Control and mitigation of invasive carp species have largely focused on efforts to remove or divert them in an attempt to minimize short- and long-term changes in ecosystems where they are already…

The U.S. Fish and Wildlife Service awarded a $286,681 Project Grant to the Nebraska Game & Parks Commission from October 2023 through December 2025. This grant is funded through the Fish and Wildlife Management Assistance program (CFDA 15.608), which provides funding to states to implement Aquatic Nuisance Species Management Plans.

The goal of this project is to better understand how flow and habitat dynamics in the Platte River basin influence the egg and larval life stages of invasive carp species. Researchers will analyze otolith microchemistry to investigate the natal origins of invasive carp collected in the Missouri River basin, which could reveal unaccounted-for source-sink dynamics sustaining carp populations. The project will also evaluate the drift dynamics of invasive carp eggs and larvae in the braided, shallow Platte River system, which differs from the single-channel Illinois River where previous modeling has been conducted. This information could help identify concentration areas where young invasive carp become concentrated due to flow patterns, allowing for more targeted control and removal efforts.

Control and mitigation of invasive carp species have largely focused on efforts to remove or divert them in an attempt to minimize short- and long-term changes in ecosystems where they are already established. Much of this work has focused on larger sub-adult and adult-sized fish in an attempt to decrease populations in larger river systems. However, emerging data from otolith microchemistryanalyses show that many individual carp collected in the missouri river basin have natal origins from tributaries rather than the mainstem portion of the basin. This information suggests an unaccountedfor source-sink dynamic that could sustain carp populations even in the presence of large-scale removalefforts if successful recruitment is occurring in these tributaries regularly. We have a basic understanding of the requirements invasive carp need to successfully reproduce and thus survive through their early life stages (e.g., free-floating eggs to larval drift stages). For example, the fluegg model has been used to simulate drift requirements for invasive carp in rivers characterized as a single channel (e.g., illinois river waterway). However, many tributaries in the missouri river, and especially those flowing through the great plains are characteristically shallow, braided systems (e.g., platte river)that incorporate additional complexity that has yet to be evaluated. Therefore, understanding the dynamics of early life-stage outcomes in braided river systems may shed light on new avenues to affect control measures. Better knowledge of how eggs and larvae drift in the water column in these braided systems could prove beneficial for innovation in population control. Specifically, being able to determine how eggs and larvae move throughout a system could identify potential habitat types and locations where young invasive carps become concentrated due to flow dynamics. These concentrationhabitats could then be targeted for intensive carp management practices to remove individuals more effectively. Our goal is to better understand how flow and habitat dynamics in the platte river basin influence EGG and free-floating life-stages of invasive carp.