Of all the caught worldwide in 2015, 78 percent came from stocks at healthy levels, an increase of 2 percent since last reported in February this year, finds the latest update of the International Seafood Sustainability Foundation (ISSF) “Status of the Stocks” report.
The NGO attributes the improvement to the fact that skipjack stocks contribute more than half of the global tuna catch, and they are all in a healthy situation.
Of the remaining 22 percent of tuna stocks, 11 percent of the global catch comes from overfished stocks and 11 percent is at an intermediate level of abundance.
ISSF’s report states that there have been some “encouraging changes” since the previous Status report. Notably, there have been abundance improvements for Eastern Pacific bigeye, Western and Central Pacific bigeye, Mediterranean albacore and Western Atlantic bluefin. At the same time, there was improved fishing mortality for Western and Central Pacific bigeye, North Pacific albacore and Indian Ocean albacore.
In contrast, the two Southern and Pacific Ocean bluefin stocks, the Indian Ocean yellowfin stock and the Atlantic Ocean bigeye stock remained overfished.
According to ISSF, the total major commercial tuna catch in 2015 was 4.8 million metric tons (MT), a 4 percent decrease from 2014. Fifty-eight percent of this was skipjack tuna, followed by yellowfin (28 percent), bigeye (8 percent) and albacore (4 percent). Bluefin tuna accounted for only 1 percent of the global catch.
Globally, 57 percent of the stocks ranked by the report are at a healthy level of abundance, which is 5 percent more than the February report; 17 percent are overfished, and 26 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, included both Southern Hemisphere and Pacific Ocean bluefin, Indian Ocean yellowfin and Atlantic bigeye.
Some 64 percent of the catch is made by purse seining, followed by longline (12 percent), pole-and-line (9 percent), gillnets (4 percent) and miscellaneous gears (11 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 tonnes are Western Pacific Ocean skipjack, Western Pacific Ocean yellowfin and Indian Ocean yellowfin.
