The global tuna catch has remained stable at around 5 million tonnes in recent years.

 

Globally, the seven major commercial oceanic tuna species are assessed and managed as 23 distinct stocks by the five tuna Regional Fisheries Management Organizations (RFMOs): CCSBT, IATTC, ICCAT, IOTC and WCPFC. These stocks include six albacore, four bigeye, four bluefin, five skipjack, and four yellowfin tuna stocks. The global tuna catch has remained stable at around 5 million tonnes in recent years. In 2023, the total catch was approximately 5.2 million tonnes, a figure similar to the previous year. Skipjack tuna accounted for the largest share (57 percent), followed by yellowfin tuna (31 percent), bigeye tuna (7 percent), albacore tuna (4 percent), and the three bluefin tuna species collectively contributing just 1 percent of the total catch. From a stock perspective, based on the most recent stock status adopted by tuna RFMOs, 16 out of the 23 assessed tuna stocks are not overfished, and overfishing is not occurring. Additionally, five stocks are classified as overfished but are not currently subject to overfishing, indicating they are in a rebuilding phase. Meanwhile, two stocks remain both overfished and subject to ongoing overfishing: Indian Ocean bigeye tuna and Mediterranean albacore tuna. Encouragingly, 95 percent of the total global tuna catch originates from stocks that are not overfished and where overfishing is not occurring. This is largely due to the healthy status of skipjack tuna stocks, which contribute more than half of the total tuna catch. It should be noted that FAO uses different criteria to determine fish stock status, which may result in discrepancies between RFMOs’ assessments and the FAO assessment, as shown in the population-specific stock status tables. Since the adoption of the first management procedure for southern bluefin tuna in 2011, several other tuna stocks have also implemented them, which has contributed to both rebuilding depleted stocks and maintaining the health of existing ones (BOX E.1.2). Additionally, ongoing management strategy evaluation processes are in place to develop and adopt new management procedures for remaining tuna stocks, ensuring their longterm sustainability. The estimated MSY for all 23 commercial tuna stocks is approximately 6.3 million tonnes. Stocks of bigeye, yellowfin, bluefin and albacore tuna are being fished at levels consistent with MSY, while skipjack tuna could potentially sustain slightly higher yields, particularly in the WCPFC region. However, in the WCPFC, which accounts for the main difference between total catch and potential MSY (approximately 1 million tonnes), a target reference point and a management procedure for skipjack tuna have already been established. Fishing in this region is occurring at the defined sustainable level, meaning further increases in skipjack tuna catches are not feasible under current management. Moreover, because skipjack tuna fishing globally is primarily conducted using FADs, and the tropical tuna fisheries is multispecies in nature, an increase in skipjack tuna catch would inevitably result in higher catches of bigeye and yellowfin tuna stocks globally, which could negatively impact these species. In conclusion, the current scenario suggests a management focus that maintains yields and catches rather than expanding them. Under existing management frameworks, the global tuna fishery appears to have reached or is close to reaching its maximum, and further increases in catch are not advisable. Instead, efforts should continue to focus on strengthening management measures, where required, through adopting management procedures, maintaining stock health, and ensuring the long-term sustainability of tuna populations.

MAJOR COMMERCIAL TUNA SPECIES BIOLOGY AND STOCK INFORMATION

There are three species of bluefin tuna, and one each of albacore, bigeye, yellowfin and skipjack tuna. Due to differences in their distributions and the different fisheries that exploit them, the species are classified as “temperate” or “tropical”. The temperate tunas are the bluefin, plus albacores tuna; they are found in waters as cold as 10 °C, but can also be found in tropical waters. Skipjack and yellowfin tuna are classified as tropical and are found in waters with temperatures greater than 18 °C (although they can dive in colder waters). Although bigeye tuna could be classified as being between both groups, it is mostly treated as a tropical species by tuna RFMOs.