Using Lifetime Fecundity to Compare Management Strategies: A Case History for Striped Bass

To evaluate possible regulatory schemes for restoring the stocks of striped bass Morone saxatilis in Rhode Island coastal waters, we constructed a computer simulation model of a cohort's expected lifetime egg production. The model demonstrated that the expected increase in egg production from a proposed increase in minimum legal harvestable size (from 17 to 24 in) also could be achieved by an alternate management regime which, unlike the proposed size increase, would allow continued use of traditional fishing gears. The alternative regime increased the minimum size (but only to 18 in) and simultaneously reduced instantaneous fishing mortality from 0.45 to 0.30. Our findings of equivalence between the two regimes are reasonably robust to errors in population parameters. We then used the simulation model to generate curves of egg production per female recruit under a wide range of regulatory regimes. Such curves can illustrate the potential effects of management measures on depleted stocks.