Juvenile Pacific bluefin tuna are plentiful in Japanese coastal waters, but the country’s fishermen aren’t celebrating as a low total allowable catch (TAC) is forcing them to release target fish to avoid catching too many bluefin, losing out on lucrative mackerel and yellowtail in the process.
Juvenile bluefin – defined as bluefin under 30 kilograms – is considered a choke species, or a species with a small quota often caught as bycatch that prevents the efficient utilization of quota for target species. The high presence of juvenile bluefin and its relatively low quota hampers fishing for other species.
Some fisheries in the U.S. have tackled the problem of choke species by pooling TAC among vessels, but Japanese fishermen typically want to possess as much bluefin quota for themselves as possible until the end of the year, when holiday spending on the species can cause prices to rise by as much as 50 percent.
Complicating the matter further, set-nets are a common and traditional fishing method in Japan, but give fishermen little control over what species they catch. When bluefin are mixed in with target catch, fishermen release them by sagging or opening a part of the net, leading to the inevitable escapement of target species as well.
“Such releases are becoming more frequent all over Japan due to the significant gap between growing stock levels and fixed catch limits,” the Japanese delegation at the meeting of the Joint Working Group on Pacific Bluefin Tuna said in Fukuoka, Japan, over the summer.
The delegation wanted the two regional fishery management organizations (RFMOs) that set rules for tuna fishing in the Pacific Ocean – the Western and Central Pacific Fisheries Commission (WCPFC) and the Inter-American Tropical Tuna Commission (IATTC) – to increase catch quota in light of the species’ faster-than-expected stock recovery. That request was denied, but is sure to be a prevalent theme at future meetings.
Besides set-net fishing, purse-seiners also have to deal with bluefin compromising targeted mackerel catch. The penalty for exceeding quota is ...
Photo courtesy of feathercollector/Shutterstock
