Research and training on bycatch to protect marine life
Baseline research on bycatch
Ecological risk assessments identify the animals that are most vulnerable to being inadvertently caught during fishing. The most vulnerable are animals that interact more with the tuna targeted in fishing or with fishing vessels, and that also reproduce slowly. The most common ones are sharks, turtles, marine mammals, and seabirds.
Bycatch numbers vary with fishing methods. It is hard to get sufficient data on bycatch for methods of fishing where there are fewer official observers, but baseline research summarises what is known. The Western and Central Pacific Fisheries Commission makes bycatch data for the WCPO publicly available.
In the purse-seine fishery, about 1–2% (by weight) of the total catch is bycatch. Bycatch from fishing of free-swimming tuna is lower on average (1.0%) than bycatch from fishing using fish-aggregating devices, or FADs (2.0%). Dolphins are rarely encircled by purse seines in the WCPO; the most significant bycatch species are sharks. In 2017, SPC produced a report on bycatch in purse-seine fisheries for the years 2003–2016. SPC’s Neville Smith provides an overview of the report (2.09 mins).
Most sharks are caught in the longline fishery, with the purse-seine fishery estimated to catch only 2–3% of the total. Most of the WCPFC’s designated key shark species – they include shortfin mako, silky, oceanic whitetip, thresher, porbeagle, hammerhead, and whale sharks – must be conserved, and action is occurring to reduce bycatch of these species.
Billfish continue to form a significant proportion of the non-target catch, but are mostly retained due to their commercial value.Seabird deaths due to longlines are very low in the tropical WCPO compared with deaths in higher latitudes, where albatrosses and petrels, in particular, are prone to becoming caught. But low observer coverage on many longline fleets means that the number of interactions is largely unknown.
Other research projects
The sustainable tuna fisheries part of the Common Oceans ABNJ Program includes a significant component on sharks. It centres on the Pacific, and is led by the WCPFC Secretariat. It ran until 2019.
- A summary of research into improving the design on FADs to prevent animals becoming entangled was presented to the Scientific Committee of the Western and Central Pacific Fisheries Commission in October 2018
- Workshops to define a strategy to move forward on the use of biodegradable FADs in the Western Pacific Ocean, ISSF, February 2019
- A major WCPFC initiative, the Bycatch Mitigation Information System (BMIS) provides a central repository of information on the mitigation and management of bycatch in the WCPO
- Summary of research and results of the second cruise of the International Seafood Sustainability Foundation bycatch project in the Western and Central Pacific Ocean, WCPFC, 2013
- At-sea experiment to evaluate the effectiveness of multiple mitigation measures on pelagic longline operations in western North Pacific, WCPFC, 2013
- At-sea experiment to develop the mitigation measures of seabirds for small longline vessels in the western North Pacific, WCPFC, 2015
- WCPFC shark research and conservation and management measures
- Off the hook: Can a new study in the Pacific reel in unsustainable fishing?, The Guardian, May 2016. Discusses tests conducted in Palau on new hook designs to lessen the amount of bycatch, with funds from the Nature Conservancy.