess biological integrity to manage water resources is gaining popularity everywhere. The index of biotic integrity (IBI) uses the comparison of fish species richness and composition, and abundance as primary criteria for the evaluation of water quality. At present, further development of IBI has taken place at regional level suggesting that each geographical region has its own unique set of fish species.

In addition, either to initiate conservation programs or to start commercial production of any species of fish, a sound knowledge of its distribution, abundance, ecology and biology are the primary requirements. Although fish base assessment has become a standard and regular method to evaluate the conditions of the rivers and stocks in North America and Europe, it is in the premature stage in most of the developing countries including Nepal. Nepal, with a huge amount of water resources and rich diversity of fish species, has a tremendous potential for fisheries development as well as enormous opportunity to develop fish base assessment techniques.

The inland water resource of Nepal includes natural waters such as rivers, lakes and reservoirs, and also village ponds, marginal swamps and irrigated paddy fields and equals

-230- 9 Discussion

818500ha (Khanal 2001). Out of this, the network of rivers and streams, which are more than 6000 in number alone covers around 395000ha of surface. In total, the length of rivers and its tributaries in Nepal exceeds well past 45000 km mark. Similarly, a total of 182 species of fish belonging to 93 genera under 31 families and 11 orders has been reported from Nepal (Shrestha 2001). The high diversity of life forms including fish in Nepal is mainly attributed to its unique location and spectacular geography.

Some information on ecological and population characteristics of the fish, such as region and altitude of occurrence, habitat preference, temperature range, maximum length, feeding habit, life history and a crude status of many of the fish species are available. However, the information is still not in the state that a scientific fish base assessment such as IBI could be directly applied. The list of fish species from very large as well as some important rivers from Nepal has been developed by various authors. Rajbanshi (1982) developed the first list of fish base work in Nepalese rivers and some of these works carried the species lists. Talwar and Jhingran (1991) have number of fishes from Nepal mentioned in their work. Similarly, Shrestha (1990 and 1995) has also listed the fish species from the number of rivers and streams.

Edds (1993) studied the first spatial and temporal patterns of fish assemblage composition in Gandaki River and found that the highest numbers of species (33 species) were found in the lowland site. However, the first descriptive list of the fishes of Nepal in the regional basis was made by Shrestha (1994), which was also used as one of the key for identification of fish in this work. In 1995, she worked for the Department of National Parks and Wildlife Conservation and IUCN, Nepal to enumerate the fishes of Nepal, where a threat category were tried to assign to each species. She also came up with another list in ‘Coldwater fish and fisheries in Nepal’ (1999). Similar kind of list with more or less same title was also worked out by Swar (2001).

The same year Rajbanshi (2001) presented a paper with title ‘Zoogeographical distribution and the status of cold water fishes of Nepal’. Shrestha (2001) again made the taxonomic revision of all the fishes of Nepal. Sharma and Shrestha (2001) studied fish diversity and fishery resources of Tinau, which is an important river in this study. Thus, there are a fair number of lists of fish from different regions and rivers in Nepal but most of them are not quantitative. Seasonal variations on the species composition for the rivers and regions are

-231- 9 Discussion hardly mentioned. Many of the list mentioned above is also based on secondary data. However, the present work is based on primary data collected from the fieldwork mainly in the rivers of Central and Western Developmental Region of Nepal for one complete seasonal cycle.

Among the rivers studied in this work, Narayani River, the main channel of the Gandaki System has been perhaps the most studied river in Nepal. Since the main river has hundreds of tributaries, it is often confusing on the total number of species found in the river. Even in this work, out of nine rivers studied six belongs to Gandaki system. The number of species recorded from Narayani River varies among authors. Shrestha (1999) reported 35 species from this river, but then they were mentioned as coldwater species. Rajbanshi (2001) has mentioned around 47 species in this river but there is no discrimination between coldwater and warm water species. Similarly, Swar (2001) has also mentioned 35 species from this river as coldwater species. The number of species in this river recorded during this work was 32 and was the highest among all the rivers. In any case this number is not significantly less if we consider that due to the size of the river the fishing was possible only in the bank and that too just in three sampling sites.

East Rapti, one of the tributary of Narayani River recorded 30 species during this study period. There are some studies regarding fish in the river as it flows through the National Park, but again the number of species is not consistent. Rajbanshi (2001) has listed 41 species from this river. Once again, the number recorded here though less is not so less enough as the sampling sites were just two. Similarly Tinau River was found to possess 29 fish species during this work from six sampling sites. The number is very near to the one mentioned by Sharma and Shrestha (2001) for this river.

Arungkhola had the next highest number of fish species recorded in this work at 27 and signified that how small rivers like this are important for the fish diversity. No prior records regarding the fish fauna were available for this river and thus, the number mentioned above should hold good till the next study. Likewise, Karrakhola was found to consist of 25 fish species. There might be a few studies of fish in this river especially as a master’s dissertations, but an authentic record was still missing. Aandhikhola and Seti River both recorded 18 species each during this study. For Aandhikhola, no list of fish fauna were found though some of the species were found mentioned in UNDP (1978), while Seti has a

-232- 9 Discussion several list. According to Rajbanshi (2001) the river consist of only 7 fish species and thus, the species recorded in this study was significantly high.

Jhikhukhola a small tributary of Koshi System was found to possess 12 species from two sampling sites. Once again, there were no records of the fish from this river available and this number should hold good for sometime to come. Bagmati River due to its religious significance and the location on the other hand is one of the most studied rivers in Nepal. Several lists and records of fish fauna for this river are available. The latest one by Shrestha (2001) recorded 21 fish species from this river whereas; during the present study only 3 species were recorded. The high number of fish recorded by various authors may be due to the extensive sampling sites particularly after the river recovers itself from one of the worst pollution case and the historical evidences. If any recent list mentions a high number of species in this river before it enters urban area of Kathmandu then it must be highly inflated.

Seasonal availability of some important fishes in some rivers of Nepal could be found mentioned in the number of literature, but a detail seasonality of all the fish in specific rivers are wanting. This could be a new work in this direction where all the fish in the studied rivers are accounted for their temporal behavior. Some species like N. hexagonolepis, P. conchonius, P. sophore, B. barila, B. bendelisis, B. vagra, G. gotyla gotyla, A. botia, S. beavani, S. rupecula, L. guntea, A. mangois, C. punctatus and M. armatus were found almost in all seasons in the rivers they were recorded, while some species such as G. chapra, C. reba, P. chola, S. semiplotus, T. tor, N. chelynoides, A. morar, B. barna, D. dangila, C. latius, P. pseudecheneis, C. garua, G. pectinopterus, G. trilineatus, P. sulcatus and G. giuris showed some to high degree of seasonality.

The work done regarding the abundance and density of fish species in Nepalese rivers are very few. Shrestha (1995) while working together with Department of National Parks and wildlife conservation and IUCN had assigned different threat categories to the fishes of Nepal. Her work should include some quantitative analysis but is not mentioned. Thus, there is no concrete basis for assigning threat categories to different species on one hand and to assess the fisheries potential on the other hand. This study has calculated the abundance measured in CPUE, that is, number of fish captured in 10 minutes of electrofishing of all the fish species recorded during this study (Table 8.1.3). Some of the fishes assigned as common by literatures might not be so as was found in this study.

-233- 9 Discussion

The study also showed that the small rivers could not be ignored for potential of fisheries as the rivers like Jhikhukhola and Arungkhola were found to possess high abundance of fish. Relative low abundance of fish found in Narayani river could be due to the fact that the river could not be waded properly and was restricted to shoreline only. Less abundance of fish in Bagmati River was probably due to its geographical region as it was at the highest altitude. Normally, cold and oligotrophic water possess less fish than the warm water lowland rivers.

Density of fish calculated in this study is just to have an overview and should not be taken as hard data. The calculation of density requires the measurement of area accurately using digital devices. The area calculated by taking manual measurement of length and width of the river would only give a rough estimate. In any case, the exact calculation of the area of the river is extremely difficult and thus to decrease the margin of error it was calculated in 100 m² instead of general practice in hectare. The density of fish as was shown in table 8.1.4 appeared relatively less but could be explained by that it is the density of fish in natural conditions and in absence of stockings. Again, the density of fish shown for Narayani River in the table could be with error but for other rivers it looked fine and healthy.

In short, the species richness, composition, abundance and density of fish vary greatly among seasons and rivers. Thus, assessing the fisheries potential and assigning threat categories according to the distribution and abundance described above should be started for conservation and management of the aquatic resources.

9.2 River classification based on biotic and abiotic factors:

The use of cluster analysis to classify and group various ecological entities for better management and conservation is a common process these days in all parts of the world. There are several examples of these kinds of works in the field of aquatic ecology as well. Eekhout et al. (1997) classified the rivers in South Africa using this tool. In Japan too, river system were classified from a landscape ecological aspect using cluster analysis (Nakagoshi and Inoue 2003). While assessing benthic macroinvertebrates in stream ecosystems, Park et al. (2004) also used this tool. In India, Singh et al. (2004) also used this tool to see spatial and temporal variations of water quality in Gomti River.

-234- 9 Discussion

This work is the beginning of the use of cluster analysis (CA) as a tool to classify the rivers and river systems in Nepal. Nepal consists of 4 main drainage basins of Koshi, Gandaki, Karnali and Mahakali representing different regions of the country. In addition to these, there is a network of southern rivers and Mahabharat rivers in each regions (Sharma 1997). The rivers are classified according to origin and geology but hardly with their biological characteristics. This work to a large extent proves that the species richness and the abundance could be utilized as variables to classify the Nepalese river system for the management and conservation purpose. The result as could be seen in the cluster analysis was amazing as it is exactly the copy of the classification from origin, region and geology.

The six rivers studied in this work belongs to Gandaki system and this analysis showed all six of them, Aandhikhola, Seti, Arungkhola, East Rapti, Karrakhola and Narayani were comparatively closer with each other than the other rivers. Even within that it was interesting to see how Arungkhola, East Rapti and Karrakhola, which originates from lower Mahabharat and mainly flows through lowlands with similar structure formed a cluster. The group of six was found to be little different than the independent system Tinau, though the region was same. They were more different than Bagmati as it another independent system from another region, and there was the highest difference with Jhikhukhola which is a small tributary of completely different river system. Thus, this kind of fish base classification was found to work in the Nepalese situation.

Similarly, the application of Canonical Discrimination Analysis (CDA) is increasing rapidly in all sectors to classify or group any set of entities. It is especially common when there is a huge pool of data and high number of variables. Pitkanen (1998) in the work on classification of biodiversity in managed forest used this analysis to determine the variables that best describe the classes. Similarly, Lu et al. (2003) used CDA to differentiate successional stages and to identify the best forest stand parameters to distinguish these stages.

The CDA was found to be used in classifying the species from different regions too. Silva A. (2003) in her study in sardine population of two regions used this technique and found that the two groups of sardine were significantly separated by this method. There are many application of this analysis in river and stream ecology as well. Legleiter (2003) worked on stream habitat mapping and used this analysis in conjunction with remotely sensed data.

-235- 9 Discussion

Singh et al. (2004) in their work on spatial and temporal variations in water quality of Gomti River have applied discriminant analysis and found that it showed best results for data reduction and pattern recognition during both temporal and spatial analysis.

The present work used this analysis to classify different rivers and river system of Nepal in the basis of morphological and physico-chemical characteristics of rivers and water. Altogether twelve variables were used from each of the 184 cases spreaded over nine rivers and four seasons. Thus, it made it a huge pool of data normally useful in CDA. The best discriminant variables in Nepalese rivers were found to be altitude, substratum such as boulders, pebbles rock and silt, and other characteristics such as dissolved oxygen (DO) and conductivity.

The variables discriminated themselves making four distinct groups corresponding to the classification available for the Nepalese rivers, Bagmati, Gandaki, Koshi and Tinau. 94.6% correct case for the original group and 93.5% correct case for the cross-validated group indicated that the classification based on those variables are very near to the reality. This also suggested that this method could be extended to other rivers and river systems in different regions once the enough data are collected. In addition, the discrimination analysis for classification helps in the management and conservation of water resource, fisheries resource and restoration of the depleted resources.

