<<

Our resources and . the role of in their fluctuations

Part II

IMARY AND FISHERIES POTENTIAL

M. KUMARAN Pelagic Project. Cochin-16

organic matter by higher utilization of the incident light is initiates the whole marine possible only if the is Con­ chain, which terminates in the larger centrated in the upper layers, where light and marine mammals. The prime absorption by water is low. Plant growth "oesiiselrs of organic matter in the .sea occurs \\hereyer exceeds re­ the planktonic found in the upper spiration. Therefore , higher rates of produc­ where there is sufficient light penetra­ tion is expected in coastal waters. for photosynthesis. Tberefore. a know­ of tbe standing crop and rate of pro­ Nutrients and primary prcductil'ity of phytoplankton in different regions The availability of essential nutrients in

"~g;lIi(lnS on organic production to assess the productive uPFer la yers is one of the Rlative fertility of the sea were being important fact ors governing the magnitude of out during the past two decades. orga nic producti on. The nutrients are 14 experiments on primary produc- brought up into the euphotic zone by tbe vertical mixing of the water cau sed by wind inshore and offshore and wave actio n; processes associated with c~rren\S and by upwelling of deep waters. The general level of nutrieats is bigh important factors infiu­ in the Arabian Sea, especially so in the the amount of euphotic zone, \I hich is a potentially produc­ reaching the surface of the sea. A tive condition. In the Arabian Sea during

n.orv, 1978 9 mon'won, the coastal water is enriched by in the Bay of Bengal and in the Andaman S the nutrients brought up from sub.;urface phosphates are almost utilised by the phyt levels. A direct correlation between the . The magnitude of primary pr content of phosphates and ri ch phytoplankton duction is influenced primarily by the ava was ob,ecved during the monsoon months. ability of nutrients as other conditions a The hydrographical conditions during this never limiting. Hence a study of the seaso period seem to be mainly responsible for the variations of nutrients could provide valua rate of replenis hment of nutrients far exceed­ information on the primary productivity. ing their utilization. The precess of replenish­ ment is more intense towards the southern Regional and seasonal variations in part of the west of India. During the primary productivity postmonsoon the nutrient levels decreases 57 million hectares of shallow due to theincreasing vertical stability of the contiguous to the coast line of India. T waters. In the offshore regions marked of India is much wider· variations in the nutrient levels are observed certain regions en the west coast than on t in different seasons. But in the inshore east coast. There is considerable season regions, the seasonal variations in nutrient and regional va riation in the magnitude concentration is relatively less because ofthe organic production. Some of the m constant mixing of the water. On the south­ productive regions are found on the con· west coast theemaximum production of phyto­ nental slope. plankton takes place during the south· west monsoon. There is another peak of le sser The Arabian Sea is highly productive cause of the presence of regions of deep wat magnitude in the north-east monsoon months ascent. Generally the level of organic pr between December and February. Plankton duction is high near the coast and becom production during the south-west monsoon less seaward. Studies on the primary pr on the west coast surpasses those from some duction in the seas around India have sho of the most fertile coastal regions of the that the shallow areas of the Gulf of Mann world. The nutrient concentrations in the Palk Bay and Wadge Bank are extreme Bay of Bengal is of a lower order compared productive, with an average rate to the Arabian Sea. The absence of large 2.0 gC/m'/day during most of the year a scale upwelling is presumably responsible for with the highest values of over 6.0 gC/m"/da the lower level of nutrients and phytoplank­ These high rates are almost equal to tho ton concentration here. found in some of the worlds most producti waters as in the regions of the Somali coast. A direct correlation exists between pri­ mary production and nutrient concentration - In the shelf waters of India, the avera low values of primary production coincided gross production comes to 1.19 gC/m"/da with the deficiency of nutrients. In the which amounts to an annual gross producti central part of the Arabian Sea and in the of 434 gC/m'/day. Assuming that 40% open ocean nitrates are practically absent and this is being utilized for respiration, the n

