Biological Reference Points for the Nutritional Status of Chesapeake Bay Striped Bass

The assessment of the nutritional status of fish is a central requirement of fisheries management. However, there has been little consensus on the appropriate indicator to use, and even less effort toward defining biological thresholds and reference points. With current efforts to manage fisheries in an ecosystem context, environmental effects and trophic relationships need to be considered and appropriate indicators developed. To address this concern, we compiled five different studies in which multiple indicators of nutritional status were applied to Striped Bass Morone saxatilis of different age‐classes, geographical origins, and environments (cultured and wild). Proximate composition analysis was used to compare measured lipid concentrations in the anterior dorsal muscle against selected indicators, including Fulton's condition factor, relative weight, percent moisture, and an index of visceral body fat. The results suggest that weight‐at‐length indices are less sensitive than proximate analysis and poorly related to lipid concentration. However, models developed for both moisture and the body fat index adequately represent tissue lipids and offer clear thresholds of lipid depletion. We propose the use of the proportion of Striped Bass with anterior dorsal muscle composed of more than 80% moisture, or classified as having no observable visceral body fat, as a working protocol for thresholds of poor condition in ecosystem approaches to Chesapeake Bay Striped Bass management. Further, based on historical data we propose an interim target condition of 75% of individuals containing less than 80% moisture as a management goal. Received May 3, 2011; accepted December 19, 2012