Native diadromous fishes have been extirpated from much of the Susquehanna River system for nearly a century. Recent restoration efforts have focused on removal of dams, but there are hundreds of dams and presently there is no biologically based system to assist in prioritizing their removal. We present a new method that uses existing habitat suitability index models (HSI) for American shad Alosa sapidissima, alewife A. pseudoharengus, blueback herring A. aestivalis, and American eel Anguilla rostrata to prioritize the removal of non-hydropower dams within the Susquehanna River system. We ranked HSI scores for each of the four species, association between a landscape-scale factor and HSIs, length of river opened by removing a dam, and distance from the mouth at Chesapeake Bay for each dam and then calculated a mean rank prioritization for dam removal by averaging the ranks for the seven criteria. This prioritization method is resistant to outliers, is not strongly affected by somewhat arbitrary decisions on metrics included in the analysis, and provides a biologically based prioritization for dam removal that can be easily amended to include other metrics or adapted to other river systems and that complements other social and economic considerations that must be included in decisions to remove dams. Published in

Limited information exists on the marine diet of the Atlantic sturgeon Acipenser oxyrinchus oxyrinchus. We examined the food habits of 275 Atlantic sturgeon (total length, 106-203 cm) caught in the commercial fishery off the coast of New Jersey. Stomachs were provided by fishermen. Significantly more stomachs were empty in the spring than in the fall. Sand and organic debris were a major component in the stomachs (26.3-75.4% by weight). Polycheates were the primary prey group consumed, although the isopod Politolana concharum was the most important individual prey eaten. Mollusks and fish contributed little to the diet. Some prey taxa (i.e., polychaetes, isopods, amphipods) exhibited seasonal variation in importance in the diet of Atlantic sturgeon. Identification of the offshore diet of Atlantic sturgeon is an important step in developing a better understanding of the life history requirements and marine ecology of this species.

Although die1 food habit studies have been undertaken on a number of individual species, few studies have examined die1 variation in the diets of fish communities. We examined the die1 diet variation and feeding periodicity of a fish community in the Juniata River, Pennsylvania. Nine species, totalling 1,098 fish, were collected at 4-h intervals over a 24-

Growth and survival of 16-and 18-day-old American larvae (Alosa sapidissima) increased with prey density (0, 500, and 1000 Artemia l 1 ), though differences were not always significant. Significant differences were not observed in growth parameters and survival for larvae fed 500 v. 1000 Artemia l 1 in laboratory experiments. Food deprivation for as little as 2 days had significant effects on survival but growth effects were not detectable until 4 days of starvation. These findings have application to the Susquehanna River where c. 11 million 2·5-week-old shad larvae are released annually as part of a basin wide effort to restore the species. Larvae released at upriver sites where food may be limiting would drift for 2-3 days to reach reservoirs with higher prey densities. Based on these laboratory findings, survival of shad may be reduced significantly if larvae do not feed prior to reaching reservoir environments.