Winter Habitat Selection and Efficacy of Telemetry to Aid Grass Carp Removal Efforts in a Large Reservoir

Grass Carp Ctenopharyngodon idella were introduced in North America to control aquatic vegetation small, closed systems. However, when they escape into larger systems which can reproduce, have the potential cause significant declines and alterations communities. These turn affect native species that are dependent on vegetation. Increased captures observations of spawning elevated concerns about establishment new locations, with particular concern for Lake Erie its tributaries. Recent efforts using telemetered fish co-locate wild conspecifics, sometimes aggregations susceptible harvest, been used successfully invasive Common Cyprinus carpio populations. If aggregate winter similarly Carp, might be similar or harvest methods. During winters (December–March) 2017–2019, we tracked 86 tagged acoustic transmitters Truman Reservoir, Missouri, evaluate habitat selection determine effectiveness locating removing by comparing at locations sites believed suitable habitat. Discrete-choice models showed exhibited strong shallow water, as 75% littoral habitats depths 3 m less. On average, harvested more where located (3.6 fish/attempt) than (1.2 fish/attempt). Full guts individuals may indicate shallow-water feed. Our results suggested did not usually form large aggregations, although targeting slightly increased success compared without them, reduce populations via difficult widely dispersed.