An Assessment of the Interactions between Species in Multispecies Demersal Fisheries in the Southern Part of the Gulf of Thailand

Abstract

The demersal fisheries in the Gulf of Thailand are a good example of multispecies fisheries which have been studied intensively. Since the early 1960’s, catch per unit of fishing effort (CPUE) statistics, in terms of kilograms per hour of otter board trawling by a research vessel, have been systematically compiled by the Thai Department of Fisheries based on the surplus-production models. These studies were reported on by many authors such as Isarankura (1971), Gulland (1972), Marr et al. (1976), Boonyubol and Honhdkul (1978) and Boonyubol and Pramokchutima (1982). In These studies, the authors assumed a single fish stock for the whole of the Gulf of Thailand. Recently, Pope (1979), Pauly (1979) and Sommani (1983) have considered the demersal fisheries in the Gulf of Thailand as multispecies fisheries and studied the effects of the fisheries on these stocks. The first two authors treated the demersal fish stocks inhabiting the whole of the Gulf as a single stock but the last author assumed that the demersal fish stocks in the Southern part of the Gulf, covering the areas off the coast of Surat Thani to Narathivat Provinces, are isolated from those inhabiting the other parts of the Gulf.