Methods for assessment of maximum sustainable yield using recruitment curve parameter

For different recruitmen-t fishing types, the methods for estimate of maximum sustainable yield (MSY or YS ) and maximum sustainable catches ( CS ) using recruitment curve parameters are different. This paper presented and discussed the methods for two recruitment- fishing types. The two types are: Type 1 is one time reproduction in all one. s life and continuous fishing. Type 2 is many times reproduction in all one. s life and seasonal fishing. We combined catches equation with Ricker reproduction model or Beverton- Ho lt reproduction model to produce new equilibrium catches equations:These equations may be used separately to estimate CS , YS , fishing mortality coefficient need for CS ( FcS ) , and fishing mortality coefficient need for YS ( FS ) . We calculated CS , YS , FcS , and FS at same M for type 1 and type 2. The results show that, FS does not equate with FcS . We considered that FS may be less than FcS but FS can not be greater than FcS for same recruitment curve.