Over-exploitation of the demersal resources of Manila Bay and adjacent areas [Philippines]
1987
Silvestre, G. | Federizon, R. | Munoz, J. | Pauly, D.
A review of the multispecies fishes of Manila Bay [Philippines] and adjacent waters is presented covering an area of 5,200 km and a depth range from 0 to 100 m. The available data on species and size composition of trawl catches are two scanty to allow strong inferences, although they indicate over fishing. Trends of effort, catch and standardized catch per effort for 1948 to 1984 provide, on the other hand, strong support for the occurrence of massive overfishing, as is confirmed by relating a number of single-species optimum mesh size estimates with the current trawl cod and mesh size of 2 cm. A plot of aggregate landings vs fishing mortality was used to obtain estimates of economic rent from the fishery and of maximum economic yield (MEY = 8,600-17,400 metric tons per year). It appears that the demersal stocks of the Manila Bay area, which has an MSY of 13,100-20,000 mt per year (and whose economic rent is probably negligible at present), are capable of generating, at MEY, an economic rent corresponding to 3,100-9,700 mt per year (i.e., approximately US$ 1.5-4.8 million worth of fish and invertebrates per year. To realize all of this rent however, the prevailing fishing effort would have to be reduced to almost a third of the 1983-84 level.
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