GOVERNMENT OF INDIA FISHERY SURVEY OF INDIA Department of Fisheries
Ministry of Fisheries, Animal Husbandry and Dairying

A Study Of The Demersal Resources Of The Wadge Bank And The Gulf Of Mannar

T.E.SIVAPRAKASAM

Demersal resources survey of Wadge Bank and Gulf of Mannar were carried out by the FSI vessel, Matsya Nireekshani during October 1981-April 1983 and October 1983-March 1985 respectively. Analysis of data on relative abundance shows that in the case of Wadge Bank the catch per hour is relatively less (98.6 kg/hr) compared to Gulf of Mannar (133 kg/hr). Perches gave catch rate of 19.8 kg/hr in Wadge Bank and 24.8 kg/hr in Gulf of Mannar. Relative abundance in relation to depth strata reveals that in Wadge Bank, 100-200m depth zone yields highest catch rate in contrast to Gulf of Mannar, where 20-50m depth yields highest catch rate. Observation of seasonal variations indicated that in Wadge Bank January and February gives the highest catch rate while in Gulf of Mannar it is December. Present study gives an opportunity to calculate the biomass in the study area. In Wadge Bank total biomass in 20-200m depth with regard to area 7-77 and 8-77 works out to 38.663 tonnes, while in Gulf of Mannar in the same depth range it is 24.114 tonnes.

Paper 1. Salient Observations On The Results Of Fishery Resources Survey During 1983-84

K.M.JOSEPH

Surveys carried out by Fishery Survey of India vessels in different regions of EEZ forms the basis for this paper. Information regardingnew demersal resources such as Bulls eye, Indian drift fish, black ruff,deepsea lobster and deepsea prawns along both the coasts in addition to exploited resources are brought out. Deepsea resources exploration reveals that deepsea lobster Puerulus sewelli occurs along the west coast from Gulf of Mannar to Karwar and deepsea prawns such as Heterocarpus spp. and Aristeus spp. were found to occur along Kerala-Karnataka coast in the depth range 200-500m. Results of longline and purse-seine survey are also presented.

PAPER 2. A NOTE ON THE DEMERSAL FISHERY RESOURCES SURVEY OF GULF OF MANNAR

V.S.SOMVANSHI AND P.K. BHAR

During 1983 the FSI survey vessel, Matsya Nireekshani, operating from Tuticorin Base, surveyed five major areas viz., 7-78, 8-78, 8-79, 9-78 and 9-79 in the Gulf of Mannar. Results of the survey is discussed in the Bulletin. The main groups/species supporting the demersal fishery in Gulf of Mannar were Barracuda, Perches, Elasmobranchs, Carangids, and Pomfret. The study has shown that the depth ranges between 0-50m and 101-200m are the most productive areas. The deepsea lobster Puerulus sewelli is available throughout the depth belt of 150-500m in Gulf of Mannar in varying quantities. The deepsea prawn Solenocera hexti is also caught from Gulf of Mannar in varying quantities. Sepiellainermis, Sepia pharaonis and S.aculeata constitute the cephalopods occurring upto 200m depth. Thus, Gulf of Mannar offers high scope for demersal fishery resources developement in the region.

PAPER 3. OBSERVATION ON THE DEMERSAL FISHERY RESOURCES ALONG ANDHRA PRADESH COAST

T.V.NINAN, S.P. BASU AND A.K.BHARGAVA

The results of the survey carried out during 1983-84 by the survey vessel Matsya Shikari, between lat. 14oN and 18oN upto 500m depth along the east coast are discussed here. During the period the vessel conducted 617 hrs. of actual fishing and landed 176 tonnes of fish. The results of survey indicate that the area 17-82 is the most productive area, registering a catch rate of 815.98 kg/hr. Analysis of depth-wise and month-wise catch reveals that 71-90m depth zone yields higher catch and that February is the most productive season. Sardine registered 18.48% of catch along the Andhra coast.

PAPER 4. A NOTE ON THE DEEPSEA DEMERSAL RESOURCES OFF KARNATAKA-NORTH KERALA COAST

K.P.PHILIP, B.PREMCHAND, G.K. AVHAD AND P.J.JOSEPH

Results of the survey carried out by FSI vessels Matsya Shakti and Matsya Vishw during 1983-84 are dealt with in this paper. The area between Lat.10N to 15N and Long.70E to 76E within 50-500m depth had been systematically surveyed using 27m fish trawl and 47m shrimp trawl and totally 314 tonnes of fish was landed. Species composition reveals that Nemipterids dominate the catch. A gradual increase in catch rate with increase of depth is observed during the survey. Variation in catch rate by month is also observed. The highest overall catch rates were obtained during the months of April (289.02 kg/hr) and May (241.89 kg/hr).