9.3 The size structure of sucker head, Garra gotyla gotyla (Gray, 1830):

A. Length frequency distribution: The sucker heads (Garra gotyla gotyla) were found to be one of the most common fish species in Nepal as they were recorded from eight of the nine rivers sampled in this work and in sufficient number. The species was not found in Bagmati River maybe because of the altitude of the sites, which is more than 1560 masl described as its altitudinal range (Shrestha 1995). The species has a much wider distribution below that elevation and is found in the rivers and lakes on the foothills of the entire Himalayan region (Talwar and Jhingran 1991). The status of the species was found to be consistent as ‘fairly common’ described by Shrestha (1995).

-236- 9 Discussion

No previous records of length frequency distribution of this species could be traced from the related literature. However, some authors have mentioned its maximum size. Talwar and Jhingran (1991), Shrestha (1994) and Shrestha (1995) have recorded the maximum size 140mm, 160mm and 150 mm respectively. This work has found the species measuring up to 180 mm, which is a new record. The range of lengths and the distribution of length frequencies together with length-weight relationship showed some variations in space and time suggesting that the habitat conditions, stock size and health, and population characteristics too might vary in different rivers and seasons.

Among the rivers, judging by the numbers of sucker heads captured and length frequency distribution, Aandhikhola was found to hold a good and healthy population. The range of length groups and the highest mean length suggested that the habitat conditions for this species is the best in this river. However, the absence of 20 mm category suggested that the main channel might not be most appropriate for the breeding. Arungkhola and Karrakhola had the similar results indicating the similar conditions for the fish. The presence of 20 mm category in these streams suggested that the habitat conditions are good for breeding but the absence of large adults indicated that the conditions are not favorable for the optimum growth due to natural conditions or some man made disturbances and these adult may migrate to other bigger channels or may be harvested.

Jhikhukhola, which belongs to Koshi River System, also showed a narrow range of length groups just up to 120 mm considerably less than Aandhikhola. In addition, absence of 20 mm group indicated that the breeding ground is not suitable. The absence of larger adults suggested that the conditions were similar to that of Arungkhola and Karrakhola. East Rapti and Seti showed more or less similar situations. Both of these rivers didn’t have 20 mm length group indicating harsh condition or disturbances for spawning. The number of the fish captured in Seti was also very low. The numbers of large adult fish were also less though the maximum sizes of the sucker heads in these rivers were 140 mm and 130 mm respectively.

Narayani, one of the biggest rivers in Nepal was found to hold a good population of this species. The range of the length groups was very high but there was a complete absence of length groups 20 mm –35 mm indicating that the river is not the site of breeding. However, presence of very large adults and the mean total length of the population suggested that the

-237- 9 Discussion habitat conditions here are very good for the optimum growth. Tinau River perhaps was found to hold the best population of sucker heads both in terms of abundance and distribution of length frequencies. The substrate, temperature and good sequences of pools and riffles seemed ideal for this population. It was found to be good for breeding as well as for larger length groups. There were lots of disturbances in the river but still the population was found to be healthiest. The absence of very large adults might just indicate that they are the target of anglers and fishermen.

The temporal variation of the length frequency distribution mainly gave the insight of the breeding season. Breeding season is normally characterized by the presence of lowest length group and the low mean length of the population. Presence of the lowest length group (20 mm) and the lowest mean of the population in premonsoon indicated that the breeding season starts in this time of the year. However, the record of the lowest length group in postmonsoon suggested that the breeding period is quite long starting from premonsoon till the beginning of autumn including the entire monsoon period. Shrestha (1994) had also mentioned the breeding season of this species as premonsoon, but has not mentioned how long it lasts. The mean total length of the population in autumn was higher than in premonsoon.

The winter and the spring seasons completely lacked the lowest length categories and thus, should not be the time of breeding. More over, the mean total length of the population in winter increased than that of autumn and was highest in spring indicating that these seasons are mainly for the growth. Thus, there seemed to be a cycle in the life history of sucker head where the population has the lowest mean of length in premonsoon, which increases gradually in autumn, winter and till the spring.

B. Length-weight relationship: The length-weight relationship was also found to vary in space and time. As in length frequency distribution, there are no records of length-weight relationship for this species and hence there were no comparison to be made. Looking at the relationship in different river systems of Nepal for this species, it was found that Koshi System provided the optimum growth and the stock there were the healthiest. The Gandaki System, from where the largest numbers of sucker head collected were found to be with very fluctuating biomass whereas, Tinau had the intermediate length-weight relationship.

-238- 9 Discussion

The absence of 20 mm category of sucker heads in Jhikhukhola of the Koshi System indicated that the main channel of this river is not so suitable for the breeding, but presence of higher length groups suggested that the river might be very suitable for the growing fishes. As the river flows through highly agricultural area, there could be very high amount of nutrient in the river due to overflow and hence the optimum growth of the species. However, there was only one river from Koshi system that had been sampled and that too in the highly agricultural area, more rivers and streams of Koshi System has to be sampled to make comparison with Gandaki System, which already has the sample from six different rivers.

The length-weight relationship of the species from the Gandaki System should be very near to the normal relationship due to many reasons such as, the high number of sampled rivers, the high number of the species collected, and the presence of all the length groups. Seasonal variations in length-weight relationship of the sucker heads here showed interesting regressions and revealed the aspects of life history as well as the period of stress. Tinau river, with the largest number of sucker heads recorded during this work and with intermediate but good length-weight relationship was found to hold good stock and biomass. The unusually low number of the fish species recorded in premonsoon season due to massive poisoning, however has decreased the correlation and increased the standard error (R² = 0.67420788 and Std. Error = 0.0010), suggesting that more sampling has to be done in the river.

The highest biomass was found to be in premonsoon. The first reason for that is the optimum growth of gonads as it is the beginning of the breeding season. The other reasons could be the warm temperature and the high availability of foods and organic matter. The autumn had the weakest relationship and hence the least biomass except in the Jhikhukhola of Koshi System. It is simply because it marks the end of breeding season and hence the gonads are emptied. In addition, the stocks have to face massive floods due to monsoon and are in great physiological stress.

Winter and spring had an intermediate length-weight relationship. Between autumn to winter, the sucker heads were found to gain weight rapidly, but between winter to spring they marginally lose the weight. It may be due to the plunge in temperature and subsequent coldness that puts them in some kind of physiological stress. However, after spring another

-239- 9 Discussion phase of gaining weight was noticed which peaked in premonsoon season. After spring, temperature gradually increases and so are the foods and nutrients in water.

Garra gotyla gotyla has a potential to become more than minor fisheries in Nepal as could be evident from its distribution and abundance. The information regarding its habitat condition, life history, abundance, health, biomass and other population characteristics are important to raise it into a major fishery program. The most important parameters to gather that information are the length frequency distribution and the length-weight relationship. This study has tried to give some baseline information on the sucker heads regarding these parameters. Like in any natural fish population, these two parameters were found to vary in space and time for this species as well. And a careful study of this information should help to estimate its abundance, growth, health and stock size, which are so important in fisheries management.

9.4 Assessment of integrity of the river system:

As mentioned before (Chapter II), integrity is a difficult and tricky concept, which changes in time and space. Integrity, normally, means pristine and natural state without human interference and there are hardly any information regarding fish communities of rivers in that state anywhere in the world. The characteristics of the rivers and streams, particularly, fish communities that indicate the integrity today might be very different from the characteristics in historical times. In the absence of historical data regarding fish communities from all the rivers studied in this work, it was difficult to make comparisons and to assess the integrity of the systems. However, it is accepted in this work that whichever section of the sampling sites showed better fish community structure are better in integrity.

Another difficulty to assess the integrity of the river systems is related with the spatial dimension of the integrity. In general practice, two sampling sites, reference or upstream site and disturbed or downstream sites are sampled in river ecological studies and the comparisons are made referring reference sites as the one having ecological integrity. However, depending upon the conditions, there are disturbances, which affects the upstream more to lose their integrity. In any case, running waters are now seen as 4-phase system

-240- 9 Discussion with horizontal, vertical and lateral interactions together with temporal interactions, and the integrity is lost if one of them gets disrupted.

Thus, in many cases where the disturbances in river systems are studied, choosing a reference site is becoming increasingly difficult. In the country like Nepal, it is even more difficult as even a short distance at many places, mark a big topographical differences, which is associated with series of other differences in both biotic and abiotic factors. Hence good comparisons cannot be made between reference and disturbed sites. In addition, if the reference sites are taken too far away upstream, multitude of other disturbances are added in its course and the case can no longer be the study of a specific disturbance. For example, the reference site should not be established at Sundarijal in Bagmati River to study the impacts of disturbance in the same river when it enters the plain.

This study also fixed upstream and downstream sites for each disturbance in each river. The upstream or the reference sites were fixed a little distance before the disturbance to avoid regional differences in fish communities for fair comparison. However, for the study of agricultural disturbance, the distance between upstream and downstream sites were quite high as the disturbances come from large fertile areas. Comparisons between upstream and downstream sites were made to see if there were any differences in some fish population characteristics. If there are substantial variations between them then it is generally accepted that the particular disturbance has the potential to alter the integrity of the river system.

There are relatively few literatures regarding the disturbances and specific fish base analysis of water quality and river conditions of Nepal, except for some EIA reports. Sharma (1996) and Khanal (2001) worked on water quality and various disturbances on the rivers by taking biological indicators, but macrozoobenthos. Similarly Ormerod et al. (1997) did river habitat survey of many rivers in Nepal but used diatoms, bryophytes, invertebrates and birds. However, some authors have generalized the impacts of various disturbances on fish communities. A report prepared for UNDP (1978), has discussed the effects of dams on fish population and had recommended the fish passing facilities in dam constructions. Edds (1993) while working in Gandaki River concluded that the fish assemblage was influenced by geography, water quality and stream hydraulics. Shrestha (1994) has mentioned about erosion, deforestation, industries and dams as major threats to fishes in Nepal.

-241- 9 Discussion

Shrestha (1995) has described the effects of various man made disturbances such as dam construction and pollution on the fish population. Shrestha (1999) has described soil erosion, dam construction, chemicals, and over exploitation among others as the main cause of the decline of fishes. Rajbanshi (2001) has mentioned industrial activities, construction of dams and overfishing as the reasons for the depletion of the indigenous fishes. Swar (2001) also listed silt, chemical pollution, introduction of exotic species, over and illegal fishing and hydraulic engineering as the main causes of the decline of natural fish communities. Meanwhile, Sharma and Shrestha (2001) have studied the impacts of dam in Tinau River and found that it is affecting the fishes adversely.

However, there are so many works regarding the field from elsewhere of the world. Assessment of river quality through fish assemblage, though started earlier was established by Karr (1981) in the form of Index of Biotic Integrity (IBI). Angermeier et al. (1986 and 1994) mainly improved the methods of sampling and interpreting the results. Fausch et al. (1984) modified the application of IBI on regional basis with the main hypothesis that as human society degrades watersheds, the aquatic communities they support are modified to varying degrees. Latter he studied the general environmental degradation by taking fish communities as indicators (Fausch et al.1990).

Hughes and Gammon (1987) in their study found that a modified IBI appeared to reflect changes in fish assemblage patterns and habitat quality better than the other indexes. Miller and Leonard (1988) studied the regional application of IBI and found that it holds promise for direct biological monitoring because of its strong ecological foundation and flexibility. Similarly, Oberdorff and Hughes (1992) modified IBI to use in France and found that it would offer a reliable means of assessing spatial patterns and temporal trends in water body improvement or degradation in France. Lenat and Crawford (1994) studied the effects of various disturbances on water quality and aquatic biota and found that the abundance of some fish species and average size increase at the agricultural site whereas, urban site was characterized by low species richness, low biomass and the absence of intolerant species.

As mentioned before (Chapter VI), four types of disturbances – agriculture, city, dam and industry in rivers were studied in this work. All disturbances had three examples making 12 cases, and each case was studied for four seasons, thus, making it 48 cases in total. The results are discussed below according to the disturbances.

