Final Technical Report on Ecology and Conservation of Residential Populations of Gangetic Dolphins in Brahmaputra River System, India

FINAL TECHNICAL REPORT ON ECOLOGY AND CONSERVATION OF RESIDENTIAL POPULATIONS OF GANGETIC DOLPHINS IN BRAHMAPUTRA RIVER SYSTEM, INDIA

Submitted by Abdul Wakid, Ph. D Project Leader, Dolphin Conservation Project Aaranyak Guwahati, Assam, India [email protected], [email protected], www.aaranyak.org

ACKNOWLEDGEMENT

Without the funding support by BP Conservation Programme, this important project would not be possible. Therefore, we are expressing our sincere thanks to the BP Conservation Programme for funding this work. We are grateful to the Department of Environment & Forest, Govt of Assam and Centre for Energy of Indian Institute of Technology (Guwahati) for their collaborations to the project. We offer our sincere thanks to Prof. R. K. Sinha, Prof. S. P. Biswas and Dr. Hilloljyuti Singha for their kind guidance; Mr. M. C. Malakar (Principal Chief Conservator of Forest, Govt of Assam) for cooperation; Krishna Das, Dipak Das, Mahendra Bhuyan and many others for field assistance. Finally, thanks to our team members Sanjay Das, Dhruba Chetry, Siddartha Saikia, Mayur Mahanta and Abdul Mazid for their sincere and dedicated efforts without whom the work would not be possible and to all the members of Aaranyak for the great support they provided during the execution of this project.

Place: Guwahati (Abdul Wakid)

Date: 10th December, 2007 Team leader

PROJECT AT A GLANCE

1. Title of the Project: Ecology and conservation of residential populations of Gangetic dolphin in Brahmaputra river system, India.

2. Project Leader: Dr. Abdul Wakid Programme Leader, Gangetic Dolphin Research & Conservation Programme Aaranyak, Survey, Beltola, Guwahati – 28 Assam, India Phone & Fax: 91 361 2228418 Web: www.aaranyak.org, Email: [email protected]

3. Team members: Dhruba Chetry, Siddartha Sikia, Sanjay Das, Abdul Mazid

4. Project duration: 1 year (June, 2006 to May, 2007)

6. Project Advisors: Prof. R. K. Sinha IUCN Cetacean Specialist Patna University, India

Prof. S. P. Biswas Dept. of Life Sciences, Dibrugarh University Assam, India

Executive Summery:

Detail ecological investigations and site based conservation efforts were conducted from June, 2006 to May, 2007 on the dolphins of Kulsi and Subansiri River, the last two endangered Gangetic dolphin populations surviving in these two tributaries of Brahmaputra River of North East India. A best estimate of 28 and 25 dolphins were recorded in the 76 km and 99 km dolphin inhabited river stretch of Kulsi and Subansiri River. Depth, width, substrate types, riparian conditions, food abundance (fish) and anthropogenic activities in these two rivers were investigated at one km interval. Physico- chemical characteristics (temperature, Ph, Conductivity, TDS, dissolved oxygen,

transparency, free CO2, total hardness, calcium hardness, chloride) were investigated at monthly interval. Rate of sand mining in the dolphin habitats were assessed. Anthropogenic activities (fishing, poaching, by-catch mortality) were recorded. Awareness campaigns among local communities were conducted in disturbed area. Youths from the local communities were trained up for dolphin monitoring and engaged in the protection of threatened dolphin habitats in these two rivers. 4

CONTENTS

Page no.

Introduction 5

Materials & methods 7

Results & Discussions 19

Recommendations 79

Reference 80

Chapter-1: Introduction

The Gangetic dolphin is found in Ganges-Brahmaputra-Meghna and Karnaphuli river system of India, Nepal and Bangladesh (Anderson 1878, Kasuya & Haque 1972, Jones 1982, Mohan 1989, Reeves & Brownell 1989, Shrestha 1989 and Reeves et al., 1993). About three decades ago the species was the commonly sighted aquatic mammal throughout its distributional ranges, especially in India and Bangladesh. However, due to various natural and anthropogenic pressures the distributional ranges and abundance of this species has been sharply declined in its entire distributional ranges (Reeves & Leatherwood 1995) and for which the IUCN revised its threatened status from vulnerable (Klinowska 1991) to endangered (IUCN 1996). At present there are less than 2500 individuals of Gangetic dolphin in the world (Sinha & Sharma, 2003). The Brahmaputra river system within Assam is one of the major habitats of Gangetic dolphin in the world, which is still comparatively safer place for the species as the river system is relatively pollution free and also no major dam or barrage has been constructed in the mainstream, for which Brahmaputra has been considered as one of the last refuge for the species. Even than several other anthropogenic factors viz. habitat degradation, deliberate and accidental killing etc were responsible for the gradual decline of the species from this river system. Before two decades dolphins are one of the commonly sighted aquatic megafuna in most of its major tributaries of Brahmaputra River. However, due to habitat degradation and other anthropogenic factors now except Brahmaputra mainstream dolphins are found only in two tributaries of Brahmaputra - one in Kulsi River of Kamrup district and another in the Subansiri River of Lakhimpur district (Wakid, 2005). However, these populations are also declining due to same factors, for which there is an urgency to undertake effective conservation strategy for these two residential populations of Gangetic dolphin. Understanding the details of the dolphin habitats, threats to these habitats and initiate measures to conserve these dolphins through protecting their habitats are the best approaches at the current situations for these two populations. Although there are a few attempts to understand the status of dolphins and their habitats in different parts of Brahmaputra Valley (Mohan et al. 1997, Biswas & Baruah 2000, Wakid 2006a & 2006b), there are very little studies (Mohan et al. 1997, Wakid 2005) and 6

conservation initiatives for the dolphins of Kulsi and Subansiri River. Therefore, with an aim for future restoration works and site based conservation initiatives for the last two populations in the tributaries (Kulsi and Subansiri River) of Brahmaputra, the current project was undertaken.

Chapter-2: Materials & Methods

2.1. Study area:

2.1.1. Kulsi River: Kulsi River is in the Kamrup district of Western Assam (Fig-1). The river originates from Meghalaya (25038/ N, 91038/ E) where it is known as Khri River. After crossing about 12 km from its origin, the river enters into the Kamrup district of Assam at Umkiam (25038/ N, 91038/ E). The river known as Kulsi from Umkium. After crossing about 15 km from Umkium the Kulsi reaches Kulsi village of Assam. The river finally discharges into the Brahmaputra at Nagarbera, which is about 76 km downstream from Kulsi (Fig-2).

2.1.2. Subansiri River: Subansiri is the largest tributary (443 km stretch) of Brahmaputra River (Fig-1) originating from Purum peak (5059 msl) of Tibet, where it is known as Lokong Su. From its origin the river crosses about 143 km through Tibet enters into Arunachal Pradesh of India. The River crosses about 191 km through Arunachal Pradesh and finally enters Assam near Garukamukh of Lakhimpur district. It crosses 37 No. National Highway at Sawoldhuwaghat, which is about 10 km downstream of Garukamukh. The river finally discharges into the Brahmaputra at Jamugurighat which is about 99 km downstream from Sawoldhuwahghat (Fig-3).

