Bottom trawl discards in the Gulf of Suez, Egypt

No abstracts are to be cited without prior reference to the author.

This study is the first assessment of discard composition of the bottom trawl fishery in the Gulf of Suez. The data were collected on board of a commercial trawler from about 77 hauls. The trawl fishery in the Gulf of Suez is directed for shrimp but many finfish species and invertebrates are caught as by-catch, the ratio of shrimp catch to by-catch was estimated as 1:15. About 56.1 % of the total catch was discarded at sea. Rate of discards per hour was found to be 28.2 % higher than the rate of landed catch per hour. The main components of the discards were fish and crustaceans. The discarded quantities were studied in relation to depths, duration of the hauls, landed catch of each haul and the area (eastern and western sides of the Gulf of Suez). The discarded catch of fish showed more precise relationship with their landed catch in each haul than did crustaceans and echinoderms. Discard percentage is decreasing with the increase in depth. The size frequency distributions of discarded fish and invertebrates proved to be a good measurement to study discarding, to compare differences between the two areas and to investigate the discarding procedure in relation to depth.