Where Is Most Tuna Caught Around the World?

The Pacific Ocean is where most of the world’s tuna is caught, and it is not particularly close. Skipjack tuna alone, the single most harvested tuna species on Earth, draws nearly 70% of its global catch from Pacific waters.¹ The Indian and Atlantic Oceans contribute meaningful volumes, and the Mediterranean has its own high-profile bluefin fishery, but the sheer scale of Pacific tuna harvests dwarfs everything else. The geography of tuna fishing has changed dramatically over the past seven decades, though, and it continues to shift as ocean temperatures rise and fishing technology evolves.

Why the Pacific Dominates

The Pacific Ocean covers more area than all the land on Earth combined, and its warm tropical and subtropical bands create ideal habitat for the species that make up the bulk of global tuna landings: skipjack, yellowfin, and bigeye. Skipjack is the workhorse of the canned tuna industry, and the western and central Pacific is its stronghold. The region’s equatorial waters stay warm year-round, supporting the dense schools of small prey fish that skipjack feed on, and the fishery there has grown enormously since the mid-20th century.

Pacific Island nations sit at the center of this abundance. Countries that participate in coordinated fishing-access schemes in the region have seen their tuna catches jump by more than 200% compared to non-participating neighbors, a sign of how productive these waters are when fleets have organized access.² The western and central Pacific Commission area, stretching from the waters around Papua New Guinea and the Solomon Islands out toward Kiribati and the Marshall Islands, is the single largest tuna-producing zone on the planet. Industrial purse seine fleets from distant-water fishing nations, including Japan, South Korea, China, Taiwan, and the United States, operate alongside local fleets across this vast expanse.

The eastern Pacific, closer to the coasts of Central and South America, is a separate but also significant fishing ground. Bigeye tuna caught by longliners in this region show distinct spatial patterns depending on their size: adults concentrate in a broad band between roughly 110° and 140° west longitude, while juveniles cluster farther southwest.³ El Niño and La Niña events reshuffle these distributions, pushing adults east or west and scattering younger fish in the opposite direction. That variability means catch locations in the eastern Pacific are less fixed than in the western Pacific, where equatorial productivity is more consistently high.

How Tuna Fishing Spread Across the Globe

The geography of tuna harvesting today looks nothing like it did 70 years ago. In the 1950s, industrial tuna catches were concentrated in just two areas: off the coasts of North and Central America in the eastern Pacific, and around the western Pacific islands. Relatively little fishing effort reached the Atlantic or Indian Oceans at that time.⁴ Over the following six decades, large-scale fleets expanded outward from those two starting points, pushing into every major ocean basin as refrigeration technology, vessel range, and fishing gear improved.

By the 1970s and 1980s, the Indian Ocean and tropical Atlantic had become significant tuna fishing grounds. Purse seine fleets moved into the western Indian Ocean, longliners fanned across the southern Atlantic, and new canning infrastructure sprouted in coastal developing nations to process the catch. This global expansion is one of the most dramatic spatial shifts in modern fishing history: what began as a two-region industry became a truly worldwide one within a single human lifetime.

The Indian Ocean Under Pressure

The Indian Ocean is the third-largest tuna fishing ground after the western-central Pacific and the eastern Pacific. Its warm waters support large populations of yellowfin, bigeye, and skipjack, and the fishery there has grown rapidly since the 1980s. But that growth has come at a steep cost. The IUCN now classifies Indian Ocean yellowfin tuna as “Vulnerable,” and biomass estimates suggest the population has declined by roughly 70% since 1950.⁵

Fishing effort in the Indian Ocean is spread across both industrial and small-scale fleets. Industrial purse seiners and longliners, many flagged to distant-water nations, operate alongside a large artisanal sector in countries like Kenya, Sri Lanka, Indonesia, and the Maldives. In Kenya’s artisanal tuna fishery, for example, troll lines are the most commonly used gear, accounting for about half of all sampled fishing trips, while ringnets are the most productive per trip, averaging over 500 kilograms of tuna per outing.⁶ These small-scale fleets are often underrepresented in official catch statistics, which means the Indian Ocean’s total tuna extraction is likely higher than reported figures suggest.

