India has extensive molluscan resources along both the coasts, in the numerous islands, bays, back waters and estuaries and also in the seas around the Sub-continent

Nayar, K Nagappan

CMFRI Digital Repository

• i . • • REFERENCE 0 Nly SUI-IMER INSTITUTE IN \ CULTTIRE OF rnIBLE MOLLUSCS HELD AT TurrCCRIN RESEARCH CENTRE OF CENTP.AL l-I.ARINE FISHERIES RESEARCH INsrITUTE trom 26 May to 24 June 1980 ,. , . ~ Centr a l ~!arinc Fis her ies Research Institut e P .B . 1912, COGHill - 682018 , I NDIA " Indian Council of Agri cult1Z'al Resoarch September' , 1980 \.If \ .. 1 , PRESENr STATUS OF MOLLUSCAN FISHERIES AND CULTURE IN INDIA K. NAGAPPAN NAYAR India has extensive molluscan r es ey-oes along both the ooasts, in the numerous islands, bays, baokwaters and estuaries and also in the seas around the Sub-oontinent. A good quantity of mussals, oysters, pearl oysters, different speoies of olams, 'lToohus, Tlrbo, ehanka !KId oephalopods are r egularly fished thI'oughout the-year--at various plaoes. These lave been exploited from time iJmnemorial for food, pearls, am. the shells for commercial purposes mainly for making curios and in the preparation of lime. Out of the total fish landings of the world, reported by the F.A.O., the molluscan landings ammmt to only 5%. So far as the Indian Sub-omtinent is concerned the marine fish landing figtr es funiished by-the CMFRI indicate a tot al of 1.4 million tonnes. Of thiS, the -percentage of mollusCan landings is meagre and comes only to about 1%. The picture that emerges would apparently indioate that mo1J.USOB are not very important for thed.r fishery value Which is contrary to fact. The reason for this anamoly is not far to Beek ; wh:I.1e the figures for the landings of commercially impcrtant species of cephalopods have been incltrled; the actual landings of various species of clams, mussels, oysters, pearl oysters am heavy shelled ferm soob as cbanks, Trochus am !!!!:!22 have not been estimated end incluied due to lack of precise data . In terms of weight landed, _ the above forms contribut e substantially to the total landings and . -would give much higher figures of total landings of molluscs in India. Some of the above mentioned farms are fis red not for the meat but for industrial utilisation. However, a proper assessment of the total landings of these farms appears essential. The available literature an mo1J.uscan fisheries in India, past as wall as recent publications, enables us not ally to get a fairly • , - ,~ --, comprehensive idea of the immensely rich reS01.l['ces of molluscs but !\lso indicates the p-esent statlE of the different molluscan fisheries. However, specific information in respect of many species is far from canplete thus calling for a thorough coverage to ' give 'US upto-date details on the fishary, impcrtant. species . biology, population density and ecology of , MOLLUSCAN FISHERIES Mussels occur all along the coastal region, wherever rocky or submerged hard substrata are present. Two species of mussels are found along tho Indian coast, the green mussel ~ viridis and brown mussel E. indica: whereas the former is found along the east and west coasts the latter is confined only to the southern part of the peninsular India. At P,t'esent, regular exploitation of mussel is limited to certain regions like Goa - Karwar, Cannanore - Kozhikode, Varkala - Vizhinjam, and Colachel - Capo Comorin on the west coast and Chinna Muttom, Madras and Kakinada on the oast coast. crean mussel E. viridis is reported fran Gulf of Kutch and scattered t.ods are present from Ratnagiri to Mangalore. South of Cannancre upto Callcut this spocies is abundant. The croen mussel is found upto Varkala on the south west ·coast. In the east coast, green mussel is found <It Porto Novo, Madras, Kakinada, Waltair and Sonaplr. BrO'.lll mussel E. i!Ldi~ :las a restri:!tod d:i.stribution fr om ~on in the south west coast up to Cape Gomorin . Althoug'l th9re is a regular seasonal mussal fishery of considerable l ocal irtportance along certain areas on t ho mst ar.d west coasts , i t still remins an insignificant fishery of minor I!l'lgnitude . Mussel flesh is popularly eaten, even consider E.