Fig-1: Location map of Kulsi and Subansiri River 9

Brahmaputra

Kulsi River

Fig-2: Map of Kulsi River

Subansiri River

Brahmaputra River

Fig-3: Map of Subansiri River 11

2.2. Habitat ecology study:

2.2.1. Population status and distribution assessment: Three visual, boat-based dolphin survey was conducted in both Kulsi and Subansiri River to determine recent population status. Survey techniques was followed those recommended by Smith and Reeves (2000) for visual surveys which was also followed in Wakid (2005). All the channels were surveyed. Recent satellite imageries were used to identify all the potential channels. Altogether 5 observers were used at a time with 3 Primary Observers (2 will search 600 right & left, whereas the 3rd Observer in the central 300 right & left), 1 data recorder and 1 rear observer (observing 1800 behind the survey vessel). Vessel speed was minimized in preferred dolphin microhabitats, viz, confluences, meanderings, downstream of mid-channel islands and where there is large aggregation of fishermen or water birds A dolphin group is defined as dolphins no more than 500 m apart, within an area of similar hydrological characteristics. Group size was evaluated with a best, high and low estimate of numbers to incorporate a degree of uncertainty. A low and best estimate of zero was used if the sighting was unconfirmed or if there was a possibility that the dolphin is following the vessel and might have already been counted. A 20 minute stoppage was made in high dolphin abundance area to make a best estimate of the group. When a dolphin was sighted, the vessel continued moving downstream but active surveying for new dolphin groups was temporarily suspended while observers focused on obtaining an accurate group size estimate. All sightings were confirmed by a second observer. A dolphin with estimated body length of > 1.5 m and body colour of pale brown / grayish was recorded as ‘adult’, < 1 m as with dark colour as ‘calf’ and in between 1-1.5 m as sub-adult.

2.2.2. Ecological investigation of dolphin habitats:

2.2.2.1. Physico-chemical characteristics of dolphin habitats: For understanding the critical physico-chemical characteristics of dolphin habitats in Kulsi and Subansiri River, monthly water samplings and laboratory as well as field analysis were conducted in 4 dolphin inhabited stretch of Kulsi River and 4 in Subansiri River (Table-1).

Table-1: Name and location of sampling stations in Kulsi and Subansiri River

Stations Kulsi sampling stations Subansiri sampling station no. Name Location Name Location 1. Kukurmara 26o04/ N, 91o26/ E Sawoldhua 27o26/ N, 94o14/ E 2. Jiakur 26o05/ N, 91o26/ E Dholghat 27o15/ N, 94o12/ E 3. Samariya 26o03/ N, 91o09/ E Khabolu 27o02/ N, 94o07/ E 4. Nagarbera 26o07/ N, 90o59/ E Badati 26o56/ N, 93o57/ E

Following physico-chemical parameters were assessed in these stations. (i) Water temperature: It was recorded by a mercury thermometer graduated upto 1100C. (ii) PH: The pH was determined by using a portable pH Meter (model EC-PH Scan-2). (iii) Transparency: The transparency of the water was determined by Secchi Disc Method (Trivedy et al., 1987). (iv) Conductivity: The conductivity of the river water was estimated by a Conductivity Meter (model no. 621E). (v) Total Dissolved Solids: Trivedy et al. (1987) was followed to determine the TDS. (vi) Alkalinity (bicarbonate): This parameter was estimated in the field by titration method using methyl orange as an indicator (Welch, 1952). (vii) Dissolved Oxygen: This parameter was calculated following Wrinkler’s modified method (Trivedy et al., 1987).

(viii) Free CO2: It was determined in the field by titration using phenolphthalein as indicator (Welch, 1952). (ix) Total hardness: It was estimated by EDTA titration method using Ammonia buffer and Erichrome Black T as indicator (APHA, 1992). (x) Calcium hardness: This parameter was estimated by EDTA titration method using Murexide Indicator (APHA, 1992). (xi) Chloride: Argentomeric method was followed using potassimum chromite as indicator (APHA, 1992). (xii) Silicate: It was estimated following Jhingran et al. (1969).

Fig-4: Team members in review of ecological methodology in the field before the study

Fig-5: Prof. R. K. Sinha, an IUCN-Cetacean Specialist and Advisor to the Project Team in the field with team members 14

Fig-6: Team members are conducting habitat ecology study in the field

Fig-7: Habitat ecology study in the field 15

Fig-8: Physico-chemical parameter study in the field laboratory.

2.2.2.2. Geomorphological, riparian vegetation and sand mining rate study of dolphin habitats: Arunachalam (1999) was followed to analyze the geomorphological features and the riparian conditions of dolphin habitats with some modifications depending on the local conditions. Substrate conditions (boulder, cobble, gravel, fine sand etc.) and habitat types (run, meandering, pool-riffle, confluence, wide channel, narrow channel etc.) were recorded to analyze the geomorphological characteristics of the surveyed habitats. Depth and width of the habitats and the status of the riparian vegetations were also assessed. All these investigations were carried out at reach level of approximately 1 km interval. GPS and recent satellite imageries of 1:50,000 scales were used during these investigations. Rate of sand mining from the dolphin inhabited stretch of Kulsi River was determined at per day. 16

Fig-9: Satellite imageries are widely used in the habitat ecology study

Fig-10: Sand mining impact study in Kulsi River 17

Fig-11: Team member working on GPS for habitat ecology study

2.2.2.3. Food abundance estimation: Since dolphins are mainly piscivorous in nature, therefore to estimate the availability of food, the diversity and abundance of fish fauna in the Kulsi and Subansiri River were investigated in details during the study period. Fish specimens were collected from the selected water bodies with the help of cast net. Efforts were made to avoid statistical bias. Samples were preserved in 10% formalin and brought to the laboratory for identification and further studies. Identifications were made with the help of Jayaram (1999), Dattamunshi and Shrivastava (1988), Talwar and Jhingran (1991). For determination of the global status of the identified fishes, CAMP (1998) was followed.

2.4. Monitoring of dolphins & awareness campaign: Awareness campaign through organizing public meeting and informal meeting with the local communities residing near the dolphin habitats of Kulsi and Subansiri River were conducted during this project. Community youths from these localities were trained 18

Fig-12: Team members in the dolphin food (fish) abundance study

up in dolphin monitoring. Any dolphin mortality records were immediately conveyed to the team members by these community based volunteers and the Project Team in collaboration with the local management authority (Department of Environment & Forest, Govt of Assam) immediately undertook field based initiative to reduce the killing.

Modifications in the Project: The reviewers of this proposal at the beginning of the project (sent to us by BPCP alongwith the project result) advised to concentrate more on conservation efforts than the proposed extensive ecology study. Based on these advices, to maximize the time and effort for the conservation of these last remaining two residential populations of Gangetic dolphins in the Brahmaputra Valley, the team concentrated more on the community based awareness campaign and other conservation efforts than the proposed ecological studies. As a result some of the proposed studies viz., planktonic study, food availability study and behavioural observations of dolphins response to sand mining etc (as outlined in the project proposal) were not conducted during the project duration.

Chapter-3: Results & Discussions

3.1. Kulsi River:

3.1.1. Population status and distribution pattern: Altogether 28 (best estimate) dolphins (minimum 24 to maximum 30) (Table-2) with an encounter rate of 0.37 dolphins per km were recorded in Kulsi River. The highest encounter rate was in Sector-2 (1.1 dolphin per km) followed by the Sector-6 (0.6 dolphin per km) (Fig-13). Adults were maximum (39%) followed by sub-adults and calves (Fig-14) (details in Table-3).

