Indian J. Fish., 58(3) : 13-22, 2011 13

Exploited fisheries resources of the Pampa River, Kerala, India

C. R. RENJITHKUMAR, M. HARIKRISHNAN AND B. MADHUSOODANA KURUP* School of Industrial Fisheries, Cochin University of Science and Technology, Fine Arts Avenue Kochi - 682 022, Kerala, India *Kerala University of Fisheries and Ocean Studies, Panangad P. O., Kochi - 682 506, Kerala, India e-mail: [email protected]

ABSTRACT River Pampa is one of the longest river systems of Kerala. Out of the 60 species of fishes reported from the river, 26 species, belonging to 5 orders and 21 genera contributed to the exploited fishery. The landings were represented by one endangered (Gonoproktopterus curumca), two each vulnerable (Horabagrus branchysoma and Channa diplogramma) and near threatened (NT) fish species (Wallago attu and Ompok bimaculatus). The annual average landings from this river was estimated to be 394.22 t. Highest landings were recorded during pre-monsoon season (194.48 t) and lowest in monsoon (38.97 t). Labeo dussumieri (75.98 t), Puntius sarana subnasutus (39.61 t), W. attu (37.65 t), Channa striatus (36.34 t) and Amblypharyngodon microlepis (34.32 t) were the dominant fishes in the landings. Catla catla (17.28 t) and Clarias gariepinus were the exotic species observed in the landings. Macrobrachium rosenbergii was the most priced species used for export. Among the landing centers, Parumala accounted for 65.3% of total landings, followed by Edathua (14.5%). About 77% of exploited fishery was accounted from the gillnets followed by seines (19%), castnets (3%) and hooks and lines (1%). Highest catch per unit hours (CPU) was recorded in seines in respect of A. microlepis (2.40 kg unit-1). The major fishery resources, fishing methods, catch per unit hour and various biodiversity threats prevalent in the Pampa River system are discussed in this paper. Keywords: Biodiversity status, Exploited fishery, Pampa river, Quantification

Introduction Randatinkara and Edathua (Fig. 1), where regular systematic surveys and sampling were conducted during Pampa River is one of the longest rivers in Kerala pre-monsoon, monsoon and post-monsoon seasons during (179 km) which spreads as an arterial network in Kuttanad, 2007-2009. Details of landings were collected from more the extensive low lying agricultural fields of the state. than 30% of the gears, giving emphasis to type of gear, Ichthyofaunal investigations in the rivers of Kerala had mesh size, species composition and weight, size groups drawn attention with the outstanding works of Jerdon represented in the catch, actual fishing hours and man (1849), followed by the classical work of Day power engaged. Selection of fishing units for detailed (1865;1878;1889), Pillai (1929), John (1936), Hora and observation was done following Alagaraja (1984) and Nair (1941), Chacko (1948), Silas (1951;1952), Menon Kurup et al. (1992). Catch Per Unit Effort (CPUE) was (1951), Thobias (1973), Antony (1977), Remadevi and Indra (1986), Kurup et al. (1994; 2000; 2006), Easa and Basha (1995), Easa and Shaji (1997), Ajith Kumar et al. (1999) and Gopi (2000). Among 174 fish species known from various rivers of the state, 55 are reported from the Pamba River (Radhakrishnan, 2006). Information on fish production from any water body is important for its judicious exploitation and management. This paper is a pioneer attempt in this direction and provides details of exploited fishery resources of Pampa River. Materials and methods The exploited fishery of Pampa River was estimated based on the data generated from major landing centres, Neeratupuram, Chakkulam kadavu, Parumala, Pavukkara, Fig. 1. Map of Pamapa River showing sampling locations C. R. Renjithkumar et al. 14 computed following Scaria et al. (1997). Fish samples Table 1. Inventory of fish species of Pampa River and their collected were preserved in 8% formalin and brought to biodiversity status the laboratory for species level identification following Species Cultivable/ Biodiversity Endemism Day (1878), Talwar and Jhingaran (1991), Jayaram (1999) Ornamental/ status and Radhakrishnan (2006). Daily landings from each type Food fish (IUCN) of gears and fishing methods were computed following Kurup et al. (1992). Anguilla bengalensis Cultivable LC - Cyprinus carpio Cultivable VU EX W = (w/n) X N Cirrhinus mrigala Cultivable LC TR where W = total weight of fish, w = total weight of Gonoproktopterus curumca Food fish EN EN-WG fish from gear sampled Labeo dussumieri Cultivable LC EN-K Labeo fimbriatus Cultivable LC EN-IS n = number of gear sampled, N = total number of Catla catla Cultivable LC similar gears operated. Osteobrama bakeri Ornamental LC EN-K Monthly catch was estimated by multiplying daily Puntius amphibius Ornamental DD - catch with total number of fishing days in a month. Puntius bimaculatus Ornamental LC EN-WG Season-wise landing was estimated by multiplying monthly Puntius chola Food fish LC - catch to number of months in the season. The annual Puntius denisonii Ornamental EN EN-K exploited quantity was calculated by summarising the Puntius vittatus Ornamental LC - landings of three seasons. The fish species inventory was Puntius fasciatus Ornamental LC EN-WG prepared based on data collected as part of a previous study Puntius filamentosus Ornamental LC EN-WG (Kurup et al., 2005) and present observations. The Puntius ticto Ornamental LC EN-WG biodiversity status of such fishes was assigned following Puntius sarana subnasutus Food