Does Condition of Young-of-the-Year Fish Vary Among Nursery Habitats in Chesapeake Bay?

Fisheries managers typically use indices of relative abundance of young-of-the-year (YOY) fish to assess year-class strength, however, purportedly strong year classes may not always produce subsequent recruits to the fishery.  The condition of individuals in a year class has the potential to influence recruitment variability due to differential survival of poor- and well-conditioned individuals.  Individuals in poor condition may be more susceptible to mortality (from predation, disease, or physiological compromises) and may not survive to recruit to the fishery.  We hypothesized that variation in fish condition may reflect differential suitability of nursery areas for YOY fish.  Condition is often assessed via lipid content because lipids are high-energy compounds important for survival during periods of food scarcity or environmental stress, and for performing energetically demanding activities (migration).  We assessed the performance of several metrics presumed to measure condition of YOY fish (Fulton’s K, hepatosomatic index, and fatmeter lipid estimates) by correlating them with lipid and energy content.  Using these metrics, we examined the spatial variation in condition of YOY summer flounder, striped bass, and Atlantic croaker from Chesapeake Bay.  Detecting variability in condition is dependent on the scale of interest, and conclusions concerning habitat suitability are species-specific.