-242- 9 Discussion

9.4.1 Disturbances due to the Agriculture: Study of the of the agricultural disturbance on the integrity of the river system or simply the effects and impacts in the running water by taking fish as an indicator is widespread in the world, particularly in the developed countries. In fact, the first application of index of biotic integrity (IBI) was to assess the integrity of the river flowing through highly fertile agricultural land (Karr 1981). Since then, a number of fish base studies on agricultural impacts has been done. Foy and Kirk (1996) studied the relationship of water quality measured on a fisheries ecosystem scale with the stocking rate of grazing animals and found that the manure produced significantly increased biological oxygen demand (BOD). Thus, it is not only the chemicals such as pesticides and fertilizers coming from agricultural areas but also organic wastes from livestock have impacts on the rivers and streams.

McCarthy et al. (1997) studied the bioaccumulation of various chemical compounds in fish tissues coming from agriculture and industries in Slave River of the Northwest Territories in Canada. Mensing et al. (1998) found that the fish diversity and richness generally decrease with increasing cultivation in the landscape. In one of the study in Honduras, Kammerbauer and Moncada (1998) found that in river water samples, more pesticides residues at higher concentrations were associated with areas of more intensive agricultural production. In Nepal too the similar situation is found in the areas of intensive agriculture but more studies are needed in this direction.

In Mexico, Soto-Galera et al. (1998) found that 50% of the sites in Rio Lerma Basin were no longer capable of supporting fish and one of the reasons behind was agricultural development. In one of the study towards the management of wastewater due to industries and agriculture, Liang et al. (1999) studied the accumulation of varieties of chemicals in fish flesh and viscera and found that the viscera played an important role in storing chemicals. Berg (2001) studied fish farms in Mekong delta, analyzed the use of pesticides and found that the farmers growing fish in their rice field used less pesticide than farmers growing only rice. This kind of approach could be very beneficial to Nepal in lowering the intensive use of pesticide, as the paddy is also the main crop in the country.

Bohn and Kershner (2002) in their study regarding aquatic restoration found that non-point source pollutants including runoff from agriculture and livestock grazing accounted for more than half of the United States water quality impairments. In Nepal, the story may not

-243- 9 Discussion be so but the impairments of water quality are high in the areas of intensive cultivation. This study has investigated three such areas with fish as an indicator and the results showed the effects of agriculture were present in those areas. In many African countries, the economy, mainly, depends upon the agriculture and as such pesticides constitute the major contaminants in the river water. In their study about tilapia exposed to organochlorine pesticides Okoumassoun et al. (2002) found significant amounts of Vitellogenin in fish from contaminated sites.

Similarly, Balogh et al. (2003) studied methylmercury (MeHg) in rivers draining cultivated watersheds and found that the land use in these rivers was over 90% row-crop agriculture, and extensive artificial drainage systems deliver runoff and associated solids quickly to local streams and rivers. They also urged for further studies regarding mercury uptake mechanisms in resident fish populations. In a similar study in Brazil, De Oliveira-Filho et al. (2004) studied the susceptibility of fresh water species to copper-based pesticides and fertilizers as they were widely used in agriculture and compared the toxicity to different fresh water species including B. rerio, a fish, which is also found in Nepal.

The literatures cited above represent the state of art regarding the study of agricultural pollution in rivers and streams and their effects on fish population. It is also established from above that the use of chemical fertilizers and pesticides are a global problem and due to their runoffs to the rivers, aquatic species are suffering. Chandroo et al. (2004) even studied whether fish can sense pain, fear and stress and found that they do experience these factors in similar ways as in tetrapods. Thus, it is now well established that the fish population through their various characteristics indicates the degree and extent of impacts due to various disturbances including agriculture.

The significance of agriculture in Nepal’s economy has already been described in earlier chapters. It is a backbone of country’s economy and utilizes large amount of fertilizers, pesticides and organic manures. Thus, it is one of the factors of river pollution, especially, in the areas of intensive cultivation. Three different such cases, Jhikhukhola in Kavre district, East Rapti in Makawanpur and Chitwan districts and Tinau in Palpa district were studied in this work. Some differences in the abundance of fish (CPUE) and total number of species were seen between upstream and downstream sites (Fig.8.5.1 and 8.5.2), but the differences were not decisive. The value of nonparametric Mann-Whitney test for the

-244- 9 Discussion impact of agriculture in terms of abundance of fish in all rivers also showed no significance (P > 0.05). In the same way, parametric one-way ANOVA for the impact of agriculture in terms of number of species too showed no significance (P > 0.05)

However, the impacts should not be generalized as there were visible differences between upstream and downstream in some rivers and in some seasons and these differences were also backed by statistical tests. For example, though one-way ANOVA for seasonal variations between the sites in terms of number of species showed no significance (P > 0.05), the nonparametric Kruskal-Wallis test for the same in terms of abundance showed significant seasonal differences in downstream (P < 0.05). This indicated that downstream site exhibits seasonal differences of the impacts of agriculture. The median value of abundance was highest in spring and lowest in premonsoon (Fig.8.5.3) indicating that due to the lowest flow of water the concentration of the pollutants was highest and thus less abundance. This was further proved by the second variable, number of species, which was lowest in premonsoon in downstream. Nevertheless, the individual cases were found to be different.

For the individual cases, Jhikhukhola downstream consistently showed significantly higher abundance of fish indicating higher productivity probably due to the nutrient input from the agricultural field (Fig.8.4.93 and 8.4.94). The downstream in this river also showed a few more species than the reference sites. Species such as B. vagra, B. rerio, H. fossilis and N. corica were missing from the upstream sites suggesting that they are more suitable to the mesotrophic habitat. However, the high abundance of fish and their richness do not necessarily denotes a better condition as it is well known fact that a cool oligotrophic water supports less number and varieties of fish than the warm mesotrophic water. With this theory, it can be concluded that the upstream sites were better in terms of integrity, though, the productivity was higher in the downstream.

Further, the seasonal variations in abundance also showed interesting picture. The abundance of fish in the reference site was consistent throughout all the seasons of the year, but downstream showed a fluctuating trend. It was highest in winter and lowest in autumn indicating the role of agricultural season and the monsoon. During monsoon due to high current and discharge, the fishes are either drifted away further downstream or the nutrients

-245- 9 Discussion were washed away. Thus, there was a more or less visible impact of agriculture in this river and downstream was found to be a disturbed site.

The second case of agricultural disturbance was that of East Rapti River in the fertile valley and plains of Makawanpur and Chitwan. The impacts of the agriculture were probably least visible in this river compared to other rivers and it may be due to relatively larger discharge of water. The yearly data showed marginally higher abundance and the lower number of fish species in the reference site compared to disturbed site (Fig.8.4.95 and 8.4.96). However, the seasonal pattern in abundance and the species number showed more inclination towards the seasonal climate than the impacts of agriculture.

In the reference site in this river, the abundance was least in autumn just after the monsoon season indicating the flushing of fish population by very high current, while the highest was in the spring when the water is less and cool. The downstream site showed the consistent abundance of fish in all seasons except also in spring when it is exceptionally high. Relatively larger number of species in disturbed sites may be due to various reasons such as the geographical and substrate, downstream connectivity with large river as this river drains in Narayani River some kilometers downstream, and the location as it is in the sensitive area of the National Park. The same thing could also be the reasons for the differences of species composition between two sites. The downstream site showed more of the lowland warm water species.

The third case of agricultural disturbance was that of Tinau River in Palpa district. The impact of agriculture was visible in this river too, but in a different way. Unlike Jhikhukhola, the yearly data (Fig.8.4.97 and 8.4.98) of this river showed very high abundance of fish in upstream compare to downstream, though the numbers of species on both the sites were more or less the same. This fact suggested that it is not only the nutrient content in water is important but also the substrate and other physical factors. The upstream site was a small channel with smaller substrate and the large abundance was mainly due to the small fish P. sophore, which dominated the number. Though, structurally downstream site was better with boulders, rocks and cobbles dominating, it might be due to the chemicals that the downstream site had less number of fish. However, the bigger fish species such as T. putitora and N. hexagonolepis and some catfishes, which prefer the structured habitat, were never present in the reference site.

-246- 9 Discussion

Seasonal abundance was consistent in the upstream site suggesting the least impact of the chemicals coming from cultivated areas, whereas, the fluctuation of abundance in downstream corresponded with the general agricultural practice of the people and hence suggesting its impact. Both the abundance and the number of species in downstream were lowest in premonsoon season, indicating the high concentration of toxic chemicals in water due to low flow. The number of species recorded in this season was merely 5, which in favorable time was recorded as high as 16. The best assemblage of fish both in terms of abundance and the species richness were recorded in spring, which follows the winter normally marked by the least agricultural activities. Least agricultural activities mean the least application of chemical fertilizers and pesticides in the field. Marginally better species richness in the downstream, however, could be linked as mentioned before to the better structure of the river.

In short, the study of the impacts of agricultural disturbances produced mixed results indicating that the impacts could not be generalized and the cases must be assessed individually. Nevertheless, the study also pointed that this particular disturbance has the potential to alter the water quality of the rivers and streams, and thereby affecting the integrity of the system.

9.4.2 Disturbances due to urbanization (City): Like the agriculture disturbances, disturbances due to urbanization on the integrity of the river system by focusing on fish too are important and popular studies all over the world, especially, in the developed countries. There are numerous studies in this field, but the studies from Nepalese cities are clearly lacking. Weaver and Garman (1994) studied urbanization and long term changes in a stream fish assemblage, and found that the observed changes were consistent. Even a high-tech ecological assessment using GIS to assess river watershed had included fish health as one of the indicator (Zandbergen 1998). It must be because fish based characteristics are good indicators of water quality and conditions. The disturbances due to urbanization, particularly, sewage inputs in the rivers and its impact was one of the main areas studied by Penczak and Kruk (1999). They found a high correlation between them.

Wichert (1995) found that better waste water treatment and management allowed sensitive species to colonize. In one of the studies by Miltner et al. (2004), they found that the

-247- 9 Discussion biological health of lotic communities was negatively correlated with the amount of urban land use in the surrounding watershed. This highlights the rational of including the study of the impacts of city by taking fish as an indicator in Nepalese rivers. Bohn and Kershner (2002) also found that one of the major non-point source pollutants comes from runoff from municipalities and is the cause of water quality impairment. This also supports why there was a need to investigate the effects of cities in the rivers in Nepal.

Nepal is still a predominantly rural society, but there has been a tremendous growth of urbanization, especially, in past few decades. The numbers and sizes of the urban centers in Nepal have already been discussed in earlier chapters. However, one point to stress is that the cities in Nepal are, generally, growing haphazardly without many facilities like sewage and sanitations, sufficient water supply and efficient waste management. The lack of these basic municipal facilities puts enormous burden on nearby rivers and streams as they are seen as the remedies for all. This is why the study of impacts of cities on the rivers was included in this work.

Three different cases, Narayanghat, Butwal and Pokhara were studied to see their impacts on rivers Narayani, Tinau and Seti respectively. There were not substantial differences observed between upstream and downstream both in terms of the abundance and species richness (Fig. 8.5.1 and 8.5.2) in the first glance except that both of these variables were, marginally, less in downstream sites. The nonparametric Mann-Whitney test for the impact of cities in terms of abundance of fish in all rivers too showed no significance (P > 0.05). Similarly, parametric one-way ANOVA for the same impact in terms of number of species also showed no significance (P > 0.05). This indicated that, overall, the cities studied here have not impaired the water conditions in the respective rivers.

The seasonal variations of the impacts too were proved not significant in terms of abundance of fish by nonparametric Kruskal-Wallis test (P > 0.05). In the same way, one- way ANOVA for the seasonal variations of the impacts in terms of number of species was no different (P>0.05). Thus, all the statistical hypothesis tests uniformly showed that there were no substantial differences between upstream and downstream sites for this impact and thus, these cities have not impaired the integrity or the conditions of corresponding rivers.

