Los recursos de peces demersales de la Plataforma Continental del Ecuador. Parte uno. Distribución, abundancia y variaciones

Abstract

A survey of demersal fish resources of the Continental Shelf of Ecuador was carried out between October 1980 an July 1985 by the National Fisheries Institute of Ecuador, with British Technical Cooperation. This report deals with the stock assessment part of the work. In the course of seven cruises, 366 valid diurnal hauls were made with a high-opening bottom trawl. The demersal fish resources were estimated by swept area methods and the results are presented. The overall average standing stock of demersal fish was 78 000 t of which 22 000 t was good fish, but 36 000 t were gurnards (Triglidae) and 3 000 t of unusable fish. The main stocks were gurnards, grunts and croakers, sharks and corvinas Cynoscion spp. The southern areas especially the Gulf of Guayaquil had the highest densities of fish (9,6 t.Km-2 or 4,0 t.Km-2 excluding gurnards). There was a massive abundance of the gurnard, Prionotus stephanophys in 1984 and 1985. There was a general decrease and other changes in the demersal stocks due to the effects of the ”El Niño” in 1983.