Table-2: Population status and distribution pattern of dolphins in Kulsi River

Sectors Area Location No. Min Max Best S-1 Kulsi to N 25058/, E 91025/ - 1 1 1 Borpit N 26002/, E 91026/ S-2 Borpit to N 26002/ , E 91026/ - 10 11 11 Jiakur N 26005/, E 91025/ S-3 Jiakur to N 26005/, E 91025/ - 2 2 2 Ambari N 26005/, E 91021/ S-4 Ambari to N 26005/, E 91021/ - 1 3 2 Jambari N 26003/, E 91016/ S-5 Jambari to N 26003/, E 91016/ - 1 1 1 Dakhin Laruajan N 26003/, E 91011/ S-6 Dakhin Laruajan N 26003/, E 91011/ - 5 6 6 to Pub halmara N 26003/, E 91007/ S-7 Pub halmara N 26003/, E 91007/ - 1 1 1 to Jonglai N 26005/, E 91002/ S-8 Jonglai to N 26005/, E 91002/ - 3 5 4 Nagarbera N 26006/, E 90059/ Total 24 30 28

1.2

0.8

Dolphin/km 0.6

0.4

0.2

0 S-1 S-2 S-3 S-4 S-5 S-6 S-7 S-8 Sectors

Fig-13: Encounter rate of dolphins in Kulsi River

Sub-adult Calf (36%) (25%)

Adult (39%)

Fig-14: Age class analysis of dolphins in Kulsi River

Table-3: Age-class distribution of dolphins in Kulsi River

Sectors Area Location No. of dolphins Calf Subadult Adult Total S-1 Kulsi to N 25058/, E 91025/ - 1 0 0 1 Borpit N 26002/, E 91026/ S-2 Borpit to N 26002/ , E 91026/ - 2 6 3 11 Jiakur N 26005/, E 91025/ S-3 Jiakur to N 26005/, E 91025/ - 1 0 1 2 Ambari N 26005/, E 91021/ S-4 Ambari to N 26005/, E 91021/ - 1 0 1 2 Jambari N 26003/, E 91016/ S-5 Jambari to N 26003/, E 91016/ - 0 1 0 1 Dakhin Laruajan N 26003/, E 91011/ S-6 Dakhin Laruajan N 26003/, E 91011/ - 1 1 4 6 to Pub halmara N 26003/, E 91007/ S-7 Pub halmara N 26003/, E 91007/ - 0 1 0 1 to Jonglai N 26005/, E 91002/ S-8 Jonglai to N 26005/, E 91002/ - 1 1 2 4 Nagarbera N 26006/, E 90059/ Total 7 10 11 28

3.1.2. Physico-chemical characteristics of dolphin habitats: During the study period, water temperature of Kulsi River ranged from 17.2-29.7 0C, Ph was 7.1-8.5, transparency 13.5-45.7 cm, conductivity 82.5-141.2 µS, total dissolved solids 50-221 ppm, bicarbonate alkalinity 41.8-123.8 mg-l, dissolved oxygen 7.4-13.1 mg-l, free carbon-di-oxide 1.8-10.3 mg-l, total hardness 56.3-103.5 mg-l, calcium hardness 26.3-50.3 mg-l, chloride 2.4-8.1 mg-l, silicate 3.5-17.1 mg-l (table-4).

3.1.3. Geomorphological and Riparian characteristics: The substrate of entire 76 km dolphin inhabited river stretch of Kulsi River comprised of fine sands (Table-5). Major habitat types were river meandering and narrow straight channel and riparian areas were used for agriculture (Table-5).

Table-4: Average physico-chemical characteristics of dolphin habitats in Kulsi River

Parameter Kukurmara Jiakur Samariya Nagarbera

Water temperature 17.2-27.1 18.3-29.2 19.5-28.7 19.5-29.7 (0C) pH 7.1-7.9 7.3-8.1 7.1-8.5 7.0-8.1 Transparency (cm) 13.5-34.5 18.2-45.2 16.6-58.2 18.0-45.7 Conductivity 95.2-132.5 88.1-141..2 82.5-128.7 98.2-132.7 (µS) TDS (ppm) 60-125 64-221 88-160 50-123 Bicarbonate 52.8-66.2 43.2-65.5 54.2-123.8 41.8-85.7 Alkalinity (mg-l) Dissolved oxygen 7.4-9.5 7.8-10.7 8.2-11.5 8.3-13.1 (mg-l) 3.8-7.4 3.7-6.8 5.1-10.3 1.8-7.2 Free Carbon dioxide (mgl-1) 62.3-103.5 58.2-77.3 56.3-83.5 62.3-103.5 Total hardness (mgl-1)

Calcium hardness 26.3-43.1 31.5-48.3 34.5-42.1 33.2-50.3 (mgl-1) Chloride (mgl-1) 2.4-10.1 3.3-8.1 3.4-5.2 1.8-7.1 Silicate (mgl-1) 3.5-9.0 4.5-8.1 4.6-17.2 4.1-12.2

Table-5: Geomorphological and riparian characteristics of River Kulsi

Riparian cover Reac Reach location Substrate Habitat h no. Right Left

riparian riparian zone zone 1. FS N 25058/129//, E 91025/085// MCI VL WL 2. FS N 25058/719//, E 91025/388// MCI GL WL 3. FS N 25059/135//, E 91025/527// NSC GL VL 4. FS N 25059/632//, E 91025/515// NSC VL VL 5. FS N 26000/122//, E 91025/664// NSC AG VL 6. FS N 26000/560//, E 91025/984// RM VL VL 7. FS N 26001/103//, E 91026/026// NSC VL VL 8. FS N 26001/774//, E 91026/261// MCI AG AG 9. FS N 26001/263//, E 91026/291// RM AG GL 10. FS N 26002/748//, E 91026/346// RM AG AG 11. FS N 26003/198//, E 91026/523// RM AG AG 12. FS N 26003/623//, E 91026/570// RM GL SL 13. FS N 26004/089//, E 91027/529// NSC GL GL 14. FS N 26003/823//, E 91027/030// CF GL GL 15. FS N 26003/934//, E 91026/569// RM GL GL 16. FS N 26004/026//, E 91026/230// CF SM GL 17. FS N 26004/133//, E 91025/996// RM VL VL 18. FS N 26004/519//, E 91025/953// RM VL VL 19. FS N 26004/871//, E 91026/062// RM VL VL 20. FS N 26005/342//, E 91025/833// NSC AG AG 21. FS N 26005/549//, E 91025/355// NSC AG AG 22. FS N 26005/480//, E 91024/827// RM AG AG 23. FS N 26005/912//, E 91024/515// RM AG AG 24. FS N 26005/882//, E 91023/954// RM VL AG 25. FS N 26095/694//, E 91023/419// CF VL VL 26. FS N 26005/638//, E 91022/954// MCI AG VL 27. FS N 26005/548//, E 91022/449// RM AG AG 28. FS N 26005/164//, E 91022/072// NSC AG AG 29. FS N 26005/476//, E 91021/653// RM AG AG 24

30. FS N 26005/192//, E 91021/527// RM VL AG 31. FS N 26005/368//, E 91021/087// MCI AG AG 32. FS N 26005/337//, E 91020/513// NSC AG AG 33. FS N 26005/100//, E 91019/986// NSC VL AG 34. FS N 26004/949//, E 91019/453// WSC VL AG 35. FS N 26004/839//, E 91018/889// RM AG AG 36. FS N 26004/581//, E 91018/422// RM AG AG 37. FS N 26094/389//, E 91017/960// NSC AG AG 38. FS N 26004/220//, E 91017/394// RM AG AG 39. FS N 26003/987//, E 91016/978// RM VL AG 40. FS N 26003/837//, E 91016/408// MCI VL AG 41. FS N 26004/098//, E 91016/026// RM VL GL 42. FS N 26003/809//, E 91015/547// NSC VL VL 43. FS N 26003/773//, E 91014/984// NSC AG VL 44. FS N 26004/054//, E 91014/497// RM VL VL 45. FS N 26004/096//, E 91013/875// RM VL AG 46. FS N 26003/804//, E 91013/396// NSC AG AG 47. FS N 26004/041//, E 91013/052// RM AG AG 48. FS N 26003/744//, E 91012/607// RM AG AG 49. FS N 26003/438//, E 91012/225// RM AG VL 50. FS N 26003/680//, E 91011/743// CF VL AG 51. FS N 26003/801//, E 91011/224// RM AG AG 52. FS N 26003/720//, E 91010/678// MCI VL VL 53. FS N 26003/987//, E 91010/200// RM GL GL 54. FS N 26003/644//, E 91009/855// CF VL AG 55. FS N 26003/258//, E 91009/762// CF WL AG 56. FS N 26003/521//, E 91009/379// RM WL AG 57. FS N 26003/638//, E 91008/822// RM GL VL 58. FS N 26003/533//, E 91008/280// CF VL VL 59. FS N 26003/634//, E 91007/687// WSC AG VL 60. FS N 26003/910//, E 91007/305// RM AG AG 61. FS N 26004/301//, E 91006/963// RM VL VL 62. FS N 26004/382//, E 91006/385// RM AG AG 63. FS N 26004/664//, E 91005/910// WSC AG VL 25

