RED = stocks determined by the most recent science to be stocks that are below a level that can produce MSY and the RFMO has been unsuccessful in adopting conservation measures. Such stocks cannot support sustained increases in catch and, in fact, require reduced catches;
ORANGE = stocks determined by the most recent science to be stocks that are below a level that can produce MSY but the RFMO is making progress towards having or does have conservation measures in place to ensure the stock’s recovery to a level at or above that which can produce MSY. Such stocks cannot support increased harvests;
YELLOW = stocks determined by the most recent science to be stocks that are at a level that can produce MSY, meaning current catches are potentially sustainable, at least in the short run, but most likely cannot support increased harvests and the RFMO should implement conservation measures for the stock to retain this status;
GREEN = stocks determined by the most recent science to be above a level that can produce MSY, meaning current catches are sustainable, at least in the short run, and it’s even possible for there to be well-managed increases in harvests of such a stock
These stock listings are created as reference points for the actions taken by ISSF.
The International Seafood Sustainability Foundation (ISSF) is committed to embracing science-based initiatives to ensure the conservation and sustainability of the world’s tuna stocks and the overall health of the marine ecosystems on which they depend.
An annual report titled Status of the World Fisheries for Tuna – compiled by the chair of the ISSF Science Advisory Committee from assessments conducted by individual RFMOs and then reviewed by members of the ISSF Science Advisory Committee for accuracy – provides the framework for ISSF Board Members to take action. This includes a legend for reference on the currently recognized 19 stocks that support commercial fishing for tunas used for canning or shelf-stable pouches.
The treaties that establish the tuna RFMOs all contain the management objective of keeping stocks of tunas at or above levels that can produce maximum sustainable yield (MSY).
When a stock is above the MSY level the stock is considered to be healthy and may be capable of sustaining well managed increases in catch. A stock at the MSY level is capable of sustaining maximum yields on the average. When below the MSY level the stock is considered to be in an unhealthy state, able to support only low levels of catch and in need of reduced fishing pressure to allow it to rebuild to the MSY level.
All levels of stock abundance and corresponding yields are moving targets as how many fish can be caught sustainably next season depends on how many are caught this season as well as natural changes in the environment.