PAPER 5. SOME OBSERVATIONS ON THE TUNA RESOURCES OF INDIAN OCEAN

K.K.VARGHESE, M.E. JOHN AND V. SHIVAJI

Results of 12 months survey from April 1983 with distribution of sampling in the Arabian Sea, Bay of Bengal and North west Indian Ocean by Matsya Sugundhi, the tuna long liner attached to Cochin Base form the basis for this paper. Altogether 83,000 hooks were operated and the aggregate hooking rate recorded is 2.27%. Results show that the continental shelf waters are richer than the equatorial sea. The maximum hooking rate of 5% is recorded in the area 10-74, situated north west of Cochin. The catch consisted of three species of tunas, viz., Bigeye tuna, yellowfin tuna and skipjack tuna, forming 25% of the total catch. Among billfishes which made up 9.4% of catch, striped marlin and Indian sail fish, are the more frequent ones. Pelagic sharks represent 64.2% of catch. Though equatorial waters give better harvest rate for yellowfin and bigeye tunas, the bill fishes and skipjack tuna yield higher rates from east coast.

Observations On The Fish Catches Of Some Poaching Vessels Recently Intercepted Along The North-west Coast Of India

K.M.JOSEPH

This Bulletin brings out an account of species composition in the catch of 8 confiscated Taiwanese trawlers poaching in north west coast of India and that of project vessel, Matsya Nireekshani and other commercial vessels operating in the same area, which reveals that the poaching vessels fished mainly along Saurashtra region. The difference in the percentage composition of some species such as squid and cuttle fish among the catch of different vessels is attributed to the mode of operation of the poaching vessels and it is inferred that these foreign vessels are fishing in relatively deeper and distant waters during day time and in shallow waters during night. High incidence of cuttle fish and squid (28%) in the catches of Taiwanese stern trawlers lend support to the preliminary findings of the project that there exist potential resources of cephalopods along the north-west coast.

Comparative Study Of The Demersal Fishery Resources Of The Indian Waters Assessed By 17.5m Trawlers

K.M.JOSEPH

This Bulletin presents a comprehensive picture of demersal fisheries resources along the Indian coast from the data gathered by 17.5m trawlers operated from 11 bases during the period 1970-71 to 1979-80. The data obtained on CPUE, seasonality and species composition are presented in the form of charts, diagrams and tables to make it easily discernable. In the west coast, depth upto 80m yielded highest catch rate with cat fish as the dominant group whereas in the east coast depth range between 20-60m shows highest catch rate of perches and leiognathids. The potential yield of demersal fish resources from within 75m depth based on swept area method is estimated as 16,79,000 tonnes.

Results Of Exploratory Fishing Conducted During 1978-79

M.SWAMINATH

During the year 1978-79 with 23 vessels of varying specifications an area of about 39,000 sq.km. was surveyed by bottom trawling and pelagic trawling, and by other diversified fishing methods such as purseseining, tuna longlining and trolling from selected bases an area of 3,000sq.km. was covered. The results of these surveys are discussed in the Bulletin. The results show that in west coast elasmobranchs formed the dominant group while cat fish constituted major catch in the east coast. Relative abundance of important varieties in the different geographical divisions and depth zones and seasonal variation with respect to quality and quantity of catch are also discussed. Along Bombay region the productive zone is between 30-39m depth and highest yielding months are December and February. In the east coast, Visakhapatnam region registered good catch and 60-69m is identified as productive zone.Highest catch rate recorded was in January. Purse-seining, long lining,trolling and mid water trawling are also attempted and the results are promising.