10 Export Journ uction would amount to 260 gC/m'/year. rents. The migration of these organisms or the zone between 50 m depth and the the animals that feed on them can sustain of the continental shelf, the average large stocks of pelagic li>hes in the open is 0.43 gC/m'/day which is moderately ocean where the apparent organic production In this region the annual gross pro­ is of a lower order. Hence large shoals of of carbon would amount to 157 pelagic could sustain in the open parts •.__ .~ /year and the net production 94 gCfm'f of the Arabian Sea in vi ew of the high The net production on the western productivity in certain re gions. Generally, has been estimated at 46 x 10' tonnes the trend ~nd magnituJe uf production arc year, which is about 3 times that of the reflected in the fishery potential of the regions production on the shelf regions of the concerned. coast. Observations carried out on the In the Ba y of Bengal, the areas of highest ...- .. coast have clearly indicated a gradual phytoplankton concentration were near the in the rate of production from shore on the northern and eastern regions "olIow waters to the deeper regions of the where there was replenishment of nutrients to and slope. Beyond the shelf the level of a crrtain extent due to upwelling. The "pnic production falls to < 0.2 gCfm'/day. a verage value of 0.63 gC/n.'/day found in the _Bhc:r rates of production are found near Bay of Bengal is moderately high. However, Laccadive and Minicoy Islands. Certain it is only about one half of tbe productivity !":ciClDS of Arabian Sea is highly productive of the west coast within 50 m depth and account of the presence of unusually high slightly more than the average value for the of organic nutrients at shallow depths region outside the shelf. The total net within or in close proximity to the production over the shelf amounts to 15 x 10· zone. When these nutrient s are tonnes. T hus it could be seen that the west ~1JU1!ht to the euphotic zone a high level of coast of India \',"ith a wider continental shelf Fim.,ry production could be sustained. The and a more pronounced upwelling accounts ...soon shift provides the required energy for three· months and the east coast one· the vertical mixing of the fourth of the entire net primary production. brings appreciable quantities of nutri­ This disparity is reflected in the magnitude of to the surface layers. High concentration the fisheries resources along these . phosphates (3.73 ug. at/ I) during May­ have been observed in the eastern Standing crop of plankton .an:tan Sea between 0 and 200 metres. In The Arabia n Sea has been found to be ...,'esltern Arabian Sea also high concentra­ the richest part of the Indian Ocean in plank­ of phosphate (>2.0 ug. at/l) have been ton production. This goes to sustain the at depths of 100-500 metres. The pelagic fisheries of oil , and ri ch water from the intermediate several olhers, high seas fishery and the de­ when brought up to the surface sup­ mersal fisheries on the sbelf chiefly a heavy growth of planktonic organisms which feed on the organic matter at the spread seaward with the surface cur- bottom. The presence of upwelled waters

ft!l],ruB'rv 1978 11 7'ot OVtlt 4 7 'ftltl.t~

B U I L D IN GIN T ERN A T ION A L UN D E R S TAN DIN G through INTERNATIONAL TRADE

We are one of the pioneers in the INDIAN FROZEN SEAFOOD TRADE We are specialists in INDIAN FROZEN SEAFOOD

We want to do business with you

Exclusively represented in India by our buying agents: J M M Enterprises c/o Shapoorji Pallonji & Co. Gresham House, 4th Floor, Sir P. Metha Road, BOMBAY 400001, India.

ARISTA INDUSTRIES, INC. 500 Summer Street, Stamford, CT 06901 u. s. A. Telephone: (203) 327 - 2393 Cable Address : HACKBEN, Stamford, Conn. Telex: 996493

