Retained and Discarded Bycatch from Kuwait’s Shrimp Fishery

Abstract

The quantity and species compositions of both retained and discarded bycatch of the Kuwait’s shrimp fishery was investigated for the first time directly through onboard observation and sampling of a fishing vessel. The observations were conducted on a 131 tonne double-rigged shrimp trawler twice a month during the shrimp season from September 2010 through January 2011. The shrimp catch rate declined sharply from 19.6 to 1.1 kg/h as the season progressing, while bycatch rate remained in a high and relatively stable between 106 and 81.5 kg/h, and resulted in a large variation (5.4-73.6) of byatch-to-shrimp ratio from the season’s start to the season end. The retained bycatch was always low (11.6-15.9% of the total bycatch) throughout the season. The total species recorded in the bycatch was 112, with 55 retained and 93 discarded at sea. Thirty-nine species occurred both in retained and discarded bycatches. Saurida tumbil, Nematalosa nasus, Sphyraena flavicauda, Acanthopagrus latus and Otolithes ruber were the most dominant fish species in the retained bycatch. Discards dominated both by undersized commercially valuable species including Ilisha melastoma, Pomadasys stridens, Nematalosa nasus, Saurida tumbil and Upeneus doriae, and by non-commercial species such as catfishes, sharks and rays. Based on monthly bycatch-to-shrimp ratio, the percentage of the retained bycatch and the recorded shrimp landings, the total bycatch of Kuwait’s shrimp fishery was estimated to be 15,704 t for the 2010/11 season. Of the total bycatch, only 2192 t (14%) was retained, while the majority 13, 512 t (86%) was discarded at sea. Of the 93 discarded species, 55 are commercially valuable species, representing 61% (8242 t) of the total discarded bycatch.