Jacob Peterson, “Age and Gender Matter: Acute Impact of Chlorine Contamination and Heat Shock on Yellow Perch (Perca flavescens)”
Mentor: Dong Fang Deng, Freshwater Sciences
Poster #144

Yellow perch (Perca flavescens) is a crucial ecological and economic freshwater fish in the Great Lakes. However, the population of yellow perch has faced a significant decline, attributed to environmental stressors such as habitat loss, contaminant pollution, food web disruption, and climate change. This study aims to understand the effects of chlorine contamination, primarily from the widespread use of disinfection chemicals (bleach), and heat shock on yellow perch. Initially, the impact of varying chlorine concentrations (0, 0.1, 0.2, 0.4, and 0.6 ppm) on larval fish (25 days post-hatch) over four hours was measured. Each treatment comprised three replications, with forty fish in each replication. Subsequently, juvenile fish (average weight, 25.1 g) were exposed to the same chlorine concentrations in a 24-hour test, with six fish per tank and three tanks per treatment. The third test subjected yellow perch (average weight 72.1 g) to heat shock, raising the temperature from 20°C to 32°C at a rate of 1°C/15 mins. Mortality was monitored for 20 hours with the fish exposed to 32°C. Results revealed significant mortality in larval fish at 0.4 and 0.6 ppm chlorine (100%), 0.2 ppm chlorine (92.5%), and 0.1 ppm chlorine (35.8%), with less than 1% mortality in the control. Juvenile fish exhibited 5.5% mortality at 0.4 ppm and 25% at 0.6 ppm chlorine, with no mortality in other treatments. All mortalities in the chlorine tests were female. In the heat shock, male fish experienced 100% mortality, while female fish had 46% mortality. These findings highlight that 1) larval fish are more susceptible to chlorine contamination than juvenile fish; 2) males display greater resistance to chlorine contamination, while females demonstrate higher tolerance to heat shock. The results contribute a baseline to our understanding of immediate environmental threats faced by yellow perch, informing conservation and management strategies for this fish.