There are three major areas of concern when it comes to sharks – observed bycatch, unobserved mortality due to entanglement in fishing gear, and waste from (and poor data about) finning.
WHY IT’S IMPORTANT
The shark bycatch-to-tuna catch ratio in purse seine fisheries is small, on average, less than 0.5% in weight. But the global magnitude of catch of the purse seine fisheries is quite large, so reducing the shark mortality caused by these fisheries can positively impact global shark conservation efforts.
WHAT WE ARE DOING ABOUT IT
Each year, ISSF supports multiple initiatives to track, report on and minimize unwanted bycatch like sharks among purse seine fishing vessels, as well as conduct research across all fishing methods to define and promote best practices that positively impact this important issue. We also advocate for the adoption of mandatory shark bycatch data-collection and mitigation measures, appealing to the world’s tuna RFMOs for the adoption of science-based shark conservation and management measures.
- Reducing entanglement under FADs through the use of non-entangling materials in the underwater hanging structure or by other procedures such as tightly wrapping hanging nets with ropes, which results in a tight cylinder (“sausage” or “chorizo”)
ISSF is currently investigating other methods to avoid encircling sharks or to release sharks from the net. Scientists, in partnership with purse seine vessel owners, are testing the use of escape panels to release sharks from the net, as well as whether the “backdown maneuver” used to release dolphins in tuna-dolphin aggregations could also be effective in releasing sharks and other bycatch.