18 Seafood Export JOUTlI - along the coast between Cape Comorin to order during the south·west monsoon season. Karwar is responsible for the high nutrient several times the magnitude of that during the content of the west coast. It may be seen north-east monsoon season. The that the standing crop of pbytoplankton is of crop does not show such sharp oscillation a high order throughout, but during the because their peak development succeeds that lOuth-west monsoon period it attains the of the primary producers. the phytoplankters peak of development. The fan in tbe stand­ and are probably being eaten up or carried ing crop of phytoplankton during the north­ away by the prevailing currents to distant east monsoon season is partly due to the places. An forms of life are directly or Brazing effect and probably also owing to indirectly dependant on the phytoplankters, lack of some essential nutrients which act as the prime syn thesizers. The fluctuations in a limiting factor. abunda nce of plankton is sure to eflect the The standing crop of zooplankton along different le \ els of our harvest of wealth. the west coast fluctuates from 100 - over 700 ml / IOOO rn' over the shelf and decrea ses Primary production in relation to fisheries ..mewhat beyond. The ri chest area is from resources Quilon to Calicut, Cannanore to Karwar and The phytoplankton sustain a host of Wadge Blnk in the south. The peak pro­ herbivores. mostly . and carn ivorous "Dction is in June-JUly and another of less cope pods and a host of higher forms includ­ iDtensity in October, the value fluctuating ing so me fi soes, and these in turn nourish the (rom 221-76 1 ml /m' over the shelf. Relative­ carni vore s and larger forms. Therefore, ly steady but quite low volumes of plankton a r elation ~ hip which commences as a direct are noticed from December to April. For one gradually becomes inverse with forms at the oceanic area high value of 144 ml/lOOO rn' a higher tr.' ?hic level. was recorded in July and tbere was no con­ When t'rimary production is considered spicuous secondary peak of abundance. An in the overall role of the relation aamination of the data relating to primary in the sea. it becomes necessary to know the ..oduction also indicates that in almost efficiency of energy transfer from one step in whole of the area where standing crop of the food chain to another. When the steps ,&a nkton is ric h, organic production also is of are fe w in the food chain higher efficiencies a bigh order. It bas been found that the of food energy transfer a re found. The most abundance of surface shoals of mackerel and im portant direct c('nsumers of phytoplankton ei1 sardine during September-October 15-30 are the copepods and euphausids. These lilometres offshore coincided with the pre­ CrU !) laCear s and their la rvae constitute the ....c e of a dense plankton belt from Cochin bulk of the food of other plankton amimals 10 Karwar. including pelagic fi sh larvae and the plankton In general, the standing crop of plankton feedi ng fhb . 1 he foed is converted by the is rich in certain regions and exhibits seasonal fi sh panly into growth. The efficiency of hetuations. The standin g crop of phyto­ conversion is higher in young fish and lower plankton in the shelf is fOUl;d to be of a high in old fish as the growth is slower in the

February, 1978 13 latter. It has been observed that the landings 2-3 million tonnes of fish from both the of commercial fi sh in intensely ex ploited coasts. It is therefore rea s(l nable to thilik waters is ab out O.4 ~{, of the orga ni c matter that fish landings in In dia could be increased produced by the phytoplankton. The ratio to at least two fold o r more by increasing of phytoplankton production to the fish land­ effort. Thus primary productivity ed a long the coast of India is only about a studies apart from giving an idea of the half of that found in the which is relative fertilit y of water masses, enable a an intensely fished area. quantitative asse5sn~ent of the potentia l re­ sources and provide valuable information On Based o n the data co llected so far. the the possibi lit ies of la rge scak fi shing. gross o rganic pr0duction on the shelf within 50 metres over an area of 1, 14.520 square POTENTIAL RESOURCES kilometres. where th ere is acti\e fishi ng ha s Explorat o ry and sciemifi c expeditior s by 6 been estimated at 50 x 10 Wnnes a nd t he net Som e research vessel s in re cent years have production available to the environment furn ished valuab le info rm ation o n the 6 would be abo ut 30 x 10 toones of carbon. po te ntial marine fishery re sources of the The present yield o f fish fru m the west coast country. i nY esl igatio ns o f the Central Marir.e is 10.32. 137 tonnes which is caught mostly Fisheries Resea rch Institu te, Integrated fr om th is shall ower inshore a r~a s. In terms Fisheries Proj ect, Explo rat 0ry Fisheries. of carbo n it amounts to O. ~ ~ 0 which is only Project and UNDPj FAO Pelagic Fishery one hal f of the maximum sustainable yield. Project have thrown some light on the For the rest of the continental shel f area. the magnitude o f the resources. So me a speps of 6 net production amounts to 16 x 10 lannes the oceano graphical features influenci ng the wh ich would yield another 3.2lakh ton nes flu ctuati ons in the important zonal fishe ries. even at the present rate of exploitation. So have al so been eluciruted to S0 me e\l cnt. the minimum han'estable crop from th e "est Fisheries resourCes along the continental coast seem to be around 2 milli o n la nnes. shelf edge and the upper continental slope For the east coast, taking the average pro­ duction rate of 0.63 gCfm'/day the total Till recently. hardly anything \' as ho\\ n net production over the shelf area would about the commercial tra\d ing possibilities along tbe continental shelf edge and the amoun t to 15 x 106 (cnn es of carbon and the optimum yield of fi sh would be 6.00,000 uprer cont inen ta l slope. The re search vessel tonnes. As the present yield is 3.86.521 Varuna and the mechanised fi shin g vessels lannes, the potential harvest on the east Klaus Sun nana. and Velamin of the c oast also would be about 3 ti mes the present Integrated F is[ieries Project have made yield . exploratory surve ys al o ng the \vest coast and the south-east coast of India to locate poten­ Thus considering the east and west coast ti al fishery resources in depths beyo nd 50 m. together the potential resources over the These surveys indicated that potentially good entire shelf region based on the yield ratio fi shing grounds for demersal fishes exist at from carbon production would be at least different depths along the continental slope.

