“These fish will take over,” out of town visitor Kathy Becker said.

Even tourists like Becker understand how the jumping, voracious invaders are knocking on the door. Just last week it was announced that five of the big head carp were caught in the St. Croix River near Stillwater.

“I think it’s hugely important you all acted so quickly because there are so many examples all around the globe,” Becker said.

Had the invasive carp been able to navigate upstream of St. Anthony Falls, it could spell catastrophe for Minnesota sport fishing. That’s because a breach at the Coon Rapids dam, which was recently fortified, could give the carp a pathway into Minnesota’s north central lake country.