Rate, ratio and amount of annual discards in commercial trawl net in northwestern part of the Persian Gulf (Khuzestan Coastal Waters)

The main goal of this study was estimating discards of trawl nets in north western part of the Persian Gulf. Data were collected from fishing boats in fishing areas of Lifeh, Boseif, Khure-mussa and Bahrakan from October 2011 to September 2012 with collaboration of fishery office. Discard samples include 101 species from 61 families which are 39.5% of commercial catch and 60.4% of non-commercial catches. Rayfish and catfish have been observed in most fishing nets. The average size of bony fishes in discard samples was lower than 15 cm. Total weights of discards was estimated about 1109 tons per year. Total weight of commercial fishes with small size in discards was estimated 2736 tones. The rate and proportion of discards in total catch of trawl was estimated 0.5 and 1.03 respectively. Osteichthyes with 70 species and 50.7% of trawl catch has the highest percentage of discards in trawl nets. High rate of small fishes in commercially important species of discards is probably due to nursery role of Khuzestan coastal waters.