Population Level Impacts of Cooling Water Withdrawals on Harvested Fish Stocks

Trillions of gallons are withdrawn every year from U.S.
rivers, estuaries, lakes, and coastal waters to cool the
turbines of power plants and other equipment in manufacturing
facilities. In the process, large numbers of aquatic
organisms die from entrainment into the plant or impingement
against the outer portion of the intake structure. In this
paper, we develop a generalized age-structured population
model with density dependent survival of sub-adult age
classes, and we use the model to perform a screening
analysis of the effects of entrainment and impingement for
15 harvested fish stocks off the California and Atlantic
coasts. Stock sizes are estimated to be depressed
by entrainment and impingement by less than 1% in 10 of
the 15 cases considered, between 1 and 3% in two
cases, and between 20 and 80% in three cases. A variety
of sensitivity analyses are conducted to evaluate the
influence of several sources of model and parameter
uncertainties.