fish LC - IUCN (2010). Tor khudree Cultivable EN - Results Salmostoma acinaces Food fish LC EN-WG Salmostoma boopis Food fish LC EN-I Inventory of fish species of the River Pampa Amblypharyngodon microlepis Ornamental LC EN-I Sixty species of fishes belonging to 17 families and Barilius bakeri Ornamental LC EN-WG 36 genera were identified from Pampa River (Table 1). Barilius gatensis Ornamental LC EN-WG It was noted that five species each belonged to endangered Danio malabaricus Ornamental LC EN-IS and vulnerable category (8% each), three belonged to near Danio aequipinnatus Ornamental DD EN-IS threatened (5%), 39 least concern category (65%) and Rasbora daniconius Ornamental LC - 8 species were assigned with data deficient status (14%). Garra ceylonensis Food fish DD - (Fig. 2). Among the 60 species, only 26 species contributed Garra mullya Ornamental LC EN-I to the exploited fishery. Family Cyprinidae ranked first Garra hughi Ornamental EN EN-K among different fish groups with a numerical strength of Garra surendranathanii Ornamental EN EN-K 30 species followed by Bagridae with five species. Bhavania auatralis Ornamental LC EN-WG Mesonemacheilus triangularis Ornamental LC EN-WG Mesonemacheilus guentheri Ornamental LC EN-WG Lepidocephalus thermalis Ornamental LC EN-IS Bataso travancoria Food fish VU EN-K Horabagrus brachysoma Cultivable VU EN-K Mystus gulio Food fish LC - Mystus armatus Food fish LC EN-IS Mystus menoda Food fish DD EN-IS Ompok bimaculatus Ornamental NT - Wallago attu Ornamental NT - Heteropneustes fossilis Cultivable LC EN-IS Xenentodon cancila Food fish LC EN-IS Parambassis dayi Food fish LC EN-K Fig. 2. Biodiversity assessment of fish species in the River Pampa. Parambassis thomassi Ornamental LC EN-WG LC : Least concern, NT : Near threatened, Nandus nandus Ornamental LC - VU : Vulnerable, EN : Endangered, DD : Data deficient Pristolepis marginatus Ornamental LC EN-K Exploited fisheries resources of the Pampa River 15

Etroplus suratensis Cultivable LC EN-IS Quantification of exploited fishery resources Etroplus maculatus Ornamental LC EN-IS The average annual exploited fishery of the Pampa Glossogobius giuris Food fish DD - River was estimated at 394.22 t. Highest landings were Anabas testudineus Food fish DD - recorded during pre-monsoon season (194.48 t) whereas, Channa striatus Food fish LC EN-WG it was lowest in monsoon (38.97 t). The species-wise Channa orientalis Food fish DD - landings are given in Table 2. Labeo dussumieri, commonly Channa marulius Cultivable LC - known as ‘Thooli’ recorded the highest landings (19.27%) Channa diplogramma Food fish VU En-K in the river. This species supported a lucrative fishery year Macrognathus aral Food fish LC - around and sustained as the major source of livelihood Clarias dussumieri Food fish NT EN-I source to the fishermen. The size group 110-159 mm Mastacembelus armatus Food fish LC - dominated the landing. W. attu formed 9.55% of total Clarias gariepinus Food fish DD EX landings and the dominant size group was 300-990 mm. Tetradon travancorius Ornamental VU EN-K Channa striatus (36.34 t), C. marulius (30.06 t) and LC - Least concern, NT - Near threatened, VU - Vulnerable, EN-Endangered, C. diplogramma (0.79 t) formed other major groups in the DD - Data deficient fishery, constituting 17% of total landings. Genus Puntius EX: Exotic, TR : Transplanted, EN-G:- Endemic to Western Ghats, EN-IS : Endemic to Indian sub-continent, EN-I : Endemic to India, represented by three species viz., P. sarana subnasutus EN-K: Endemic to Kerala. (39.61 t), P. filamentosus (20.64 t), and P. amphibius (0.07 t) constituted 15% of total landings. The annual Exploited fishery landings of M. rosenbergii in the river was estimated at Twenty six fish species belonging to five orders and 27.05 t. The small-sized fish A. microlepis, commonly 21 genera were identified in the exploited fishery of Pamba known as ‘Vayambu’, formed a major fishery in the river River. The commercially important species, their local accounting 34.32 t in the landings. P. thomassi and P. dayi, names, and size ranges are presented in Table 2. Percentage the two species of glassy perchlets, were represented by contribution of various fish families to the total riverine size ranges 60-179 mm. P. dayi was more abundant during fishery is depicted in Fig. 3. Among 26 fish species recorded post-monsoon season. in the landing centres, family Cyprinidae was the most Among the six landing centres, Parumala contributed dominant group with 8 species (31%) followed by 65.3% to the total fish landing, followed by Edathua Channidae (11%). Catla catla and Clarias gariepinus were (14.5%) (Fig. 4). There was only marginal fishery recorded the exotic species observed in the landings while, the giant in other landing centres such as Neerettupuram (7.2%), freshwater prawn Macrobrachium rosenbergii formed the Chakkulathukadavu (6.9%) and Pavukkara (3.8%). The only invertebrate species in the exploited fishery. The fishery was poor in Randattinkara (2.3%). Fish landings landings were represented by one endangered were invariably high in all the landing centres during (Gonoproktopterus curumca), two each vulnerable pre-monsoon season except in Neerettupuram and in (Horabagrus branchysoma and Channa diplogramma) and Pavukkara, where post-monsoon was the major season. near threatened (NT) fish species (Wallago attu and Ompok Among the fishes landed, Etroplus suratensis and W. attu bimaculatus). were the highly priced species.