64. FS N 26004/804//, E 91005/375// RM AG AG 65. FS N 26005/042//, E 91004/934// RM AG AG 66. FS N 26005/194//, E 91004/655// RM AG VL 67. FS N 26005/236//, E 91004/187// RM AG AG 68. FS N 26005/511//, E 91003/733// RM AG AG 69. FS N 26005/544//, E 91003/217// WSC AG AG 70. FS N 26005/621//, E 91002/642// WSC AG AG 71. FS N 26006/014//, E 91002/204// CF AG AG 72. FS N 26006/072//, E 91001/708// WSC AG AG 73. FS N 26006/444//, E 91001/251// MCI AG VL 74. FS N 26006/631//, E 91000/735// WSC AG VL 75. FS N 26007/050//, E 91000/366// MCI AG WL 76. FS N 26007/008//, E 90059/781// CF VL VL 77. FS N 26006/715//, E 90059/239// RM VL VL

Abbreviation

FS: Fine sand RM: River meandering CF: Confluence WSC: Wide single channel NSC: Narrow single channel BR: Braided channel GL: Grassland SL: Shrubland VL: Village WL: Woodland AG: Agriculture TG: Tea garden

3.1.4. Depth and width pattern of Kulsi River: Minimum water depth and width of Kulsi River was observed in winter. The details of these recoded depth and width of each sector are mentioned in the following figures (Fig-15 to Fig-38).

Sector-I:

1.2

0.8 ) m

h ( 0.6 pt e

D 0.4

0.2

0 R-1 R-2 R-3 R-4 R-5 R-6 R-7 R-8 R-9 R-10 Reach no.

Fig-16: Water depth

) 25 m ( h

t 20 d i

w 15 r te 10 Wa

0 R-1 R-2 R-3 R-4 R-5 R-6 R-7 R-8 R-9 R-10 Reach no.

Fig-15: Satellite image of Fig-17: Water width

Sector-II:

3.5 3 2.5 )

m 2 h (

pt 1.5 e D 1

0.5

0 R-11 R-12 R-13 R-14 R-15 R-16 R-17 R-18 R-19 R-20 Reach no

Fig-19: Water depth of Sector-II

50 ) 40 (m h t d i 30 w r 20 Wate 10

0 Fig-18: Satellite image of Sector- R-11 R-12 R-13 R-14 R-15 R-16 R-17 R-18 R-19 R-20 Reach no.

Fig-20: Water width of Sector-II

Sector-III:

2.5 2 ) m (

h 1.5 t p

De 1

0.5

0 R-21 R-22 R-23 R-24 R-25 R-26 R-27 R-28 R-29 R-30 Reach no.

Fig-22: Water depth of Sector-III

50 )

m 40 ( h dt i 30 w r e t

a 20 W 10

0 R-21 R-22 R-23 R-24 R-25 R-26 R-27 R-28 R-29 R-30 Reach no.

Fig-21: Satellite image of Sector-III Fig-23: Water width of Sector-III

Sector-IV:

2.5

) 1.5 m h ( pt

e 1 D

0.5

0 R-31 R-32 R-33 R-34 R-35 R-36 R-37 R-38 R-39 R-40 Reach no.

Fig-25: Water depth of Sector-IV

) 50 m

h ( 40 dt i

w 30 r e t a 20 W

0 R-31 R-32 R-33 R-34 R-35 R-36 R-37 R-38 R-39 R-40 Reach no.

Fig-24: Satellite image of Sector-IV Fig-26: Water width of Sector-IV

Sector-V:

4 3.5 3

) 2.5 m

h ( 2 pt e

D 1.5 1 0.5 0 R-41 R-42 R-43 R-44 R-45 R-46 R-47 R-48 R-49 R-50 Reach no.

Fig-28: Depth of Sector-IV

50 45 40

) 35 (m

h 30 t d i 25 w 20 ter a 15 W 10 5 0 R-41 R-42 R-43 R-44 R-45 R-46 R-47 R-48 R-49 R-50 Reach no. Fig-27: Satellite image of Sector-V Fig-29: Width of Sector-IV 31

Sector-VI

2.5

) 1.5 m h ( pt

e 1 D

0.5

0 R-51 R-52 R-53 R-54 R-55 R-56 R-57 R-58 R-59 R-60 Reach no.

Fig-31: Water depth of Sector-VI

50 )

m 40 ( h t d i 30 w r e t 20 Wa 10

0 R-51 R-52 R-53 R-54 R-55 R-56 R-57 R-58 R-59 R-60 Reach no.

Fig-30: Satellite image of Sector-VI Fig-32: Water depth of Sector-VI

Sector-VII 3.5

2.5 )

m 2 h (

pt 1.5 e D 1

0.5

0 R-61 R-62 R-63 R-64 R-65 R-66 R-67 R-68 R-69 R-70

Reach no.

Fig-34: Water depth of Sector-VII

) 50 m

h ( 40 dt i

w 30 r e t a 20 W

0 R-61 R-62 R-63 R-64 R-65 R-66 R-67 R-68 R-69 R-70

Reach no.

Fig-33: Satellite image of Sector-VII Fig-35: Water depth of Sector-VII

Sector-VIII

4 3.5 3

) 2.5 m

h ( 2 pt e

D 1.5 1 0.5 0 R-71 R-72 R-73 R-74 R-75 R-76 R-77 Reach no.

Fig-37: Water depth of Sector-VIII

180 160 140 )

m 120

h ( 100 dt i 80 r w e t

a 60 W 40 20 0 R-71 R-72 R-73 R-74 R-75 R-76 R-77 Reach no.

Fig-38: Water width of Sector-VIII Fig-36: Satellite image of Sector- 34

3.2. Subansiri River: 4.2.1. Population status and distribution pattern: Altogether 25 (best estimate) dolphins (minimum 21 to maximum 28) were recorded in Subansiri River (Table-6) with an encounter rate of 0.25 dolphins per km. The highest encounter rate was in Sector-9 (0.5 dolphin per km) (Fig-40). Adults were maximum (39%) followed by sub-adults and calves (Fig-41) (details in Table-7).

