LurdEniRd MARINE FISHERIES INFORMATION SERVICE

COREMetadata, citation and similar papers at core.ac.ukProvided by CMFRI Digital RepositorylurdEniRdMARINE FISHERIESINFORMATION SERVICEAPRIL, MAY,.TT hJloicllTECHNICALEXTENSIONANDSERIESMARINE FISHERIESSTT FTF TFT RESEARCH INSTITUTEtF%r , 'JTRrf COCHIN, INDIA FVCENTRALINDIAN COUNCIL OF AGRICULTURAL RESEARCH1997

W HlirHi iH w : w H\\ 4\ qr arrenf ar terFT MR"imT \M\ A' ,-qoPT5 MTHE MARINE FISHERIES INFORMATION SERVICE: Technical and Extension Seriesenvisages dissemination information on marine fishery resources based on research results tothe planners, industry and fish farmers and transfer of technology from laboratory to field.Abbrerviation - Mar. Fish, Infor. Sew., T&ESer.,No. 147: March, April 1997' CONTENTS 3 7 c T 1.Environmental impact assessment in the shrimp farming areas at Nagapattinam Quaid-E-MillethDistrict, Tamil Nadu2.High abundance of large sized rock cods (Epinephehis spp.) of Karnataka coast during the postmonsson month of September3.Heavy landings of whelks. Babylonia spp. in trawl catches of Quilon, southwest coast of India4.Trichodes imium and mortality of Chanthigaster margaritatus in the Lakshadweep sea5.A note on whelk (Babylonia spp.J fishery in Pondicheny6.Stranding of a baleen whale6.cT3 'TT «W 'FH BlIc H frPftFront cover photo: Heterocarpus Woodmasoni - an important commercially exploitable praAvnresource of the southwest coast of India. (Photo: Dr. C. Suseelan.Back cover photo: The marine hatchery facility being developed at the Field Laboratory of CMFRIin the Cochin Fisheries Harbour. . #3Tnrm wt tTPT xjtp anr an HIICW IA«i\\ # # T% # ? 5 I ? T M T f f pftrcr oiiAciicriw

