Proximate composition, energetic value, and relative abundance of prey fish from the inshore eastern Bering Sea: implications for piscivorous predators. Polar Biol

• Main Authors: Jevrey R Ball, Daniel Esler, Joel A Schmutz
• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Published: 2007
• Subjects: Bering Sea; Yukon; Kuskokwim; Alaska
• Online Access: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.1079.3741; http://www.sfu.ca/biology/wildberg//papers/BalletalPolarBio07.pdf

Abstract Changing ocean conditions and subsequent shifts in forage Wsh communities have been linked to numerical declines of some piscivorous marine birds and mammals in the North PaciWc. However, limited information about Wsh communities is available for some regions, including nearshore waters of the eastern Bering Sea, where many piscivores reside. We determined proximate composition and energetic value of a suite of potential forage Wsh collected from an estuary on the Yukon-Kuskokwim Delta, Alaska, during 2002 and 2003. Across species, energy density ranged from 14.5 to 20.7 kJ g ¡1 dry mass and varied primarily as a function of lipid content. Total energy content was strongly inXuenced by body length and we provide species-speciWc predictive models of total energy based on this relationship; some models may be improved further by incorporating year and date eVects. Based on observed energetic diVerences, we conclude that variation in Wsh size, quantity, and species composition of the prey community could have important consequences for piscivorous predators.