Fig. 4. Percentage contribution of six fish landing centres supporting fishery from Pampa River The average annual revenue of the fishery of the Pampa River was estimated at 37.21 million rupees. Among Fig. 3. Percentage representation of species at family level in the 26 species, M. rosenbergii was the most valued species the exploited fishery in River Pampa. (2007-09). (6.55 million rupees), followed by E. suratensis C. R. Renjithkumar et al. 16

Table. 2. Species composition in the exploited fishery of Pampa River Scientific name Common name Size range Landings Price range Revenue (mm) (t) Price per kg (Rs.) (Million Rs.) Order: Cypriniformes Family: Cyprinidae Puntius filamentosus Black spot barb 50-209 20.64 40-60 1.02 Puntius sarana subnasutus Peninsular olive barb 100-279 39.61 50 2.01 Labeo dussumieri Kerala labeo 110-359 75.98 40-60 4.22 Amblypharyngodon microlepis Carplet 40-129 34.32 40-50 1.40 Puntius amphibius Scarlet banded Barb 100-139 0.07 40-50 .0001 Catla catla Catla 350-649 17.28 70-80 1.21 Gonoproktopterus curmuca Curumuca barb 250-299 0.04 60-70 0.0001 Osteobrama bakeri 120-139 0.01 40-50 0.0001 Order: Siliuriformes Family: Bagridae Horabagrus branchysoma Yellow cat fish 90-230 17.11 40-60 0.96 Mystus armatus 60-99 0.09 40-60 0.01 Family: Heteropneustidae Heteropneustes fossilis Stinging catfish 110-199 15.97 50-60 0.88 Family: Claridae Clarias gariepinus African catfish 210-340 0.1 70-90 Family: Siluridae Wallago attu Boal 300-990 37.65 80-160 5.07 Ompok bimaculatus Goan catfish 1.44 50-60 0.07 Order: Synbranchiformes Family: Mastacembelidae Mastacembelus armatus Marble spiny eel 190-388 0.24 40-60 0.01 Macrognathus aral Spiny eel 110-329 0.42 40-60 0.03 Order: Perciformes Family: Anabantidae Anabas testudineus Climbing perch 160-199 2.88 30-40 0.14 Order: Beloniformes Family: Belonidae Xenentodon cancila Long -nosed needle fish 160-289 0.55 40-60 0.03 Family: Channidae Channa striatus Banded snakehead 160-439 36.34 100-120 3.84 Channa marulius Giant snakehead 110-490 30.36 100-130 3.04 Channa diplogramma Snakehead 210-329 0.79 130-140 0.11 Family: Cichlidae Etroplus suratensis Banded pearlspot 130-329 31.88 120-200 6.41 Family: Pristolepidae Pristolepis marginata Malabar catopra 136-150 0.06 50-60 0.0001 Family: Ambassidae Parambassis dayi Day’s glass fish 60-179 1.30 40-50 0.06 Parambassis thomassi Glassy perchlet 100-139 0.07 40-50 0.0001 Family: Nandidae Nandus nandus Leaf fish 60-159 2.30 40-50 0.13

(6.41 million rupees) and W. attu (5.07 million rupees). Craft and gear The fishery of A. microlepis is high in Pampa River, but The percentage contribution by weight of various gears the value of this species is very low (1.40 million rupees). in the exploited fishery from Pamba River is given in Exploited fisheries resources of the Pampa River 17

Fig. 5. Gillnet locally known as ‘odakkuvala’ is the River. Castnets of size 2 to 4 m are commonly operated predominant fishing gear operating all along the river and with a wide range of mesh sizes (10 to 45 mm). they accounted for 77% of catch. Seines (19%), castnets L. dussumieri and A. microlepis constituted the main catch (3%) and hooks and lines (1%) were also operated in this in castnets (2.50 kg h-1 and 0.63 kg h-1 respectively) river. Gillnet size varied from 30-150 m and are operated (Fig. 8). Castnets are operated throughout the year, at a depth of 2-6 m. Mesh size was in the range 22-150 mm including during June - August when the river gets flooded with monsoon runoff. Hooks and line is commonly used during post-monsoon season for catching mainly W. attu with a catch per unit hour of 1.22 kg h-1.

