Aquatic Ecosystem Health

Bigheaded carps, composed of bighead ( Hypophthalmichthys nobilis) and silver carp ( H. molitrix), have specialized structures that increase their hearing range and sensitivity. Recent results from controlled laboratory studies have indicated that the playback of an outboard boat motor was effective at altering the behavior of bigheaded carps. The possibility of being able to use specific sounds...

Invasive carps including bighead carp ( Hypophthalmichthys nobilis), silver carp ( H. molitrix), grass carp ( Ctenopharyngodon idella), and black carp ( Mylopharyngodon piceus) are invasive fish species established throughout the Mississippi River Basin. The spread of these four species threatens the ecosystems of the Great Lakes and other major waterways. Substantial work has been done to...

Invasive carp management in the Tennessee and Cumberland River Basin focuses on removal, and interest exists in extending removal efforts to tailwater environments of high-head locks and dams along the Tennessee and Cumberland Rivers. Aggregations of Silver Carp and Bighead Carp (collectively referred to as bigheaded carp) can spend substantial amounts of time in the tailwaters of high-head dams...

Silver Carp continue to expand their range in North American river basins, necessitating efforts to limit the spread with a combination of management actions. Within the Tennessee and Cumberland River Basin, locks and dams serve as bottlenecks that slow range expansion of invasive carps. Dams in the Tennessee and Cumberland Rivers are high-head dams that restrict upstream passage to the lock...

This project supports goals and objectives of the Illinois River Monitoring and Response Work Group (MRWG) by (1) providing a real-time network of acoustic receivers to detect movements and alert key management partners of invasive carp movements beyond normal ranges (i.e., above Brandon Road Lock and Dam in the Des Plaines River), (2) coordinating partner efforts to maintain a passive 69-kHz...

Environmental DNA (eDNA) and related molecular methods are important tools for helping to detect and monitor invasive carp presence in the Mississippi River and Great Lakes basins. The use of eDNA has become a common method for detecting presence of invasive carp in areas of low density and uncertain presence. Furthermore, eDNA can be used to identify activities such as spawning. However, an eDNA...

We aim to develop control tools for eliminating invasive carps (silver carp – Hypophthalmichthys molitrix, bighead carp – H. nobilis, grass carp – Ctenopharyngodon idella, and black carp – Mylopharyngodon piceus) that use natural gene regulation mechanisms (RNA-induced gene silencing; RNA interference; RNAi) to be species-specific without non-target effects. Invasive carps cause substantial...

Fish management agencies often rely on removal strategies for population control of aquatic nuisance species, such as invasive carps. Pesticides, or management chemicals, could supplement removal techniques within an Integrated Pest Management plan for invasive carps. This project is developing selective pesticide formulations that target invasive carps with the goal to control unwanted...

Researchers and managers have documented spawning by Grass Carp ( Ctenopharyngodon idella) in three tributaries of Lake Erie, with additional rivers potentially providing suitable spawning habitat. Spawning events can be targeted by managers to disrupt reproduction and remove aggregating fish. Prior research has identified the temperature and streamflow conditions that can help predict spawning...

The Invasive Carp Open Data Hub is an easy-to-use repository for the public to access data, publications, and tools stemming from USGS research on invasive carp. Much of this work has been done in collaboration with invasive carp researchers at federal and state agencies and universities. Ongoing updates to the Invasive Carp Open Data Hub are planned to maintain the Hub as a critical resource for...

Bighead carp and silver carp (collectively known as bigheaded carps) first escaped to the Mississippi River Basin in the 1970s and by 1989 had invaded the Tennessee and Cumberland Rivers. The species threaten the economies and ecosystems for these rivers and are currently spreading upriver. USGS scientists are developing population-level models to help guide and inform control strategies and...

The Obed Wild and Scenic River, located on the Cumberland Plateau, is in a region where major declines and mass mortality of mussels have been observed. The Wild and Scenic River contains designated critical habitat for the federally endangered endemic Tennessee Bean ( Venustaconcha trabalis; aka Purple Bean). Water quality and habitat conditions in the Obed are critical factors for recovery of...