The largest catch that can be maintained from the population, at whatever level of stock size, over an indefinite period. It will be identical to the sustainable yield for populations below the level (of biomass) giving the MSY, and equal to the MSY for populations at or above this level .
MAINTAINABLE YIELD
Meaning of MAINTAINABLE YIELD in English
Fishery English glossary. Английский глоссарий рыболовства . 2012