<i a delicious it em of food by t he people of vest coast. Since t.her e is no authentic reccrd of mussel-landir>.gs from various landing cert;res, it i s difficult to give 11 conect e~ti-t C.-::l'\e8 mate of the annual l andings . It is , howGVer, est ireted t hat 20l '- 'l r • .1 - 33 -are landed from Ratnagiri to South Kanara, 900 tOlUles from Cannanor~ Callcut area, 180 tOlUles at Vizhinjam,325 tonnes from Colachel -Cape Comorin~ the east coast about 2.4 and. 7 tonnes fran Madras and Kaldnada respectively pEr annun which gives the total annual lan-dings of mussels as 1435 tOlUles. Edible oYSters " Edible oysters ar e found all along the coastal strips, estuaries and backwatErS wher ein suitable hard substrata are available for their young ones to settle down and grow. Oysters are collected fran such natu-al beds by a good numbEr of fisbEl!'mm in the west coast, _~pe-. cially in the coastal regions of Karnataka and Msharashtra ani sald in the local market. The e dible oystEr, Q. madrasensiB is a form which grows abundantly in a wild state forming extensive beds :in the tidal - , creeks a m backwater areas of the east coast. Q. gr:yphoides and Q. discoidea are mostly found in the northwestErn coast of India. Nowhere :in the east coast this valuable resource is commercially fished for edible purpose, except for a limit'ed eJqJloitation by the Tamil Nadu Fisheries Department arranging to collect a few thousand oystErS every year fr an the wild .stock at Pulicat lake and »mere estuary for supply t o a few western style hotels and for westetnErS in Madras. It has reported from Bombay (Rai, 1932) that ~ oyster fishErY was a r egular featuo e during the twenties and mare than 5000 persons wer e engaged in collecting oysters fran the natural beds all along t he erstwhile Bombay Presidency. Because of continued irrational and indiscriminate fishing by local fishermen the ·oyster pupulation was wiped out . The under-exploited oyster population in many estuarine r <3gions of t he east coast on the othEr hand are :-- i periodically subj ected t o large-scale destruction on accoont of freshwater aclmixturc during N.E . monsoon. In the rest of too areas they settle dow season a fter season ferming thick and rugged bed for-mations and the individuals in the bed become so avercrowded and stunted and perish without be:ing exploited. ,.. . ~~. - 34 - . ' . . 'Pearl oYSters j The pearl ' oys'ters are .the most thoroughly exploited fer the pearls and mother of pearls~ 'ft.·i:1n ·tiJne immanario.1. In the Indian region pearl oystjS exist ·in t~e ~f' of Mannar and ~ the Gulf of Kutch and recently': it has als o' ·beeo, reported fr an Tri varidruncoast. ~ ~ . . Six species of pearl oysters , are reperted in the. Indian coastal waters. Of these, E. fucata is the I!!oot importElli:.. - , . __ ",--Among cl.aniS, those belonging to the fumily Veneridae are the , most ~~"" found all along the :-fudil!n ··Coa'B-ts. in the baYs~ -. ... . ......... . --- ' . '-'~". . .