Fig. 5. Percentage contribution of various gears in the exploited fishery from the River Pamba. in different designs. The main catches of this net consist of L. dussumieri (17%), W. attu (11%) and Fig. 7. Catch per unit hour of major fish species exploited E. suratensis (5%). The catch per unit effort of gillnets in by seinenets in the River Pampa (2007-‘09). respect of the major commercially important fish species in Pamba River is depicted in Fig. 6. Highest catch per unit was recorded for A. microlepis (1.88 kg h-1) in gillnet followed by C. catla (1.50 kg h-1), P. sarana subnasutus (1.33 kgh-1), W. attu (0.93 kg h-1), L .dussumieri (0.87 kg h-1) and C. marulius (0.77 kg h-1). M. rosenbergii was mostly caught by gillnets (0.37 kg h-1). Seinenet is commonly operated in pre-monsoon season because of low water level in the river. The main species caught by this gear consist of C. marulius (19%), L. dussumieri (18%), A. microlepis (15%) and P. filamentosus (14%). The catch per unit hour of seinenet for various fish species in Pamba River is depicted in Fig. 7. A. microlepis recorded the highest catch per unit -1 Fig. 8. Catch per unit hour of major fish species exploited hour in seines (2.40 kg h ) while L. dussumieri and by castnets in the River Pampa (2007-‘09). C. marulius contributed 1.22 kg h-1 and 1 kg h-1 respectively. Castnet contributed only a very small fishery in Pampa Discussion The fish fauna of Pampa River is very unique and diverse. Twenty six species of fishes were identified in the exploited fishery of Pamba River. Radhakrishnan (2006) reported 55 fish species from this river system including 10 threatened and 42 non- threatened species. In the present study, five more species were added to the fish fauna of river Pampa, viz., C. diplogramma, Macrognathus aral, Osteobrama bakeri, C. catla and Clarias gariepinus. Information regarding estimates of fish production from river stretches in India is scarce (Jhingran, 1991; Kurup,1993; Sinha, 2002), though many reports on estuarine, lacustrine or reservoir fisheries are available Fig. 6. Catch per unit hour of major fish species exploited by (Ramakrishnah, 1987; Rani and Manoharan, 2010). gillnets in the River Pampa (2007-‘09). Riverine fisheries are highly dispersed and unorganized, C. R. Renjithkumar et al. 18 making collection of data on fishing and fish yield difficult predominantly represented by 30-40 cm and 20-30 cm, (Sinha, 1999). The Central Inland Capture Fisheries respectively (Kurup, 1982). Institute (CIFRI), Barrackpore has collected data from selected stretches of rivers Ganga, Brahmaputra, Narmada, Labeo dussumieri is the only species of the genus Tapti, Godavari and Krishna. These rivers harbour a rich Labeo which is indigenous to Kerala waters with a confined and varied fish fauna, of which the Gangetic system alone distribution to Peninsular India and Sri Lanka (John,1936; has 265 species, followed by the Brahmaputra system with Hora and Law,1941). John (1936) listed L .dussumieri as 126 species and the peninsular rivers harbouring 76 species one of the most common species of the rivers of Travancore (Sinha, 1999). Available data show fish yield in these rivers where it was frequently encountered in gillnets. In the river ranges from 0.64 to 1.6 t km-1 (Sinha, 1999). Pampa, the occurrence of this species was encountered in the downstream regions by Kurup et al. (1991). It attains There are many constraints in quantification of about 50 cm in total length and more than 2.0 kg in weight exploited fishery in river stretches, in contrast to estuarine (Kurup, 1988). This species supported annual landings of and marine habitats, mainly because of lack of organized 5.14 to 7.08 t in Pampa River during 1987-1990 (Kurup, landing patterns. Pampa River spreads into an arterial 1993). According to Kurup (1993), the landing from network in Kuttanad. Agriculture and fisheries are the major Pavukkara and Parumala landing centres varied from economic activities of Kuttanad and these are linked by 2.4 to 3.2 t and 2.02 to 2.64 t respectively. On the contrary, their common use of water. The annual fish production in in the present study, the landings was estimated at 6.38 t open waters and adjoining wetlands of Kuttanad is and 37.56 t respectively in the above landing centres. The estimated at 746.76 t (Padmakumar, 2002). The estimated size ranges of L. dussumieri reported was (110-359 mm) annual average exploited fishery of 394.22 t in river Pampa, lower when compared to 90 – 454 mm by Kurup (1993). when compared to the data of Padmakumar (2002) is on In 1990’s, there was an alarming depletion of population the lower side. The depletion of the fish stocks of Kuttanad of this species. Kurup and Kuriakose (1991) developed the region is mainly due to man made impacts on the ecosystem captive breeding technology of L. dussumieri. and ranching such us habitat alteration, reduction of natural growout of this fish species has been carried out in this river which systems due to intensification rice cultivation and cropping may be attributed for the significant increase in its landings pattern, physical obstruction caused in the migratory in major fishing points in the river. pattern, overfishing and pollution hazards due to excessive use of chemicals and pesticides in the paddy fields of John (1936) reported that W. attu is found abundantly Kuttanad (Kurup, 1996). in Kuttanad during February, March and April when the streams and rivers are partially dry. In the present study, Kurup et al. (2006) quantified the exploited fishery in W. attu formed a good fishery (9.5%) in the hooks and lines. Periyar Lake located in the upstream of Periyar River. Rao (1991) reported that W. attu constituted a fishery to The recorded annual fish landing from this lake is 2.32 t. the tune of 7.4 to 8.2% in the Narmada River. C. catla is Gillnet accounted for 94% of landing while the share of an exotic fish which