14 Seafood Export Journal The in vestigations of the Pel1gic Fishery upper contine ntal slope off Quilon have been obtained, The resources of kalava along the If a narrow belt void of any fish re;: orJings south \\·est coast from Ponnani to Quilon is us to be separati ng t he coastal resources immense and awaits exploitation. These a c:Jntinuous dispersed di stribution of facls indicate the availability of good poten­ inly bottom fi;;h on the outer part of the r and upper slope. tial resources al ong the continental slope.

The average resources of ribbon fish Com·entional demersal fishery resources ng the south-west coast of India has been The depths upto 50 m:Ires are being -mated at 67,200tonnes whereas the highest fished intensively by country crafts and -mate ever recorded was fuund in :\1ay- small mechanised boats along certain stretches e 1975 (3 ,09,300 tonnes), The average of the coast. There has been a concerted -mate is highest d.Llng the coast effort on the part of those using mechanised ,600 tonnes), followed by that of Southern boats for almost exclusively for harashtra (20,800 lOnnes), Off the coast prawns. This results ina shift in gear and Kerala the greatest abundance "was from effort exclusively towards fisheries and y to September with the highest estimate hence some other inshore fisheries have re­ 1,69,000 tonnes during July-August 1'975, mained underexploited or unexploited. A e average standing stock of cat fish was wider shelf on the west coast invariably sup­ 000 tonnes \'.,'hereas the highest in 1975 ports a greater abundance of demersal fishery d uring June/July (3,98,900 tonnes), The resources. In the shelf waters beyond 50 est estimated average of cat fish metres there are consid erable resources wh ich re main virtually untapped, [n the depth owe d by Karnataka and G l)a 06,670 zone 75-100111 the thread bream, nes). Along the Kerala coast. the period .\lemipterus japoniclis predominated in ex­ abundance is during the second and third ploratory and experimental fishing operations, :.lalrtees of the ye"r In the depth zone 50-80 sometimes forming 75~ ·~ of the trawl catch. Although the narrowness of the shelf has cat fish landings In the region were high an adverse effect on the supply of demersal the third and f"urth quarteL This fishes on the east coast. N. japonicus resource situation is mainly due to the fact along the east coast is also high. Suffici ent tne tradltion<11 fishery cannot effectively fishing has not been made along this coast in the resources during the monsoon the depth zone in which this species is pre­ when the stocks are highest in the dominant to obtain a clear picture of the resources. There is every reason to be optimistic and with diversification of fishing Good catches of Puerulus to exploit all types of demersal fishery re­ and deep sea prawns Panaeopsis sources, the fish catch rates and production r-"""cuta, Aristeus semideillalus etc along the should go up considerably.

