Content as most Minnesotans are to wait near the top of the Mississippi River drainage and hope that invasive Asian carp don't arrive this far north anytime soon, Mark Ellenberg for many years has done the opposite: He's hunted them down wherever they are and tried to kill them. ¶ Ellenberg and I were talking about this the other night in the dark, on the St. Croix River, not far from the Allen S. King power plant in Bayport, where five bighead carp were caught recently, some by fishermen, others by the Department of Natural Resources (DNR). ¶ By about 7 miles, it's the farthest north bigheads have been captured in the St. Croix. ¶ Their arrival shouldn't have been a surprise, said Ellenberg, 47, of White Bear Lake. ¶ "Ten years from now, there'll probably be a lot of them," he said. ¶ As he spoke, he stood in the bow of his 27-foot custom-made bowfishing boat, one hand on the electric trolling motor that pulled the craft forward, the other on a compound bow, an arrow nocked.
He's used the same equipment to kill bighead carp in South Dakota, Illinois and Iowa. Forays to these distant locales sometimes have been for challenge and enjoyment, other times to compete in bowfishing tournaments.
How invasive can invasive carp be?
"In one tournament on the Illinois River, my partners and I won by bringing 5,500 silver carp to the dock in 12 hours," Ellenberg said. "This was a 'by any means' tournament, so about 20 percent of the carp we shot, while the others jumped in our boat as we ran down the river."
Known for their acrobatic leaps when startled by the underwater whine of boat motors and other disturbances, silver carp might represent the biggest threat of all invasive carp to aquatic habitats and fisheries, and to water sports.
Bigheads and grass carp, meanwhile, are in many instances the pioneering species, the ones that arrive first.
Bigheads like those caught near Stillwater last week are challenging to locate and even more challenging to kill, Ellenberg said.
"Bigheads are among the most sensitive fish there are," he said. "That's why the DNR and others who have tried to net them usually don't come up with anything. Bigheads accept almost no disturbance. Any boat noise or motor noise and they're gone."