Impingement Survival Using Two Different Fish-Friendly Screen Types in the New York Bight

Studies of impingement survival studies with full-scale installations of fish-friendly screens have been conducted at three existing cooling water intake structures located in brackish or marine waters of the New York Bight.  Two fish-friendly intake screen technologies were evaluated, modified Ristroph screens and Hydrolox screens, both equipped with fish buckets and low pressure screen wash systems.  In each of these studies, impingement survival was evaluated through 48-hours after impingement.  Over the course of these studies, sufficient numbers of individuals were collected to permit estimation of impingement survival for 30 fish species, all common inhabitants of the brackish and inshore marine waters of the Bight.  More than 8,000 individuals of these species were collected across all three studies, most of which were Age 0+.   Overall, impingement survival was relatively high for most species with more than 60 percent exhibiting survival rates of 70 percent or more after 48 hours.  Survival was affected by fish length, water temperature and salinity.  While there were a limited number of species in common between the two screen types, the results suggest that impingement survival off Hydrolox screens was within the range, and possibly greater than that, observed from the more conventional Ristroph screens.