Variability in Daily Ration Estimates of Age-0 Striped Bass in the Chesapeake Bay

Abstract

Abstract Previous studies have developed and applied bioenergetics models to estimate trophic demand for prey by striped bass Morone saxatilis in Chesapeake Bay. Although these models were validated with laboratory studies, no field estimates of daily ration of striped bass were available in Chesapeake Bay for comparison with bioenergetics model estimates. This study estimated growth and daily ration of age-0 striped bass in the upper Chesapeake Bay for two dates (6 and 19 October 1993) using the Eggers model. Experiments on the gastric evacuation rate of captive striped bass at 17°C found that stomach contents were evacuated at a rate of e −0.12h , where h is time in hours since feeding. Daily ration estimates only 14 d apart varied by 66% (0.0326 g · g−1 · d−1 on 6 October and 0.0542 g · g−1 · d−1 on 19 October). Bioenergetics model estimates of consumption over this period averaged 0.0559 g · g−1 · d−1. Based on the variability in Eggers estimates, it would require more than two estimates (2.4) of dail...