Knowledge for policy
Glossary item

Maximum sustainable yield

The highest theoretical equilibrium yield that can be continuously taken (on average) from a stock under existing (average) environmental conditions without affecting significantly the reproduction process. Also referred to sometimes as Potential yield.
Source category: International Organisations

The largest average catch or yield that can continuously be taken from a stock under existing environmental conditions. For species with fluctuating recruitment, the maximum might be obtained by taking fewer fish in some years than in others. Also called: maximum equilibrium catch (MEC); maximum sustained yield; sustainable catch. - Note: It is estimated from surplus production models (e.g. Schaefer model) and other methods. In practice, however, MSY, and the level of effort needed to reach it are difficult to assess. Referred to in UNCLOS, it is an essential fisheries management benchmark but it is also only one of the possible Management reference points, considered also as an international minimum standard for stock rebuilding strategies (i.e. stocks should be rebuilt to a level of biomass which could produce at least MSY). Sometimes confused with: Optimum yield.
Ricker, W.E., 1975, 'Computation and interpretation of biological statistics of fish populations'. Bulletin of the Fisheries Research Board of Canada, 191: 2-6
Source category: Scientific & Technical Literature