ENVIRONMENTAL IMPACT ASSESSMENT IN THE SHRIMP FARMINGAREAS OF NAGAPATTINAM gUAID-E-MILLETH DISTRICT, TAMIL NADUR. Paul Raj, M. Rajagopalan, M. Vijayakumaran, G.S. Daniel Selvaraj, E. Vlvekanandan,R. Sathiadhas, R. Narayanakumar, P. Kaladharan, A. Nandakumar, R. Thangavelu,L. Jayasankaran, L.R. Khambadkar and A. Ahmed Kamal BashaCentral Marine Fisheries Research Institute, Cochin-682IntroductionIn India, commercial shrimp farming madea beginning in the early 1980s and attainedindustrial proposition in the late 1980s. As thereturns were attractive, many medium and smallfarmers and corporate sectors started extensive,semi-intensive and intensive culture operations.It is estimated that 74,850 tonnes of shrimpsvirere produced through culture from 1,00,700hectares of brackishwater area during 1994-'95.There was remarkable growth of the industry inAndhra Pradesh and Tamil Nadu. Since 1994'95, however, the shrimp farming sector isexperiencing stiff opposition from the residentsof coastal villages, especially in Tamil Nadu. Thecoastal villagers believe that the brackishwatershrimp farming is detrimental to human habitation. Their major claims and apprehensionsare: (1) most of the agricultural lands areconverted to shrimp farms and there is apossibility that agriculture may not be feasiblein future in the shrimp farming areas, (2) thestagnant brackishwater in the shrimp pondswould seep through the soil and convert thepotable well water brackish, (3) the untreatedeffluent water of the shrimp farms which isallowed to stagnate around the farms and thedwellings, would be a health hazard, (4) manyagricultural labourers are displaced due todepleted agricultural activity and (5) the waterintake pipes of the farms which pass through thebeach project into the sea, causing hindrance tothe fishing activity of the coastal fishermen.To assess the effects of shrimp farming onthe environment and on the coastal population,a study was undertaken by a team of scientificand technical staff of CMFRl in NagapattinamQuaid-e-Milleth district, Tamil Nadu in September, 1995. Several small and large farms andcorporate farms in nine coastal places, viz.,ThirumuUaivasal, Perunthottam, Poompuhar,Manikkapangu, Tharangampadl, Karaikkal(Pondicherry, U.T.), Thirumalairayanpatnam014, India(Pondicherry, U.T.), Nagapattinam and Velanganni,where a number of farms are located werecovered in the study. With the help of the mobilelaboratory of the CMFR Institute, the teamcollected and aneilysed soil, water and planktonsamples in the inlet and outlet of the farm areas,shrimp ponds and from the wells of the nearbyvillages.Estimations on hydrological parameters, nutrients and total and differentialcounts of bacteria in the water and soil sampleswere made following standard procedures. Themarine fish landings data which are availablewith the Fisheries Resources Assessment Division (CMFRI), for the relevant fishing villages,were analysed.The team also interviewedhundreds of flsherfolks and villagers.During the team's visit, many of the farmswere functional. After the viral attack on theshrimps during the first half of 1995, most ofthe ponds had been restocked and were indifferent stages of cultivation. This facilitatedassessment of the effects of shrimp farmingactivity on the environment, on the fishery andon the coastal villagers. The highlights of theresults, supported by the earlier investigations ofthe different organisations of the Government ofTamil Nadu before and after the commencementof shrimp farming are given below.Location of shrimp farmsThe total geographical area of Sirheizi,Tharangampadl and NagapattinEmi taluks isabout 1.07 lakh hectares (Source : AssistantDirector of Statistics, NQM District). The netsown (agriculture) area in the three taluks ofSirhazi, Tharangampadl and Nagapattinamaccounts for 57, 60 and 58% of the respectivetotal geographical area. The area under prawnfarming in these three taluks is about 2,000 ha,,which is less than 2% of the total geographicalarea.Prawn farming has paved way for utilizationof the barren, uncultivable lands. Further, the

land which was under cultivation about 20 yearsback, h a s now become uncultivable/cultivablewith the prospect of a maximum of 1 crop peryear due to inadequate and untimely watersupply as this area comes under the tail end ofCauvery irrigation system. Hence, farmers werefrantically looking for an alternative use of theirland for the last few years.In the NQM District, the shrimp farms arespread over 31 villages in Sirhazi, aranyam taluks. In these taluks, more than100 farms are in operation. All the farms arelocated in proximity to the coast or in the vicinityof estuarine systems (Map 1).coastal alluvial or unconsolidated, excessivelydrained and rapidly permeable (Map 2). According to the 1984 survey, it is also clear that thecoastal area was affected by surface and subsurface salinity and alkalinity (Maps 3 & 4). InThiruthuraipoondi, Nagapattinam and Sirhazitaluks, where most of the shrimp farms arelocated, about 4,814 ha, 1,502 h a and 13,807ha of the coastal areas were affected by surface,sub-surface and complete salinity respectively inthe year 1984 itself.NAGAPATTINAMQUAID -MILLETH DISTRICT, TAMILNADUNAGAPATTINAM QUAID-t-MILLETH DISTRICT, TAMILNAOUTIRUMULUAIVASALPERUNTHOTTAM1 POOMPUHARTIRUMULUAIVASAL»»» 'MANIKKAPPAN6UTHARANGAMPADI PERUNTHOTTAM POOMPUHARi NPATNAM IDSiSSZUJ'""UNDERSHRIMPBU1M1N6%%%% SANDY, COASTAL ALLUVIAL SOILOQs U U s COASTAL ALLUVIAL AM S S I f t u N C O N S O U D A T E D , EXCESSIVELYVELANKANNIDRAINED S RAPIDLY PERMEASLE SOIL* V f l N E TO VERYFINE LOAMY TEXTUREDV V V MARINE ALLUVIAL SOL WITH SLTYCLAYMAP-1NA6APATTINAMtclllNEUTRAL TO MILDLY ALKALINESOIL FROM RIVEft ALLUVIUMhSSOOOOii\\\AREA UNDER SHRIMP n R M m e SAMPLtN6 SITES AThe shrimp farming activity in the districtcommenced in 1991 on a smedl-scale and becameintensive from 1993. For understanding thenature of soil and water prior to the commencement of shrimp farming activity, the soil mapprepared during 1984 by the Soil Survey andLand Use Organisation, Thanjavur, Governmentof Tamil Nadu was referred to. The soil in theareas of shrimp farming Eire mostiy sandy, SANDY, FINE, LOAAIV, SALINE ANDALKAUNESi MARINE A L U I V U I INORISWIn the Special Report No. 85 (1994), the SoilSurvey and Land Use Organisation (SS and LUO)and Soil Testing Laboratory, Aduthurai, TamilNadu Agricultural University have concluded that"all the shrimp farms are located in uncultivablewaste lands where crops have not been raisedfor the last 20 years". Hence the question ofconversion of productive, functional agriculturalland for aquaculture purpose does not arise.SoilPrior to the commencement of shrimpfarming activity in the coastal areas ofNagapattinam, the Tamil Nadu Government has

