Abstract
Boubyan Island is essentially undeveloped and the largest island in the northwest of the Arabian Gulf. Small otter trawls were used to sample 12 stations circling Boubyan Island each month, except November, from February 2004 through February 2005. All trawl catches, with the exception of large Skates and Rays, were returned to the laboratory for identification and processing. The total number of individuals captured by all 431 five-minute trawl tows was 81659. Species caught included 31 Crustaceans, 7 Mollusks, 5 Echinoderms, 1 Tunicate, 90 fishes, and 1 Sea Snake. The monthly total occurred species ranged from 27 to 78 and was high in the summer months (June to August) and low in the winter (December to February). Species richness and Shannon’s diversity showed a similar seasonal change pattern with a range of 3.41–7.93 and 0.80–2.58, respectively. The seasonal changes of the number of species, abundance, species richness and diversity were probably caused by the migration and reproductive circle of the organisms. However, the variations for all these indices among different stations were relatively small and suggested a similar environmental conditions for the areas around Boubyan Island.