The hotspots for bigeye and yellowfin in the Indian Ocean cluster in the northwest, around the Arabian Sea region. Bigeye concentrate in a band between roughly 63° and 69° east longitude, while yellowfin spread more widely but still center on similar longitudes closer to the equator.⁷ These spatial clusters matter for management because they tell fisheries managers where the most vulnerable aggregations are, and where overfishing pressure hits hardest.

The Atlantic and Mediterranean

The Atlantic Ocean accounts for a smaller share of global tuna catch than either the Pacific or Indian Ocean, but it hosts some of the most economically valuable tuna fisheries in the world. Atlantic bluefin tuna, in particular, commands extraordinary prices, especially fish destined for the Japanese sashimi market. The International Commission for the Conservation of Atlantic Tunas (ICCAT) manages the fishery by dividing the stock at a line in the mid-Atlantic, treating the eastern and western populations separately for assessment purposes.⁸

The Mediterranean Sea is the primary spawning ground for eastern Atlantic bluefin tuna, and it has been fished for this species for thousands of years. In recent decades, though, industrial purse seining combined with the expansion of tuna ranching (capturing live fish and fattening them in sea cages before slaughter) has dramatically intensified pressure. The spawning stock biomass dropped by about 60% from 1974 levels, and official catches ran around 24,000 tonnes per year. But illegal, unreported, and unregulated (IUU) catch in the Mediterranean was estimated to be potentially as high as 47,800 tonnes, roughly double the legal take.⁹ Stricter quotas and enforcement measures introduced since the late 2000s have helped the stock recover somewhat, but the Mediterranean bluefin fishery remains one of the most politically fraught in the world.

Beyond bluefin, the tropical Atlantic supports catches of skipjack, yellowfin, and bigeye, though at volumes well below Pacific levels. West African nations along the Gulf of Guinea have growing tuna industries, and European purse seine fleets have long operated in the eastern tropical Atlantic.

High Seas Versus National Waters

Tuna are unusual among commercial fish because they migrate across vast stretches of open ocean, which means they are caught both inside countries’ exclusive economic zones (the 200-nautical-mile band of coastal jurisdiction) and on the high seas beyond any nation’s control. Tuna and billfishes make up a large fraction of what gets pulled from international waters. One analysis found that 39 fish and invertebrate species account for virtually all targeted high-seas catch, and tuna are among the most prominent.¹⁰

This split between national waters and the high seas creates a governance headache. When a school of skipjack swims out of Kiribati’s EEZ and into international waters, it shifts from one management regime to another. Regional fisheries management organizations, like the Western and Central Pacific Fisheries Commission and the Indian Ocean Tuna Commission, exist to coordinate rules across this patchwork, but enforcement on the open ocean remains difficult. Satellite tracking and vessel monitoring systems have improved surveillance, and some countries are now combining these with satellite imagery to detect unauthorized foreign fishing in their waters.¹¹

How Drifting Fish Aggregating Devices Changed the Map

One of the biggest shifts in where tuna is caught has less to do with the ocean and more to do with a piece of technology: the drifting fish aggregating device, or dFAD. These are satellite-tracked rafts set adrift on ocean currents. Fish, including tuna, naturally congregate beneath floating objects, so dFADs essentially create portable fishing hotspots. An estimated 1.41 million dFAD buoys were released between 2007 and 2021, drifting across at least 134 million square kilometers, or about 37% of the entire ocean surface.¹²

dFADs have been especially transformative for skipjack catches. Before their widespread adoption, purse seine fleets targeted free-swimming schools of larger yellowfin and bigeye. Once dFADs became common, fleets could reliably find and encircle the schools of skipjack and juvenile yellowfin and bigeye that gather beneath them.¹³ Global skipjack catches rose markedly as a result. But the technology raises conservation concerns because it also catches juvenile bigeye and yellowfin that have not yet reproduced, and it generates bycatch of sharks, sea turtles, and other marine life.

