Jon K. T. Brodziak

In Search of Optimal Harvest Rates for West Coast Groundfish

Abstract In this paper, I explore how patterns of compensatory mortality, as assessed through stock–recruitment relationships, may influence optimal harvest rates and relative yields for several West Coast groundfish stocks. To do this, I revisited Clarks (1991) groundfish life history model and maximin (i.e., maximize the minimum) yield approach to evaluate target harvest rates for five stocks (Dover sole Microstomus pacificus, lingcod Ophiodon elongatus, sablefish Anoplopoma fimbria, Pacific hake Merluccius productus, and widow rockfish Sebastes entomelas) using recent estimates of fishery and life history parameters and stock–recruitment data. I found that a spawning-stock-per-recruit target of roughly 35% of its unfished amount would be reasonable for these stocks if Clarks assumed stock–recruitment parameters are representative and the policy goal is a maximin yield. In contrast, use of estimated stock–recruitment parameters suggested more conservative percentages of the unfished spawning stock per...