Case Study - Dover Sole Range from Baja California to the Bering Sea. On mud or muddy-sand, at 35 to 1400 m depths. Feed on polychaete worms, shrimp, brittle stars, and small bivalves. Winter spawning (December to February). Planktonic larval stage lasts at least one year. Gradual movement to deeper waters with growth. FW599Winter 2008

US West Coast Dover Sole - Landings FW599Winter 2008

Dover Sole – Sexual Dimorphism FW599Winter 2008

Dover Sole – Fishery Size Composition FW599Winter 2008

Dover Sole – Changes with Depth FW599Winter 2008

Dover Sole – Changes in Mean Weight FW599Winter 2008

Dover Sole – Small Fish are Discarded FW599Winter 2008

Dover Sole – Recent Discard Data FW599Winter 2008

Dover Sole - Assessment Data Landings to 2004 Fishery length compositions to 2004 Fishery age compositions to 2004 Trawl logbook CPUE to 1995 Shelf survey biomass to 2004 Slope survey biomass to 2004 Survey length compositions Observer Program discards & 2003 FW599Winter 2008

Dover Sole - Assessment Model Structure Two fisheries - South (CA+S.OR) & North. Separate slope surveys - AFSC (1992 to 2001) and NWFSC (1998 to 2004). Fixed size-retention functions - Early (to 1980); Late (1986 to 2004); and Transition. The fisheries now retain smaller fish. Fixed maturity-at-size functions - Early (to 1954); Late (1985 to 2004); and Transition. Maturation now occurs at smaller sizes. Natural mortality fixed at 0.09/yr. FW599Winter 2008

Dover Sole - Model Structure (continued) Growth parameters estimated, but fixed relative variation (CV) in length-at-age. Three periods for fishery selection L50s: Early (to 1979); Middle (to 1995); and Late. Recruitment deviations from Beverton & Holt stock-recruit curve with fixed steepness (0.8) and variability (0.35). Reduced lambdas on length-at-age (0.1) and age composition (0.2) data. FW599Winter 2008

Dover Sole – Estimated Stock Trends Available Data Fishery Lengths Fishery Ages Shelf Survey Slope Survey Trawl Logbook CPUE FW599Winter 2008

Dover Sole – Fit to the Tuning Indices FW599Winter 2008

Dover Sole – Fit to the Length Compositions Females Males Southern Fishery Pearson Residuals (Black=Neg.) FW599Winter 2008

Dover Sole – Fit to the Age Compositions Females Males Southern Fishery Pearson Residuals (Black=Neg.) FW599Winter 2008

Dover Sole – Estimated Selection Curves FW599Winter 2008

Dover Sole – Likelihood Profile FW599Winter 2008

Dover Sole – Recruits versus Spawners FW599Winter 2008

Dover Sole – Random Starting Values FW599Winter 2008

Dover Sole – Retrospective Analysis Data through 2005 through 2004 through 2003 through 2002 through 2001 FW599Winter 2008

Dover Sole – Compared to Last Assessment FW599Winter 2008