C'MKRI ' jlletin 32 Kll. 1982 RESOURCES OF TUNAS AND RELATED SPECIES AND THEIR FISHERIES IN THE INDIAN OCEAN E. G. SILAS & P. P. PILLAI CENTRAL MARINE FISHERIES RESEARCH INSTITUTE (Indian Council ui Agricultural Research) P.B. No. 1912, Cochin 682 III8, India CMFRI bulletin 32 APRIL 1982 RESOURCES OF TUNAS AND RELATED SPECIES AND THEIR FISHERIES IN THE INDIAN OCEAN E. G. SILAS & P. P. PILLAI CENTRAL MARINE FISHERIES RESEARCH INSTITUTE {Indian Council of Agricultural Research) J>.B. No. 1912, Cochin 682 018, India Bulletins are issued periodically by Central Marine Fisheries Research Institute to interpret current knowledge in the various fields of research on marine fisheries and allied subjects in India. G Copyright reserved Edited and Published by E. G. SILAS Director Central Marine Fisheries Research Institute Cochin-682 018, India Restricted circulation Dr. Richard S. Shomura (left) noting the weight of a bigeye tuna (Co. 82 Kg) taken by the longline gear on board R/V ANTON BRUUN from the s3ulhsrn Indian Ocean. (Photo by E. G. Silas) CONTENTS I. INTRODUCTION .. .. .. .. .. ., .. 1 II. TAXONOMY AND DISTRIBUTION OF TUNAS, TUNA-LIKE FISHES AND BILLHSHES IN THE INDIAN OCBAN 3 List of species Tunas and tuna-like fishes—Distinctive characteristics of the species Billfishes—Distinctive characteristics of the species III. FISHING METHODS .. .. .. .. .. ., .. 24 Surface fishery School identification Pole and line (live-bait) fishery Purse seine fishery Surface trolling Fish aggregating devices (FAD) Sub-surface fishery Longline fishery Other methods of fishing Drift gillnet fishery Set nets Harpooning IV. TUNA ENVIRONMENT .. ., ,. ,. ,. ., .. 41 Temperature and oxygen Tuna migration Salinity Transparency Mixing process Oceanic islands and banks Submarine topography Food supply Satellite imagery V. TUNA FISHERY IN THE INDIAN OCEAN : TREND IN THE EXPLOITATION OF THE STOCKS, PRESENT STATUS OF THE FISHERY AND RESOURCES OF TUNAS AND RELATED SPECIES .. .. .. 72 General review of the present trend of fishery Group-wise production of tunas, tuna-like species and billfishes Species-wise production of tunas, tuna-like fishes and billfishes Review of the level and status of participation in the Indian Ocean tuna fishery (country- wise) Japanese longline fishery Taiwanese longline fishery V l-A Executive summary of tire state of stocks of tunas, tuna-like fishes and billfishes—current level of exploitation and potential for expansion Yellowfin tuna Albacore Bigeye tuna Southern bluefin tuna Striped marlin Blue marlin Black marlin Sailfish Swordfish Skipjack tuna Other tunas and tuna-like fishes Tuna fisheries in the Indian waters : present status Resources Crafts and gears Trend in all India catch State-wise catch Tuna landings at selected centres Future prospects BAIT FISHES .. .. .. .. .. .. .. 136 Live-bait for pole and line fishery Fishing techniques Floating receivers Transportation Bait for tuna longline Culture of bait fishes BY-CATCH .. .. .. .. .. .. .. 141 POST-HARVEST STORAGE, PROCESSING AND MARKETING .. .. .. .. 147 MANAGEMENT PLAN FOR THE TUNA FISHERY IN THE INDIAN OCEAN .. .. .. 151 Tuna fishery in the continental shelfwaters Surface fishery from the EEZ of island states Tuna fishery in the high seas Longlining from within and outside the EEZ Tuna fishery from the surface waters of the high seas Controls Surveillance Options open for tuna fishery development in the EEZ of India and the contiguous seas Augmenting production Management Need for foreign expertise THE NEED FOR AN INTERNATIONAL COMMISSION FOR THE CONSERVATION OF INDIAN OCEAN TUNA (ICCIOT) .. .. .. .. .. .. 16S REFERENCES .. .. .. .. .. .. .. 165 APPENDIX I-III .. .. .. .. .. .. 172 PREFACE In 1961,1 had an occasion to discuss with one of India's leading fishery technocrat and policy planner my researches on Indian tuna and tuna-like fishes. I was shocked when he retorted with a question whether we really had any tunas in our waters and if so whether they were only zoological curiosities. Such was the official attitude and my attempt to explain matters was just brushed aside. In January 1962, I convened an International Symposium on Scombroid Fishes at Mandapam Camp under the auspices of the Marine Biological Association of India and the Proceedings published in 1964 and 1967, combined with the scientific contributions sent from India to the FAO sponsored ' World Scientific Meeting on the Biology of Tunas and Related Species' held in July 1962 at California amply justifies that we do have sizeable tuna resources and India is placed in an advantageous position to exploit these from her waters and from the contiguous high seas. Unfortunately there has been an apathy on the part of our fishery planners to not even look at tuna fishingseriously, resulting in our lagging in this area offisheries as compared to some of the smaller nations who have limited facilities but are looking at development of tuna fisheries more positively. Indecision for some reason or other has been rampant and in the past two decades a stream of potential entrepreneurs