-248- 9 Discussion

When seen individually, there were marginal differences between upstream and downstream in Narayani Rivers in yearly data in terms of both the variables (Fig.8.4.99 and 8.4.100). This proved that though, slightly, the upstream site still had a better condition. This was further proved by the presence of the species like S. richardsonii and T. tor, which normally prefer cool and less contaminated water in the upstream site. Further, the seasonal variations in two sites showed the abundance of fish always higher in the reference site compared to disturbed site except in spring season when it was lower. This could be because the downstream site had a little warmer temperature than the upstream site.

The second example of the impact of urbanization studied was that of Pokhara city on Seti River. In fact, the yearly data of impacts in upstream and downstream in this river showed a little bit reverse trend. Though the differences between upstream and downstream, in terms of both the variables, were not so substantial, it was, slightly, in favor of downstream (Fig.8.4.101 and 8.4.102). Again, the same law, that the fish assemblage all the time does not, necessarily, show the better conditions might be applied here. The upstream site with cool oligotrophic water directly coming from the Himalayas were expected to support less fish than a more warm and nutrient enhanced water in downstream.

Another reason for the fish assemblage to be higher in downstream was also because of the connectivity of this river with other major rivers, while the upstream is completely cutoff due to a weir just before the city. The species missed in reference site such as A. botia, B. rerio, C. orientalis, D. dangila and H. fossilis also indicated that the downstream had more nutrients. However, in any case, the differences were not so big and this meant, surprisingly, that the city of Pokhara has little impact on the integrity of this river.

The seasonal differences in the abundance of fish in upstream and downstream site showed interesting picture corresponding with hydrological regime and temperature rather than the impacts of the city. The abundance of fish was found to be, comparably, higher in upstream in premonsoon season while it was reverse in autumn, when downstream had more fishes. Premonsoon, normally marked by high temperature and low flow showed water shortage in the downstream, especially, due to the diversion by a weir some distance after the upstream site. Thus, there were more fish in upstream due to more water and warm temperature. In autumn, the season just after monsoon, the water flow was not a constraint in downstream

-249- 9 Discussion and hence showed the larger abundance of fish. Also, by autumn, the temperature declines and some of the species have to find warmer water.

Another example of the impacts of urbanization studied was that of Butwal in the bank of Tinau River. There were clear differences between upstream and downstream in this river both in terms of abundance of fish the number of species (Fig.8.4.103 and 8.4.104). The fish based indicators showed a clear picture of impacts in this case. The yearly data showed a huge dip in the abundance of fish in downstream indicating that the conditions there were not good. Similarly, the number of species too was considerably low highlighting the serious impacts of the city. In addition, the missing species such as B. rerio, C. latius, G. pectinopterus, G. telchitta, L. dero, N. corica, N. hexagonolepis, P. sulcatus and T. putitora indicated the poor water quality. The reference site, in this case, clearly had the better water quality and structure.

Seasonal differences in the abundance and species richness between reference and disturbed site were also big and consistent in all seasons except premonsoon. This further confirms the serious impacts of Butwal city in this river. If, the impacts were not so grave, the abundance and number of species surely would have fluctuated according to water regime and fish life history. However, premonsoon was an exceptional case that year because a massive poisoning of the river to collect big volume of fish was reported just about a week before the sampling in this season. In fact the abundance of fish in disturbed site was higher in this season indicating that tolerant species survive more in such incidents.

In short, the study of the impacts of city on the river also produced mixed results indicating that the impacts could not be generalized for all the cities. The cases must be assessed individually as was shown by this study. Though hypothetical tests showed no significant impacts in both the sites in any seasons, the case of Butwal city showed that some visual judgments could produce better result than the statistics. There were no visible impacts of city in Narayani River because of the couple of reasons. First, the river is one of the largest rivers of the country and has a great carrying capacity. Second, the city has grown across the river and not along the river, which limits the interaction of the city and the river to a very small area.

-250- 9 Discussion

Some impacts of Pokhara city on Seti River were very much expected as it flows through the heart of the city. But surprisingly, here too no substantial impacts were detected. The reasons behind this must be the source of water, which is clean and directly coming from the mountains with high carrying capacity, and connectivity of downstream with other rivers. However, Butwal city gives a clear account of the impacts of city on the river. It was such a remarkable difference within a very short distance. The upstream site was just a kilometer before the main city in the river and downstream always had been the point from where the river gets underground and disappear. In fact the river is seen braded into a number of channels and all get terminated midway through the city. This area was also marked by open toilets, haphazard slums and massive gravel extractions. Thus, the impacts seen on the river was fully expected.

9.4.3 Disturbances due to dams: Another important disturbance having potential to influence the integrity of the river system is the construction of dams and weirs. Judging by the researches done on the impacts of dams on the river world wide, their significance in changing the ecology of aquatic systems is well established. Thus, it could not be ignored in Nepal as well since the biggest resource of the country is water. In his study regarding the conservation of native fresh water fishes Moyle (1995) has described that the construction of dams and reservoirs in every major stream in California is the main reason for depleting fish resources. In Nepal, the result might be the same but the studies are required.

Brain and Kinsolving (1993), in their study have found that the longitudinal pattern of species occurrence and fish abundance was consistent in the free flow river, while inconsistent in the river with dams. In their study, Rinne and Stefferud (1999) have also acknowledged the marked alteration of historic hydrology by dams and diversions. When hydrological regime is altered, then the entire aquatic ecosystem too is changed. Jager et al. (2000), in their description of population viability analysis of riverine fishes have mentioned about the conflicts between cost-efficient hydropower and the protection of riverine fishes. This also indicates that the construction of dams inevitably affects the fish population and thus, the fish population studies reveal the degree of severity.

Hagglund and Sjoberg (1999) likewise have studied the effects of beaver dams in forest streams but unlike others, they have concluded that these dams might enhance fish species

-251- 9 Discussion diversity. This indicates the natural soft barrier, sometimes, increases the types of habitat and so increases the diversity. However, once the size and material of the dam changes, the adverse effects to fish population get started. This could be seen from the work of Howard and Layzer (2002) in large regulated river, where they observed that significant differences occurred temporally and spatially. They also concluded that downstream sites were more diverse and supported higher abundance indicating that the upstream is affected more by the construction of dams in terms of fish population.

Jackson and Marmulla (2001) have also pointed the mixed nature of impacts of dams in their work. In one hand, they say that there are negative impacts of dams on the native fishes, but on the other hand argues that the reservoir created could be utilized well with exotic commercial species. However, Larinier (2001) concludes that the construction of dams on rivers block or delay upstream migration and thus contribute to the decline and even the extinction of species that depend on longitudinal movements along the stream continuum. Further, he lists, habitat loss or alteration, discharge modifications, changes in water quality and temperature, increased predation pressure as well as delays in migration as significant issues, all affecting the fish resource.

Fish base evaluations for the disturbances such as dams are very useful as was found by Penczak and Kruk (1999). In fact, they have concluded that the abundance/biomass comparison method is applicable for detecting all human impacts on fish population. Thus, the fish based analysis done in this work is a standard method to detect the impacts. The literature cited above illustrates different aspects of fish base studies of the impacts of dams in different parts of the world. However, this study could be the first of this kind from Nepal.

The importance of dams for power and irrigation in Nepal has already been discussed in earlier chapters. In fact, the future of the country largely depends on the utilization of water resource and for that the construction of dams will continue for sometime until the alternatives are explored. Three different cases of dams for their impacts by taking some of the fish base characteristics were studied in this work. The dams in Aandhikhola River at Galyang, Syangja, in Bagmati River at Sundarijal, Kathmandu and in Tinau River, Palpa are the three cases. Some similarities of these dams are that all of them are not a massive construction and also not new.

-252- 9 Discussion

There were not visible differences in terms of both the abundance and the number of species between upstream and downstream sites of the dams as seen through box plots (Fig.8.5.1 and 8.5.2). Similarly, nonparametric Mann-Whitney test showed no significant impacts due to the dam in terms of the abundance of fish (P > 0.5). The parametric one-way ANOVA test in terms of the number of species too showed no significance. This indicated that if all the cases are seen together, no significant impacts due to dams were apparent. However, as already mentioned before, individual cases should be analyzed in both spatial and temporal (seasonal) basis to see the clear picture of the impacts.

Accordingly, significant seasonal variations in impacts were shown by nonparametric Kruskal-Wallis test in the reference sites in terms of abundance (P < 0.05). This meant that the conditions in upstream sites were not stable temporarily, which further indicated that the fish and fisheries were highly affected in upstream. Amazingly, the upstream of the dam was only the second instance of significant impacts shown by this hypothesis test after agriculture downstream in this study and hence must be very important. Though, the one- way ANOVA test for seasonal variations of impacts of dams in terms of the number of species did not show any significance in either of the sites.

Most importantly, the individual cases normally showed some kind of better conditions in downstream rather than upstream in terms of both variables. The yearly pictures of fish attributes in upstream and downstream of dam in Aandhikhola showed more abundance as well as richness in downstream indicating that the dam has restricted the upstream migration of the fish (Fig.8.4.105 and 8.4.106). It also seems that the fish ladder built at the side of dam is not working, but this needed to be verified. The good abundance and richness of fish in downstream could be because the river is connected with one of the largest river of Nepal, Kali Gandaki further down. However, the situation in upstream was not so bad as was expected in terms of these variables and this could be because the river could maintain a fine structure of its banks and substrate.

The seasonal variation of abundance and number of species between upstream and downstream in Aandhikhola was interesting to note. There was a big difference of abundance in premonsoon season in favor of downstream indicating that the fish from Kali Gandaki were migrating in Aandhikhola, though water flow was minimum in this season, probably for spawning. In other seasons, there was not substantial variation in the

-253- 9 Discussion abundance. In terms of number of species, upstream was rather consistent in all seasons but in downstream in autumn it was too low. This consistency of species richness in upstream meant that the fishes are either resident or they are restricted from traveling due to the dam. On the other hand fluctuations in downstream indicated that there were to and fro movement of fish species between Kali Gandaki and Aandhikhola.

The second case of disturbances due to dam studied in this work was that of Bagmati River at Sundarijal. There lies one of the oldest dams of the country. The result of this dam was just opposite of the first case, which means, highly in favor of the upstream if we take the fish attributes as indicators. The yearly data of the study in this river showed that the abundance of fish was significantly higher in upstream site compared to downstream indicating that the upstream has better conditions than the disturbed site (Fig.8.4.107 and 8.4.108). However, the number of species in both the sites was too low with just 3 and 2 species respectively. This value of species richness is too low to talk about even though the cool water in high altitudes supports less number of fish. Good news for fish communities in these sites is that they lie inside Shivapuri National Park.

Too less abundance in downstream of the dam in this case was probably because of the low flow due to diversion and lack of connectivity with other tributaries further down. The river once it reaches Kathmandu Valley, gets so polluted that it is virtually impossible to trace any fish communities, thus, further disrupting the longitudinal corridor within the same channel by the pollutants. In any case, it is even difficult for fishes to reach the base of the dam, naturally, also due to steep gradient and in low flow the river at some places appear as a water fall.

The seasonal differences of fish attributes between upstream and downstream were found to be consistently in favor of upstream. The biggest difference between two sites was in winter season and the least (almost equal) in premonsoon. This could be because in winter the fishes come as near to dam as possible to counter the temperature and pre monsoon, most likely, marks the beginning of the spawning time and thus, the fishes move further upstream for that. In any case, there were visible differences between upstream and downstream of the dam in Bagmati River and judging by the fish assemblages, the upstream of dam was in better condition.

-254- 9 Discussion

The third case study of the impacts of dam studied in this work was in Tinau River in Palpa district. This dam too is small and fairly old. The yearly data of fish assemblage showed little difference between upstream and downstream, marginally better situation in downstream (Fig.8.4.109 and 8.4.110). However, there were some differences between the two sites in terms of species composition. Upstream site was found to possess T. putitora and T. tor, the presence of which generally marks the better quality of water, while downstream site showed up some tolerant lowland species.