Fig-39: Subansiri River in its upstream

Table-6: Population status and distribution pattern of dolphins in Subansiri River Sectors Area Location Dolphin No. Min Max Best S-1 Sawoldhuwa to N 27026/, E 94014/ - 1 1 1 Khaliamari N 27002/, E 94013/ S-2 Khaliamari to N 27002/, E 94013/- 2 3 3 Bhurbandha N 27018/, E 94012/ S-3 Bhurbandha to N 27018/, E 94012/ - 2 2 2 Dholaghat N 27015/, E 94012/ S-4 Dholaghat to N 27015/, E 94012/ - 1 2 2 Pokimari N 27011/, E 94010/ S-5 Pokimari to N 27011/, E 94010/ - 2 3 3 Goalbari N 27006/, E 94010/ S-6 Goalbari to N 27006/, E 94010/ - 3 4 3 Khabolu N 27003/, E 94007/ S-7 Khabolu to N 27003/, E 94007/ - 3 5 3 Baralimara N 27000/, E 94003/ S-8 Baralimara to N 27000/, E 94003/ - 1 1 1 Kumoliya N 26058/, E 93059/ S-9 Kumoliya to N 26058/, E 93059/ - 4 5 5 Misamari N 26054/, E 93057/ S-10 Misamari to N 26054/, E 93057/ - 2 2 2 Jamuguri N 26052/, E 93053/ Total 21 28 25 35

0.5 0.45 0.4 0.35 Encounter 0.3 rate 0.25 (dolphin/km) 0.2 0.15 0.1 0.05 0 S-1 S-2 S-3 S-4 S-5 S-6 S-7 S-8 S-9 S-10 Sector no.

Fig-40: Encounter rate of dolphins in different sectors of Subansiri River

Adult (56%)

Sub-adult (20%) Calf (24%)

Fig-41: Age class analysis of dolphins of Kulsi River 36

Table-7: Age-class distribution of dolphins in Subansiri River

Sectors Area Location No. of dolphins Adult Subadult Calf Total S-1 Sawoldhuwa to N 27026/, E 94014/ - 1 -- -- 1 Khaliamari N 27002/, E 94013/ S-2 Khaliamari to N 27002/, E 94013/- 1 1 1 3 Bhurbandha N 27018/, E 94012/ S-3 Bhurbandha to N 27018/, E 94012/ - 1 -- 1 2 Dholaghat N 27015/, E 94012/ S-4 Dholaghat to N 27015/, E 94012/ - 2 -- -- 2 Pokimari N 27011/, E 94010/ S-5 Pokimari to N 27011/, E 94010/ - 2 -- 1 3 Goalbari N 27006/, E 94010/ S-6 Goalbari to N 27006/, E 94010/ - 2 -- 1 3 Khabolu N 27003/, E 94007/ S-7 Khabolu to N 27003/, E 94007/ - 2 1 -- 3 Baralimara N 27000/, E 94003/ S-8 Baralimara to N 27000/, E 94003/ - 1 -- -- 1 Kumoliya N 26058/, E 93059/ S-9 Kumoliya to N 26058/, E 93059/ - 2 2 1 5 Misamari N 26054/, E 93057/ S-10 Misamari to N 26054/, E 93057/ - -- 1 1 2 Jamuguri N 26052/, E 93053/ Total 14 5 6 25

3.2.2. Physico-chemical characteristics of dolphin habitats: During the study period, water temperature of Subansiri River ranged from 18.2- 28.7 0C, Ph was 7.1-8.3, transparency 14.0-58.2 cm, conductivity 82.6-142.6 µS, total dissolved solids 40-221 ppm, bicarbonate alkalinity 44.6-110.8 mg-l, dissolved oxygen 7.8-14.7 mg-l, free carbon-di-oxide 2.8-10.6 mg-l, total hardness 46.3-104.2 mg-l, calcium hardness 22.3-50.8 mg-l, chloride 2.8-9.1 mg-l, silicate 3.7-13.2 mg-l (table-8).

3.2.3. Geomorphological and riparian characteristics of dolphin habitats Except first 3 km stretch, the substrates of rest of the reaches of Subansiri River were of fine sand (Table-9). Riparian zones were occupuied mainly by grassland and human settlements. The habitats comprised of river meandering, confluence, mid-channel island and wide straight channel (details in Table-9).

Table-8: Average physico-chemical characteristics of dolphin habitats in Subansiri River

Parameter Sawoldhua Dholaghat Khabolu Badati

Water temperature 18.2-28.3 19.3-28.1 19.1-27.7 19.0-28.7 (0C) PH 7.1-8.3 7.2-8.2 7.2-8.0 7.1-7.8 Transparency (cm) 18.5-45.5 18.2-44.2 15.6-58.2 14.0-42.7 Conductivity 93.1-130.5 85.2-134.1 82.6-138.7 93.2-142.6 (µS) TDS (ppm) 66-123 68-221 95-160 40-116 Bicarbonate 51.7-75.2 44.6-65.1 50.2-110.8 45.8-83.7 Alkalinity (mg-l) Dissolved oxygen 7.8-9.9 8.1-14.7 8.2-10.5 8.2-10.1 (mg-l) 3.5-6.4 3.5-5.8 5.3-10.6 2.8-6.2 Free Carbon dioxide (mgl-1) 60.3-102.5 48.2-67.0 46.3-89.5 52.3-104.2 Total hardness (mgl-1)

Calcium hardness 22.3-45.2 34.5-44.3 35.2-48.1 36.2-50.8 (mgl-1) Chloride (mgl-1) 3.4-9.1 3.8-8.5 2.8-6.2 2.8-6.1 Silicate (mgl-1) 3.7-9.3 4.2-8.6 5.6-13.2 5.1-12.8

Table-9: Geomorphological and riparian characteristics of River Subansiri

Riparian cover Reac Reach location Substrate Habitat h no. Left Right

riparian riparian zone zone 1. BL N 27026/083//, E 94014/496// MCI GL VL 2. BL N 27025/610//, E 94014/296// WSC GL VL 3. BC N 27025/099//, E 94014/369// RM GL GL 4. FS N 27024/586//, E 94014/476// RM GL GL 5. FS N 27024/096//, E 94014/764// RM VL GL 6. FS N 27023/553//, E 94014/854// WSC GL GL 7. FS N 27023/397//, E 94014/398// WSC GL GL 8. FS N 27023/352//, E 94013/802// RM GL GL 38

9. FS N 27022/966//, E 94013/381// RM GL GL 10. FS N 27022/438//, E 94013/250// RM GL GL 11. FS N 27021/937//, E 94013/362// NSC GL GL 12. FS N 27021/379//, E 94013/477// WSC AG GL 13. FS N 27020/805//, E 94013/413// RM GL GL 14. FS N 27020/377//, E 94013/051// CF GL GL 15. FS N 27020/121//, E 94012/639// WSC GL GL 16. FS N 27019/823//, E 94012/151// RM GL VL 17. FS N 27019/554//, E 94011/709// WSC GL VL 18. FS N 27019/124//, E 94011/926// WSC GL GL 19. FS N 27018/754//, E 94012/399// WSC VL GL 20. FS N 27018/280//, E 94012/513// RM GL GL 21. FS N 27017/915//, E 94012/130// WSC GL VL 22. FS N 27017/841//, E 94011/673// RM GL GL 23. FS N 27017/654//, E 94011/151// RM GL GL 24. FS N 27017/169//, E 94011/271// RM GL GL 25. FS N 27016/940//, E 94011/835// WSC GL GL 26. FS N 27016/740//, E 94012/369// WSC GL GL 27. FS N 27016/413//, E 94012/822// WSC VL GL 28. FS N 27016/113//, E 94013/272// RM VL GL 29. FS N 27015/590//, E 94013/217// RM GL GL 30. FS N 27015/249//, E 94012/778// RM GL GL 31. FS N 27014/841//, E 94012/365// RM GL GL 32. FS N 27014/356//, E 94012/185// RM GL GL 33. FS N 27013/942//, E 94012/124// WSC GL GL 34. FS N 27013/589//, E 94012/013// WSC GL GL 35. FS N 27013/090//, E 94011/015// WSC GL GL 36. FS N 27012/566//, E 94012/020// RM GL GL 37. FS N 27012/092//, E 94011/909// RM GL GL 38. FS N 27011/870//, E 94011/404// WSC GL GL 39. FS N 27011/600//, E 94011/913// WSC GL VL 40. FS N 27011/201//, E 94010/546// WSC GL GL 41. FS N 27010/740//, E 94010/426// WSC GL GL 42. FS N 27010/221//, E 94010/631// WSC GL GL 39

