CHICAGO (AP) — Officials say genetic material from Asian carp has been detected near Lake Michigan, but a follow-up search turned up none of the invasive fish.

The U.S. Fish and Wildlife Service posted results last week from sampling conducted in the Chicago Area Waterway System in early April.

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Most of the 401 water samples were negative, but six registered DNA hits for silver or bighead carp in Lake Calumet, a few miles from Lake Michigan.

Scientist say if the fish become established in the Great Lakes, they could out-compete native species.

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Asian carp DNA has been found repeatedly in Lake Calumet and other spots beyond electric barriers intended to block them.

An official with the federal agency told the Milwaukee Journal-Sentinel crews searched for live Asian carp last week but found none.

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