The scale of deployment is staggering. Estimates from the world’s largest tuna fishery put total buoy or dFAD deployments at roughly 21,000 to 39,500 per year during the early-to-mid 2010s.¹⁴ Each device can drift for months across entire ocean basins. The result is that the effective fishing footprint of purse seine fleets now covers far more ocean than the vessels themselves could ever patrol.

Bycatch Geography

Where tuna are caught also determines what else gets caught alongside them. Bycatch hotspots do not distribute evenly; they cluster in specific regions depending on the gear type, the tuna species being targeted, and the local marine community. In the Indian Ocean, overlapping hotspots for bycatch of multiple species, including the silky shark, have been predicted in the Arabian Sea throughout most of the year.¹⁵

In the eastern Pacific, where purse seiners deploy nets around floating objects, silky shark bycatch is a persistent problem, with higher rates for small sharks north of the equator. Researchers have evaluated spatial closure areas between 5° and 15° north latitude that could reduce silky shark bycatch by as much as a third while costing only about 12% of the tuna catch.¹⁶ That kind of trade-off analysis illustrates a fundamental tension in tuna fisheries management: the most productive fishing grounds often overlap with vulnerable marine ecosystems, and moving fleets to reduce bycatch means accepting lower tuna yields.

Climate Change Is Shifting Where Tuna Live

The map of where tuna are caught is not static. Ocean warming is already pushing tuna populations toward higher latitudes. From 1965 to 2011, the proportion of tropical tuna species in longline catches at subtropical latitudes showed a significant upward trend across the Atlantic, western Pacific, and part of the Indian Ocean. This pattern points to tropical tuna moving poleward as their traditional equatorial waters warm.¹⁷ The same study found that while these tropical species were showing up more at subtropical latitudes, their catches in tropical waters were actually declining in the Atlantic and Indian Oceans. The fish are not becoming more abundant; they are moving.

Modeling work on skipjack tuna projects a continuation of this trend. Simulations show skipjack habitat deteriorating across most tropical waters while improving at higher latitudes, with ocean warming as the primary driver followed by changes in food availability.¹⁸ For tropical Pacific Island nations whose economies depend heavily on selling fishing access to tuna fleets, this is an economic threat. If the fish move toward the subtropics, the revenues follow them, potentially shifting wealth away from some of the world’s most climate-vulnerable small island states and toward wealthier nations at higher latitudes.

The picture is not uniform across species or oceans. Bluefin tuna, which already inhabit cooler temperate waters, face different pressures than tropical skipjack. And ocean currents, oxygen levels, and prey distributions all interact with temperature in ways that make simple “fish move north” narratives incomplete. But the broad direction is clear: the equatorial tuna belt that has defined global catch geography for decades is loosening, and the center of gravity for tuna fishing is slowly drifting poleward.

Where the Catch Goes After It Leaves the Water

The geography of tuna catching and the geography of tuna processing are two different maps. A large share of the fish caught in the western Pacific gets processed thousands of miles from where it was landed. Tuna canneries in Africa, Latin America, and the Pacific islands tend to supply the European market, largely because of favorable tariff arrangements, while Southeast Asian processors serve the United States, Japan, and Europe.¹⁹ Countries that only can tuna from pre-processed loins, without doing the initial butchering, are all in wealthier nations, while the labor-intensive loining work takes place in developing economies.

This means a can of tuna on a supermarket shelf in Paris might contain skipjack caught by a Taiwanese purse seiner in Kiribati’s waters, transshipped to a loining plant in Thailand, processed into canned product in a Ghanaian factory, and shipped to France under a tariff preference. The supply chain is remarkably globalized, and the country where the fish was caught often receives the smallest share of the final retail value. Understanding where most tuna is caught, then, answers a geographic question but only begins to answer an economic one. The money flows along a very different map than the fish.