Some anglers say cormorants prevent steelhead recovery.

The Knife River was flowing like turbid root beer on Tuesday morning. A sinuous column of steelhead anglers worked the east side of the river in the morning sun.

Anglers were catching a few fish in the 38-degree water. But Gary Siverson of Duluth thought they should be catching a lot more steelhead on their way upstream to spawn.

“This is absolutely brutal,” Siverson said. “If you could draw up a perfect spring, this would be it, and nobody’s catching any fish.”

The problem, Siverson and some other steelheaders contend, is cormorants. Anglers contend that cormorants nesting on Knife Island near the river’s mouth in Lake Superior feast on down-migrating juvenile steelhead in the spring. That means fewer adults returning to spawn in the future, anglers contend.

Siverson, a board member of the nonprofit Lake Superior Steelhead Association, thinks the island’s cormorant population should be eliminated or at least controlled.

But not everyone is buying that theory.

“There’s no need for any kind of control because nobody has been able to demonstrate that they’re impacting any fishery,” said Jan Green, a long-time birdwatcher representing Duluth Audubon and the Hawk Ridge Bird Observatory.

Minnesota Department of Natural Resources in St. Paul and U.S. Fish and Wildlife Service officials agree. No control of cormorant numbers on Knife Island is planned.

A BRIEF HISTORY

The nation’s cormorant population began recovering after the pesticide DDT was banned in 1972. Some say the population is growing, too, because cormorants feed on fish at aquaculture farms where the birds winter in the South.

Cormorants are federally protected as migratory waterfowl. They fall under the jurisdiction of the U.S. Fish and Wildlife Service.

According to the DNR, cormorant nests increased on Knife Island from just a few in the 1990s to 26 in 2004, then 50 in 2006 and more than 122 in 2007.

Audubon’s Jan Green disputes some of those figures. Since an official DNR count of 26 nests in 2004, she has personally counted 40, 45, 52 and 44 occupied nests from 2005 through last year. She thinks some herring gull nests, on the ground, may have been misidentified as cormorant nests.

Under a Fish and Wildlife Service permit, U.S. Department of Agriculture animal damage control officials killed 25 cormorants at Knife Island and used pyrotechnic devices to prevent others from nesting on the island in 2004. Harassment techniques had little effect because the cormorants renested.

Stomach contents of 10 birds killed at Knife Island were analyzed to see what they had been eating. When stocked trout were available, the cormorants had eaten some of them, said Don Schreiner, DNR Lake Superior area fisheries supervisor. But the birds also ate burbot, suckers and a whitefish, he said.

The sample was too small to make sweeping conclusions, he said.

No further management has been done at the island since then. About 11,000 cormorants have been killed in the past four years on Leech Lake, where cormorants were perceived to be affecting the game fish population.

MORE EVIDENCE NEEDED

Fisheries officials with the Minnesota DNR concede that Knife Island cormorants are eating some steelhead.

“We say, certainly, we know they’re eating some smolts [juvenile steelhead],” Schreiner said. “They [DNR officials in St. Paul] say, ‘Is it a significant amount?’ And we say we don’t know. That’s where it ends.”

Steelheaders see it differently.

“They’re wiping out our fish,” said Craig Wilson, president of the Lake Superior Steelhead Association.

Steelhead angler and Knife River resident John Whaley saw eight to 10 cormorants feeding in the river well above Lake Superior on Monday morning, he said.

“They’re just devastating that river. It’s pretty obvious what’s going on,” he said.

But Audubon’s Jan Green disagrees.

“The birds mostly feed in the [Duluth] harbor,” she said.

There’s no evidence that cormorants are taking too many steelhead, she said, and no action to control them is warranted.

“It would be a crime against fisheries management to jump to conclusions based on a predetermined idea,” Green said.

Anglers and the general public can be too quick to cite cormorants as the principle problem in a fishery, some officials say.

“Cormorants have been an issue in a number of places around the country,” said Steve Hirsch, director of the DNR’s Ecological Resources division in St. Paul. “There tends to be a guilty-until-proven-innocent attitude because they do eat fish.”

The DNR is not convinced Knife Island cormorants are guilty, he said.

“At least so far, we haven’t seen any evidence that would justify removal of a large segment of the colony,” Hirsch said.

Getting more data about the cormorants’ impact on fish will be difficult.

“If it’s a significant enough problem, I think we should get out there and take a hard look at it,” the DNR’s Schreiner said. “Let’s gather enough information to say, yeah, it’s a problem or it’s not. And how much can we spend doing that?”

DNR budgets are tight, and the French River fisheries office is not fully staffed, Schreiner said.

Schreiner and others say several factors contribute to the low numbers of steelhead in North Shore streams. Those include a growing lake trout population and a scarcity of smelt that lake trout once fed on near shore, Schreiner said.

I do believe that the commorants are part to blame in it. It could also be part of poor management.

cormorants Are A very big issue around the lakes here, they eat one hell of a lot of walleye fry here, and they are very messy birds and will kill an island of trees in just a years time with there waste.