Evaluating the Potential for Overwinter Survival of Young-of-the-Year Grass Carp in the Great Lakes Basin

Establishment of aquatic invasive species are a leading threat to aquatic biodiversity.  One of the most acute threats facing the Great Lakes is the introduction of Asian carps, which have potential to cause extensive changes to ecosystems and the fisheries they support. Grass Carp Ctenopharyngodon idella was introduced to the United States as a biocontrol agent and has since established reproducing populations in several rivers of the United States and now threatens to invade the Great Lakes.  Recent triploid captures from the Great Lakes has highlighted the need to assess its ecological risk, such as the likelihood of species establishment following arrival and survival. Vulnerable periods during early life history, such as the onset of cold, winter temperatures, can influence survival and population dynamics and represents a potential critical limiting factor to establishment of these temperate fishes.  We present model predictions for overwinter survival of young-of-the-year Grass Carp under varying temperature regimes for each of the Great Lakes.  These results will better inform ecological risk and the overall probability of establishment of Grass Carp to the Great Lakes basin.