""j, TI7,O r tl. 1 978 1S ALLANASONS PVT. LTD. ALLANA BUILDING, 424, MAULANA AZAD ROAD , BOMBAY - 400-004

332163 Telegram : " ALLANASONS " Telephone: { 332772 Telex 011 - 3317 "ALLANA"

Packers and Exporters of ALLANA BRAND fROZEN fOOD & MARINE PRODUCTS

Owners of most modern quick Freezing Plant and Cold Storage for Marine Products

ALLANA COLD STORAGE Pvt. Ltd. D-38, TRANS-THANA CREEK, M.I.D.C. IND. AREA. THANA - BELAPUR ROAD, THANA DISTT" MAHARASHTRA INDIA

i

16 Seafood Export jourlJl c:...entional pelagic fishery resources mackerel (Mega/aspis sp., scads ( Decapterus) The exploitation of the pelagic shoals and trevallies ( spp.). In the Project carried out by non-mechanised fishing craft area alone, the average standing stock of en the shoals move close to the shore. The horse mackerel estimated through stock DP/ FAO Pelagic Fishery Project has con­ assessment surveys is of the magnitude of b ed the earlier findings that along the wes t 1,40,500 tonnes which is con,iderably higher st in depths upto 40 metre there exists a than the present all India yield. The hi ghest rsity of species predominantly constituted estimate in 1973, 1974 and 1975 were 1,69,300, the oil sardine, mackerel, . caran­ 2,29,300 and 5,52,800 tonnes respectively. It , horse mackerel, silver bellies, lesser was observed that the average stock is the dines etc. The average magnitude of the highest along the Kerala coast (70,260tonnes), ve resources in the project area has been foll o"ed by that of Sourhern Tamilnadu atimated to be around 2 million tonnes, (56,240 tonnes). They are found in good concentrations on the middle and outcr shelf Upto 15 metres depth there is a conti­ extending from 30 to 100 m bottom depth, -.ous belt of shallow water mix composed of but in certain seasons and areas their distri­ carangids, lesser , silver bellies, bUller bution extends sborewa rcs upto 15-20 ni 6sh etc. In the Project area the resources of depth. Tbe bighest abundance of the horse llow water mix in 1975 have been found mackerel re sources offSoulhern Maharashtra vary between 25,000 and 1,84,000 tonnes occurs during the first and second quarters, -th an average of 90,000 tonnes. At the along the coast of Goa and Karnataka it is llcight of the upwelling they probably move during tbe second and fourth quarte rs and reward and live pelagically. The shallow off Kerala and Southern Ta mil Nadu coasts tee mi x stocks are of sufficient magnitude il is during the second and tbird quarters of support commercial fi shery using small the year. _chanised boats with pelagic trawl. The -.Jurces of whitebait found slightly away There are good pelagic fishery resources livm the coast was estimated at over half a supported chiefly by mackerel and sardine. .uJion tonnes in June/July, while the average The receot investigations by aerial and was 0.34 million tonnes. They undertake acoustic surveys conducted by tbe Pelagic quIar annual migration, moving southwa rd Fishery Pr0ject have confirmed that both with the onset of the monsoon and con­ oil sardine and maeke rel shoals occur between 30-45 kilometres from the shore ~trating in dense .hoals east of Cape when they are not available in coastal waters. Comorin in July- August. Preliminary work Generally, sardine sc hools are located closer shown that whitebait is easily amenable to the shore than those of mackerel. For fishing with smalI and medium sized both oil sa rdine and mackerel the area between 10°_14° wa s particularly rich wit h One of the resources of considerable 82% and 94% respectively of the total gnitude in the Project area is that of horse number of schools located in the whole area_ cke rel comprising mainly of true horse The mag nitude of the sardine resources at

