Interpreting biomass and catch per unit area (CPUA) to assess the status of demersal fishes in Oman Sea

Abstract

This study aimed to assess the biomass and catch per unit area (CPUA) of demersal fish resources in the northern part of the Oman Sea based on trawl survey. The study area was stratified into five stratum (I, II, III, IV and V) covering the depth layers of 10-20, 20-30, 30-50 and 50-100 m. A total number of 68 stations were monitored during the study period. The highest values of biomass were belong to stratum V and IV in the east coast of the Oman Sea and the highest species biomass was belong to batoid fishes (8054.4 tons). The lowest CPUA was recorded in the central region of the study area (stratum III, approximately 8212 kg/nm 2 ) and the highest CPUA was on both sides of the study area (the east and west coast). Moreover, the highest CPUA (2031 kg/nm 2 ) was observed in 20-30 m depth layer. The results showed the changes in biomass and CPUA based on different depths and the most abundant species groups were Trichiurus lepturus (50-100 meter), Sphyraena jello (30-50 meters), Caranx ignobilis (20-30 meters), and Pomadasys kaakan (10-20 meters).