Cetacean bycatch in Indian Ocean tuna fisheries: recent updates and perspectives from the 13th Meeting of the Working Party on Ecosystems and Bycatch of the Indian Ocean Tuna Commission

Bycatch is the most significant threat to cetaceans around the world. However, the magnitude of bycatch is still poorly known, particularly in certain ocean basins such as the Indian Ocean. Tuna fisheries, both industrial and small-scale, are of major socioeconomic importance throughout the Indian Ocean. Published information suggests that cetacean bycatch rates in this region are relatively low in pelagic longlines and in purse-seines. However, the increasing use of drift gillnets, particularly in the northern Indian Ocean, is of concern. Preliminary estimates have suggested that as many as 60,000 cetaceans are caught annually in gillnets in the Indian Ocean. Further investigations are required to refine these estimates. The Indian Ocean Tuna Commission (IOTC) is responsible for the management of tuna and tuna-like species. The IOTC’s Working Party on Ecosystems and Bycatch (WPEB) reviews and analyzes information on non-target species. At its annual meeting in September 2017 the WBEP formally acknowledged the importance of cetacean bycatch and adopted a work plan that included this subject as a research priority. While a severe shortage of data remains, the stage is set for collaboration with the IOTC on data collection and ultimately for mitigating bycatch in the region.