estimated that about 75% of the coastal eirea inthe district is saline in nature either in thesurface or in the sub-surface or both. The causeof saline soil is due to a combination of factorswhich are geographical, climatic, hydrologicaland monsoonic. The survey also showed that80% of the soil is highly alkaline (pH 8.5). In1984, the Tamil Nadu Government has recommended shrimp farming as a potential venturefor improving the socio-economic condition of theNagai Qaid-E-Milleth district.the possibility of polluting the ground water(which is already brackish) by the aquaculturefarms is minimum.NAGAPATTINAM aUAID- -MILLETHDISTRICT, TAMILNADUTIRUMULLAIVASALPERUNTHOTTAMNAGAPATTINAM QUAID-E-MILLETH DISTRICT, TAMILNADUPOOMPUHAR THIRUMALAIRAYANPATNAMMANIKKAPPAN6U mPOOMPUHARTHARAN6AMPA0I00'O'HRUMULLAIVASAL IDZNASAFATTINAM«'VELANKANNIoKARAIKAL THIRUMALAIRAYANMTNAM" 0 AREA UNDER SHRIMP FARMINS - y i SURFACE* SUB-SURFACE ALKALINEAAA2 5 " SURFACE ALKALINE MAP-3 MKNAGAPATTINAMh250000jEIVELANKANNI; AftEAUNDEASHRtMPFAflMINS SURFACE a SUB-SUffiUE SAUNEI SURFACE SALINEI SUB-SURFACESAUNEWaterThe quality of ground water in the entirecoastal area is saline. Water samples collectedfrom the bore holes of aquifers in the depth rangeof 30-294 m (SS and LUO, 1984) revealed thatthe quality of medium and deep aquifers wasmoderate to poor. Though the top aquifer isbetter in quality, the potential is very less andis not sufficient for irrigation.As all the shrimp farms are located in themarine deposits, the quality of ground water isalready brackish as established by the PublicWorks Department (SS and LUO, 1994). HenceSJB-SURnCEALKilLlNEIn general, ground water is not used bythe aquaculture farms. Very few farms whichwere using ground water have stopped doingso due to the Tamil Nadu Government rules andawareness on land subsidence. Presently, allthe shrimp farms are using saline water eitherby pumping from the sea or from thebackwaters.Hydrological charactersAnalyses of the hydrological peirameters inthe water samples revealed the following features:i.In t h e U p p a n a r e s t u a r i n esystem(ThirumuUaivasal), the salinity increasedfrom 0.1 ppt in the upstream to 30.9 pptin the bar mouth and 34.2 ppt in the sea(off ThirumuUaivasal). There are a numberof shrimp farms on both sides of the estuarydrawing water in the salinity range of 6.1to 35.6 ppt.