The Optimum Yield (OY) is the catch of fish that will provide the greatest benefit to the Nation, as reduced by any relevant economic, social, or ecological factor.
The Acceptable Biological Catch (ABC) is the biologically based amount of fish that may be harvested each year without jeopardizing the productivity of the stock. It is calculated by applying the fishing rate that generates the Maximum Sustainable Yield (FMSY) to the exploitable stock biomass. The OY cannot exceed the ABC.
The F40% rate of fishing mortality reduces the spawning potential per female to 40% of the unfished level.