Assessing Potential Effects of Entrainment and Impingement on Fish Stocks of the New York–New Jersey Harbor Estuary and Long Island Sound

We assessed the potential effects of entrainment and impingement at the Charles Poletti Power Project (hereafter, Poletti) on fish stocks of the New York-New Jersey (NY-NJ) Harbor Estuary and Long Island Sound by (1) estimating, for five fish stocks, the conditional mortality rate (CMR) for entrainment of eggs, larvae, and young-of-the-year (age-0) fish and the CMR for impingement of age-0 fish, and (2) for two of those stocks, using the CMR estimates to calculate the proportional reduction in biomass of spawners from an unfished stock under equilibrium conditions. Estimates of entrainment CMR for eggs and larvae were low and ranged from 0.02% for tautogs Tautoga onitis to 0.11% for Atlantic menhaden Brevoortia tyrannus, based on the spatial and temporal distribution of those life stages in the NY-NJ Harbor Estuary and Long Island Sound study area and the probabilities of entrainment generated by a particle tracking model, coupled with a three-dimensional estuarine circulation model that simulated the transport of ichthyoplankton. Estimates of entrainment CMR for age-0 fish were low and ranged from 0.00% for tautogs and winter flounder Pscudopleuronectes americanus (none were collected in entrainment samples) to 0.11% for cunners Tautogolabrus adspersus, based on age-0 numbers entrained and standing crop estimates. Impingement CNIRs ranged from 0.00% for windowpanes Scophthalmus aquosus (none were impinged) to 0.80% for tautogs. The proportional reduction in the biomass of spawners from an unfished stock would increase only 0.09% for winter flounder and 0.01% for Atlantic menhaden as a result of entrainment and impingement at Poletti. These effects are extremely small relative to the effects of fishing mortality.