Commercial tuna fishing is common in waters around the globe. There are many methods used in commercial tuna fishing. Each has different attributes. Some catch hundreds of fish at once on long trips far into the ocean. Others may yield only a few at a time on shorter trips closer to shore.
Professional fishermen using efficient, modern methods are what enable tuna companies in the U.S. and around the world to provide an affordable and vital source of nutrition for millions of families. Below is information about the most common commercial methods used to catch tunas.
No matter the method, Bumble Bee®, Chicken of the Sea® and StarKist® are deeply committed to responsible commercial tuna fishing that also strives to reduce the unintended by-catch of other marine creatures and carefully follows “dolphin safe” regulations.
Since the early 1990s, the leading U.S. tuna brands made a commitment to sell only dolphin safe tuna – and that commitment still stands firm today.
Purse seining is the most common commercial fishing method. It is also the most efficient and effective, providing families around the world with a steady, reliable supply of affordable tuna.
Purse seine vessels spread a giant net around and below a school of fish in the water and then pull the net together at the bottom, like a drawstring, to catch the fish. These nets can be up to a mile in length. Weights carry one edge of the net deep into the water. When the fish are surrounded, the bottom of the net is drawn together – or pursed – so that the fish are caught and hauled aboard the boat.
Purse seining, like all methods, can result in the unintended catch of other marine life. The tuna industry is continuously working to develop new technologies and gear to reduce by-catch in purse seine fishing.
Almost 62% of tuna today is caught by purse seine vessels. To learn more about purse seining, visit the United Nations’ Food and Agriculture Organization
Long-line fishing is the second most common commercial tuna fishing method. It is most often used to catch albacore tuna, which is used in white tuna products. Long-lining catches less fish per voyage than purse-seining. The methods also generally target different species. Purse seining targets tunas that live closer to the surface, such as skipjack. Long-lining aims at catching tunas who live in deeper waters, such as albacore.
Long-lining is exactly what it sounds like – a very long line is set out from a fishing boat with baited hooks attached. The lines can be up to 80 miles in length. The lines are supported by floats and marked with flags. Branch lines attached to the main long line are sunk with baited hooks to depths of 55 to 150 meters (150 to 500 feet). The branch lines catch two to three fish for every hundred hooks.
Long-lining can also result in the unintentional catch of seabirds and sea turtles. But it is a generally targeted tuna fishing method and low on fuel consumption. Tuna companies have been involved in developing special gear and programs to reduce seabird and sea turtle by-catch in long-line fishing.
Almost 14% of tuna is caught by long-line fishing. Long-line fishing supplies tuna mainly to the sashimi, fresh and frozen markets but also accounts for about 80 % of the world’s albacore tuna harvest. To learn more about long-lining, visit the United Nations’ Food and Agriculture Organization
As of 2009, only about 11% of commercial tuna is caught by pole and line fishing. Pole and line fishing results in less by-catch of other marine animals. But, because of the relatively small number of tuna caught per voyage, is not able to supply tuna at a rate that satisfies global demand and allows for affordable pricing.
In this method of commercial fishing, bait (smaller fish) are dumped from the fishing boat into the water to bring the tuna into a feeding frenzy. This is called “chumming”. Fishermen on the boat drop lines with hooks into the school of fish, hook them and bring them aboard. Hydraulically operated rods or automatic angling machines may be used on larger pole and line vessels.
Pole and line vessels vary in size and can carry from 3 to 25 people. To learn more about pole and line fishing, visit the United Nations’ Food and Agriculture Organization
Trolling is not used as often as other commercial tuna fishing methods, yielding only about 1% of the global tuna catch. It is often used to catch albacore tuna which is used in specialty tuna products supplied to niche markets. While touted as the environmentally-preferred method by some environmental groups, trolling does not yield plentiful amounts of tuna caught per voyage. Its efficiency and ability to fulfill global tuna demand at a rate that keeps most tuna affordable and available for families around the world is questionable.
Trolling involves towing eight to twelve lines with baited hooks through the water behind a fishing boat. The lines – and the tuna they’ve caught – are pulled back aboard by hand or hydraulic haulers.
To learn more about trolling, visit the United Nations’ Food and Agriculture Organization
Various other non-commercial tuna fishing methods, such as artisanal fishing that supports the diets and economies of coastal communities worldwide, represent about 12% of the global tuna catch as of 2009.