11 March 2023
Winner of the E.J. Crossman Award for Best Student Oral Presentation
Abstract: Bighead Carp threatens to expand northward and invade the Laurentian Great Lakes, but there is uncertainty about whether the winter conditions encountered there could impose a population bottleneck. Population growth of Bighead Carp is highly sensitive to the survival of young-of-year (age-0), but this life stage is often implicated in population bottlenecks at northern latitudes. The reduced size and capacity to store energy makes young-of-year particularly vulnerable to overwinter starvation. By modelling how spawn timing, growth, and the onset and duration of winter could be affected by climate warming, we explored how the recruitment and overwinter survival of young-of-year Bighead Carp could change in response to climate change. Given that young-of-year are highly influential to population performance, increases in temperature that help them overcome overwinter starvation could contribute significantly to changes in the overall risk of invasion. Our results suggest that anticipated warming could increase overwinter survival primarily by enabling young-of-year to grow larger before the onset of winter and, to a lesser extent, by reducing the extent of overwinter starvation. Accordingly, projected warming conditions could enable populations to establish farther north than previously possible by mid-century.