--.est.UIll:ies, andjo.ckwnters. The 1Jnportant species which oon~~ibute to -. . . tba fishEries are M'eretrix spp., . Paphia SW., KatelysH\ .. spp., Vi]] rita, ~ spp., and Gafrarium sp. Among others ~odesnii- giabr.o.tu!! (~ck), ~ ~ Preston, Sanguinolaria di~os (Ilnalin) and nma""'x SW;, . . are also ..t'01Pld to OCCIr ;in cert.ain places all along our coast. the ., . . . true cockles Cardium o.ssimj] e Rel(Ve and Q. asiaticum Bruguiere, though OCCtrrillg at several places, are not of much cODJllerci'8f iiIIpCll'w tanc&. The ark-shell Anadara granoso. (Linnaeus) which is re'ferred to as cockle in some countrios, ferma a minor fiShery in Kalcinada. A detailed account or: the clam cockle am. oyster rOSOUI'ces of the Indian coasts m .s been given by Alagnrswami and Narasimham (1973). Meretrix meretrix is the main species wch constitutes the. fislury . along.,!.!le Harorashtra, Goa and North Knnara coast though it OCc'lrB all. along the mst GIld Host coasts. . Rlinride (1 %4) has estimated that 3600 persons are engaged in the fish~y and collect 24,03,000 .. p~s of cJ..ams annua.JJ:t vnluod at. Rs . 2, 88,000 • . In Goo it is estimated that mare than JIXJ .p.or-som are engaged in clam fisbary. In tho Karwar region also the !llo.m fishery is good and more than 450 pars OIlS are angaged in t~ fishery fer the collection of li. meretrix and f,. malo.barica. Along the Karala coast li. casta is found to OCC1%' in most of the estuaries and backwaters and fonDS a fishery but the magnituie of the same has nct been estimated properly" <n the east ,coast clam ' ; -." : '-- • 35 -,. . ' . . . occurs .. m most of t he estuaries and in addition to the live cl~'f " .... . . fishery at most of t he centres there nrc certain plo.cos fr em ..mere ' sub-fossil deposits nrc being regularly removed. In llatoogiri area ~ kEJllpi is being fished . Over 3 tonnes are fished allllual.ly. The 1dndow pane oyster Placenta placenl;a. known for its seed pearls-it prodmes, has been under elCploito.tion in the Mf of Kutch where it OCcurs in abund.::ur::e . In Knkinada more than I{X>b tonnes of she)) S are fishe:i annUcilly which is valued at about Rs. 1,OO,OCfJ/- KatelYsia opima am lit marmorat a are also fished in J.arge qlBlItities in Mlharash-tro. State a!rl in certain ·places the density of populatic:rLis ou-4,OO,OOO/km 2. '---There exists a good fishery of Gafrarium tumidiUD in Palk_ Bay area and about 5 tonnes of clams ar,e Wlflw.llY fished. ~ lIP- is . alSOl widely distributed o.long the sanely sheres <?,f Indian coast' but there does not seem to be a, well organised fishing for these clo.ms. . - , The ribbed ark shell !. granosa is found in a fow ·places. In' Kald.nada Bay a -good fishary exists (N:J.rasimham (1968» and a total . . quantity of 10CfJ tonnes valued at Rs.50,000/- are fished annually and used in the mo.nufacture of lime. Cbanks ](ancus p:yrum, the cOllmon chank is abundant ,. on. the east coast , of India from Cape Coma-in to Madras although the ' density of its occu-rrence nppears to thin out north of r oint Calimere . ,CKt. the "est coast good number of ,cMnks are fished from the Gulf of Kutch coast, bu. southward of this no chnnk is found till the southern coast line of KErala State ..mere it forms 0. smruJ. fishery" It is also found around Andaman islands t o some extent. A detailed account of the chank fishery of Indi a has been given by Ihynr and Malndevan (1975). CKt an average about .12,000 cMnks are fished 'fran Gujarat per annum. ", - 36-Fran Kerala coast, about 17, 000 chanks from trawl catches at ~on, and fro~ Vizhinjrun area about 6,200 cbanks by hooks and line are fished o.nnual.ly. In Colache1, Eilaynrn and Kadayapo.tnam regular chnnk diving is being done and on D.Il average lD.I1d about 2,000 chanks annually. en the east coast Tuticorin is considered to be too best chank fishing ground from wher e over 1 mollion Chanks were fished during' 197~79. Mere than. 900 di vcrs are engaged in this fishery at Tuticorin. Kannira japurrun to Tirup..'1l.akudi in the Pall<: Bay 'is also a very prodlrtive aroo and on an average 3,00, 000 clnnks arc fished fNery year. ITom the other centres on the south-east coast such as