Results Of Exploratory Survey Around The Andaman Islands

D.SUDARSAN

Results of survey conducted by three vessels using different fishing methods around the Andaman Islands, form the basis of this bulletin. During the period, a total of 2420.3 hrs. of fishing effort was expended. Among five methods of fishing adopted, about 50% of effort was put in by bottom trawling, which indicates the scope for this method in Andaman and Nicobar waters.Leiognathids,sciaenids, upenoids, elasmobranchs, cat fish and perches are the major components of the catch. The seasonal abundance of catches show that the period from October to March was generally more productive than other periods. Among fishing methods adopted longlining, trolling and hand line for Kalava yielded better results. Stock assessment of demersal resources based on swept area method is made. The standing crop is worked out to be 2.78 t/sq.m.The total standing crop of demersal resources is assessed in the order of 44,576 m.t. which is about 10 times of the figures arrived at by earlier authors.

Results Of Exploratory Fishing Conducted During 1977-78

M.SWAMINATH

Results of fisheries resources survey conducted by the Project during the year 1977-78 are discussed in this bulletin. Twenty two essels conducted demersal fishery resources survey from twelve bases. During the course of survey the vessels landed 1,134 tonnes of fish and prawns. The composition of trawl catch, the relative abundance in each area and bathymetrical and seasonal fluctuations of important groups have been analysed for each region. In the west coast Kandla region was found to yield 269 kg/hr constituting elasmobranchs as the major component of catch in the month of May. The main components of trawl catch obtained in east coast were perches, rays and sciaenids, which were found to yield better catch in July-August months. The depth range between 20-30m was comparatively more productive than other depths. Longlining and trolling also yielded encouraging results.

Results Of Exploratory Fishing Conducted During 1976-77

M.SWAMINATH

This Bulletin brings out the highlights of results of exploratory fisheries surveys conducted during 1976-77 in the area between Lat.7oN-20N and Long.76E-88E by various classes of vessels of the project.During the period an area of about 46,000 sq.km. was surveyed and about 1806 tonnes of shrimps and fish were landed. The percentage composition of commercially important species inthe trawl catches obtained from different regions was studied. Of all the bases of west coast, the percentage of ranifish was the highest in Mangalore. Perches and elasmobranchs constituted about 2/3rd of the catch in Tuticorin region whereas leiognathids, elasmobranchs, perches and pomfrets were the main groups obtained from Madras. Relative abundance of resources and monthly variation of catch rate of important species have been discussed. North-west coast and lower east coast were found to be yielding more than other regions. Tuna long lining from Port Blair yielded average hooking rate of 3.8% which is viable for commercial operation.

Demersal Fisheries Resources Off The South-westcoast Of India

K.M.JOSEPH, N. RADHAKRISHNAN AND K.P.PHILIP

Attempts made by the vessels of EFP to study the demersal resources off the south-west coast during the period 1957-1974 have been presented. The area of operation was between Lat.7N and 15 and long. 73E and 78E. and total study area was 80,000 sq.km. Eighteen vessels of varying sizes, horse power, tonnage etc. were employed in the survey. The distribution of sampling intensity in the areas of operation, the relative abundance of the demersal resources in general and of commercially important species in particular with refer ence to area, depth and time were analysed in detail and have been presented. Out of the total of 29,400 hrs. of actual fishing, about 65% was expended in areas within 20-39m. The intensity of sampling in 0-19m and 40-59m was of the order of 23% and 10% respectively of the total fishing effort. Analysis done with regard to the catch composition by depth and area revealed some interesting observations. The occurrence of prawns in abundant quantity has been noticed in areas below 20m; elasmobranchs in 40-59m; kilimeen and Lactarius in 20-39m and cat fish in 40-79m from the different regions studied, thus giving an idea of resources for future exploitation.

Results Of Exploratory Fishing Conducted During 1975-76

K.M.JOSEPH

The results of exploratory survey conducted by the project during 1975-76 are dealt with in the Bulletin. During this period of study the project operated 22 steel trawlers, out of which 19 were indigenously constructed 17.5m trawlers. These vessels were operated from eleven bases of the project viz., Kandla, Bombay, Goa, Mangalore, Cochin,Tuticorin, Madras, Visakhapatnam, Paradeep, Calcutta and Port Blair. The survey programme included demersal fisheries resources survey by conducting exploratory and experimental bottom trawling and "Kalava"hand line fishing and pelagic resources survey employing purse-seining,midwater trawling, tuna longlining and trolling. In addition special shrimp survey programme was also conducted from Goa, Mangalore,Cochin, Visakhapatnam and Paradeep. The details of fishing methods and gear employed in the survey, and relative abundance of resources in general and of commercially important species in particular with special reference to area, depth and time have been discussed.