Status of mobulid rays in Sri Lanka

Citation
Fernando D (2018) Status of mobulid rays in Sri Lanka. In: IOTC - 14th Working Party on Ecosystems and Bycatch. IOTC-2018-WPEB14-39, Cape Town, South Africa
Abstract

Mobula rays, while pelagic in nature with a circumglobal distribution, have one of the most conservative life cycles among elasmobranchs. They are frequently encountered as bycatch in Sri Lankan fisheries targeting tuna and billfish, and retained and landed due to their highly valued gill plates that are exported. Sri Lanka is among one of the highest mobula catching nations due to single and multi-day fishing vessels capturing these species as bycatch off the continental shelf edge and in high seas. Over 303 surveys at 19 landing sites, a total of 632 mobula rays were recorded at 11 of the sites. Across all species, the proportion of juvenile, immature rays were greater than mature adults. This, together with their life history and the fact that multiple countries catch these species within the Indian Ocean, make them extremely poor candidates for commercial fisheries. Recommendations such as improved data collection, mitigation and retention measures, are strongly recommended to curb population decline and enable recovery.