Habitat Use in a Depleted Population of Winter Flounder: Insights into Impediments to Population Recovery

The distribution and demographics of a population of Winter Flounder Pseudopleuronectes americanus were examined for changes related to habitat quality over a fishery-independent survey period of 29 years, encompassing an 82% decline in abundance. We tested for spatial and temporal variation in indicators of fitness to determine whether they revealed likely processes that resulted in the observed patterns of habitat use. We also assessed temporal changes in fitness and inferred changes in habitat quality associated with population decline. We focused on the condition of postspawn (resting) mature and immature fish of both sexes during a critical period of spring feeding prior to summer migration. Analysis of variance of individual condition indices (log10[length]–log10[weight] regression residuals) by sex/maturity group and time period identified consistent and significant differences among six survey strata. Highest condition indices were observed for fish that were captured in shallow (