Fish and Shell Fish Fauna of the Retting and Nonretting Zones of the Kadinamkulam Kayal, Kerala
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Fish and shell fish fauna of the retting and nonretting zones of the Kadinamkulam kayal, Kerala Item Type article Authors Bijoy Nandan, S.; Abdul Azis, P.K. Download date 02/10/2021 13:10:23 Link to Item http://hdl.handle.net/1834/32164 Journal of the Indian Fisheries Associank at. 35 23, 1993, 35-43 FISH AND SHELL FISH FAUNA OF THE RETTING AND NONRETT1NG ZONES OF THE KADINAMKULAM KAYAL, KERALA S. BUOY NANDAN* AND P.K. ABDUL AZIS Department of Aquatic Biology & Fisheries, University of Kerala, Trivandrum - 695 007 AI$STRACT Retting of coconut husk is one of the major problems of pollution hi the estuaries (kayals) of Kerala. Retting activity has resulted in the mass destruction of the flora and fauna and has converted sizeable sections of the kayal into virtual cesspools of foul smelling stagnant waters. Levels of hydrogen sulphide, phosphate and BOD, increased while dissi lived oxygen and fish and shellfish fauna decreased in the ambient waters. In the Kadinamkulam kayal a total of 37 species of fishes belonging to 26 families, 5 species of prawn and 2 species each of crabs and molluscs were recorded from the nonretting zone, whereas only 20 species of fish in dead condition were collected from the rating zone. Prawns, crabs and molluscs were absent at the vetting zone. IVIajority of the fish fauna in the kayal were marine forms. INTRODUCTION MATERIAL AND METHODS The rating of coconut husk has led to Two stations were selected in the extensive pollution of the clean and highly Kadinamkulam. kayal (lat.8°35'-8°40'N and productive estuaries of Kerala, The process of long. 76°45'-76°52'E), the largest among the retting involves the immersion of raw coconut estuaries in Thiruvammthapuram district, Kerala, husks in shallow waters for a period of 6-10 India (Fig.1). Station 1 (Kotrakiri) represented inontlasresulting in the microbial decomposition a polluted zone, which is an interior bay of the of the husks. Retting is brought about by the kayal used entirely for the rotting of coconut pectinolytic activity of microorganisms like husk. Station TI (Peruinathura) is an area free bacteria, fungi and yeast releasing large amounts from rotting activity and is exposed to fresh of organic matter like pectin, ployphenol, tannin water influx and estuarine in nature. The etc. into the medium. The mat or bacterial groups Vamanapuram river empties into the estuary at associated with retting are Aerobacter, its northern extensity at Perurnathura. 13seuclomonas, Bacillus, Paracolobactruin, Escherichia and Micrococcus (Ghat and The study was conducted from October Nambudiri, 1971). Fungi like Rhodowrulaflava 1987 to September 1988. Surface and bottom and Saccromyces fructum were also reported water from both stations were collected at (Bliat and Nainbudiri, 1971) from the vetting fortnightly interval for estimation of temperature, zones. salinity, dissolved oxygen, hydrogen sulphide, BOD5, nitrate and ammonia following standard A proper knowledge of the available fish procedures (Strickland and Parsons, 1972). Fish fauna in the coastal ecosystems is a pre-requisite and shell fish were collected at random from the for the successful fishery development, culture local fishermen for one year, Amongst the cast practice and conservation. Preliminary survey nets and seine nets used commonly, the latter of the fish fauna was carried out at the accounts for the major share of the catch. Kayamkulam lake by John (1958); &lava- Identifications were carried out following Day Nadayara estuary (Abdul Azis and Nair, 1978) ( 1 878), Munro (1967), Whitehead (1972) and and Aslitamudi estuary (Nair and Abdul Azis, Ihingraii (1975). 1987). This is the first report on the effect of rotting of coconut husk on the fish and shell fish fauna of the Kadinamkulam kayal. Present At.:clress : Central InlAnd Fisherie Research Centre (ICAR), Alappuzha-688 001, Kerala 36 NANDAN AND AZIS 7 4 4 5' 40' ANCNUMENGU- AKA THUMURI KAYAL 51.1 EDANAPIOOLA 51.1 PERumAINURA 1ff WING ZONES ALONG lit KAUNAmKULAM KAYAL 76152 Fig. 1 Location of Stations FISH AND SHELL FISH FAUNA OF KADINAMKULAM KAYAL 37 SULTS AND DISCUSSION species), (Munro, 1955). Megalops cyprinoides and Gerreomoipha setifer were the true estuarine Water quality : forms occurring in the kayal. It is thus apparent The temperature of the surface and bottom that nearly 50% of the fish fauna in the water at the retting zone (St.I) varied from 26 to Kadinamkulam kayal are marine forms which 34°C whereas that at the nonretting zones migrate into the kayal when hydrobiological (St.II) varied from 25 to 32.5 °C. The salinity conditions are favourable as observed in other values in the surface and bottom water ranged kayals of India (Jhingran and Gopalakrishnan, from 2.55 to 30.19%0 at the retting zone and that 1973). from 8.15 to 31.70%0 at the nonretting zone. Depletion of dissolved oxygen leading to anoxic Of the 5 species of prawns recorded trom condition coupled with the production of large the nonretting zones, Penaeus indicus showed amount of hydrogen sulphide was the the highest numerical density followed by characteristic feature of the retting zone. The Metapenaeus dobsoni. Scylla serrata showed dissolved oxygen concentration ranged from higher abundance when compared to Neptumus zero to 0.72 mg/1 at the retting zone whereas that pelagicus. Among the shellfish fauna, the bivalve at the nonretting zone ranged from 2.28 to 6.21 Villorita cyprinoides showed the highest mg/1 in the surface and bottom waters (Fig.2). numerical density. (Table II) The hydrogen 7.6 to 40.2 mg/1 and that at the nonretting zones ranged from zero to 3 mg/1, in Salinity and temperature were the most the surface and bottom waters (Fig .3). Very high significant factors which determined the BOD5 values ranging from 4.96 to 24.39 mg/1 distribution of fishes in the Kadinamkulam kayal in the surface and bottom waters were another also as found in other estuaries (De Silva and notable aspect of the water quality in the retting Silva, 1979). Since this kayal is not permanently zone and that it ranged from 0 to 3.74 mg/1 at the connected to the sea, condition of the barmouth nonretting zones (Fig .4). Generally the nitrate has a significant role in the recruitment of content was found to be lower whereas the marine species. nitrite and ammonia contents were higher in the retting zone. The NO 3-N values at St.' varied Retting activities at station I led to an from') 0 to 2.48 pg at /1 and that at St.II from 0 anoxic condition concomittant with the to 4 tg at/1. The nitrite and ammonia production of large quantities of hydrogen concentrations ranged from 0 to 1.78µg at/1 and sulphide and ammonia which in turn had a fatal 6.40 to 37.70 fig at/1 respectively at the retting effect on all the 20 species of fish fauna collected zone and from 0 to 1.66 pg at/1 and 0 to 11.70 from the retting zone during the present study. tg at/1 at the nonretting zone. Of the 36 species of fishes recorded from Fauna : the nonretting zone, 28 were economically A total of 37 species of fishes belonging to important (Thingran, 1975) and most of the 26 families, 5 species of prawns, 2 species of marine species were occasional visitors. crabs and 2 species of molluscs were collected Mugilids, tachysurids, cichlids and centropomids from the nonretting zone. (Table I) There was were the most common groups contributing considerable reduction in the fauna at the retting substantially to the fisheries. Among the mullets zone and only 20 species of fish in dead condition recorded, Liza parsia and L. macrolepis and were collected. Of the 37 species of fishes from cichlids, Etroplus surratensis and E. recorded from the nonretting zone, 13 were maculatus were most common and caught round typically marine while others are transient forms the year. Earlier studies conducted by Nair et al. inhabiting different habitats viz., marine, (1983) from the Kadinamkulam kayal recorded estuarine (11 species), Estuarine/riverine (4 67 species of fishes belonging to 34 families. A species) and marine/estuarine/riverine (4 sharp depletion of fauna was observed from the ▪ 38 NANDAN AND AZIS SIATION I . $01114(1 VAIII .--- YAW, 0 I 01 E 0 •7 0.2 0.1 0 -1■ -• D I ► / lti 411 21,0N1115 ▪ 3(45(1 15A1111 STATION II VAPIl -Ir t e-f- , - I I 0...1 I V. .8 I I • % I ■ I I i I ■ I 0 I t , I; w 021 (21221 A 215 1 A 01 Is el 21014I/IS Fig. 2 Fortnightly variation of dissolved oxygen in the Kadinainkulain estuary FISH AND SHELL FISH FAUNA OF KADINAMKULAM KAYAL STATION I /IMO VIII PAM fIND HAM) /AS 61 110NTIIS SIAHON 155tH! PIUS 1111101 VAN /3 U. a t S 03 11 14 0 ► r H A 11 11 HONTHS Fig. 3 Fortnightly variation of hydrogen sulphide in the Kadinamkulam estuwy 40 Fig. 4Fortnightly variationofBOD, intheKadinainlailain estuary. 1/61u )'a NANDAN ANDAZIS . o a S T.I SUR FA CE MA TE ? BOTTOH MAT ER S T.0 S U:=. FACE MA TE7'. OTTOM MA TER FISH AND SHELL FISH FAUNA OF KAD1NAMKULAM KAYAL 41 Table 1. List offishes of the retting and nonretting zones in the Kadinamkulam kayal Family Species Local Name Habitat No. Collected (Munro 1967) Non-retting retting 1 2 3 4 5 6 Megalopidae Iviegalops eyprinoides Nunna Chankanni 10 6 Clupeidae Sardinella sp. Chaala 7 2 Engraulidae Stolephorus indicus Netholi M 9 7 Chanidae Chanos chanos* Poomeen M 15 2 Tachysuridae Tachysurus maelf idtlIS *41 Koori Thedu E 3 1 Heiniramp4idae Hyporhamphus limbatus Koralan M, E 9 Hemiramphus cantori M, E 12 4 Rynehoramphus georgi 7 2 Sphyraenidae Sphyraena jells * Cheelavu M 16 7 Mugilidae cephalus * Kanambu 22 Liza macrolepis M, E 1.