Post-Impingement Survival and Inferred Maximum Thermal Tolerances for Common Nearshore Marine Fish Species of Southern California

Abstract

The effectiveness of a pilot post-impingement fish return program was studied at Los Angeles Department of Water and Power’s Scattergood Generating Station during six heat treatments from February 2005 to August 2006. Speciesspecific total percent survival was computed for all individuals impinged, with an overall survival of 0.4% across all species impinged during monitored heat treatments, ranging from 30.2% for Paralabrax clathratus to 0.0% for Seriphus politus. Species-specific critical thermal maxima was inferred from surveys of the abundances returned by San Onofre Nuclear Generating Station’s highly effective and unique Fish Return System during heat treatments from 2000–2005. Abundant species such as queenfish exhibited low thermal thresholds (15–20C), while spotfin croaker and barred sand bass became stressed at higher temperatures (25–30C).