Tanj a»e, South Arcot and Chinglcput a total of 40, 000 oh:mks are landed annoo.:q.y. Tr ochus and T\r be Trochus -niloticus and Turbo marmoratus are the other CClllIDer-cially impertant gast.ropods fishod all along the Andamm am Nicooar Islazt?s for the past several years. Appukuttan (1977) has given D.Il account about the TrockUl and !l!:l22 fishEry in Andamuns. It has been estimated that on an average 400 - 600 tonne~ of Trochus and 100 ~ 500 tannes of !l!:l22 shells are fis rod anmnlly from Andaman and Nicobar waters . Trochus shells fetch a price of Rs.4000/- per tonne whereas ~ shells are sold not less than Rs .10,OOO/- per tonne. Shell oraft industry is well estnblishoo. and a good number of artisans are regularly engnged in cleaning, polishing, cutting and carving these shaUsand vnrious articles are made out of them. Of late the D!:122. fishery is showing a decline perhaps due tb over fishing. Apart frOlil the detailed study made by Rno (19.37) no other work seems to have been made in recent years . In 1978 two teams of Scientists of the CMFRI visited almost all the Andannn and ~!icobar Islands during the period January - M:ly to make general survey to find out suitable places fer exterxling mariculture activities in and around the islands. During tho mrvey the pot entialities of the molluscan fisheries were also studied in detail . But a detailed sttrly exten<!ing over a few yoors is absolutaly essential to make a proper IlSsessmont of thoso commercially - 17-- ~ ' impcrtanl; . fisheries in and arourrl the Andaman and Nicobar islands. ,< Cephalopods Cephalopods comprising of squids, cuttle fishes and octopi are fished in api1'eciable quantities in India •. 15,931 toones of oepba--lopods were landed d.ur:"ing the year 1978 oul; of which 4, 557 tonnes ware' -:from Maharashtra .state, 6,516 tonnes :from Karala state, 1959 tonnes :from Gujarat State, 1,).46 tonnes :fran Kar.nataka state am 1,042 :from Tamil Nadu. The impcrtalt; species are Sepia rouxii, ~. aculeata, ~. r,artrata, Sepiella inermis, Seipiateul;bis arotipinT4s, Loligo dwaWRl i, 1.. bardwickii, OctOPUS rugusua, - Q. octopodia and Q. favoma. The oephalopod catches are got incidentally only in sh<re-seines, boat seines and trawl nets operated for ~fishes. The oephalopod rescnr-ces of the offsh<re waters are practically not exploited. stuties comucted a decade ago (Silas, 1968) have shown that.. a rnJDbEr of . , speoies BUlh as Synml ectateul;his ?,ulaiAJi. ~ aculeata. ~.pAAraonis. Sepi'" ] a inermis and Lollgo duvauceJ.i are ava.:i.lable in the offshore waters of west coast. SystEllJllI!;ic explcratcry fishing should be carrUld oul; en the continental shelf an:l. beyond to locate new gra.uns in the Indian Ocean and in the Arabian "sea. The method of jigging used in other countries for ; fishing squids and outtlefish should also be Employed here to improve ,the cephalopod fishery. MOLLUSCAN CULTURE IN INDIA Molluscan culture is of wry recen't origin. Attempts have recently been made to cultU"e mussels, edible oysters, pearl oysters, clams and also cephnJ.opods by CMFRI. 11ussels Investigations on the cultu-,e of the lrOIol'l mussel (perna indica) were carried out from the Research Centre at Vizhinjam ft-om 1971 following the rope culture method using coir ropes fer suspend;l.ng.tee. the mussels. The initial results were so encOll['aging that the wcrk - 38-was ' extended to a few ma'e centres such as Kozhikode, Madras and also Vizagapatnam, to find out the feasibility of cultUl'ing ~ v:i.ridis , (green mussel). The open ~ea green IllUlSel culture work at Kozhikode has given positive results 4 Ellible oySters The ilI!Pa'tance of oyster culttre was visualized as early as in 1910 by; Hornell. He initiated oyster culture work on lines followed in &ance a."ld