Book Description

Invasive species are a major concern for fish populations globally, and the ability to predict the susceptibility of ecosystems to additional invasions or range expansions is needed. Bigheaded carp [Silver Carp (Hypophthalmichthys moltrix) and Bighead Carp (H. nobilis)] pose a serious threat to the Great Lakes Basin and numerous other aquatic ecosystems, where suitable habitat for spawning could allow for the establishment of breeding populations. Evaluating a surrogate would be useful to predict how bigheaded carp behave beyond their current range. To determine whether Common Carp (Cyprinus carpio) is an appropriate surrogate for bigheaded carp, their potential overlap in diets, habitat selection, and behavior must be considered. Fifty-seven adult Common Carp and 7 adult bigheaded carp were acoustically tagged in the Starved Rock Pool on the Illinois River in April 2019. Active tracking occurred monthly during the summer (June-October) of 2019 and 2020, as well as with an array of passive receivers in the Illinois River. Common Carp serve as a viable surrogate for bigheaded carp in dam passage, habitat selection during summer (avoidance of main channel, and channel border while selecting for side channel habitats), and movement probability (significance for both species for weekly average discharge). However, these results should be used with caution when predicting range size (larger core ranges for Common Carp, larger total ranges for bighead carp) and movement (different environmental variables influence movement). Because bigheaded carp are likely to spread much farther and faster than common carp, a more migratory surrogate should be explored such as Paddlefish (Polyodon spathula) or Blue Sucker (Cycleptus elongatus).