Seventy-eight percent of all the tuna caught worldwide in 2016 came from stocks deemed to be at healthy levels, the same proportion as the previous year, finds the latest update of the International Seafood Sustainability Foundation (ISSF) “Status of the Stocks” report.
The NGO also reports that the total commercial catch reached 4.9 million metric tons (MT), an increase of 2 percent compared with 2015. Of this, skipjack accounted for 57 percent of the catch, followed by yellowfin (30 percent), bigeye (8 percent) and albacore (4 percent). The three bluefin tuna species collectively accounted for 1 percent of the global catch.
These species percentages changed only slightly from ISSF’s previous update, issued in November 2017.
One notable change in the latest stock status is for southern bluefin tuna, which has moved from orange to yellow in abundance ratings. While the stock abundance (spawning biomass) is low at about 13 percent, ISSF said the stock is continuously rebuilding as a result of a “robust management procedure” implemented by the Commission for the Conservation of Southern Bluefin Tuna, the regional organization in charge of managing the stock.
In contrast, the Pacific bluefin stock, along with the Indian Ocean yellowfin and Atlantic Ocean bigeye stocks, remains overfished.
Globally, 57 percent of the stocks ranked by the report are at a healthy level of abundance, 13 percent are overfished and 30 percent are at an intermediate level.
The report assigns color ratings (green, yellow or orange) on stock heath, stock management, and ecosystem impact. Stocks receiving orange scores, indicating overfishing or overfished status, continued to include Pacific Ocean bluefin, Indian Ocean yellowfin and Atlantic bigeye.
Some 65 percent of the catch is made by purse seining, followed by longline (12 percent), pole-and-line (8 percent), gillnets (3 percent) and miscellaneous gears (12 percent).
There are 23 stocks of major commercial tuna species worldwide: six albacore, four bigeye, four bluefin, five skipjack and four yellowfin stocks. The three largest catches in tons are Western Pacific Ocean skipjack, Western Pacific Ocean yellowfin and Indian Ocean yellowfin.