The seasonal variation of the impacts in terms of the abundance and the number of species in upstream and downstream of this dam was also interesting to note. The spring season showed no differences of impacts in two sites with nearly the similar abundance of fish and the same number of the species. The impacts were least visible in this season. The premonsoon season on the other hand showed big but mixed differences of impacts between the two sites. The abundance of fish in upstream was too low though the species richness was higher than the downstream site. However, too less abundance in upstream could be because of a massive poisoning in the river just before the sampling. Little higher abundance with less number of species in downstream also suggested that it might be due to high numbers of a few tolerant species, which could withstand the poisoning. In any case the variations here looked more because of this reason than the dam.

The autumn season marked the good recovery of abundance and the species richness in both of the sites indicating that the monsoon that appears between premonsoon and autumn flushed all the residues of the poison and the health of the river was vastly increased. Thus, in this season too there were no visible differences of impacts of dam in the two sides. But in winter, the impacts of dam were most visible. Very less abundance and the number of species in upstream site compared to the downstream site could not be simply related with the event of poisoning and seasonal variations in water regime, but to the effects of dam. And though, in winter the river disappears underground after some kilometers downstream of dams, it highlighted the importance of longitudinal connectivity the floods in monsoon bring about. The very one connectivity was found to be enough to sustain the fish communities in downstream till the dam. The dam however completely blocks the movement of fish upstream and hence was found to put some impacts on the integrity of the river.

-255- 9 Discussion

In short, the results showed that the impacts of dams on the integrity of the rivers and river system too were of mixed nature, depending upon so many factors and as in the case of other disturbances could not be generalized. The statistical backing for the impacts of dams in upstream was found to be very strong in terms of the abundance of species, which were illustrated by the case study of Aandhikhola and Tinau. However, the case study of Bagmati River was found to be just opposite in the fact that there were visible impacts of the dam in downstream site. Downstream large river connectivity, seasonal fluctuations in water regime and the externalities such as poisoning are some of the factors found to modify or determine the impacts of dams. Nevertheless, one thing is surely established by this research, that the dams play a big role in changing the conditions of the rivers and thus affecting the integrity of the systems.

9.4.4 Disturbances due to the industries: The impact of industries in the local water bodies is well established all over the world. In Nepal too, how the industries are related with water pollution was already discussed in earlier chapters. Relatively, more studies on the effects of industries to water quality compared to the other disturbances are reported from Nepal. However, most of the studies focused on physico-chemical and pathogenic aspects of the pollution. Thus, study of the impacts of industrial disturbances on the integrity of the river system is included in this work. As in the study of other disturbances in this work, the fish base analysis of the impacts of industries is also a new field of study in Nepal.

There are so many researches done on the effects of industrial pollutions on fish and fish base analysis of industrial impacts, again particularly, in developed countries. Grant (1997) has mentioned about applying ecosystem principles to all of the industrial activities such as site and building design, landscape planning and site management policies where they have also described the effects of water pollution on fish communities and how to overcome it.

McCarthy et al. (1997), studied the fish tissue to find contaminants, mainly the chemicals coming from variety of sources including industries. Similarly, Liang et al. (1999) studied the bioaccumulation of trace metals in fish, which normally comes out from effluents of some of the industries. Zann (2000) has also mentioned that one of the main reason due to which fisheries are declining is the industrial pollution. Kim et al. (2004) studied the accumulation of cadmium in fish, while Nikl and Farrell (1993) studied the toxicity of the

-256- 9 Discussion wood preservative agent and found the reduced swimming performances due to this agent. Gomaa et al. (1995), studied the distribution pattern of some heavy metals in Egyptian fish organs, highlighting the effects of industrial effluents on fish. Since, fish are the important food resource for human beings, there are numerous such studies where the industrial pollution, particularly, affects fish primarily and to other organisms through the food chain. However, these kinds of studies are yet to get momentum in Nepal.

In their study in the Rio Lerma Basin, Soto-Galera et al. (1998) used fish as indicators of environmental quality, which is mainly degraded by industrial development. Violette et al. (1998) in their study of indicators of biotic integrity in Quebec Rivers, they have illustrated that how industrial pollution affects aquatic communities, especially the fish communities. Schulz and Martins-Junior (2001) used a fish species, Astyanax fasciatus as bioindicator of water pollutions mainly coming from industries. Karels and Niemi (2002) studied fish community responses to pulp and paper mill effluents and found that different species have different sensitivity towards this pollution. One of the case studies of industrial impacts included in this work is also regarding the same industry.

Mrakovcic et al. (1995), in their study discussed the status of freshwater fish in Croatian river systems, which are, generally, marked by industrial pollutions. Similarly, Balik (1995) also studied the status of freshwater fish in Turkey and found that industrial pollution was the main reason of their decline. Detail effects of the various pollutants, especially from the industries on fish and fish populations are well described by Lloyd (1992) in his book titled ‘Pollution and freshwater fish’.

As mentioned earlier, there are very few literatures regarding industrial pollution and its effects on fish community in Nepal, though there are some on the other aspects of the pollutions. There is one study by Pradhananga et al. (1998) that compares the effluent of two paper mills in the country on their effects on local biotic communities. Kharel and Thapa (2003) studied effluent impact of Bhrikuti Pulp and Paper Mill on water quality of Narayani River mainly in terms of physico-chemical parameters. There also exists series of reports on the tolerance limits for industrial effluents discharge into inland surface waters by Ministry of Industry.

-257- 9 Discussion

Though, not an industrial nation, the studies of industrial pollution are important in Nepal mainly because of two reasons. Firstly, the process of industrialization will continue for the development of the country, and secondly, most of the established industries are related with water pollution. Thus, this work has included the impacts of industrial disturbances on the river system of Nepal. The analysis of the health and integrity of the rivers in Nepal with the help of fish communities marks the field of new research and this work is just a starting point. Three different cases of industrial pollution, Shree Distillery on Arungkhola, Hetauda Industrial District (HID) on Karrakhola and Bhrikuti Pulp and Paper Mill on Narayani River were selected in this work for the study.

Differences in the median value of abundance of fish and total number of species were found between upstream and downstream sites for this disturbance when seen from broader look (Fig.8.5.1 and 8.5.2). In terms of both the variables, it was found that the downstream site was more impaired, as is normally found for this disturbance. The impacts from the industries were the only impact studied in this work showing significance by nonparametric Mann-Whitney test (P < 0.05). This meant that there were significant impacts by this disturbance in terms of the abundance of fish. In addition to that, this disturbance was also the only case where parametric one-way ANOVA showed significant impacts (P< 0.05) indicating that the impacts in terms of the number of species too were significant.

However, nonparametric Kruskal-Wallis test for the seasonal variations of impacts in terms of the abundance of fish in upstream and downstream sites showed no significance (P > 0.05) indicating that the impacts were rather uniform and did not fluctuate much according to the seasons. Similarly, one-way ANOVA for the seasonal variations of impacts in terms of the number of fish species in upstream and downstream sites too did not vary much. The generalization that could be made from these tests is that there were significant impacts of industries on the rivers studied and the impacts were uniform all through the year. These facts were also illustrated by the box plots (Fig.8.5.9 and 8.5.10) on the impacts of industries in terms of two variables where except during the premonsoon season for the abundance, all the differences between upstream and downstream are more or less consistent and in favor of the upstream. However, it still looked useful to see the individual cases.

-258- 9 Discussion

Arungkhola, which receives the effluents from the distillery, showed much less impacts than expected as could be seen from the yearly data (Fig.8.4.111 and 8.4.112). The differences of abundance of fish between upstream and downstream sites were negligible and in terms of the number of species there were minor differences. Through this data, it appeared that the upstream site was only marginally better than the downstream and that too if we consider the species composition. The species, such as B. shacra, D. aequipinnatus, M. pancalus, M. blythii and S. semiplotus, which were never present in downstream site but in upstream site indicated that it was still in healthier conditions with good water quality.

The seasonal variations of the variables were interesting to note. The abundance of fish was always higher in upstream site compared to downstream except in the winter season when even the number of species there greatly improved. This suggested that in winter due to warmer water and nutrient availability, many fishes move downstream and colonize the area. Another thing to note here is that the abundance of fish in upstream was not less either. In premonsoon season the case was just found to be reverse. The abundance of fish downstream was too low in comparison with the other seasons and with the upstream. This indicated that due to low flow of water the effluent concentrations in that site increased. The condition must increase the toxicity of chemicals or the Biological Oxygen Demand (BOD) and in either case the abundance of fish declines.

Thus, the case of Arungkhola illustrated the impacts of the industry though the impacts were very less. The impacts of the industry appeared within the carrying capacity of the river. However, the analysis was able to discriminate between upstream and downstream sites and the health or the integrity of upstream site was found to be in better condition.

Karrakhola, which receives the effluents from the entire industrial district of Hetauda, was taken as the second case study in this work. Unlike from the previous case, the effluents received by this river are of mixed nature, which come from variety of industries inside the industrial district as described in the earlier chapters. However, the yearly picture showed little differences in terms of the abundance and the number of species between upstream and downstream sites (Fig.8.4.113 and 8.4.114) indicating either the industrial impact is not significant in this case or the presence of other factors that compensate the impacts.

-259- 9 Discussion

The composition of the species gave some trends of the impacts as some tolerant species such as N. corica and P. conchonius were only present in the disturbed site and the species such as B. barna, E. danricus and P. sulcatus, which were found relatively sensitive only in the reference site. It’s a small trend, which was mainly compensated by the downstream confluence of this river with a larger order river East Rapti, a little distance after the downstream site. The fish from this larger river get access to Karrakhola making it rich in terms of species diversity.

Seasonal variations of the abundance showed some glimpses of the industrial impacts, though it was never very low in both the sites in all seasons. The abundance of fish in upstream site was found to be higher in all the seasons except premonsoon. There could be, mainly, two reasons for this. The water flow in this season was found to be very low in this season and the fishes tend to move downstream towards the confluence with East Rapti. This could be one reason for more abundance in downstream site. The other reason could be the nutrients coming from the effluents of industries. In premonsoon, the concentration of the nutrient increase due to low flow and the fishes seem to feed there. The advantage, they have is if the effluents are not desirable, the fishes can quickly escape to another river as the confluence is very near from the downstream site.

Thus, the case study of Karrakhola for the study of the impacts of industries did not produced an alarming situation as was pointed out by the statistical case. Most of the time the statistical tests of the impacts proved it less significant than the general overlook of the case, but the case of Karrakhola was quite opposite as there were powerful statistical evidence whereas very moderate situations of the impacts. Nevertheless, the case showed some mild glimpses of the impacts.

The third case of industrial disturbance studied in this work was of the Narayani River, which receives the effluents from Bhrikuti Pulp and Paper Mill. Some information regarding this industry and its effluents were already described in the earlier chapters. The yearly picture of the abundance of fish in upstream and downstream of this river showed a big impact matching with the statistical tests (Fig.8.4.15 and 8.4.16). The impacts in terms of the number of species were a little less, though it was a big difference between upstream and downstream in terms of species composition. The downstream site or the disturbed site was found to have a significant impact of this industry. Moreover, the absence of the

-260- 9 Discussion species such as B. bendelisis, B. shacra, C. latius, G. gotyla gotyla, G. telchitta, L. dero, P. pseudecheneis, S. semiplotus, T. putitora and T. tor, some of them even considered as lowland and relatively tolerant species indicated that the integrity of the river at this point was highly threatened.

The downstream site was found to possess highly tolerant species such as C. orientalis, C. punctatus and P. conchonius. The only exception was G. giuris, which was found to be rare in number in this study, was present in this site. The overall yearly picture, in any case, showed a grave situation in this site and it could be a matter of further study to find if the river recovers this impairment further downstream.

Seasonal differences of impacts in terms of the abundance and the number of species consistently showed better conditions in the upstream and impaired conditions in the downstream. The premonsoon season showed a comparatively better situation in downstream site and there could be some reasons for that. It was not sure if the production activities of the industry was very less in this season and hence less effluents coming in or the fishes might find more nutrients in this site in this season. The fish assemblage showed a large number of juveniles in this season indicating that it could be an easy feeding and growing ground because of the nutrients and absence of predators.