supported a moderate fishery in hooks and line and trap fishing were 2 and 4% respectively. River Pampa (17.28 t year-1). This species is known to be In Pampa River, gillnet (77%) and seinenets (19%) denizen of north Indian rivers. Rao (1991) reported that contributed bulk of the fish landings. C. catla supported a lucrative fishery in River Narmada The landing of H. brachysoma in Pampa River was with an average annual production of 7.8 t. C. catla is low (17.11 t) when compared to that of Vemband Lake known to be introduced in Kerala for the first time in (67.44 t) (Kurup et al.,1992). Kurup et al. (1993) reported Periyar Lake from Godavari River (Chacko, 1948). Hora that this species was facing a serious population decline. and Law (1941) did not mention the presence of any Due to rapid depletion of wild population, the fish has been introduced species in their list of freshwater fishes of listed as endangered category in the Conservation Travancore. Gopalakrishnan et al. (2000) reported the Assessment and Management plan workshop for assessing introduction of Indian major carps in Pampa, Manimala the status of freshwater fishes of India (Molur and Walker, and Meenachil rivers. The present report on the landings 1998). Sreeraj et al. (2007) reported a size range of of C. catla is definitely a pointer towards its chance of 160 - 330 mm in its population from Vembanad Lake. On establishment of propagation in the rivers and reservoirs the contrary, the present study revealed that this species of Kerala. The ranching of Indian major carps may pose has been subjected to size overfishing in the river Pampa potential threats to indigenous species in future. Studies as evident from its lower size range represented in fishery on fish diversity of Bharathapuzha, showed abundance of (90 - 230 mm). The juvenile fishery of this species is mainly Tilapia population, replacing native fish fauna in many areas due to the use of fine mesh seinenets having a mesh size of (Bijukumar and Sushama,1999). The alien invasive species 10-30 mm. In Karuvannor and Vemband, the catches were are the major threat to biodiversity conservation and second Exploited fisheries resources of the Pampa River 19 major cause of extinction of native and endemic species 1994; Mikschi et al., 1996; Ruhle,1996). However, the around the world (Wilcove et al., 1998). Non-native fish impact of river corridor engineering on fish habitat has are introduced around the world mainly for improving resulted in the disappearance of Puntius dubius, a gravel fisheries, sport, ornamental fish trade and for biocontrol of spawner from Stanley reservoir in Tamil Nadu due to mosquito (Bijukumar, 2000). Introduced fish frequently smothering of breeding grounds by fine silt (Singh, 2000), alter the aquatic ecology by changing water quality and the disappearance of mahseers Tor khudree and also cause the extinction of native fish by predation and Acrossocheilus hexagonolepis from the Cauvery river resource competition (Pimentel, 2002). system owing to habitat changes consequent to construction of Stanley and Bhavanisagar reservoirs (Singh, 2000), Data on exploited fishery of Pampa River indicate decline in the Hilsa (Tenualosa ilisha) fishery in the that Etroplus suratensis (31.88 t ) is one of the dominant upstream of Farakka Barrage on the river Ganga (Bilgrani fish species appeared in the fishery, the availability of which et al., 1979), the adverse impact on the anadromous is largely constrained by poor recruitment. Tetradon migration of hilsa in the Cauvery and Godavari rivers owing travancoricus is an ornamental fish with export potential to the construction of small dams for the purpose of (Kurup et al, 2003) in recent years. regulating the flow to irrigation systems (Sundar Raj, 1942; The three air breathing fishes (Channa striatus, Sreenivasan, 1976, 1977), and the disappearance of Puntius Channa marulius and C. diplogramma) which contribute carnaticus from Thirumoorthy and Amaravathy reservoirs a significant fishery in the river Pampa (17%) in contrast (Sreenivasan, 1976). Habitat alteration in Himalayan waters to the Narmada River (0.8 to 2.9%) (Rao,1991). Among have affected the distribution and abundance of native fishes them, C. marulis was reported as the most common murrel in the mountain streams of India and Nepal (Sehgal, 1994). of Kerala rivers (John, 1936) where as C. diplogramma Dhanze and Dhanze (1998) reported that the Beas River was rare (Hora and Law, 1941). Ompok bimaculatus is a system has shown a decline in the native population of vulnerable fish in the river Pampa which consisted only Tor putitora and Schizothorax richardsoni and abundance 0.37% in the annual landing. The landing of this fish in of the bottom inhabiting predatory catfishes (Mystus the Narmada River varied from 0.14 to 1.8% (Rao, 1991). seenghala and allied species) due to the impoundment of The native air breathing fish species found in the rivers of the river at Talwara in the form of a big reservoir covering Kerala are under threat and are slowly eliminated owing to an area of 24,000 ha. Construction of a dam and consequent various reasons, notably due to diseases like Epizootic impoundment bring a sudden transformation of a lotic Ulcerative Syndrome (EUS). Introduction of exotic species environment to lentic one. This process triggers a series of is also responsible for their elimination. The results of this changes in the riverine community. A number of organisms study revealed that C. diplogramma contributed to the tune perish, some migrate to more comfortable environs, and of 0.79 t in the exploited fishery. This species was subjected the more hardy ones adapt themselves to the changed to alarming decline in its population due to destructive type habitat. Construction of dams on river affects the migration fishing activities including dynamiting and poisoning, EUS, range of fishes. With the commissioning of