43. FS N 27009/736//, E 94010/791// RM GL GL 44. FS N 27009/231//, E 94010/842// RM GL GL 45. FS N 27008/748//, E 94011/050// RM GL GL 46. FS N 27008/148//, E 94010/450// WSC GL VL 47. FS N 27008/016//, E 94010/370// RM GL GL 48. FS N 27007/526//, E 94010/131// WSC GL GL 49. FS N 27007/030//, E 94010/222// RM GL GL 50. FS N 27006/633//, E 94010/543// RM VL GL 51. FS N 27006/366//, E 94010/251// CF VL GL 52. FS N 27006/065//, E 94009/768// WSC GL GL 53. FS N 27005/965//, E 94009/250// RM GL GL 54. FS N 27005/745//, E 94008/727// RM GL GL 55. FS N 27005/271//, E 94008/645// WSC GL GL 56. FS N 27004/784//, E 94008/403// WSC GL GL 57. FS N 27004/460//, E 94007/930// MCI GL GL 58. FS N 27004/195//, E 94007/435// RM GL GL 59. FS N 27003/668//, E 94007/597// MCI GL GL 60. FS N 27003/175//, E 94007/725// RM GL GL 61. FS N 27002/630//, E 94007/705// RM GL GL 62. FS N 27002/215//, E 94007/407// WSC GL GL 63. FS N 27001/870//, E 9407/001// WSC GL GL 64. FS N 27001/459//, E 94006/655// CF GL GL 65. FS N 27001/452//, E 94006/056// RM GL GL 66. FS N 27001/561//, E 94005/885// WSC GL GL 67. FS N 27001/566//, E 94005/292// RM VL GL 68. FS N 27001/292//, E 94004/803// RM GL GL 69. FS N 27000/913//, E 94004/412// WSC VL GL 70. FS N 27000/954//, E 94003/835// WSC VL GL 71. FS N 27001/163//, E 94003/289// WSC GL GL 72. FS N 27001/308//, E 94002/733// WSC GL GL 73. FS N 27000/901//, E 94002/350// WSC GL GL 74. FS N 27000/616//, E 94001/817// WSC GL GL 75. FS N 27000/157//, E 94001/528// RM GL GL 76. FS N 26059/875//, E 94001/278// RM GL GL 40

77. FS N 26059/720//, E 94000/743// RM GL VL 78. FS N 26059/300//, E 94000/381// CF GL GL 79. FS N 26058/911//, E 94000/011// NSC GL GL 80. FS N 26058/392//, E 93059/880// MCI GL GL 81. FS N 26057/820//, E 93059/592// NSC GL GL 82. FS N 26057/377//, E 93059/361// NSC GL GL 83. FS N 26056/960//, E 93059/190// WSC GL GL 84. FS N 26056/317//, E 93058/242// MCI GL GL 85. FS N 26056/554//, E 93057/960// RM GL GL 86. FS N 26056/321//, E 93057/998// RM GL GL 87. FS N 26056/276//, E 93057/600// RM GL GL 88. FS N 26055/778//, E 93057/389// RM GL GL 89. FS N 26055/241//, E 93057/424// RM GL GL 90. FS N 26054/781//, E 93057/189// RM VL GL 91. FS N 26054/448//, E 93056/382// RM GL GL 92. FS N 26054/550//, E 93055/923// RM GL GL 93. FS N 26054/306//, E 93055/391// MCI GL WL 94. FS N 26054/063//, E 93054/931// CF GL GL 95. FS N 26053/535//, E 93054/885// WSC GL GL 96. FS N 26053/143//, E 93054/716// RM GL GL 97. FS N 26052/921//, E 93054/206// RM GL GL 98. FS N 26052/740//, E 93053/732// RM GL GL 99. FS N 26052/246//, E 93053/506// WSC GL GL

Abbreviation

BL: Boulder BC: Boulder + Cobble

3.2.4. Depth and Width of Subansiri River:

The details of the depth and width of each sector are mentioned in the following figures (Fig-42 to Fig-71).

Sector-I:

8 ) m

h ( 6 pt e

D 4

0 R-1 R-2 R-3 R-4 R-5 R-6 R-7 R-8 R-9 R-10 Reach no.

Fig-43: Minimum depth of Sector-I

120

100

80 ) m (

h 60 t d

Wi 40

0 R-1 R-2 R-3 R-4 R-5 R-6 R-7 R-8 R-9 R-10 Reach no.

Fig-42: Satellite image of Sector-I Fig-44: Minimum width of Sector-I 42

Sector-II:

3.5

) 2.5 m (

h 2 t p

De 1.5

0.5

0 R-11 R-12 R-13 R-14 R-15 R-16 R-17 R-18 R-19 R-20 Reach no.

Fig-46: Minimum depth of Sector-II

140

120

100 )

m 80 h ( dt

i 60 W 40

0 R-11 R-12 R-13 R-14 R-15 R-16 R-17 R-18 R-19 R-20 Reach no.

Fig-47: Minimum depth of Sector-II Fig-45: Satellite image of Sector-II

Sector-III:

5 4.5 4 3.5 ) 3 m (

h 2.5 t p 2 De 1.5 1 0.5 0 R-21 R-22 R-23 R-24 R-25 R-26 R-27 R-28 R-29 R-30 Reach no

Fig-49: Minimum depth of Sector-III

160 140 120

) 100 m (

h 80 t d

Wi 60 40 20 0 R-21 R-22 R-23 R-24 R-25 R-26 R-27 R-28 R-29 R-30 Reach no.

Fig-50: Minimum width of Sector-III Fig-48: Satellite image of Sector-III

Sector-IV:

4.5 4 3.5 3 )

m 2.5 h (

pt 2 e

D 1.5 1 0.5 0 R-31 R-32 R-33 R-34 R-35 R-36 R-37 R-38 R-39 R-40 Reach no.

Fig-52: Minimum depth of Sector-IV

180 160 140 120 )

m 100 h (

dt 80 i

W 60 40 20 0 R-31 R-32 R-33 R-34 R-35 R-36 R-37 R-38 R-39 R-40 Reach no.

Fig-53: Minimum width of Sector-IV

Fig-51: Satellite image of Sector-IV

Sector-V:

10 9 8 7 ) 6 m

h ( 5 pt

e 4 D 3 2 1 0 R-41 R-42 R-43 R-44 R-45 R-46 R-47 R-48 R-49 R-50 Reach no.

Fig-55: Minimum depth of Sector-V

250

200

) 150 m h ( pt

e 100 D

0 R-41 R-42 R-43 R-44 R-45 R-46 R-47 R-48 R-49 R-50 Reach no.

Fig-54: Satellite image of Sector-V Fig-56: Minimum width of Sector-V

Sector-VI:

7 6 5 ) 4

pth (m 3 e D 2 1 0 R-51 R-52 R-53 R-54 R-55 R-56 R-57 R-58 R-59 R-60 Re a ch n o.

Fig-58: Minimum depth of Sector-VI

250

200

) 150 m ( h t d 100 Wi

0 R-51 R-52 R-53 R-54 R-55 R-56 R-57 R-58 R-59 R-60 Reac h no.

Fig-57: Satellite image of Sector-VI Fig-59: Minimum width of Sector-VI

Sector-VII:

4.5 4 3.5 3 )

m 2.5 h (

pt 2 e

D 1.5 1 0.5 0 R-61 R-62 R-63 R-64 R-65 R-66 R-67 R-68 R-69 R-70 Reach no.

