Minnesota's top outdoors official said Thursday the state had not been aggressive enough in the past in trying to keep Asian carp out of the state's waters, and that Minnesota should move forward with an underwater barrier even if it does not prove to be totally effective.

Tom Landwehr, the state Department of Natural Resources commissioner, made his comments after agency officials this week successfully lobbied an outdoors advisory group to set aside $3 million to explore building an underwater sound bubble barrier in the Mississippi River at Prescott, Wis.

The Lessard-Sams Outdoor Heritage Council, an advisory group to the Legislature, voted Tuesday to set aside the money, but not before a long and at times testy debate over the issue and whether the barrier would be effective.

State officials have made stopping Asian carp, which can grow to 60 pounds and push aside native fish species for food, a top priority in the state. DNR officials last month said they had found evidence that Asian carp, which have been moving upstream from the southern part of the country, may have reached the St. Croix River.

"Hindsight is always, you know, the wisest of [all] vision," said Landwehr, who became DNR commissioner earlier this year. "Could people [at the DNR] have been more aggressive? Absolutely."

But he said the DNR has "been relying on other [state and federal] agencies to step up to the plate that have not done that."

Landwehr said an underwater sound bubble barrier – even if the technology behind it is not full proof – should be tried. "We don't have all the answers, but we have to take some risks here to do what we can to slow the spread," he said.

"If that means spending, you know, $10 million on technology that might only be 95 percent effective – I think that's a worthwhile investment," he added.

"I would hate, 10 years from now, to look back and say, 'Geez, if we had only installed that barrier, we might have slowed this down enough that we could stop it somewhere else,' " said Landwehr.