habitat alteration and pollution (Kurup, 2000). In the present Thannermukkam salinity barrier across Vembanad lake in study also, this species constituted a mere 1% of total 1976, spectacular difference in fish production has been landings of Channa species in the river. John (1936) noticed in either sector, the average annual production in outlined major factors responsible for steady diminution southern sector being 58 kg ha-1 against 564 kg ha-1 of inland fishery wealth of Travancore. The devastating registered from the northern sector (Kurup et al., 1996). fishing practices prevalent during monsoonal The salt water barrage built at Thannermukkam barrier “othayilakkom” may be responsible for destruction of (TMB) appears to have played a significant role in the spawning stock. fluctuation of the physic-chemical parameters of the Excessive withdrawal of water from river courses for southern portion of the lake (Padmakumar et al., 2002). agricultural purposes is very common in Pampa River Further, there are six hydro- electric dams in river Pampa during pre-monsoon season. Extensive deforestation and which might have hampered the spawning migration of the disappearance of riparian vegetation in highland and fishes, thus acting as a major threat to the fish wealth of the midland areas of river results in increasing soil erosion. river. This may destroy the spawning grounds of fishes. The Pollution is probably the single most significant factor construction of dams in the upstream area of Pampa River causing major decline in the population of many fish may hamper the spawning migration of fishes. Siltation species. Industrial, sewage and pesticide pollution have from the catchment areas, besides changing the ecology been causing detrimental environment to fish life in many due to construction of dams, have caused destruction of water bodies (Jhingran, 1991). Paddy fields are common the feeding and breeding grounds of many fishes (Sehgal, along the downstream parts of the Pampa River, especially C. R. Renjithkumar et al. 20 in the Kuttanad area. It has been reported that an annual disorders to phytophilic and psammophilic fishes in the estimate of 485 t of pesticides are deposited in Kuttanad aquatic environment (FAO,1998). waters (KBWSP, 1989). It would thus appear that pesticide The fishes of Pampa are subjected to severe concentration from this region is beyond sub-lethal values overfishing leading to reduction in average size constituting in respect of crustaceans and fishes and this creates a the fishery (size overfishing) and killing of spawner fish stressed condition for aquatic animals. KWBSP population with the onset of monsoon. Unless and until (1987-90) conducted detailed studies on the pesticide strict management measures are taken up, most of these concentration in sediment, water and clam in this region unique germplasm resources will disappear from the Pampa and very high levels of DDT was detected in the samples River. Overexploitation of fishery resources due to its extra collected during summer months. The effects of DDT ordinary economic value has been a causative factor resulted in stunted growth, increased susceptibility to exacerbating the vulnerability of the population in different disease and decreased reproduction (George et al., 1965). ecosystems (Kirchhofer and Hefti, 1996). With the rapid Pampa is prone to pollution hazards notably from development of the country and owing to ever increasing Travancore Sugars and Chemicals Ltd., a sugar demand of fish as food, the aquatic ecosystems are under manufacturing and distillery unit having daily effluent rate constant pressure of human induced stresses to the detriment 3 in the order of 33,000 m (Anon,1990) . Furthermore, waste of the aquatic flora and fauna (Jhingran, 1991, Konar, water from rubber factories of this region amounts to 1991).The results of the present study clearly show that 3 -1 1500 m and total waste load estimated to be 50 kg day of the fish fauna of the Pampa River is highly diverse and -1 BOD, 190 kg of COD and 350 kg day of suspended solids proper management is vital for the conservation and (Anon,1990). About 108 major and minor industrial units sustainable utilization of the fish biodiversity. There is are functioning in the Kuttanad region, which comprises anurgent need for setting up of a local level management sugar mills, rubber factories and coir industries. These body for the management of fishery wealth of the Pampa industries produce various types of pollution. Moreover, River. many parts of this river forms dumping grounds for industrial and domestic wastes leading to severe Acknowledgements environmental deterioration causing mass mortality of fish. The authors are thankful to the Director, School of The biodiversity of the rivers in Kerala is alarmingly Industrial Fisheries, Cochin University of Science and declining due to unethical fishing practices. In Pampa, a Technology for providing the necessary facilities. The variety of destructive fishing practices are prevalent such financial assistance from KSCSTE project on as dynamiting, electric fishing, use of fine mesh net and “Development of database on the fish germplasm, capture fish poisoning (Kurup, 2000). Wanton killing of brood fisheries and biodiversity threats of the rivers of Kerala” is fishes and juveniles by such practices have affected a gratefully acknowledged. number of food, game and ornamental fishes of upland waters, especially in rivers and streams (Dehadrai et al., References 1994). Excessive withdrawal of water from the river courses Ajithkumar, C. R., Rema Devi, K., Thomas, R. and Biju, C. R. for agriculture, domestic and industrial uses leaving 1999. Fish fauna, abundance and distribution in Chaklakudy inadequate water for comfortable fish life is also a major River system. Kerala. J. Bombay Nat. Hist. Soc., 96(2): factor responsible for the depletion of fish germplasm 