Posted by Victor Restrepo
8 May 2012
As part of our ongoing efforts to address concerns about the future of tuna fisheries, the International Seafood Sustainability Foundation (ISSF) has put considerable effort into understanding the impact of industrial fisheries, elevating best practices, and improving conditions around the globe.
Although much attention has been paid to the bycatch associated with purse seine nets, gillnets are the dominant gear in the Indian Ocean used in artisanal and semi-industrial fisheries from developing coastal countries, and are worthy of further study. Between 2006 and 2010, gillnets contributed between 30 to 40 percent of catches recorded in the Indian Ocean Tuna Commission (IOTC) nominal catch database, with a gradual increase in proportion over the five years. Purse seine nets were responsible for only 25 to 30 percent of catches there, in contrast to other oceans where they are generally responsible for the majority of catches.
Although efforts to collect and analyze data on Indian Ocean artisanal and semi-industrial fisheries targeting tuna have proved difficult, a recent study sponsored by ISSF on the contribution of gillnet fisheries in the Indian Ocean to bycatch of non-targeted species found that catches of bycatch species from gillnet fishing were high across all species groups. This was especially true for sharks, with gillnets accounting for 64 percent of shark catches recorded by the IOTC.
Because of the nature of artisanal and semi-industrial fisheries, which are scattered and conduct fishing and landing operations at multiple locations, data collection is complex and subject to a high degree of uncertainty. For example, very little reported data was available about the impact of gillnets on turtles, cetaceans, and seabirds, although information available in current literature indicates that turtles face a high risk of mortality because of gillnets operating in the Indian Ocean.
Of the 21 coastal countries on the Indian Ocean that fish with gill nets for tuna and tuna like species, seven were identified as the major contributors to gillnet catch: India; Indonesia; Islamic Republic of Iran; Oman; Pakistan; Sri Lanka and Yemen. The gillnet fisheries targeting tuna and the fisheries institutions in these countries warrant further study and engagement.
Just this year, the IOTC passed a resolution on minimum reporting requirements for gillnet vessels with an aim of producing more accurate statistics. Additionally, there is a need to build capacity within the developing coastal countries of the Indian Ocean to improve national reporting. The design and implementation of an improved system to track Indian Ocean fisheries will require the construction of significant infrastructure and robust international support; it won’t be easy, but these measures are integral to the long-term understanding and health of the world’s tuna populations and the impact of their fisheries on the ecosystem.