http://en.wikipedia.org/wiki/Asian_carpsBecause of their prominence, and because they were imported to the United States much later than other carp native to Asia, the term "Asian carp", is often used in the United States with the intended meaning of only grass, black, silver, and bighead carp. In the United States Asian carp are considered to be nuisance invasive species. Of the Asian carp that have been introduced to the United States, only two (crucian and black carp) are not known to be firmly established. Crucian carp is probably extirpated.<6> However, since 2003, several adult, fertile, black carp have been captured from the Atchafalaya and other rivers connected to the Mississippi River.<7> Dr. Leo Nico, in the book Black carp: Biological Synopsis and Risk Assessment of an Introduced Fish, writes that the black carp are likely established in the USA.
Bighead, silver, and grass carp are known to be well-established in the Mississippi River basin (including tributaries) of the United States, where they at times reach extremely high abundances, especially in the case of the bighead and silver carp. Bighead, silver, and grass carp have been captured in that watershed from Louisiana to South Dakota, Minnesota, and Ohio. Grass carp are also established in at least one other watershed, in Texas, and may be established elsewhere....
These fish are thought to be highly detrimental to the environment in the USA where they are established.<8> Because of these concerns, the U.S. Fish and Wildlife Service convened stakeholders to develop a national plan for the management and control of invasive Asian carp (referring to bighead, silver, black and grass carp).<9> The plan was accepted by the National Aquatic Nuisance Species Task Force in the fall of 2007.
In July, 2007, all silver carp and largescale silver carp were declared by the U.S. Department of the Interior to be invasive species under the Lacey Act.<4>