Overfishing and underfishing consequences for food security and economic value in U.S. fisheries Michael Melnychuk, Jeannette Banobi, Ray Hilborn School of Aquatic and Fishery Sciences University of Washington
Worm et al. 2009, Science Georges Bank Trade-offs
B/B MSY Biomass and fishing mortality reference points F/F MSY Overfished Overfishing
Recent status of U.S. stocks Regional medians B/B MSY F/F MSY
Rank order of stock MSY in region AlaskaWest coast Northeast coast Southeast coast Cumulative yield (millions t) Maximum sustainable yield (MSY) Equilibrium yield under current exploitation rate Foregone potential yield Cumulative multispecies yield (commercial landings only)
∑ ≈ 0.15 million t Foregone potential yield ∑ > 3.5 million t
Rank order of stock MSLV in region AlaskaWest coast Northeast coast Southeast coast Cumulative landed value ($billion) Maximum sustainable landed value (MSLV) Equilibrium landed value under current exploitation rate Foregone potential landed value Cumulative multispecies landed value (commercial landings only)
∑ > 1.7 billion $ ∑ < 0.6 billion $ Foregone potential landed value
Intercept Ex-vessel price Landings Under rebuilding ? Bycatch limits for exploited species ? Bycatch limits for non-exploited species ? Typically caught incidentally ? Low market demand ? Factors affecting the degree of ‘underfishing’ or overfishing Factors F/F MSY for stocks experiencing overfishing Response variable for stocks experiencing ‘underfishing’ { Region = random effect } Generalized linear mixed effects model
Coefficient estimate Effect on F/F MSY for stocks experiencing ‘underfishing’ Intercept Ex-vessel price Landings Under rebuilding ? Bycatch limits for exploited species ? Bycatch limits for non-exploited species ? Typically caught incidentally ? Low market demand ? Effect on F/F MSY for stocks experiencing overfishing Factors affecting the degree of ‘underfishing’ or overfishing no stocks * * * *
Underfishing /
Thank you to many fishery managers, stock assessment scientists, economists, social scientists, industry association representatives, and fishermen for patiently answering our questions. And to all contributors to the RAM Legacy Stock Assessment Database
Recent status of U.S. stocks B/B MSY F/F MSY SAC red snapper OR cabezon EC winter flounder Georges Bank cod SAC snowy grouper GoMex gag GoMaine cod sNE yellowtail flounder 5YZ Atlantic halibut SWC cowcod NEC silver hake SWC rockfish: chilipepper, shortbelly, splitnose, greenstriped, blackgill, greenspotted Atlantic butterfish Widow rockfish AI walleye pollock WC bocaccio GoMex black grouper GoA rex sole GoA dover sole BSAI flathead sole WC English sole nWC lingcod NE monkfish GoA flathead sole BSAI Greenland turbot
Equilibrium
Dynamic stock status plots at: depts.washington.edu/ramlegac 2009