The world catch of tuna in the Open Ocean, taken beyond the exclusive economic zones (EEZs) of maritime countries, has increased from about 125 thousand tonnes per•year in the early 1950s to a plateau of about 3.5 million tonnes per year from 2000 to 2010. This overall catch, consisting of declining landings from the Atlantic and Indian Oceans and increasing landing from the Pacific is not likely to increase in the future, nor even to be maintained. Most of this catch, consisting of skipjack (Katsuwonus pelamis), yellowfin (Thunnus albacares), bigeye (Thunnus obesus) and albacore tuna (T. alalunga) is traditionally taken by Japan, South Korea and Taiwan, but new entrants are attempting to increase their share, notably in the Pacific. Given the current states of tuna stocks in the Open Ocean and the effects of ocean warming on tuna stocks, this should result in increased competition among the subsided fleets of developed countries with distant-fishing fleets, and between established fleets and new entrants. Of these new entrants, three are developing countries (Indonesia, the Philippines and Mexico) which appear among the 10 countries with the largest tuna catch in the Open Ocean.

Oceanic tunas are exploited using pole and line, longline, driftnet and purse seining. The catch of tuna that were taken outside EEZs in the open ocean since 2000 is only about 65% of the total catch of tuna in the world. The 10 countries with the highest tuna catch in the open ocean contribute to about 70% of all the oceanic tuna catch.

The Western Central Pacific region (FAO 71) has the highest volume of tuna landings among all FAO statistical regions, averaging 1.4 million tonnes per year. Eighty seven percent of the total tuna catch in the open oceans comprises major species: e.g. skipjack, yellowfin and bigeye.

Time series trends of tuna catch in the open ocean show that the catch of tuna increased between 1950 and 2001, then plateaud in the last decade or so. The reason for this - besides the fact that a few species (Atlantic, Pacific and Southern bluefin tuna) have been severely overfished and will not again reach the high catches of the past - is that the few species that presently contribute the bulk of tuna catches (yellowfin, albacore, skipjack and bigeye tuna), are currently experiencing fishing mortality roughly generating maximum sustainable yield, and additional increases are likely to decrease catches.

Annual catch of tuna species in the Open Ocean from 1950 to 2010