17 May 2022
Abstract: Bighead Carp populations have established and caused great ecological and economic damage throughout the Mississippi River. Their range continues to expand and they currently threaten to invade the Laurentian Great Lakes, but it is uncertain how they will perform in new environments and under climate change. Around the world, Bighead Carp populations in different climates show variation in size-at-age and age of maturity. At higher latitudes, individuals grow more slowly and mature later in life at larger adult sizes, while those in warmer regions grow faster but mature younger and smaller. This trade-off between growth and adult size could drive different outcomes across climatic conditions, as survival and fecundity correlate with body size, but earlier maturation enables shorter generation times. Under climate change, maturation and size-at-age of Bighead Carp within a location could be similarly affected. To investigate how climate change could impact a potential Bighead Carp invasion, we developed a matrix population model to simulate populations with variable growth, reproduction, and survival rates corresponding to different maturation ages and environmental conditions. We parameterized the model using published data for Bighead Carp populations with maturation ages ranging from 3 to 8 years. Decreasing age of maturity was revealed to have a non-linear effect on population growth. Maturation at younger ages was found to be advantageous up to an extent, suggesting greater population growth under climate change within temperate regions. However, while anticipated warming may benefit Bighead Carp in some cases, certain environmental conditions could also result in reduced population growth.