Testing an Impact Prediction for Larval Fish Entrainment at a Cooling Water Intake for a Coastal Thermal Generating Station in Northern New Brunswick, Canada

The potential environmental effects of cooling water intake on fish was evaluated in an Environmental Impact Assessment (EIA) for a thermal generating station on Chaleur Bay in northern New Brunswick.  The EIA predicted a low potential for effects on local fish populations; this prediction was tested in a 2004 follow-up study in which entrainment of larval fish in the cooling water intake was compared to fish densities in the intake lagoon and the harbor.  The results confirmed 1) existing structures mitigate by 90% the number of larval fish being entrained as compared to what would be expected based simply on the abundance of larval fish in the harbor; 2) larval fish of commercially important fish were either absent or represented in low numbers in cooling water; and 3) although higher numbers of larval fish were entrained in cooling water in 2004 than predicted in the EIA (sampled in 1988), a follow-up study suggests that this can be attributed to higher density present in the source water.  These findings are discussed and support the impact prediction of low potential for cooling water intake from the thermal generating station to have a significant environmental effect on local fish populations in Chaleur Bay.