WORLDWIDE: Of the total tuna catch worldwide, 86 per cent comes from stocks at “healthy” levels, an 8 per cent increased share of the total catch compared to previous reports, according to a report published by the International Seafood Sustainability Foundation (ISSF).
In its latest report on the status of the tuna stocks worldwide, the ISSF points out that skipjack tuna stocks — at healthy levels in all ocean regions — still comprise more than one-half of the total catch.
The document stresses that though many of the broad indicators of overall global stock health remain unchanged, there were several notable changes for specific commercial tuna species.
Its assessment for Western and Central Pacific bigeye was more optimistic, showing that the stock is not overfished and that recent management measures put in place by the Western and Central Pacific Fisheries Commission (WCPFC) appear to be working effectively.
On the other hand, Atlantic Ocean bigeye received a pessimistic stock assessment from the International Commission for the Conservation of Atlantic Tunas (ICCAT) and remains overfished. In 2017, Atlantic bigeye catches exceeded the total allowable catch (TAC) by approximately 20 per cent.
ISSF has long advocated that ICCAT adopt stock-specific management measures to effectively control the catch of bigeye and other overfished species in the region, including Atlantic yellowfin.
The document outlines that catches of Eastern Pacific bigeye in 2017 increased 10 per cent from 2016 levels. And, it adds that the IATTC conducted an update assessment of the stock that appears to indicate that the stock is experiencing overfishing.
The entity states that the results should be viewed with caution due to the high levels of uncertainty in the assessment. Nevertheless, several fishery indicators suggest that the management measures in place are insufficient to effectively control fishing.
The stock status of South Pacific albacore is confirmed as very healthy, but the stock assessment covers only the WCPFC Convention Area South of the equator, not taking into consideration part of the catches from the IATTC Convention Area (EPO).
Further statistics reveal in ISSF report include:
- Abundance or “spawning biomass” levels: Globally, 65 per cent of the 23 stocks are at a healthy level of abundance, 13 per cent are overfished and 22 per cent are at an intermediate level. In terms of total catch, 86 per cent come from healthy stocks, 10 per cent from overfished stocks and 4 per cent from stocks at an intermediate level. - Unchanged from the last reporting, the stocks receiving orange scores — indicating overfished status — remain Atlantic Ocean bigeye, Pacific Ocean bluefin and Indian Ocean yellowfin.
- Fishing mortality levels: 70 per cent of the 23 stocks are experiencing a well-managed fishing mortality rate and 17 per cent are experiencing overfishing.
- Largest catches by stock: The five largest catches in tonnes are Western Pacific Ocean skipjack, Western Pacific Ocean yellowfin, Indian Ocean skipjack, Indian Ocean yellowfin and Eastern Pacific Ocean skipjack.
- Tuna production by ocean region: Most (53 per cent) of the world’s tuna is harvested 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).
- Tuna production by fishing gear: 65 per cent of the catch is made by purse seining, followed by longline (12 per cent), pole-and-line (8 per cent), gillnets (3 per cent) and miscellaneous gears (12 per cent).