COS 166-2 - Spatial growth variability in marine fish: Example from northeast Pacific groundfish

Thursday, August 10, 2017: 1:50 PM
D138, Oregon Convention Center
Vladlena Gertseva1, Sean Matson2 and Jason Cope1, (1)Northwest Fisheries Science Center, National Marine Fisheries Service, Seattle, WA, (2)West Coast Regional Office, National Marine Fisheries Service, Seattle, WA

Providing fisheries resources is an important ecosystem service of the world oceans. Marine fish populations exist in a complex environment, with oceanographic and fisheries factors affecting their dynamics. Understanding fish temporal and spatial dynamics helps ensure sustainability of marine resources and ecosystem services provided by the ocean. To advance knowledge of complex and diverse dynamics of marine fishes, we examined spatial variability in growth of eight groundfish species in the northeast Pacific Ocean to identify shared spatial patterns and hypothesize about common mechanisms behind them. Growth parameters were estimated in different areas over the latitudinal range of the species and different hypotheses were tested as to how these parameters vary along the U.S. West Coast.


Clear differences in spatial growth variability emerged among the species examined. Shelf species exhibited the highest growth rate between Cape Blanco and Cape Mendocino, which may in part be attributed to area-specific upwelling patterns in the California Current ecosystem, when nutrient rich deep water are brought to the surface southward of Cape Blanco and are uniquely distributed throughout this area, providing favorable conditions for primary productivity. Slope species showed a cline in asymptotic size (L), with Lincreasing from south to north. This cline, previously attributed to fishery removals, also fits a specific case of the widely described Bergmann’s rule, and we explore specific potential ecological mechanisms behind this relationship.