Invasive Carp

Bigheaded carp, especially silver ( Hypophthalmichthys molitrix ) and bighead carp ( Hypophthalmichthys nobilis ), are invasive fish species that have established breeding populations dominating large regions of the Mississippi Drainage in the 20 years following escape from aquaculture facilities in Arkansas.

Since their introduction in the 1960’s, grass carp ( Ctenopharyngodon idella ) have spread across the North American continent as far north as the U.S./Canadian border in the Great Lakes. Grass carp are an herbivorous species and can significantly reduce the amount of macrophytes and other plant material in a body of water. Subsequently, this can lead to many detrimental effects for certain...

Flow cytometry is a technique for rapidly analyzing large numbers of animal cells using light-scattering, fluorescence, and absorbance measurements.

The invasive grass carp and black carp are artificially spawned to produce triploids, which means they have three sets of chromosomes and are sterile. WARC scientists invented an early ploidy prediction process for produced fry, and a post-mortem assessment method for carp caught either in the wild or sold and hauled live to other states.

Invasive Asian carp are problematic for native species, and managers are implementing control measures without well-quantified detection limits or a means to assess the accuracy and precision of existing or future survey data for the fish. Environmental DNA - eDNA - is already used to detect the presence of invasive species, and can be used to identify locations to focus carp control efforts.

Black carp have likely been present in the Mississippi River since the 1990s, but their current distribution and spread is not well understood. Genetics is helping to shed light on this species, including its diversity, the relatedness of wild and captive fish, and its introduction history.