Fig-61: Minimum depth of Sector-VII

250

200

150

100

0 R-61 R-62 R-63 R-64 R-65 R-66 R-67 R-68 R-69 R-70

Fig-60: Satellite image of Sector-VI Fig-62: Minimum width of Sector-VII

Sector-VIII

4 ) m (

h 3 t p

De 2

0 R-71 R-72 R-73 R-74 R-75 R-76 R-77 R-78 R-79 R-80 Reach no.

Fig-64: Minimum depth of Sector-VIII

350

300

250 )

m 200 ( h t

d 150 Wi 100

0 R-71 R-72 R-73 R-74 R-75 R-76 R-77 R-78 R-79 R-80

Reach no.

Fig-63: Satellite image of Sector-VII Fig-65: Minimum width of Sector-VIII

Sector-IX

4 3.5 3 2.5

h (m) 2 pt e

D 1.5 1 0.5 0 R-81 R-82 R-83 R-84 R-85 R-86 R-87 R-88 R-89 R-90 Reach no .

Fig-67: Minimum depth of Sector-IX

350

300

250 )

m 200 ( h t

d 150 Wi 100

0 R-81 R-82 R-83 R-84 R-85 R-86 R-87 R-88 R-89 R-90 Reach no .

Fig-66: Minimum width of Sector-IX Fig-68: Minimum width of Sector-IX

Sector-X

5 4.5 4 3.5 ) 3 (m

h 2.5 t p 2 De 1.5 1 0.5 0 R-91 R-92 R-93 R-94 R-95 R-96 R-97 R-98 R-99 Reach no.

Fig-70: Minimum depth of Sector-X

500 450 400 350 ) 300 m (

h 250 dt 200 Wi 150 100 50 0 R-91 R-92 R-93 R-94 R-95 R-96 R-97 R-98 R-99 Reach no.

Fig-69: Satellite image of Sector-X Fig-71: Minimum width of Sector-X

3.2.5. Fish composition of Kulsi and Subansiri River:

A total of 81 species of fishes (Fig-72 to Fig-75) were collected and identified both from the Kulsi and Subansiri River (Table-10). These species belonged to 25 families and 50 genera. Among the families, Cyprinidae ranked first (34.5%) followed by Bagridae (9.8%), Channidae (8.6%) and Siluridae (4.9%). Among the genera, the most abundant were Channa with seven species, followed by Labeo (6 species), Puntius and Mystus (4 species each). According to the status given by IUCN, one species (Pangasius pangasius) was recorded as critically endangered (CR), nine species as endangered (EN), thirty one species as Lower Risk-near threatened (LRnt), five species as Lower Risk-least concern (LRIc), fifteen species as vulnerable (VU), one species remained as data deficient (DD) and seventeen species were not assessed (NA) (Table-10).

Table-10: Diversity, abundance and status of fish fauna in Kulsi and Subansiri River

Family Species Abundance IUCN status

Notopteridae 1. Notopterus notopterus (Pallas) + LRnt 2. Chitala (Notopterus) chitala (Ham.- Buch.) ++ EN Anguillidae 3. Anguilla bengalensis bengalensis (Gray & Hardwicke) + EN Clupeidae 4. Gudusia chapra (Ham. - Buch.) ++ LRIc Cyprinidae 5. Amblypharyngodon mola (Ham. - Buch.) +++ LRIc 6. Aspidoparia jaya (Ham. - Buch.) +++ VU 7. A. morar (Ham. - Buch.) +++ LRnt 8. Barilius barila (Ham. - Buch.) ++ LRnt 9. B. barna (Ham. - Buch.) + LRnt 10. B. bendelisis (Ham. - Buch.) + LRnt 11. Bengala (Rasbora) elanga (Ham.- Buch.) ++ NA 12. Catla catla (Ham. - Buch.) +++ VU 13. Chela cachius (atpar) (Ham.- Buch.) +++ NA 14. C. laubuca (Ham. - Buch.) ++ LRIc 15. Cirrhinus mrigala (Ham. - Buch.) +++ LRnt 16. C. reba (Ham. - Buch.) ++ VU 17. Crossocheilus latius latius (Ham. - Buch.) +++ DD 18. Danio devario (Ham. - Buch.) ++ NA 19. Esomus danricus (Ham. - Buch.) +++ LRIc 20. Labeo bata (Ham. - Buch.) +++ LRnt 21. L. boga (Ham. - Buch.) ++ LRnt 22. L. calbasu (Ham. - Buch.) +++ LRnt 23. L. gonius (Ham. - Buch.) +++ LRnt 24. L. pangusia (Ham. - Buch.) ++ LRnt 25. L. rohita (Ham. - Buch.) ++ LRnt 26. Paraluciosoma (Rasbora) daniconius (Ham. - Buch.) +++ LRnt 27. Puntius conchonius (Ham. - Buch.) +++ VU 28. P. sarana sarana (Ham. - Buch.) ++ VU 29. P. sophore (stigma) (Ham. - Buch.) +++ LRnt 53

30. P. ticto (Ham. - Buch.) +++ LRnt 31. Tor putitora (Ham. - Buch.) + EN 32. T. tor (Ham. - Buch.) + EN Balitoridae 33. Nemacheilus (Acanthocobitis) botia (Ham.- Buch.) ++ LRnt Cobitidae 34. Botia dario (Ham.- Buch.) + NA 35. B. rostrata Gunther + NA Bagridae 36. Sperata (Aorichthys) aor (Ham.- Buch.) +++ NA 37. S. (Aorichthys) singhala (Sykes) + EN 38. S. menoda (Ham.- Buch.) ++ NA 39. Mystus bleekeri (Day) +++ VU 40. M. cavasius (Ham. - Buch.) +++ LRnt 41. M. tengara (Ham.- Buch.) +++ NA 42. M. vittatus (Bloch) +++ VU 43. Rita rita (Ham. - Buch.) + LRnt Siluridae 44. Ompok bimaculatus (Bloch) ++ EN 45. O. pabda (Ham. - Buch.) ++ EN 46. O. pabo (Ham. - Buch.) ++ NA 47. Wallago attu (Bloch & Schneider) +++ LRnt Schilbeidae 48. Ailia coila (Ham. - Buch.) ++ VU 49. Clupisoma garua (Ham. - Buch.) ++ VU 50. Eutropiichthys vacha (Ham. - Buch.) ++ EN 51. Silonia silondia (Ham. - Buch.) ++ LRnt Pangasiidae 52. Pangasius pangasius (Ham. - Buch.) + CR Sisoridae 53. Bagarius bagarius (Ham. - Buch.) +++ VU 54. Sisor rhabdophorus Ham. - Buch. + EN Claridae 55. Clarias batrachus (Linn.) +++ VU Heteropneustidae 56. Heteropneustes fossilis (Bloch) +++ VU Chacidae 57. Chaca chaca (Ham. - Buch.) ++ NA Belonidae 58. Xenentodon cancila (Ham. - Buch.) +++ LRnt Symbranchidae 59. Monopterus (Amphipnous) cuchia (Ham. - Buch.) ++ LRnt Chandidae 60. Chanda nama Ham. - Buch. +++ NA 61. Parambassis ranga (Ham. - Buch.) +++ NA Nandidae 62. Badis badis (Ham. - Buch.) + NA 54