In short, the study of the impacts of industrial disturbances produced results that indicated a strong relationship of the industries and the water quality and integrity of the rivers. However, once again the analysis showed that the cases could not be generalized. Sometimes, even the statistical analysis could be insensitive or more sensitive than the actual situations. It was thus, found that the cases should be analyzed individually and the specific changes or trends due to the impacts should be identified before applying any corrective measures to restore the integrity of the rivers.

-261- 10 Conclusions and recommendations

CHAPTER X: CONCLUSIONS AND RECOMMENDATIONS

The main aim of this work was to study the fish population dynamics and to see whether these traits show differences in contrasting disturbance regime so as to develop a tool that could assess the integrity of the river system. Since so many valuable information regarding the both, fish and water, resources were collected from the field for this purpose, the present work has tried hard not to lose the information for the good by utilizing them in the analysis.

The total number of fish recorded during this study was 47, which, by any standard, is not less if we consider that only nine rivers and 23 sites were covered. Yet, it is acknowledged that if River Narayani, one of the rivers studied in this work could be sampled by boat mounted fishing gear, the species diversity could have gone much higher. Still, this river was found to possess the highest number of species among the rivers studied. The lowest number of the species was recorded from River Bagmati, but then the sampling site in this river also had the highest altitude. The national record of 182 fish species is actually spreaded over thousands of rivers, lakes and ponds in different ecoregions of the country.

Among the species, B. barila, B. bendelisis, B. vagra, G. gotyla gotyla, S. beavani, and S. rupecula were found to be most widely distributed species as they were found in all or eight out of nine rivers, which were sampled. This implied that these species are not threatened now and there abundance could be developed into metrics to assess the river conditions. Similarly, G. chapra, C. reba, T. tor, N. chelynoides, A. morar, B. barna, D. dangila, S. progastus, P. pseudecheneis, B. almorhae, C. garua, M. blythii, G. pectinopterus, G. giuris and M. pancalus were found to have very limited distribution and thus could be vulnerable. Some of these species are listed as common by IUCN, and thus require further evaluations. In the meantime, this second group of species too could form a metrics for the evaluation of water and habitat quality of the rivers.

Further, new altitudinal ranges for G. chapra, C. reba, P. chola, S. semiplotus, D. dangila, P. pseudecheneis, M. blythii and S. beavani were recorded in this study than previously recorded indicating that more primary information is required to find out exact distribution ranges of many species. Similarly, the new records of size were also established for the

-262- 10 Conclusions and recommendations following fish species, L. dero, P. conchonius, B. barila, B. rerio, D. dangila, G. annandalei, G. gotyla gotyla, S. beavani, B. almorhae, B. lohachata, L. guntea, G. telchitta, H. fossilis, C. orientalis and M. armatus.

The abundance of all the species in each river was also calculated to see clear picture of their status. The abundance of fish was found to be highest in East Rapti River where as it was lowest in Bagmati River. However, it should be noted that East Rapti is lowland warm water river, which naturally supports more fish and the sampling sites in Bagmati were in considerably high altitude with coldwater. The low abundance of fish in Narayani could be, as mentioned before, the inadequacy of sampling technique in the large river. The other rivers, which were studied in this work, had a fairly good abundance indicating good water and habitat conditions in general.

Among the species, S. beavani, G. gotyla gotyla, S. rupecula and B. barila were found to have good abundance among the rivers sampled. Whereas, B. barna, C. reba, D. dangila, G. giuris, G. pectinopterus, G. chapra, M. pancalus, N. chelynoides, P. pseudecheneis, P. chola, S. semiplotus and Tor tor were found to have very low abundance among the species recorded. By comparing the limit of distribution and the abundance, a fairly clear status of the species could be worked out. This information not only help in the conservation of threatened species, but also give the information about the species which could be harvested sustainably. In the meanwhile, metrics based on rare or intolerant species to assess the river conditions could also be developed in the future.

Besides, the density of all the species in each river was also deducted, though it should be taken as rough minimum estimates. Minimum is, because, it is not possible to capture all the fishes of the area using any gear, even electrofishing. And rough is, because, the calculation of the area in rivers is very difficult and tricky. The best way to calculate the area is by digital map and that was not available for this study. Here the density was calculated as the number of individuals/100 m² of area. The density of fish species in each river would advance the picture of the status on one hand, and on the other hand the information would be very handy on estimating the biomass and standing crop if the information of size structures for each species is available.

-263- 10 Conclusions and recommendations

To help calculate the biomass, an example of size structure analysis was also worked out in this work. The length frequency distribution and length-weight relationship of the fish species have various applications. Not only these analysis help in calculating the productivity of the rivers but also allowed to see some life-history and ecological traits of fishes such as breeding seasons, migrations and period of stress. Thus, the size structure analysis of each fish species in the country is highly recommended.

The fish community parameters and the morphological and physico-chemical parameters were also applied to classify the rivers and river systems that were studied. The results were found to be very impressive as it classified the rivers into natural regional groups. This indicated that the fish population variables and the abiotic factors are efficient to discriminate each other to form natural groups. The application of this kind of classification is tremendous especially in management and monitoring of fish and water resources and is hence highly recommended.

The assessment of the impacts of various disturbances on the integrity of the rivers produced highly encouraging and unbiased results. The results indicated that the prevalent agricultural practices in the country have potential to change the integrity of the rivers as the chemical fertilizers and pesticides, ultimately, finds its way into the rivers. Though the species richness and the abundance of fishes were more in disturbed sites due to the nutrient input, the integrity of the river, which might be defined as the natural state, was found to be degraded. This is a classical example where the high productivity does not always means the high integrity.

Besides, the impacts of agriculture were found to be influenced by morphology and the hydrological regime indicating that the generalization of the impacts was not possible. The impacts were found to be high and low depending upon the substrate as well as the seasons. Thus, river and region specific assessment of this impact is necessary to derive any conclusion and that too should be in all the seasons.

The impacts of urbanization or the cities were found to be the weakest among the cases studied in this work. Among these, the highest impacts were seen in Tinau River that of Butwal city. It might be because in all of the seasons except monsoon the river terminates right in the middle of the city and at this point river was found to be highly polluted. This

-264- 10 Conclusions and recommendations polluted section was still found to possess some highly tolerant species. The downstream of Seti River was found to harbor, marginally, more varieties and abundance of fish and could be attributed to the mild pollution inducted by Pokhara city. This is another example of the fact that the diversity and abundance of fish rather increases in small pollution and that they decrease only when the pollution level is substantial.

The least impact of Narayanghat city on its river is another good example of the ratio of the contact areas of the river and the cities. The city is oriented perpendicularly to the river, thus decreasing the area of contact. Thus, the impacts on the integrity of the river by this disturbance was found to be least among the cases, nevertheless, the fish base metrics were able to show the trends of influences. Thus, the impacts of city could be generalized in the sense that it affects downstream, the degree again depends upon so many externalities.

The study of the impacts of dams also indicated its potential to alter the health and integrity of the rivers, and this time, the effects were found to be more serious upstream. It was found that if there are any permanent or momentary connectivity to other rivers downstream, the impacts of dam were found to be more in the upstream. However, if there is no connectivity downstream, then the impacts are more in downstream like in River Bagmati. In addition, the impacts could be much higher in the beginning of the construction of dams, which could not be seen, as all the cases in the study were quite old. In any case, the longitudinal corridor for the fish migration should be maintained through fish ladders and fish passes.

The impacts of industries were found to be the most serious among the disturbances that were studied. In all the cases there were more or less clear picture of alterations on the fish base characteristics between reference and disturbed sites indicating the influence of industry. However, the degree of impairments was again found to be fluctuating depending upon so many factors. In some cases such as the disturbed site of Arungkhola, the fish community even appears to benefit from the effluents in some seasons. But the main aim of the integrity assessment is to see the deviation from natural and normal conditions, and sudden rise of abundance of fish, sometimes, should also be taken as an indicator of impairments.

The table 10.1 illustrates the summary of the impacts of various disturbances in the rivers studied throughout the year.

-265- 10 Conclusions and recommendations

Disturbances Rivers Site Seasonal impacts Total impact Spring Summer/ Autumn/ Winter premonsoon postmonsoon East Upstream Rapti Downstream * # Jhikhu Upstream * Agriculture Downstream * * ** ** J T Tinau Upstream * * * * Downstream * Narayani Upstream * Downstream Urbanization/ Seti Upstream T City Downstream Tinau Upstream Downstream * * * Aandhi Upstream ** Downstream * Dams and Bagmati Upstream * weirs Downstream * * * ** A B Tinau Upstream * * Downstream Arung Upstream Downstream * * Industries Karra Upstream * ** Downstream # N Narayani Upstream Downstream ** ** ** **

A - Aandhikhola

B - Bagmati River

J - Jhikhukhola Visible yearly impacts N - Narayani River T - Tinau River * - Visible impact # - Visible yearly impact

*- Impacts having statistical significance

Table 10.1: Summary of the impacts in different rivers

-266- 10 Conclusions and recommendations

Based on the above conclusions the following recommendations are made:

• The fish base data of Nepal is still not sufficient as could be seen from several new findings on the distribution of the species. Thus, the studies and research on fish ecology should be highly encouraged. • There is also an urgent need to develop national data bank of fish species specific and river/region specific information, which should be easily made available to anyone who wants to use it. Department of Fisheries could be the right institution to do this.

• There are various applications of fish ecological information as was shown in this study. To determine the status of the species, to calculate biomass and productivity of the rivers, to classify the rivers and river systems of the country and to assess the water quality and integrity of the rivers are just a few examples. More applications of this information should be explored.

• Fish base assessment and monitoring river habitat and water quality are standard practice in developed countries due to various reasons. This should be encouraged in Nepal but also the other methods using macrozoobenthos, bacteria and physico- chemical parameters should supplement it.

• The rivers in Nepal face numbers of disturbances as was described in this work, but the generalization could not be made. Thus, the case specific assessment should be practiced to draw conclusions rather than blaming the larger sector.

• The disturbances to the rivers, particularly coming from the agriculture, construction of dams and weirs, and the industries were found to affect the integrity with certainty and thus, more careful approaches to lower and limit the adverse impacts of these must be encouraged to practice.

• There is an intimate relationship between fisheries and water resources. Any developmental or other activities involving water resources should deal fisheries as

-267- 10 Conclusions and recommendations

another important resource of the country, which cannot be overlooked. The best way is to integrate them.

• The studies and the research, which has the direct relation with local communities and local economy, should be made national priority rather than the works just of academic interest.

• Finally, it is just a repetition, as is mentioned in all other fields to call for education, awareness and training, which are important in this field too.

-268- 11 Executive summary

XI: EXECUTIVE SUMMARY

The present work titled, “FISH ECOLOGICAL STUDIES AND ITS APPLICATION IN ASSESSING ECOLOGICAL INTEGRITY OF RIVERS IN NEPAL” was started with the hypothesis that the fish fauna are able to reflect the differences influenced by variety of disturbances in river conditions and quality through the change in their population and community measures such as composition, diversity and abundance. The main aim of the study was to assess the integrity of different rivers in Nepal with the help of fish community metrics. However, the fish base information collected during the study was applied in much wider perspectives.

The main objectives of the study was thus widened into the study of distribution, abundance and density of the fish species, the size structure analysis, the methods of using variables in the classification of the rivers and river systems, and finally assessing the impacts of different disturbances so as to see if there were any impairments on the water quality and the integrity of the rivers.

The method used was the evaluation of fish population characteristics in contrasting disturbance regimes and comparing them. The four important disturbances on the rivers in Nepal were identified as agriculture, urbanization, dams and weirs, and the industries. Nine rivers, Aandhikhola, Arungkhola, Bagmati, Jhikhukhola, Karrakhola, Narayani, East Rapti, Seti and Tinau were selected for the study as these rivers were facing one or more of these disturbances.