244-254. resources (Kirchhofer and Hefti, 1996). Siltation from the Alagaraja, K.1984. Simple methods for estimation of parameter catchment areas, besides changein the ecology due to for assessing exploited fish stocks. Indian J. Fish., construction of dams, have destructed the feeding and 31(2): 177-195. breeding grounds of many fishes (Sehgal, 1994; Mikschi Anon, 1990. Kuttanad water balance study project - final draft et al.,1996; Ruhle,1996). According to Kurup et al. (2005), report Vol. 2, Environmental aspects, Indo-Dutch the physical habitat variable plays a leading role in the Corporation programme, Kerala, p. 91-94. distribution of many species of Pampa, Periyar and Antony, A. D. 1977. Systematics, ecology, bionomics and Chalakudy rivers. The study revealed that the habitat distribution of hillstream fishes of Trichur District. alteration consequent to indiscriminate sand mining Ph. D. thesis, University of Calicut, Calicut, Kerala, India, contribute significantly to the decline of endangered fishes 436 pp. like L. dussumieri, Puntius denisonii, Batasio travancorica, Bijukumar, A. 2000. Exotic fishes and freshwater fish diversity. H. branchysoma and Lepidopygopsis typus. Loss of in Zoos’ Print J., 15(11): 363-367. stream vegetation, sand and gravel in the river bed not Bijukumar, A. and Sushama, S.1999.The fish fauna of only affect the feeding and hiding grounds of fishes and Bharathapuzha River, Kerala. J. Bombay Nat. Hist. Soc., other freshwater animals but also induce spawning 98(3): 464-468. Exploited fisheries resources of the Pampa River 21

Bilgrani, K. S. and.Dutta Munshi, J. S. 1979. MAB Programme, John, C. C. 1936. Freshwater fish and fisheries of Travancore. UNESCO Project, Bhagalpur University, Bhagalpur. J. Bombay Nat. Hist.Soc., 38: 702-733. Chacko, P. I. 1948. Development of fisheries of Periyar Lake. KWBSP 1989. Draft final report (Indo-Dutch Co-operation J. Bombay Nat. Hist. Soc., 48(1): 191-192. Programme), Vol 2, Annexes A-E. Day, F. 1865. The fishes of Malabar, Bernard Quaritch, London, Kirchhoffr, A. and. Hefti, D. 1996. Conservation of endangered 293 pp. freshwater fish in Europe, Birkhauser-Verlag, Basael, Switzerland. Day, F. 1878. The fishes of India, being a natural history of fishes known to habit the seas and freshwaters of India, Burma Kurup, B. M. 1982. Study on the systematic and biology of the and Ceylon. Text and atlas in 4 parts, William Davson, XX+ fishes of Vembanad Lake, Ph. D. thesis, University of 778: 195 pp. Cochin, Cochin, Kerala, India, 683 pp. Day, F. 1889. The Fauna of British India, including Ceylon and Kurup, B. M. 1988. Population characteristics, bionomics, and Burma Fishes.1: 548; Bernard Quaritch, London, 2: 509 pp. culture of Labeo dussumieri (Val,), Annual progress report submitted to ICAR, 26 pp. Dehadrai, P. V., Das, P. and Verma, S. R. 1994. Threatened fishes of India. Natcon Pub., No. 4., Muzaffarmagar, 412 pp. Kurup, B. M.1993. Preliminary observation on river ranching of Labeo dussumieri (Val.) in Pamba, Kerala. Proceedings of Dhanze, J. R. and Dhanze, R. 1998. Fish genetics and biodiversity the Fifth Kerala Science Congress, January 1993, conservation. Nature Conservators, Muzaffarmagar, 115 pp. p..197-199. Easa, P. S. and Basha, S. C. 1995. An investigative survey of Kurup, B. M. 1994. An account on threatened fishes of river system stream fishes, habitat and distribution in Nilgiri Biosphere flowing through Kerala. Threatened Fishes of India. Natcon Reserve area of Kerala, KFRI research report No: 104, publication, 4: 121-126. KFRI, Peechi, Kerala, 189 pp. Kurup, B. M. 1996. Sustainable aquaculture in Kuttanad, Kerala, Easa, P. S. and Shaji, C. P. 1997. Freshwater fish diversity in Fishing Chimes, 5: 21-25. Kerala part of Nilgiri Biosphere Reserve. Curr. Sci., 73 (2): 180-182. Kurup, B. M. 2000. Management plans to arrest the decline of freshwater fish diversity of Kerala. In: Ponniah, A. G and FAO 1998. Rehabilitation of rivers for fish. Food and Agricultural Gopalakrishnan, A. (Eds.), Endemic fish diversity of Western Organization of the United Nations, Fiishing News Books, Ghats, NBFGR- NATP, National Bureau of Fish Genetic London. Resources, Lucknow, U. P. Publication, p. 164-166. Gopalakrishnan, A. and Basheer, V. S. 2000. Occurrence of Labeo Kurup. B. M. 2005. Germplasm inventory evaluation and gene rohita and Cirrhinus mrigala in Mennachil, Manimala and banking of freshwater fishes. Project report, NBFGR Pampa rivers, Kerala. In: Ponniah, A. G., Gopalakrishnan (ICAR), 212 pp. A. (Eds.), Endemic fish diversity of Western Ghats, NBFGR- NATP, National Bureau of Fish Genetic Resources, Luknow, Kurup, B. M. and Binu Kuriakose 1991. Labeo dussumieri (Val) U. P., India, p.167-168. an indigenous endangered carp species of Kerala., Fishing chimes, 14: 39-42. Gopi, K. C. 2000. Freshwater fishes of Kerala state. In: Ponniah, A. G. and Gopalakrishnan, A. (Eds.), Endemic fish diversity Kurup, B. M., Sebastain, T. M., Sankaran, M. J. and Rabindranath, P. of Western-Ghats. NBFGR-NATP, National Bureau of Fish 1992. Fishery and biology of Macrobrachium spp. of the Genetic Resources, Lucknow, U. P., India, p. 56-76. Vembanad Lake. In: Silas, E. G. (Ed.), Freshwater Prawns, KAU, Trichur, p. 78-89. George, M. G. N., Kaushik, K. and Shrivastava, S. K. 1965. Bioassay of DDT factory waste by fishes. Adv. Water. Pollut. Kurup, B. M., Sebastain, M. J., Sankaran, T. M. and Rabindranath, P. Res., 2(1): 67-78. 1993. Exploited fishery resources of Vembanad Lake –status of residents and migrants. Fishery Technology special issue, Hora, S. L. and Law, N. C. 1941. The freshwater fishes of Society of Fishery Technologists, India, 1-10 pp. Travancore. Rec.Ind. Mus., 43: 233-256. Kurup, B. M., Radhakrishnan, K. V. .and Manojkumar, T. G. Hora, S. L. and Nair, K. K. 1941. New records of freshwater 2003. Biodiversity status of fishes inhabiting rivers of Kerala fishes from Travancore. Rec. Ind. Mus., 43: 387-393. (South India) with special reference to endemism, threats IUCN, 2010. http://www.iucnredlist.org/apps/redlist/search and conservation measures. Poceedings of the Second International Symposium on the Management of large rivers Jayaram, K. C. 1999. Freshwater fishes of Indian region. Narendra for fisheries: Sustaining Livelihoods and Biodiversity in the Publication house, New Delhi, 509 pp. New Millenium, Phnom Penh, Kingdom of Combodia, Jerdon, T. C. 1849. On the freshwater fishes of South India, 11-14 February, 2003. Madras. J. Lit. Sci., 15: 302-346. Kurup, B. M., Radhakrishnan, K. V. and Manojkumar, T. G. Jhingran, V. G. 1991. Fish and fisheries of India. Hindustan 2006. Fish and fisheries of Periyar Lake, Kerala. Indian J. Publication house, New Delhi, 727 pp. Fish., 53(2): 153-166. C. R. Renjithkumar et al. 22

