Temporal and Spatial Variations of Finfish Bycatch of Cutlassfish Trawl in Bushehr and Hormozgan Marine Waters, the Northern Persian Gulf

The spatial and temporal variations of finfish bycatch assemblage cutlassfish trawl were compared in two fishing areas (Hormozgan and Bushehr). Data were collected on board of commercial vessels in the fishing grounds of Trichiurus lepturus in Bushehr and Hormozgan marine waters between early May 2010 to late November, 2010. There was a significant difference in the bycatch assemblages between Bushehr and Hormozgan fishing grounds. SIMPER showed that six species contributed as much as 65% of the biomass of the bycatch assemblages between two fishing areas as follows: Nemipterus japonicus (30.5%), Ilisha melastoma (12.5%), Saurida tumbil (8.5%), Argyrops spinifer (6%), Dasyatis bennetti (4.5%) and Arius thalassinus (4%). Differences appeared for the temporal structures of bycatch assemblage in fishing grounds of Bushehr. SIMPER also showed eight species contributed to as much as 69.3% of the dissimilarity of the biomass of the bycatch assemblages between fishing seasons. These species were S. tumbil (17.3%), I. melastoma (16.3%), N. japonicus (13.3%), Carangoides malabaricus (17.2%), Rachycentron canadun (6.3%), Upeneus sundaicus (3.5%) D. bennetti (3.5%) and Epinephelus coioides (3.2%).