Short, Warm Winters Negatively Affect Lake Erie Yellow Perch Reproduction and Recruitment

Although climate warming is expected to benefit cool-water fishes by lengthening the spring through fall growing season, declines in reproductive success following short, warm winters may counter such positive effects. We used analysis of long-term datasets (1973-2010), laboratory experimentation, field investigations (2010-2012), bioenergetics-based modeling, and population modeling, to test the hypothesis that short, warm winters would negatively affect Lake Erie Yellow Perch Perca flavescens by 1) disrupting reproductive development (i.e., gametogenesis), 2) altering spring spawning phenology, and, ultimately, 3) reducing the number of juveniles recruiting to the fishery. Our analyses revealed that failed year-classes consistently followed short, warm winters. Experimentation and field investigation demonstrated that short winters caused females to spawn at warmer temperatures and produce smaller eggs that both hatched at lower rates and produced smaller larvae than females exposed to long winters. Population modeling, which combined these mechanistic findings with future climate projections, predicted declines in yellow perch recruitment by mid-century (2046-2065) under all future emissions scenarios, with greatest declines predicted under the highest emission scenario. Ultimately, our research offers novel mechanisms to explain past Lake Erie Yellow Perch recruitment variation, as well as how continued climate warming may threaten other cool-water fishes with similar physiology and life-history.