A 20-pound (9-kg) Asian carp was fished out of a waterway close to the Great Lakes and beyond twin electric barriers designed to keep them out, authorities said on Wednesday.

It was the first time the voracious invader has been found beyond the electric barriers in the waterways that connect Lake Michigan, one of the five Great Lakes, with the Mississippi River basin, where the carp have proliferated.

“It’s important evidence, and the more information we know about where the carp are, the better … that’s the reason we’re intensifying the effort” to find any Asian carp beyond the barriers, said Chris McCloud, a spokesman for the Illinois Department of Natural Resources.