Tuna longline fisheries are one of the most scandalous fishing businesses on the planet, operating mostly out of sight and out of control. Longlining is the fishing method that catches the big valuable tunas aimed at fulfilling the growing global demand for sushi as well as for albacore tuna canned for the North American market.

Longline infographic
Click to enlarge Infographic

Nobody really has accurate numbers of just how many longline vessels are out there in the oceans but conservative estimates put the figure at over 5000. Each of these vessels can line of up to 170km long with 3000 baited hooks that lure and catch tuna, marlins and sharks and bycatch of other marine life, including endangered species such as seabirds and sea turtles, which end up tossed overboard.

Many longline vessels use techniques that target sharks, which are then finned and bodies sometimes discarded and fins sold to lucrative Asian markets. This destructive practice has caused catastrophic declines in the numbers of many species of sharks in our oceans.

These longline vessels, especially those that roam the high seas, operate without sound regulations put upon them. They are able to transfer catches at sea to mother boats leading into large amount of illegal and unreported fishing, which is a key factor in hampering accurate scientific assessments of the state of the declining tuna stocks.

Longline fisheries are not only responsible for an environmental and fisheries management tragedy. This industry also keeps a dirty secret of labour abuse and suffering put upon the men who work in deplorable conditions on these vessels, who remain for months or even years at sea, working long hours for as little as 40-200USD a month, if paid at all. Stories of abuse and even murder at sea are not uncommon.

Yet tuna is big money, the longline fisheries provide products for the world's lucrative sashimi markets. The global longline fleet operations are mostly facilitated by large companies the so-called "traders" who take care of the logistics and movements of fish from sea to the market place. Given the high volume of fish these companies handle every year, they are able to make a lot of money out of this industry of destruction and abuse.

It is these traders such as FCF, Tri Marine, Itochu and Mitsubishi that need to step up to ensure strict traceability and sustainability standards as governments are failing to act to regulate this industry.

In a few weeks time between the 2nd to the 6th of December, the Western and Central Pacific Fisheries Commission will meet to decide the fate of the tuna fisheries in the Western and Central Pacific, the world's largest fishing ground.  There is an urgent need to cut the fishing of vulnerable bigeye and yellowfin tunas and protect critically depleted shark species.

Greenpeace is calling for an overhaul of this industry to a better managed and controlled and much reduced one as well as on global longling fishing powers such as Taiwan, South Korea, China and Japan to show stronger willingness to cut fishing efforts and capacity as well as accept limits to fishing in the Pacific high seas pockets. 

To learn more about the world's oversized longline tuna fishery fleets please check our latest report here http://www.greenpeace.org/international/out-of-line/

Sari Tolvanen is an Oceans Campaigner at Greenpeace International.