Among them, Jhikhukhola, East Rapti and Tinau rivers were studied for the impacts of agriculture while Narayani Tinau and Seti were studied for the impacts of city or urbanization. Similarly, Aandhikhola, Bagmati and Tinau were studied for the impacts of dams while Arungkhola, Karrakhola and Narayani were chosen for the study of the impacts of industries. Two sampling sites each for the each case study were setup before the actual sampling representing the reference and disturbed sites. Thus, there were 23 sampling sites altogether for 12 cases and it is one short because the reference site in River Narayani was taken as the reference for both the disturbance, city and the industry.

-269- 11 Executive summary

Sampling period lasted from third week of February, 2003 to the January, 2004 during which four replicates of sampling corresponding to each major season of the country were done. Fish sampling was done by standard wading method with the backpack electrofishing gear. Sampling was done in two runs and the sum of which were never less than 30 mins in any of the sampling. All safety measures for the proper use of the gear were given topmost priority. The shocked fishes after capture were transferred into the bucket with fresh river water to note down the measurements and other information before they were released back to the river. Most of the identification of the fish species were done in the sampling site itself while unidentified specimens were preserved and latter verified with the experts.

Total length (TL) and the representative weights of every fish specimens captured were noted down in a simple but standard protocol. Basic physico-chemical parameters, geo- morphological features and exact coordinates of the sites were also recorded in a suitable protocal. For the information regarding water discharge of the river the data from Department of Hydrology and Meteorology (DHM) were utilized. Altogether 27588 fishes were captured during the entire sampling period lasting around one complete year. The captured fish represented 5 orders, 12 families, 33 genus and 47 species. A good spatial and temporal variation was seen in their distribution.

Among the rivers, Narayani was found to be richest in fish diversity while Bagmati had the least diversity. Arungkhola, Karrakhola, East Rapti and Tinau were found to hold a good diversity of fish fauna while Aandhikhola, Jhikhukhola and Seti were found to possess a moderate diversity of fishes. The abundance of the fish which was calculated as CPUE (catch per unit effort: no. of individuals/10 minutes of electrofishing) gave a different picture with East Rapti having the highest abundance and Bagmati again the least. Narayani was found to have considerably less abundance of fish, but a different method of sampling than the wading method should be applied in such a deep and large river for precision. The other rivers were found to have moderate to good abundance. The total average abundance of fish in all these rivers were found to be good at 79.23.

The density (no. of individuals/100 m²) of each species in each river was also worked out and to avoid the large margin of error it was calculated per 100 m² rather than per hectare. Narayani river was found to have the lowest density of the fish and it could be natural also as it is a big river. But as mentioned before more efficient method of sampling must be

-270- 11 Executive summary applied in this river. Jhikhukhola and Tinau river was found to have the highest density. Though, the values of density in the table may look little less, it should be noted that these are natural population and no stockings were recorded in these sections of the rivers as well as it is a crude but minimum density.

The classification of rivers and river systems was tried next by two methods, one using the fish base variables and the other the values of abiotic factors. It was remarkable to see that the cluster analysis by Ward method using biotic variables and the canonical discrimination analysis using abiotic factors produced almost the same results. Both the methods showed that the six rivers, Aandhikhola, Arungkhola, Karrakhola, Narayani, East Rapti and Seti formed one group where as the others formed their independent group. The classification was found to be absolutely matching with the reality and the age-old classification of Nepalese rivers. Thus, this kind of classification and grouping would be very helpful in managing water and fisheries resources on the larger scale.

The size structure analysis was also done to show how the result of this gives the insight of the fish biology and ecology on one hand and on the other hand the water quality and river conditions. The length frequency distribution and the length-weight relationship of the sucker head, Garra gotyla gotyla was worked out and studied. The length frequency distribution was studied of each river and each season. It was found that the frequency varied between rivers and seasons indicating that the habitat conditions in each river are different as well as seasons of breeding, stress and growth.

Finally, the main analysis was the assessment of water quality and integrity of the rivers using fish base characteristics. Two important variables, the number of species and their abundance were applied to see if there are different pictures corresponding to different disturbance regime. The two variables were compared between the reference and disturbed sites of each disturbance and the conclusions were drawn only after the significance tests. Whenever, relevant composition of the assemblage was also discussed.

The agricultural disturbance was found to exert significant impacts on the river which has a potential to degrade the water quality and integrity of the river. This could be easily observed through the comparison of bar charts of the reference and disturbed sites of each case study. The hypothesis test too backed the conclusion that this is an important

-271- 11 Executive summary disturbance on the river ecosystem. However, the general view of the figure suggested that all the cases were not same because they were influenced by several factors and most important among them was river morphology. It was also interesting to note that in general the species richness and abundance of fish rather increased in disturbed site possibly due to the high nutrient flow. Thus, high diversity and abundance may not always indicate higher integrity.

The impact of the city or the urbanization was found to have the least impacts on the rivers among the cases studied. The significance tests also showed no threats to the river integrity. However, some trends of impacts were visible when comparing the bar charts of reference and disturbed sites. This implied that though the impacts of cities on their respective rivers studied in this work had no immediate threats to the integrity of the river, the story could be different if further expansion of cities take place without increasing basic facilities.

The impacts of the dam on the river was also found to be an important threat to the river integrity, particularly, in the reference or the upstream sites. This conclusion was also backed by the hypothesis test. However, there was at least one case where more impairments were visible in the downstream of the dam. This suggested that there are other factors, too, that influence the impacts of the dams on the rivers. One of the most important factor identified in this case was the downstream large river connectivity, which often maintain fish communities downstream of the dam but the upstream or the reference section are deprived of that.

The impact of the industry on the integrity of the river was found to be the most serious among all the disturbances. Its seriousness was also highlighted by the statistical test. It was seen that the downstream sites were more affected by this disturbance than the upstream. However, here too, the evaluation of the impacts should be done carefully. In some seasons and in the disturbed sites of some industries, the abundance of fishes could be more and thus, might give the false impression of better conditions. The effluents of not all the industries are toxic and chemical intensive. In these cases more fishes colonize the affected area because of the warmer water or plentiful nutrients.

In chemical intensive industries such as paper mill, it was found that the disturbed site was consistently showing impairment of the integrity of the river. It was observed that the

-272- 11 Executive summary generalization of the impacts of the industries could be made but not the evaluation criteria. If only a single metrics such as the abundance of fish is taken, the impacts of the industries might not be explained. Hence, multi-metrics evaluation criteria must be developed to assess the exact situation not only for the industrial disturbance but also for anyone of them.

Numerous applications of fish population and fish ecological information has been shown in this work. So far, many of the information regarding fish species in Nepal were limited to the academic discussions only. The people and the country are not able to take direct benefit from this important resource. This work has shown how the most important resource of the country, the water resource could be managed and monitored by assessing its integrity through fish community parameters.

Thus, this work has tried to illustrate the relationship of two crucial resources of the country. If the management and monitoring of one resource help the same for the other then considerable costs and time would be saved. This kind of strategy is more suitable for the country like Nepal. The two resources should be integrated for studies or any developmental work concerning these resources. If that happens, not only it helps in conservation and management of these resources but also the restoration of already depleted and polluted resource. The benefits of these surely transcends to the larger population of the country.

-273- 12 References

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Appendix I : Working time table

YEAR 2002 ACTIVITIES AT KU/ BOKU FEBRUARY OÄD Scholarship has been accepted for a three years sandwich program between BOKU, Austria and KU, Nepal, leading to a PhD degree in the field of river ecology. Registration made at KU with Prof. Dr. Herwig Waidbacher (BOKU) and Dr. Subodh K. Sharma (KU) as the supervisors. YEAR 2002 ACTIVITIES AT BOKU MARCH Course works, practical, APRIL fieldworks, literature reviews MAY and consultations with the JUNE supervisor at BOKU in JULY Austria. Finalization of detail AUGUST proposal and protocols.

YEAR 2002/2003 ACTIVITIES AT KU SEPTEMBER Arrangements for OCTOBER extensive field work, NOVEMBER sampling data collection DECEMBER literature and information. JANUARY (2003) Sampling mainly includes FEBRUARY electric fishing at number MARCH of sites on both regulated APRIL and unregulated rivers. In MAY addition, other physico- JUNE chemical parameters like JULY temperature, velocity, AUGUST depth, discharge, SEPTEMBER substrate, conductivity, OCTOBER pH and dissolved Oxygen NOVEMBER are also taken into DECEMBER account.

YEAR 2004 ACTIVITIES AT BOKU JANUARY Data processing and FEBRUARY analysis, Statistics, MARCH literature review and APRIL writing a MAY comprehensive thesis JUNE for a PhD degree. JULY AUGUST SEPTEMBER AUGUST NOVEMBR DECEMBER YEAR 2005 ACTIVITIES AT KU JANUARY / FEBRUARY Defense of the thesis in front of expert panel and public set up by the exam and research committee.

KU - Kathmandu University, Dhulikhel, Nepal . BOKU - Universität für Bodenkultur, Vienna, Austria.

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Appendix II: Field protocol

GENERAL Name of the water body Locality Date Time Weather

River order River length Stretch code Stretch length Width

Depth Latitude Longitude Altitude Impact

Season

PHYSICO-CHEMICAL

Temperature Dissolved Oxygen Ph Conductivity Velocity

Discharge

MORPHOLOGY

1. SUBSTRATE Rock Boulder Cobbles Pebbles Gravels Sand Silt

2. RIVER BANK RIGHT LEFT Natural Artificial Eroded Planted Natural Artificial Eroded Planted

Bare Overhanging Woody Bare Overhanging Woody branches Debris branches Debris

3. Channel Type: 4. Geological Feature

Other Descriptions Sketch Map

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Appendix III: Field protocol (Fish base)

1.Place: 2. Run: 3. Fishing time: 4. Fished distance

No Species Length Weight Sex/dev No Species Length Weight Sex/dev

1 26

2 27

3 28

4 29

5 30

6 31

7 32

8 33

9 34

10 35

11 36

12 37

13 38

14 39

15 40

16 41

17 42

18 43

19 44

20 45

21 46

22 47

23 48

24 49

25 50

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Appendix IV: Checklist of fishes of Nepal (Source: Shrestha 2001)

NO ORDER FAMILY GENUS SPECIES THIS STUDY 1 Clupeiformes Clupeidae Gudusia Gudusia chapra * (Hamilton-Buchanan) 2 Engraulididae Setipinna Setipinna phasa (Hamilton-Buchanan) 3 Osteoglossiformes Notopteridae Notopterus Notopterus notopterus Pallas 1767 4 Chitala Chitala chitala Hamilton 1822 5 Cypriniformes Cyprinidae Neolissochilus Neolissochilus hexagonolepis * McClelland 1839 6 Carassius Carassius carassius Linnaeus 1758 7 Catla Catla catla Hamilton-Buchanan 1822 8 Chagunius Chagunius chagunio Hamilton-Buchanan 1822 9 Cirrhinus Cirrhinus mrigala Hamilton-Buchanan 1822 10 Cirrhinus Cirrhinus reba * Hamilton-Buchanan 1822 11 Labeo Labeo angra Hamilton-Buchanan 1822 12 Labeo Labeo bata Hamilton-Buchanan 1822 13 Labeo Labeo boga Hamilton-Buchanan 1822 14 Labeo Labeo calbasu Hamilton-Buchanan 1822 15 Labeo Labeo caeruleus Day 1877 16 Labeo Labeo dero * Hamilton-Buchanan 1822 17 Labeo Labeo dyocheilus McClelland 1839 18 Labeo Labeo fimbriatus Bloch 1795 19 Labeo Labeo gonius Hamilton-Buchanan 1822 20 Labeo Labeo pangusia Hamilton-Buchanan 1822 21 Labeo Labeo rohita Hamilton-Buchanan 1822 22 Oreichthys Oreichthys cosuatis Hamilton-Buchanan 1822 23 Osteobrama Osteobrama cotio Hamilton-Buchanan 1822 24 Schismatorhyncthios Schismatorhynchos nukta Sykes 1839 25 Puntius Puntius apogon Cuvier and Valenciennes 1844 26 Puntius Puntius chola * Hamilton-Buchanan 1822 27 Puntius Puntius clavatus McClelland 1839 28 Puntius Puntius conchonius * Hamilton-Buchanan 1822 29 Puntius Puntius gelius Hamilton-Buchanan 1822 30 Puntius Puntius guganio Hamilton-Buchanan 1822 31 Puntius Puntius phutunio Hamilton-Buchanan 1822 32 Puntius Puntius sarana Hamilton-Buchanan 1822 33 Puntius Puntius sophore * Hamilton-Buchanan 1822

