Scooping Up Tuna

tuna-bigeye-fad-400-lwSkipjack tuna, the most common tuna found in a can or a tin, makes up the majority of the catch in the Pacific.

While skipjack tuna populations may not be currently threatened, the gear used by industrial fishing vessels to catch them has other damaging consequences.

One of the primary methods used to catch skipjack involves the setting of enormous nets around gear known as Fish Aggregating Devices (FADs). FADs are rafts of manmade flotsam that attract all sorts of ocean wildlife, including tuna and sharks.

While international treaties demand that fishing vessels manage this gear to limit impacts on the ocean ecosystem, compliance with these requirements is dismal, and the uncontrolled proliferation of FADs is a problem that we can no longer afford to ignore.

Sharks, turtles, and juvenile bigeye and yellowfin tuna gather with skipjack tuna under FADs as stopping-off points along the highways and byways of the Pacific Ocean, leading to the bycatch of millions of juvenile tuna, as well as sharks and endangered sea turtles. This bycatch may account for up to 30 percent of the overall catch.

While nobody knows how many FADs the purse seine industry has placed in the ocean, conservative estimates suggest that over 50,000 drifting FADs are actively monitored by the global purse seine industry. The scale of such enormous FAD use could alter the overall function of the ocean ecosystem and change the natural behavior of many species.

Albacore (white meat tuna), yellowfin, and bigeye tuna are also targeted in the Pacific by a sophisticated fleet of longline vessels, operated by the United States, PR. China, Taiwan, Province of China, Japan, and the European Union. These vessels deploy lines up to or over 60 miles (100 kilometers) long with thousands of baited hooks. Bycatch is a serious problem for these vessels, since marine mammals, turtles, seabirds, and sharks regularly take the bait. Despite the existence of new, more selective hooks and fishing practices that could drastically reduce this bycatch, most longline fleets have not implemented these solutions, leading to the continued loss of marine life.