Jacob Peterson, “The Response to Environmental Stress in Normal and Deformed Yellow Perch Larvae”
Mentor: Dong-Fang Deng, Freshwater Sciences
Poster #122

Climate change is a major concern in the Great Lakes Fisheries. More specifically, Yellow Perch, a staple in Wisconsin’s “Friday Fish Fry”. In the early stages of life fish are far more susceptible to fluctuation in water quality due to their developing immune systems, nutrient storage, and competitive swimming capacity. The purpose of this study is to compare how normal and deformed (scoliosis) larval perch tolerate acute stress from hypoxia (dissolved oxygen < 2.5 mg/L), or heat shock. We hypothesized that the deformed larvae would be more susceptible to stressors. Yellow perch (49-56 days post-hatch) were exposed to hypoxia 2 mg/L??0 for 3 hours and then 4 mg/L until samples were collected (96 hours post-exposure). The control fish were maintained at 7 mg/L oxygen. For the heat shock exposure, fish were stressed by increasing the water temperature from  21 C to 29 C gradually within 2 hours and left for a 72-hour period. There were two replicates (10 fish/replication) for deformed or normal fish for each water treatment.  Fish swimming behavior and survival were recorded. Survival fish were collected for the analysis of nutrition and relevant biomarkers. After the 96 hours in hypoxia there were 9 mortalities due to fish getting stuck between the mesh wall in the tank., but it was observed that deformed fish spent more of their time towards the surface to get oxygen while the normal fish spent their time on the bottom of the tank. In the heat shock study, there was only one mortality. Fish were spending most of their time at the bottom of the tank and moving very little. This study is important because as pollutants enter waterways they can cause serious deformities in fish larvae and impact their development as a result.