Biological Reference Points for Nutritional Status of Chesapeake Bay Striped Bass

The assessment of the nutritional status of fish is a central requirement of fisheries management and aquaculture alike.  However, there has been little consensus on the appropriate indicator to use, and even less effort in defining biological thresholds and reference points for management response based on any specific indicator.  With current efforts to manage fisheries in the context of the ecosystem, such indicators are desperately needed.  To address this concern, we compiled 5 different studies where multiple indicators of nutritional status were applied to striped bass (Morone saxatilis) spanning age classes, geographical origin, and environment (captive and wild) (N= 267).  Proximate composition was used as the benchmark to compare the use of moisture alone, Fulton’s condition factor, relative weight, and an index of body fat for robustness.  Our results indicate that: 1) determination of moisture alone allows for the accurate calculation of percent lipid and energy density;  2) weight at length indices are generally less sensitive than component analysis; and 3) the relative body fat index correlates strongly with measured lipid.  Further, we propose the use of the proportion of fish > 80% moisture and/or classified as having no observable visceral body fat as thresholds for EBFM, and provide reference points based on historical data for Chesapeake Bay striped bass.