139736eo.pdf (20MB) - Japan Oceanographic Data Center

FISHERY RESOURCES IN THE NORTH ARABIAN SEAAND ADJACENT WATERSSIEBREN C. VENEMAFishery Resources OfficerMarine Resources Service, Fisheries DepartmentFood and Agricultural OrganizationRome, ItalyABSTRACTThe Arabian Sea has drawn the attention of oceanographers and marine biologists becauseof its unique oceanographic phenomena. The reported upwellings and related high primaryproduction off southwest Arabia, Somalia and the Malabar coasts of India have led to highexpectations in terms of harvestable fish resources. Schaefer, for instance, estimated that thepotential yield of the resources off southern Arabia, the Gulf of Aden and Somalia are the sameorder as that of the anchovy fisheries in Peru; viz., around 10 million tonnes. Subrahmanyanestimated the potential of pelagic fish off the west coast of India at 1,119,000 tonnes based on acomparison with the North Sea, while Shomura put it at 500,000 tonnes. He estimated a potentialof demersal fish of 1,430,000 tonnes for India and Pakistan, and an additional 800-850 thousandtonnes for Somalia, the People's Democratic Republic of Yemen and Oman. The total pelagic anddemersal production for the Arabian Sea was put at around 4 million tonnes based on Cushing'scalculations. The above estimates were all very rough and can now be replaced by better ones forpractically the entire area.The rapid developments in stock assessment by acoustic methods, in particular the echointegrator in the late sixties, made it possible to survey large areas in a relatively short time spanwith one large vessel. A UNDPFAO project aimed at assessing the resources off southwest Indiawas subcontracted to the Institute of Marine Research in Bergen, Norway, and the R.V.RASTRELLIGER, built in Norway, became the flagship of the UNDPFAO fleet of researchvessels. FAO, through the Indian Ocean Programme, later entered into a trust fund agreement withNORAD for the construction and operation of the R.V. DR. FRIDTJOF NANSEN, an improvedversion of the RASTRELLIGER, and equipped with all the then available acoustic instruments forresource surveys. A plan for a two-year survey of the waters from Pakistan to northern Kenyawas executed in 1975 and 1976, with an extension under a bilateral agreement for the first sixmonths of 1977 off Pakistan. The existence of a large biomass of fish was confirmed; but the bulkof this biomass consisted of mesopelagic fish, a resource suitable for the production of fishmeal,the economic feasibility of the harvesting is not yet known.In 1979, the R.V. DR. FRIDTJOF NANSEN returned to the Gulfs of Oman and Aden tostudy further the resources of mesopelagic fish, and in 1981 a similar survey was followed byshort surveys in the waters off Djibohti and the Gulf of Suez. In 1983, the DR. FRIDTJOFNANSEN, funded by NORAD and a global UNDP/FAO project, returned once again to theArabian Sea for a longer-term programme. The harvestability of mesopelagic fish was tested withsuccess in the Gulf of Oman in January/February. The other resources of Oman were assessed inMarch. After a short survey in the Maldives in August, the first of its kind in that country, thevessel proceeded to Pakistan and Iran to start another series of surveys in that area, followed byothers off Oman and in the Gulf of Aden.253