Catching tuna near Tulehu. (Photo: Tropenmuseum of the Royal Tropical Institute/CC BY-SA 3.0)
The world tuna catch keeps at healthy 78pct level
Thursday, March 08, 2018, 10:00 (GMT + 9)
Of the total tuna catch in 2016, 78 per cent came from stocks at "healthy" levels, unchanged since the last time it was reported, according to a report on the stock status of the International Foundation of Sustainability of Fishery Products (ISSF) issued in February 2018. The skipjack tuna stocks -- at healthy levels in all oceanic regions -- constituted more than half of the total catch of 2016.
An important change in stock status in February 2018 state report is for southern bluefin tuna, a population that went from orange to yellow in the abundance classifications. The abundance of the populations is low, around 13 per cent of the unexploited level. However, the stock is being continuously rebuilt as a result of the implementation of a solid Management Procedure (a Harvest Strategy) by the Commission for the Conservation of Southern Bluefin Tuna, the regional organization in charge of stock management.
In contrast, the Pacific bluefin stock, along with the Indian Ocean skipjack stock and the Atlantic Ocean bigeye stock, continue to be overfished.
There have been no drastic changes in the tuna stock status since the previous status report of November 2017; the updated report reflects the new data available at the meetings of the Regional Fisheries Management Organization (RFMO) of tuna at the end of 2017.
Updated several times a year, the status of the stocks assigns colour ratings (green, yellow or orange) to the health of the stocks, stock management and ecosystem impact. The report classifies the 23 stocks of the main commercial tuna around the world using a consistent methodology.
Key statistics in the report
Total catch: in 2016, the total main catch of commercial tuna was 4.9 million tonnes, an increase of 2 per cent compared to 2015. More than half of the total catch (57 per cent) was skipjack, followed by yellowfin tuna (30 per cent), bigeye (8 per cent) and albacore tuna (4 per cent). Bluefin tuna (3 species) represented only 1 per cent of the world catch. These percentages changed only slightly with respect to the reporting period of November 2017.
Abundance or levels of "spawning biomass": worldwide, 57 per cent of the 23 populations are at a healthy abundance level, 13 per cent are overexploited and 30 per cent are at an intermediate level.
Populations that receive orange scores, which indicate overfished status, include bigeye from the Atlantic Ocean, Pacific bluefin tuna and yellowfin tuna from the Indian Ocean.
Levels of fishing mortality: 65 per cent of the 23 populations are experiencing a well-managed fishing mortality rate, and 13 per cent are experiencing overfishing (unchanged from the previous report).
Larger catches per stock: The three largest catches in tonnes are skipjack from the western Pacific Ocean, yellowfin tuna from the western Pacific Ocean and Indian Ocean skipjack.
Tuna production by ocean region: most (53 per cent) of the world tuna is extracted from the western and central Pacific Ocean, followed by the Indian Ocean (20 per cent), eastern Pacific Ocean (13 per cent) and Atlantic Ocean (10 per cent).
Production of tuna with fishing gear: 65 per cent of the catches are performed with purse seines, followed by longlines (12 per cent), gunships (8 per cent), gillnets (3 per cent) and various gear (12 per cent). These percentages changed only slightly with respect to the reporting period of November 2017.
About the report
There are 23 populations of the main commercial species of tuna in the world: 6 albacore tuna, 4 bigeye, 4 bluefin tuna, 5 skipjack and 4 populations of yellowfin tuna. The status of the stocks summarizes the results of the most recent scientific assessments of these stocks, as well as the current management measures adopted by the RFMOs. This report classifies the status and management of the 23 populations using a coherent methodology based on three factors: Abundance, Exploitation/Management (fishing mortality) and Environmental impact (bycatch).
ISSF produces two annual reports that seek to clarify their position and how much more needs to be done to ensure the long-term sustainability of tuna stocks: the stock status provides a comprehensive analysis of tuna stocks by species, and the Assessment of the sustainability of the world's tuna stocks in relation to the criteria of the Marine Stewardship Council (MSC) provides scores for stocks and RFMOs based on the MSC assessment criteria. The list of fisheries certified by the MSC (Appendix 2) in Stock Status the assessment report is complemented.
Overall, these tools help define the continuous improvement achieved, as well as the areas and issues requiring further attention.
About the International Seafood Sustainability Foundation (ISSF)
The International Seafood Sustainability Foundation (ISSF) is a world coalition of scientists, the tuna industry and World Wildlife Fund (WWF), the global leader conservation organisation that promotes initiatives based on the science for the long-term conservation and sustainable capture of tuna stocks.