Manimekalan, A. and Das, H. S. 1998. Glyptothorax davissinghi Sehgal, K. L. 1994. State of art of endangered, vulnerable and (Pisces:Sisoridae) - a new catfish from Nilambur in the rare cold water fishes of India. In: Dehadrai, P. V., Nilgiri Biosphere Reserve, South India. J. Bombay Nat. Hist. Das, P. and Verma, S. R. (Eds.), Threatened fishes of India, Soc., 95: 87-91. NATCON Pub. No. 4, Muzaffarnager, p. 127-135. Menon, A. G. K. 1951. Notes on fishes in the Indian Museum Silas, E. G. 1951. On a collection of fish from the Anamalai and XLVI,.On a new fish of the genus Labuca from Cochin. Nelliampathi hill ranges (Western Ghats) with notes on its Rec. Indian Mus., 49: 1-4. zoogeographical significances. J. Bombay Nat. Hist. Soc., Mikschi , E., Wolfram, G. and Wais 1996. Long term changes in 49: 670-681. the fish community of Neusiedler see (Burgenland, Austria). In: Kirchofer, A. and Hefti, D. (Eds.). Conservation of Silas, E. G. 1952. Fishes from the high range of Travancore. endangered freshwater fish of Europe, Birkhauser-Verlag, J. Bombay Nat. Hist. Soc., 50: 232-330. Basel, Switzerland, p. 203-211. Sinha, M., Mukhopadhyay, M. K. and Hajra, A. 1999. Inland Modur, G. and Walker, R. S. 1998. Report of the workshop on fisheries development: achievements and destinations for Conservation and Management plan for Freshwater Fishes twenty first century. In: Sinha, M., Mukhopadhyay, M. K. of India, Zoo Outreach Organization ICBSH India, and Hajra, A. (Eds.), Souvenir: the National Seminar on Coimbatore, 156 pp.. Eco-friendly Management of Resources for Doubling of Fish st Padmakumar, K. G., Anuradha, K., Radhika, R., Manu, P. S. and Production-Strategies for 21 Century. Inland Fisheries Chandy, C . K. 2002. Open water fishery in Kuttanad, Kerala, Society of India, CIFRI , Barrackpore, India, p. 25-35. with special reference to fishery decline and ecosystem Singh, S. N., Sinha, M., Jha, B. C. and Khan, M. A. 2000. Impact changes, Riverine and Reservoir fisheries of India, Society of catchments and river course modifications on fisheries of fisheries Technologists, Cochin, p.15-24. of River Narmada. Environment Impact Assessment of Inland Pandey, A. C., Pandey, A. K. and Das, P. 1999.. Environmental Waters for Sustainable Fisheries Management and Issues and resources management. In: Das, P., Verma, S. R., conservation of Biodiversity Barrackpore, India. Central Guptha, A. K. and Sharma, R. K. (Eds.), Nature Inland Capture Fisheries Research Institute. Bulletin, 101: Conservators, Muzaffarmnagar, 67 pp. p. 37-56. Pimental, D. 2002. Biological Invasions: economic and Sreeraj, N., Rajeev Raghavan, and Prasad, G., 2007. Some aspects environmental cost of alien plant, animal and microbe of the fishery of the threatened yellow cat fish Horabagrus species. CRC Press, London, 384 pp.. branchysoma from Vembanad Lake with a note on their Pillai, R. S. N. 1929. A list of fishes taken in Travancore from landing at Vaikom, Kerala, India. Zoo’s Print J., 22 (4): 1901-1915. J. Bombay Nat. Hist. Soc., 33: 347-379. 2665-2666. Radhakrishnan, K. V. 2006. Systematics, germplasm evaluation Sreenivasan, A. 1976. Fish production and population changes in and patterns of distribution and abundance of freshwater some reservoirs in Tamil Nadu. Indian J. Fish., 23: fishes of Kerala, Ph. D. thesis submitted to Cochin 124-152. Univerisity of Science and Technology, 305 pp. Ramakrishniah, M. 1987. The fishery of Nagarjunasagar, on the Sreenivasan, A. 1977. Limnological studies - Parambikulam river Krishna during 1976-’80. Indian J. Fish., 34 (4): Aliyar Project. Limnology and fisheries of Trimoorty 17-22. Reservoir (Tamil Nadu) India. Arch. Hydrobiol., 80(1): 70-74. Rani, P., and Manoharan, S. 2010. Mettur Reservoir Fisheries: past and present status. Fishing Chimes, 30(1): 132-135. Sundar Jr., R. B. 1942. Dams, Fisheries, Mettur and its lessons Rao, K. S., Chatterji, S. N. and Anil K. Singh 1991. Studies on for India. Proc. Indian Acad. Sci., 14B: 341-358. the pre-impoundment fishery potential of Narmada basin Talwar, P. K. and Jhingran, A. G. 1991. Inland Fishes of India (Western region) in the Context of Indira Sagar, Maheshwar and adjacent countries, Vol I & II, Oxford and IBH Omkareshwar and Sardar Sarovar Reservoir. J. Inland Fish. Publishing Company, 536 pp.. Soc. India, 23(1): 34-41. Remadevi, K. and Indra, T. J. 1986. Fishes of Silent Valley. Thobias, M. P. 1973. Study on the ecology, systematics and Rec. Zool. Surv. India., 84 (1-4): 243-257. bionomics of freshwater fishes and paddy fields and rivers of Trichur district, Kerala. Ph. D. thesis, University of Ruhle, C. 1996. Decline and conservating of migrating brown Calicut, Kerala, 248 pp. trout (Salmo trutta t. lacustris L) of Lake constance. In: Kirchofer, A. and Hefti, D. (Eds.), Conservation of Wilcove, D. S., Rothstein, D. Dubow, J. Phillipis, A and Endangered freshwater fish of Europe, Birkhauser-Verlag, Losos, E. 1998. Quantifying threats to imperiled species in Basel, Switzerland. p. 203-211. the United States, Bioscience, 48: 607-615.

Date of Receipt : 08.12.2010 Date of Acceptance : 08.08.2011