from within and outside the country have turned up with propositions for entering on collaborative pro­ grammes in tuna fishery, but all these have been futile exercises ending only in conducted tours and dialogues. The indigenous production in our small scale fishery sector through the mechanisation and increasing effort through gill netting, purse seining, and pole and line fishing have augmented production of the coastal species of tunas and tuna-like fishes and tunas from the Lakshadweep from hardly 7800 tonnes in 1961 to 26,000 tonnes in 1979. However, we are practically at the same stage as in 1961 as far as exploitation of the resources of the Exclusive Economic Zone (EEZ) and contiguous high seas, beyond the inshore continental shelf waters are concerned. A few exercises of insufficient nature in longlining and purse seining have been carried out, but inadequacy of the gear and the cursory effort expended have given if at all only negative results. We are still deliberating on the pros and cons of entering tuna fisheries of the high seas. The two decades from the 1961 to 1981 have seen major shifts in the pattern of large scale commercial tuna fisheries in the Indian Ocean which was started by the Japanese longline fishery in 1952. The Republic of China (Taiwan) and the Republic of Korea have entered the fisheries in the 60's and early 70's respectively for longlining and a number of nations including non-Indian Ocean countries are now planning for longlining and purse seining for tunas in the Indian Ocean. The declaration of the Exclusive Economic Zone by India in August, 1976 has given a flip to the efforts in organizing development programmes for the exploitation of fishes from beyond the continental shelf waters. The Government of India had permitted some joint venture programmes to come up, but these have by and large not helped in the overall development programmes. Recently, the Government of India has pro­ claimed a chartering policy with a view to accelerate the development of deep sea fishing in this country. Tunas being highly migratory species, any development programme should envisage also the scope of harvest­ ing the resources not only from our EEZ but also from the contiguous high seas. The time has come when whatever information is known about Indian Ocean tunas and tuna-like fishes, their ecology and fisheries including present levels of exploitation should be made available to the public forum so that it will be easily accessible to the fishing industry and those interested in commercial fisheries re­ sources. Such a compendium would go a long way in educating our technocrats and policy planners to take decisions on development strategies, help in investment decisions and plan to see how India could become an important partner for sharing the tuna resources of the Indian Ocean. The fishing industry should also benefit from the same. iii I would like to place on record our indebtness to Dr. S. Jones who initiated the studies on Indian Tunas and to Late Dr. Wilbert M. Chapman for the great encouragement he gave for the studies on Indian Tunas in the early sixties. A close association of over three months with Dr. Richard S. Shomura on board the Research Vessel ' Anton Bruun' during its Vth cruise in the Indian Ocean during the International Indian Ocean Expedition from January-May, 1964 enabled me to have a deeper insight into the problems of tuna fisheries of the Indian Ocean. Most of the photographs published in this report were taken by me during this cruise which covered areas between 22°N and 48°S, and 55°E and 75°E. My sincere thanks are due to Dr. Shomura for the courtesies extended. In the preparation of this report, help has been received in the form of literature, and the authors have had the benefit of personal discussions with a number of active workers in this field. Thanks are due to Dr. Shoji Ueyanagi, Far Seas Fisheries Reseach Laboratory, Shimizu, Japan ; Dr. J. A. Gulland and Dr. Francis J. Christy, Resources and Environment Division, FAO; Dr. Wayne J. Baldwin, Hawaii Institute of Marine Biology, University of Hawaii, Hawaii; Dr. R. F. Kearney, South Pacific Commission and Dr. Peter H. Pearse, Commissioner, Department of Fisheries and Oceans, Government of Canada. To Dr. K. P. P. Nambiar, MPEDA-India, Tokyo, Japan, we are appreciative of the interest he has shown in our work on tunas, and for the fruitful discussions and the information he has sent us. In order to make this- work more meaningful, some charts and maps from earlier publications are reproduced here and their sources are duly acknowledged. I hear talks that foreign consultants are being invited to come to India to make a feasibility study of whether or not we should develop tuna fisheries of our EEZ and high seas. While we shall certainly require expertise in certain specific aspects of tuna fisheries particularly with an emphasis on training our personnel, it is highly doubtful with the information available with us, whether we should spend lakhs of Rupees on such wasteful exercises.