21 April 2022
Abstract: Bighead carp inhabits various climates around the world and have multiple traits that contribute to its successful invasion, such as high fecundity, fast growth, and large body size. However, bighead carp also exhibits variable growth and maturation in different environments, which can affect these traits and, ultimately, impact population performance. In warmer climates, bighead carp experience faster subadult growth but mature at younger ages, resulting in smaller size at maturity, while populations at higher latitudes mature later in life at larger sizes. Given that fecundity and survival are positively correlated with body size, this inverse relationship between subadult growth and adult size could drive different population outcomes across climatic conditions. Through examining this trend for global bighead carp populations, a pattern was established and used to estimate shifts in population traits under climate change. A matrix population model was developed to evaluate population performance under various scenarios of growth, reproduction, and survival rates corresponding to different maturation ages and environmental conditions. Trade-offs and demographic differences between early- and late-maturing populations revealed non-additive effects on population performance across climates. Maturation at younger ages was found to be advantageous to an extent, suggesting potentially faster population growth under climate change, but population performance changed non-linearly across maturation ages overall. While anticipated warming may enable greater population performance in some circumstances, bighead carp could also experience reduced performance under certain environmental conditions.