63. Nandus nandus (Ham. - Buch.) + LRnt Mugulidae 64. Rhinomugil corsula (Ham. - Buch.) + NA 65. Sicamugil cascasia (Ham. - Buch.) + Vu Gobiidae 66. Glossogobius giuris (Ham. - Buch.) ++ LRnt Anabantidae 67. Anabas testudineus (Bloch) + VU Belontidae 68. Colisa fasciatus (Schneider) +++ LRnt 69. C. lalia (Ham. - Buch.) ++ NA 70. C. sota (Ham. - Buch.) +++ NA Channidae 71. Channa aurantimaculata +++ NA 72. C. barca (Ham. - Buch.) +++ NA 73. C. stewarti (Playfair) ++ NA 74. C. marulius (Ham. - Buch.) +++ LRnt 75. C. punctatus (Bloch) +++ LRnt 76. C. striatus (Bloch) +++ LRIc 77. C. orientalis (gachua) (Schneider) ++ VU Mastacembelidae 78. Mastacembelus (Macrognathus) armatus (Lacepede) +++ NA 79. M. pancalus Ham. - Buch. +++ LRnt 80. Macrognathus aral (Bloch) +++ LRnt Tetraodontidae 81. Tetraodon cutcutia (Ham. - Buch.) +++ LRnt

Abbreviation

CR: Critically Endangered EN: Endangered LRnt: Low-Risk near threatened LRlc: Low-Risk least concern VU: Vulnerable NA: Not Assessed +: Rare ++: Occassional +++: Common 55

Fig-72: Fish species from Kulsi and Subansiri River 56

Fig-73: Fish species from Kulsi and Subansiri River 57

Fig-74: Fish species from Kulsi and Subansiri River 58

Fig-75: Fish species from Kulsi and Subansiri River

Sand mining on the dolphins of Kulsi River

Sand mining (Fig-76 & Fig-84) in the Kulsi River was observed for one year (from June, 06 to May, 07). The sand mining rate was maximum in winter season (November- February) and minimum in summer season (June-August) (Fig-77). There were altogether 5 different sand mining sites (locally called as Mahals), namely Pothar Ghat, Mastoror Ghat, Major Ghat, Dhubar Ghat and Amtola Ghat. Maximum sand mining rate was observed at Pothar Ghat (39%), followed by Major Ghat (29%) (Fig-78). Maximum sand mining rate was observed in February at Pothar Ghat (Fig-79), in December at Mastoror Ghat (Fig-80), February at Major Ghat (Fig-81), January at Dhubar Ghat (Fig-82) and again in January at Amtola (Fig-83).

Fig-76: Sand mining in Kulsi River 60

30000

25000

20000 Sand mining rate 15000 (cubic cm) 10000

5000

0 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Months

Fig-77: Total sand mining rate in Kulsi River in different times of the year

Pothar (39%)

Mastor (6%)

Amtola (17%)

Dhuba Major (9%) (29%)

Fig-78: Comparative sand mining rate in different sand mining areas of Kulsi River

12000 )

m 10000 c c

ubi 8000 c ( e t

a 6000 r ng ni

i 4000 nd m

a 2000 S

0 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

Fig-79: Sand mining rate at Pothar Ghat at different seasons of the year

2000 1800 )

m 1600 c c 1400 ubi c

( 1200 e t

a 1000 r

ng 800 ni i 600 400 nd m a

S 200 0 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

Fig-80: Sand mining rate at Mastoror Ghat at different seasons of the year

9000

) 8000 m

c 7000 c

ubi 6000 c ( e

t 5000 a

r 4000 ng ni

i 3000 2000 nd m a

S 1000 0 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

Fig-81: Sand mining rate at Major Ghat at different seasons of the year

2500 )

m 2000 c c ubi c

( 1500 e t a r

ng 1000 ni i

500 nd m a S

0 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

Fig-82: Sand mining rate at Dhubar Ghat at different seasons of the year 63

5000 4500 )

m 4000 c c 3500 ubi c

( 3000 e t

a 2500 r

ng 2000 ni i 1500 1000 nd m a

S 500 0 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

Fig-83: Sand mining rate at Amtola Ghat at different seasons of the year

Fig-84: One dolphin surfacing just near sand mining site

Observed threats / disturbing factors

Fig-85: Blocking in the mouth of wetlands disturbing the local migration of fish to the nearby dolphin habitats

Fig-86: Employing such drift nets in the middle of the River disturb the movements of dolphins in both Kulsi and Subansiri River 65

Fig-87: Cast netting in high fish assemblage areas disturb the feeding behaviour of dolphins in both Kulsi and Subansiri River

Fig-88: Sand mining disturbs the day time movement pattern of dolphins in Kulsi River

Fig-89: Sand mining in the river bank increasing the habitat degradation of dolphins in Kulsi River

Fig-90: The end part of a victim (dolphin) of accidental killing in Kulsi River. These dried body parts were rescued by Project Team in collaboration with local forest officials

Conservation Initiatives

Fig-91: Participants of an awareness campaign conducted among the local communities of Kulsi River

Fig-92: A community based volunteer discussing the threats of the dolphins of his area with Project Leader 68

Fig-93: A community level awareness campaign

Fig-94: Team members with local forest officials investigating a dolphin mortality case in villages residing near the Kulsi River

Fig-95: Awareness campaign among local fishermen communities in Subansiri River

Fig-96: Awareness campaign among local community leaders

Fig-97: Awareness campaign among local fishermen community in Kulsi River 70

Fig-98: Team members showing the distribution of dolphins in Brahmaputra Valley to the participants of an awareness campaign

Fig-99: Community based awareness meeting 71

Fig-100: Team member with local community leaders

Fig-101: Awareness campaign among local community youths in Subansiri River

Fig-102: Local community youths with Project team in dolphin monitoring

Fig-103: Community based volunteers are getting experience in dolphin acoustic studies 73

Fig-104: Community based dolphin conservation volunteers in dolphin monitoring survey

Following education materials (poster, booklet, sticker) prepared and distributed among different stakeholders by Project team during the project period

Experts / Observers with Project Team in 2006-07

Fig-105: Dr. Shaun Russell, an eminent UK (University of Wales, UK) conservation leader with Team members in the field

Fig-106: Dr. Rosie Travellyn (Director, Tropical Biology Association, University of Cambridge) & Mrs. Sujata Sen (Director, British Council, India) with Team members in the field 77

Fig-107: Dr. John Goold of University of Wales, UK observing the field data collected by the Project Team

Fig-108: Representative of David Shepherded Wildlife Foundation (UK) with Team members in the field 78

Fig-109: Prof. R. K. Sinha (University of Patna, India), an IUCN-Cetacean Specialist and Advisor to the Project Team with Team members in the field

Fig-110: Prof. B. C. Choudhury (Wildlife Institute of India), an Advisor to the Ministry of Environment & Forest, Govt of India with Team members in the field

Chapter-4: Recommendations

Based on our last one year experiences on the dolphins of Kulsi and Subansiri River we are forwarding following recommendations for the long term conservation of these two last remaining residential populations of Gangetic dolphins in Brahmaputra Valley.

1. Satellite telemetry and acoustic studies to understand the home range and movement pattern of dolphins in both Kulsi and Subansiri River. 2. The team has already trained up community youths residing in the villages located nearby the important dolphin habitats for the monitoring of the dolphins and their habitats in these two rivers. This monitoring process should be continued through developing community based dolphin conservation units. 3. The Department of Environment & Forest (Govt. of Assam), Department of Fisheries and local communities should work collaboratively for the conservation of the species. 4. More awareness campaign should be conducted along the bank of both of these rivers in association with already developed dolphin conservation volunteers and local managers. 5. Fishing through fine mesh-sized gill nets and in closed seasons should be banned strictly. 6. Effort should be made to keep clear the important dolphin habitats of both of these two rivers from fishing practices, especially gill netting.

Chapter-5: References

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