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NO ORDER FAMILY GENUS SPECIES THIS STUDY 34 Puntius Puntius ticto * Hamilton-Buchanan 1822 35 Semiplotus Semiplotus semiplotus * McClelland 1839 36 Tor Tor mosal Hamilton-Buchanan 1822 37 Tor Tor putitora * Hamilton-Buchanan 1822 38 Tor Tor tor * Hamilton-Buchanan 1822 39 Naziritor Naziritor chelynoides * McClelland 1839 40 Amblypharyngodon Amblypharyngodon mola Hamilton-Buchanan 1822 41 Aspidoparia Aspidoparia jaya Hamilton-Buchanan 1822 42 Aspidoparia Aspidoparia morar * Hamilton-Buchanan 1822 43 Barilius Barilius bola Hamilton-Buchanan 1822 44 Barilius Barilius guttatus Day 1869 45 Barilius Barilius barila * Hamilton-Buchanan 1822 46 Barilius Barilius barna * Hamilton-Buchanan 1822 47 Barilius Barilius bendelisis * Hamilton-Buchanan 1822 48 Barilius Barilius radiolatus Günther 1868 49 Barilius Barilius shacra * Hamilton-Buchanan 1822 50 Barilius Barilius tileo Hamilton-Buchanan 1822 51 Barilius Barilius vagra * Hamilton-Buchanan 1822 52 Brachydanio Brachydanio rerio * Hamilton-Buchanan 1822 53 Danio Danio aequipinnatus * McClelland 1839 54 Danio Danio dangila * Hamilton-Buchanan 1822 55 Danio Danio devario Hamilton-Buchanan 1822 56 Esomus Esomus danricus * Hamilton-Buchanan 1822 57 Bengala Bengala elanga Hamilton-Buchanan 1822 58 Rasbora Rasbora daniconius Hamilton-Buchanan 1822 59 Chela Chela cachius Hamilton-Buchanan 1822 60 Chela Chela laubuca Hamilton-Buchanan 1822 61 Salmostoma Salmostoma acinaces Valenciennes 1842 62 Salmostoma Salmostoma bacaila Hamilton-Buchanan 1822 63 Salmostoma Salmostoma phulo Hamilton-Buchanan 1822 64 Securicula Securicula gora Hamilton-Buchanan 1822 65 Crossocheilus Crossocheilus latius * Hamilton-Buchanan 1822 67 Garra Garra gotyla * Gray 1830 68 Garra Garra lamta Hamilton-Buchanan 1822 70 Garra Garra nasuta McClelland 1839

-291- 13 Appendix

NO ORDER FAMILY GENUS SPECIES THIS STUDY 71 Garra Garra rupecula McClelland 1839 72 Schizothorax Schizothorax richardsonii * Gray 1832 73 Schizothorax Schizothorax sinuatus Heckel 1838 74 Schizothoraichthys Schizothoraichthys esocinus Heckel 1838 75 Schizothoraichthys Schizothoraichthys labiatus McClelland 1839 76 Schizothoraichthys Schizothoraichthys macrophthalmus Terashima 1984 77 Schizothoraichthys Schizothoraichthys nepalensis Terashima 1984 78 Schizothoraichthys Schizothoraichthys niger Heckel 1838 79 Schizothoraichthys Schizothoraichthys curvifrons Heckel 1838 80 Schizothoraichthys Schizothoraichthys progastus * McClelland 1839 81 Schizothoraichthys Schizothoraichthys raraensis Terashima 1984 82 Psilorhynchidae Psilorhynchus Psilorhynchus balitora Hamilton-Buchanan 1822 83 Psilorhynchus Psilorhynchus sucatio Hamilton-Buchanan 1822 84 Psilorhynchus Psilorhynchus homaloptera Hora and Mukerji 1935 85 Psilorhynchus Psilorhynchus pseudecheneis * Menon and Datta 1961 86 Balitoridae Balitora Balitora brucei Gray 1832 87 Nemacheilus Nemacheilus corica * Hamilton-Buchanan 1822 88 Acanthocobitis Acanthocobitis botia * Hamilton-Buchanan 1822 89 Schistura Schistura beavani * Günther 1868 90 Schistura Schistura devdevi Hora 1935 91 Schistura Schistura multifasciatus Day 1878 92 Schistura Schistura rupecula * McClelland 1839 93 Schistura Schistura scaturigina McClelland 1839 94 Schistura Schistura savona Hamilton-Buchanan 1822 95 Cobitidae Botia Botia almorhae * Gray 1831 96 Botia Botia dario Hamilton-Buchanan 1822 97 Botia Botia histrionica Blyth 1861 98 Botia Botia lohachata * Chaudhuri 1912 99 Acantophthalmus Acantophthalmus pangia Hamilton-Buchanan 1822 100 Lepidocephalus Lepidocephalus guntea * Hamilton-Buchanan 1822 101 Somileptus Somileptus gongota Hamilton-Buchanan 1822 102 Anguilliformes Anguillidae Anguilla Anguilla bengalensis Gray 1831 103 Siluriformes Amblycipitidae Amblyceps Amblyceps mangois * Hamilton-Buchanan 1822 104 Bagridae Batasio Batasio batasio Hamilton-Buchanan 1822 105 Mystus Mystus bleekeri Day 1878

-292- 13 Appendix

NO ORDER FAMILY GENUS SPECIES THIS STUDY 106 Mystus Mystus cavasius Hamilton-Buchanan 1822 107 Mystus Mystus menoda Hamilton-Buchanan 1822 108 Mystus Mystus tengara Hamilton-Buchanan 1822 109 Mystus Mystus vittatus Bloch 1794 110 Aorichthys Aorichthys aor Hamilton-Buchanan 1822 111 Aorichthys Aorichthys seenghala Sykes 1839 112 Rita Rita rita Hamilton-Buchanan 1822 113 Siluridae Ompok Ompok bimaculatus Bloch 1797 114 Ompok Ompok pabda Hamilton-Buchanan 1822 115 Ompok Ompok pabo Hamilton-Buchanan 1822 116 Wallago Wallago attu Schneider 1801 117 Schilbeidae Ailia Ailia coila Hamilton-Buchanan 1822 118 Clupisoma Clupisoma garua * Hamilton-Buchanan 1822 119 Clupisoma Clupisoma montana Hora 1937 120 Eutropiichthys Eutropiichthys vacha Hamilton-Buchanan 1822 121 Pseudeutropius Pseudeutropius atherinoides Bloch 1794 122 Pseudeutropius Pseudeutropius murius batarensis Shrestha 1978 123 Silonia Silonia silondia Hamilton-Buchanan 1822 124 Sisoridae Bagarius Bagarius yarrelli Sykes 1839 125 Erethistes Erethistes elongatus Day 1878 126 Erethistes Erethistes pusillus Müller & Troschel 1849 127 Erethistoides Erethistoides montana montana Hora 1950 128 Euchiloglanis Euchiloglanis hodgarti Hora 1923 129 Gagata Gagata cenia Hamilton-Buchanan 1822 130 Gagata Gagata sexualis Tilak 1970 131 Coraglanis Coraglanis kishinouyei Kimura 1934 132 Myersglanis Myersglanis blythii * Day 1870 133 Glyptosternon Glyptosternon reticulatum McClelland 1842 134 Glyptosternon Glyptosternon maculatum Regan 1905 135 Glyptothorax Glyptothorax annandalei Hora 1923 136 Glyptothorax Glyptothorax cavia Hamilton-Buchanan 1822 137 Glyptothorax Glyptothorax conirostre Steindachner 1867 138 Glyptothorax Glyptothorax indicus Talwar 1991 139 Glyptothorax Glyptothorax kashmirensis Hora 1923

-293- 13 Appendix

NO ORDER FAMILY GENUS SPECIES THIS STUDY 140 Glyptothorax Glyptothorax pectinopterus * McClelland 1842 141 Glyptothorax Glyptothorax gracile Günther 1864 142 Glyptothorax Glyptothorax telchitta * Hamilton-Buchanan 1822 143 Glyptothorax Glyptothorax trilineatus * Blyth 1860 144 Hara Hara hara Hamilton-Buchanan 1822 145 Hara Hara jerdoni Day 1870 146 Laguvia Laguvia ribeiroi Hora 1921 147 Nangra Nangra nangra Hamilton-Buchanan 1822 148 Nangra Nangra viridescens Hamilton-Buchanan 1822 149 Pseudecheneis Pseudecheneis sulcatus * McClelland 1842 150 Sisor Sisor rabdophorus Hamilton-Buchanan 1822 151 Olyridae Olyra Olyra longicaudata McClelland 1842 152 Chacidae Chaca Chaca chaca Hamilton-Buchanan 1822 153 Heteropneustidae Heteropneustes Heteropneustes fossilis * Bloch 1794 154 Claridae Clarias Clarias batrachus Linnaeus 1758 155 Beloniformes Belonidae Xenentodon Xenentodon cancila Hamilton-Buchanan 1822 156 Cyprinodontoformes Poecilidae Gambusia Gambusia affinis Baird & Girard 1853 157 Aplocheilidae Aplocheilus Aplocheilus panchax Hamilton-Buchanan 1822 158 Perciformes Channidae Channa Channa barca Hamilton-Buchanan 1822 159 Channa Channa orientalis * Bloch & Schneider 1801 160 Channa Channa marulius Hamilton-Buchanan 1822 161 Channa Channa punctatus * Bloch 1793 162 Channa Channa stewartii Playfair 1867 163 Channa Channa striatus Bloch 1793 164 Ambassidae Chanda Chanda nama Hamilton-Buchanan 1822 165 Parambassis Parambassis baculis Hamilton-Buchanan 1822 166 Parambassis Parambassis ranga Hamilton-Buchanan 1822 167 Sciaenidae Johnius Johnius coitor Hamilton-Buchanan 1822 168 Nandidae Badis Badis badis Hamilton-Buchanan 1822 169 Nandus Nandus nandus Hamilton-Buchanan 1822 170 Anabantidae Anabas Anabas testudineus Bloch 1792 171 Belontidae Colisa Colisa fasciatus Schneider 1801 172 Colisa Colisa lalia Hamilton-Buchanan 1822 173 Colisa Colisa sota Hamilton-Buchanan 1822 174 Ctenops Ctenops nobilis McClelland 1845

-294- 13 Appendix

NO ORDER FAMILY GENUS SPECIES THIS STUDY 175 Gobiidae Glossogobius Glossogobius giuris * Hamilton-Buchanan 1822 176 Synbranchiformes Synbranchidae Monopterus Monopterus cuchia Hamilton-Buchanan 1822 177 Mastacembelidae Macrognathus Macrognathus aral Bloch & Schneider 1801 178 Macrognathus Macrognathus pancalus * Hamilton-Buchanan 1822 179 Mastacembelus Mastacembelus armatus * Lacepede 1800 180 Mugiliformes Mugilidae Sicamugil Sicamugil cascasia Hamilton-Buchanan 1822 181 Rhinomugil Rhinomugil corsula Hamilton-Buchanan 1822 182 Tetraodontiformes Tetraodontidae Tetraodon Tetraodon cutcutia Hamilton-Buchanan 1822

-295- 13 Appendix

Appendix V: Letter from Defense Ministry for safety during sampling

-296- 13 Appendix

Appendix VI: Letter from the University for cooperation during sampling

-297- 13 Appendix

Appendix VII: Permission letter from DNPWC for sampling in RCNP

-298- 13 Appendix

Appendix VIII: Permission letter from DNPWC for sampling in SNP

-299- 13 Appendix

Appendix IX: Permission letter from SNP for sampling

-300- 13 Appendix

Appendix X: Permission letter from NEA for sampling

-301-