Evaluating management actions for spotted seatrout, Cynoscion nebulosus, in Mississippi with an age-structured projection model

Spotted seatrout, Cynoscion nebulosus, is an important recreational fishery in coastal waters of the Gulf of Mexico and is the most sought after gamefish in coastal Mississippi.  The management of C. nebulosus is state-specific, and unlike other similarly managed species, data on both population structure and movement support the existence of local sub-stocks.  It is important for each state to clearly examine its own sub-stock in the context of its own state fishery in order to properly manage for local sustainability.  We used an age-structured assessment model to examine the status (1993-2008) of the Mississippi C. nebulosus population and to project several probable management actions (i.e., length limits), while also accounting for uncertainty in both fishing mortality and annual recruitment.  Model results suggest the fishing mortality rate for Mississippi C. nebulosus is likely above F_msy, but that spawning stock biomass (SSB) is not below SSB_msy.  This suggests the sub-stock is currently stable, but with high fishing pressure and a high dependence on annual recruitment to the fishery.  Projections suggest that when uncertainty in angler effort and annual recruitment are included in the analysis, more conservative management actions are warranted in order to achieve both higher fishery yield and stable SSB.