established a farm at Pulicat, 40 kin north of Madras city. The follow up programme was not carried out with the ,_ , , resUlt, the progr,ess was very much hampered. Similarly as early as in 19201 s "a good beginning was mde by some of the fishErmEn of ' '---' .... _ BClllbay (~t. ~'!J2_8) , t o cori~"the young oysters and transfer them to suitable shallow r egions in Mahim, on the t-hharashtra coast where they allowed the oysters to grow to marketable size. Periodical monitcring and 'clerurlng of the oysters were also carried out. Fairly large quantitie3 of oysters .were colleoted from all the available natlral beds, and sold :j.n the marj{et as there was great demml. for than . ---. . . ', . ,./;..-These efforts were not backed by the F.i.sher1Cs Department, or any other , -research organisation, wit,h the r esult that the fi:'Sfurmen '11M did this work could ,not make much headway am improve their techniques, and they had to give up this line of wcrk in due course. The need fa' , utilization and augmentation of resource led the Central Marine F.i.sheries Research Institut e to 1ake q> oyster culture work at Tuticorw in the year 1975. Various aspects of oyster culture such as spat collection from natural env:i.ronments, hatchery development of seeds, growth of spat by follOwing different techniques, control, purifica-, , tion of oysters, shucking and processing are being studied in a detailed way. Initial results obtained indicate a production of 150 tonnes of oysters per hectare . Some interested fishermen have taken up oyster culture. Experiments on culttr e of clams such as Anadara sp., Villorita spp., are also being tried at present fr em Mangalor e, . Cochin, Kakinada and Waltair. The r esults are being watched. Attempts are also being • • / • - 'Y1 -made te collect the egg masses ef squids and cuttlefish and rear them se that the initiul mortality ef the young enes·by predators ceuld be minimised to a very great .:tent I Pearl eysters '!'he first attanpt at cUl.turing pearl oystet's in captivity was made at Tuticorin as early as in 1864. A lot of work was carried out initially at Tuticorin and l ater on the culture work was shifted to Krusadai Island wherein it was continued for a number o~ years by the Tamil z.adu Fishet'ics Th.."'jlo'Irlment. Attempts were also made in Gujarat to produce cultured pearls . But all these <ttempts did not yield results. In 1972 pG-"!'l culture work taken up by the Central Marine Fisheries Research Institute at Tuticorin at Veppolodai ~bled production of perfectly spherical cultU'ed pearls in the year 1973. Various other aspects o f w.ork such as production of oyster spat by hatchery method, improving the techniques of growing the oysters etc., • are being pursued. Although pearl oyster beds have not been iocated at Vizlrinjam area, a gooq settlooxmt of young oystem had takEn place during 1974 spat setting season • . , The young oysters thus collected were also grown to adult size oysters which premoted the Kerala Fisheries DepartmEnt to tako;! up pearl oYster culture on a pilot scale in 1978. Farming or culture practice involving molluscs is ... yet to be taken up on a ·cOl.nnercial scale in India . Steps in this direction has been initiated t o involve. small-scalc traditional fishermen. This is being followed .. by a programma of financ:ial assistame and loans under Integrated Rural Development Programme. It is envisaged that within the next decade India will figuro as one of the i:aiportant countries with established farms for oysters, mussels and clams. 

Present status of molluscan fisheries and culture in India

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Present status of molluscan fisheries and culture in India

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