Bioenergetic responses of Chesapeake Bay white perch (Morone americana) to nursery conditions of temperature, dissolved oxygen, and salinity

Abstract

Changes in the physical and chemical structure of estuaries control the aerobic scope for activity of coastal fishes and thereby influence the quality and extent of nursery habitats. We evaluated the effects of temperature, dissolved oxygen, and salinity on the ecophysiology of a species that completes its life cycle in estuaries: white perch (Morone americana), which were reared at treatment levels that emulated nursery conditions in the Chesapeake Bay. Salinity influenced only consumption rate and energy density, which were diminished at the highest salinity level (16). In hypoxic environments (≤40% saturation), routine metabolic rates increased as much as fourfold while growth rate decreased threefold and consumption rate decreased twofold. Experimental growth rates were within the range of growth rates observed in the field. Results indicate that hypoxia substantially reduces potential nursery production for a dominant estuarine species, through its influence on diminished aerobic capacity for growth and activity.