17 the time of aerial survey in 1974 and 19 75 demand for these. Commercially important were 5,00,000 tonnes and 3.00.000 tonnes specie s (\f such as Symplec/oteuthis­ respectively. During Septe mber-October 1975 ovaleniensis occur along the west coast of the total biomass of mackerel was found India. There are good concentrations of to be of the order of about 7.00,000 tOnnes [ oligo specie. along the west coast of India. whereas, it was only about 1,00,000 tannes in Large concentrati ons of myctophids OCcur 1974. The project data indicate that the along the west coast especially near the proportion of large adult mackerel and oil Angria Banks and 0ff Bombay shelf waters. sardine is significantly greater in the offshore This resource is very important in view of purse seine catches than in the catches from their high vitamin A content as we!1 a;-the inshore areas. Medium sized vessels with oil conte It (110 litres per ton). Apart from purse seines may well pro\ e to be both the bathypelagic scattered schools and I or efficient and economic units for fishing of oil diffuse layers just off the edge, very few sardine and mackerel. since the distance from pelagic fishes have been obsecved beyond the the shore to the fishing grounds will be short middle part of the continental shelf. So fa r and the weather conditi Jns from the middle the project has not produced evidence of any of August onwards are generally quite fair' sub3tantial commercial resources of pelagic The present traditional fi sheries for both fish beyond the continental shelf. Along the species are mainly explo iting the O-group continental shelf edge of the south-west coast when these enter the near shore waters . as well as the east and north west coat of Older and larger fish are apparently accuring India , large quantities of the swimm ing , rather irregularly so as to come within the Charybdis edwards; form a dominant consti­ reach of the present traditional fisheries and tuent of the demersal fishery resources. They they are therefore exploi ted only quite spora­ abound in depth zone 101-1 80 m. Any dically. overall programme at the exploitation and Both mackerel and oil sardine have a utilization of re sources which are at present father restricted longevity, reaching sexual not properly exploited or still remains Un­ maturity at the end of first year of life. The exploited should considerably help in the di versification of fishing leadin g to a mOre fishing mortality is significant mainly during a short fishing season in the first year of life. balanced development of fishing indu'try. Therefore a high rate of natural mortality could be expected. Therefore, the present Our pelagic as well as demersal resources fishery may be well below the le vel of ex­ show large scale seasonal, annual and re­ ploitation required to produce the maximum gional fluctuations. These fluctuations in the sustainable yield . total resources is evidently related to the special environmental conditions prevailing. Non \'entional fishery resources The planned exploration and judicious ex.. Till recently, cuttle fishes obtained in the ploitatiGn of the resources and their utiliza­ regular trawling operati ons were the fi rst tion are needed for the integrated deve lopment items to be thrown out as there was only little of the marine fishery resources. • 18 Seafood Export Journn Prawn Fishery of Chilka lake: Its Contribution to the Export Trade of Marine Products of Orissa

A. B. Roy' and S. K. Mohanty" Dept. of Fisheries, Orissa

The importance of marine prawn re sour· TAB LE I as of India has been established from the Export o/marine products/rom Orissa ii.aeasing foreign exchange earnings by ex­ Year Frozen Prawn Other products Total of prawns and prawn products. Prawn, _ single largest quantity of marine products, 1968-69 res 77.2 and 90.0 percent in quantity a nd Q: 3,137 - Q: 3,13 7 alue respectively in the total export of marine V: 94,110 - V: 94,110 poducts from the country (Annon. 1974) . 1969-70 Q: 4,180 - Q: 4,180 RKporr of Marine Products fro m Orissa V: N.A. - V: N.A. Export trade of marine products from 1970-71 Orissa, though a ve ry recent development, is Q: 61,560 - Q: 61 ,560 pining much importance and contributes V: N.A. - V: N.A. abstaintially to the export promotion of [he 1971 - 72 te o Marine products from Orissa, a.t pre­ Q: 179,079 - Q: 179,079 Ialt, includes only frozen prawns. The trade V: 50,72,000- V: 50,72 ,000 ... registered a steady increase since 1968- 69 1972-73 aad the present volume of trade accounts for Q: 371,116 Q: 4395 (FL) Q: 375,511 abou[ 2.20% of [he country's [o[al export of V: 93,70,428 Y: 82,470 V: 94,52,898 frozen prawns. Most of [he processing plan[s 1973-74 • the State are, at present, located in Puri, Q: 375,042 Q: 16,766(FL) Q: 391 ,808 Paradeep and around Chi1ka lake. The pro­ V: 11, 193 ,036 V: 434,007 V:11 ,627 .043 .using future of marine products export trade 19 74-75 - the State can be seen from the trend given Q: 823.851- Q: 823,851 .. Table I. V: 24,150,505- Y: 24,150,505 -Dy. Director of fisheries. Directorate of Fisheries, 1975- 76 Orissa, Cut tack.7. Q : 1063 ,7 90- Q: 1063,790 .. Junior Fishery Scientist. All India Co·ordinated V: 44,982,000 - V: 44,982,000 Research Project on Composite Fish Culture and Fish Seed Production, Kausalyagang, Puri District, Q: Quantity in Kg. N. A. Not Available Orissa, Pin. - 751 002. V: Value in rupees FL Frozen Frog Legs February, 1978 19