Demographics of a heavily exploited deep water shark Echinorhinus cf. brucus (Bonnaterre, 1788) from the south-eastern Arabian Sea

Abstract

In the absence of direct consumption importance and considering as low value bycatch, many vulnerable non-target species, especially slow growing deep water fauna, are overlooked in tropical fisheries research and management. The bramble shark Echinorhinus cf. brucus (Bonnaterre, 1788) is one such species, subjected to a significant non-targeted deep water fishery off southern India. A length frequency based stock assessment of bramble shark caught in trawl fisheries from the south-eastern Arabian Sea suggests that, E. cf. brucus is a moderately slow growing (K=0.12 year^-1) and moderately long lived shark species (T_max = 25 years, L_¥= 333 at corresponding age of 55 years) which is overexploited (M=0.17, Z=0.39) in the region. In view of resilience capacity and vulnerability of deep sea fisheries, improved research and monitoring programmes are urgently required to ensure a sustainable future for India’s expanding deep-sea and distant water fisheries.

Keywords: Bycatch, Deep sea, Indian Ocean, India, Population dynamics, Shark fishery, Sustainability