The Sultanate of Oman shark fishery: Species composition, seasonality and diversity

Abstract

The Sultanate of Oman has a long established traditional shark fishery, which has experienced increased demand in recent years due to the shark fin trade. Despite the long history of the fishery in Oman and neighbouring countries, few studies have been undertaken to determine the biological characteristics of the fishery or its ability to withstand this increased exploitation. The present study was undertaken as a first step to remedying this situation. A total of 47 species was confirmed from Oman's coastal waters, of which 44 occurred in commercial landings. However, landings were dominated by eight species— Rhizoprionodon acutus, Iago omanensis, Carcharhinus sorrah, Loxodon macrorhinus, C. macloti, C. limbatus, Sphyrna lewini and C. falciformis. The species composition of landings varied along the coast and also with season. Brillouin Index values indicated that species diversity was greatest in the Muscat area, followed closely by Musandam. The Al-Wusta region displayed the lowest diversity. The occurrence of two uncommon shark species, Chaenogaleus macrostoma and Echinorhinus brucus, was of interest, as was the recording of a juvenile Carcharhinus galapagensis, extending its northern range in the Indian Ocean considerably.