Indiana Department of Natural Resources releases report on Asian carp movements in Wabash River Watershed

Over 180 aquatic non-indigenous species (NIS) have been introduced into Great Lakes Basin waters to date, and new introductions are expected in the future. The so-called "Asian carps" (e.g., silver Hypophthalmichthys molitrix and bighead H. nobilis) are large threats to the Great Lakes given expected trajectories of nutrient flow disruption and food web alterations that will likely accompany their introduction to the Basin. While great effort has been expended to keep these species from entering the Great Lakes Basin via the Illinois River and its connection to the Chicago Sanitary and Ship Canal, an additional pathway for introduction has recently been identified at Eagle Marsh near Fort Wayne, Indiana. Eagle Marsh may provide a corridor for transfer of these species between the Wabash and Maumee River basins during flood periods, and the direct connection of the Maumee River with Lake Erie would therefore provide a means for introduction of Asian carp to the Great Lakes Basin. Immediate action to prevent such an introduction via transfer of adult Asian carp has been taken through the installation of a physical barrier across Eagle Marsh. However, the potential trajectories and rates of movement by silver and bighead carps throughout the Wabash River, and especially into the Little River and Eagle Marsh, have not been determined to date.

Understanding the movements of invading species in new systems is important for predicting potential impacts (Degrandchamp et al. 2008), knowing where and when they utilize the environment for life history events like reproduction (Williamson and Garvey 2005), and for devising potential control strategies (Degrandchamp et al. 2008). Asian carp are known to make rapid, large scale movements that are usually associated with spawning (Abdusamadov 1987), and migrations may be triggered by several factors, including temperature (Degrandchamp et al. 2008) and river stage/flow (Abdusamadov 1987; Peters et al. 2006; Degrandchamp et al. 2008). For example, silver carp were found to move ≈10 km/day in the Illinois River (Degrandchamp et al. 2008). The specific cues triggering Asian carp movements in the Wabash River watershed are as yet unknown, and such information is critical for devising control measures.

To learn more about how Indiana DNR and Purdue University are tracking the movement of Asian carp in the Wabash River Watershed, download the complete report: An Assessment of Silver and Bighead Carp (Hypopthalmichthys spp.) Movements and Spawning Activities in the Wabash River Watershed, Indiana – Phase I Annual Report

Surgical implantation of a Vemco 16-4L acoustic transmitter into a bighead carp. Magnified area depicts the surgical area post-suturing.
Photo courtesy of Purdue University.