Problematic pike pose predicament

Posted: Friday, October 17, 2003

Alaska Department of Fish and Game biologist Tim McKinley has declared war on the Kenai Peninsula's northern pike.

Using 120-foot gillnets, McKinley has removed an estimated 1,400 pike from East and West Mackey Lakes just north of Soldotna. The idea is to try to eliminate the non-native pike, which over the past 30 years have eliminated virtually every other living thing in the lakes.

However, McKinley doesn't harbor any illusions about the pesky fish, which have already managed to colonize at least 10 lakes and likely more on the Kenai Peninsula.

"I doubt we'll ever get them all," McKinley said Wednesday after picking his nets on West Mackey Lake. "If we could get them mostly or completely out of this drainage, that would be fantastic."

McKinley said pike are believed to have been introduced to the Mackey Lakes area in the 1960s. They were first documented in Derks Lake, a small, shallow lake just to the east of the Mackeys. It's believed the pike then used seasonal water channels to quickly spread to the other lakes in the area, including the Mackeys, Sevena, Union, Tree and Denise lakes.

It's believed they were introduced by an area resident who may have brought the fish from the Interior, where they're a native species. Introducing non-native species, however, is extremely dangerous and can have disastrous consequences.

"It's a huge national and international problem we have with invasive species," McKinley said.

It is illegal to transport live fish from Alaska waters without a permit, and doing so can get you in hot water. The penalty for such action is up to one year and jail and a $5,000 fine.

"It's not a speeding ticket," McKinley said.

Since being introduced to the area, the pike are just about the only fish in a group of seven lakes that once supported healthy native populations of trout and salmon.

The lake system also is connected to Soldotna Creek, which empties into the Kenai River. That means the pike have a direct route into one of the state's most important salmon streams. McKinley's fear is that the pike could spread into the Kenai, a potential disaster for that system's native salmon populations.

"We don't want that to happen," he said.

On Wednesday, McKinley set out to check his Mackey nets. Starting on East Mackey, he and fellow ADFG biologist Larry Marsh pulled the 12 nets from the water. Most were set along the shoreline in weedy areas, perfect territory for the predatory pike.

If McKinley was being paid by the pound, Wednesday's fishing trip would have been a bust. After pulling all of the East Mackey nets, just 12 of the slimy fish lay in the bottom of the boat. A poor catch, but one that's encouraging to McKinley.

"This is one of the lowest ever," he said of Wednesday's effort. "But that's really a good thing."

Earlier in the year, McKinley said it was not uncommon for him to pull more than 100 fish from one of the two lakes. After a summer's worth of netting, he said he's definitely seen a decrease in the number of pike in his nets. However, trying to estimate just how much of a dent he's made isn't an exact science.

"We've probably taken more than 10 percent," he said. "But we probably haven't taken more than 70 percent out. I know that's not much of an estimate, but we just don't know."

What he does know is that there are fewer pike in the lakes, and that the fish that do remain are becoming smaller and smaller.

"Even the folks that live on the lakes have been telling us, yeah, they're seeing more little ones," he said.

McKinley said the pike in the lakes were never really big to begin with. That's because the fish which can grow to weigh as much as 30 pounds or more have very little to eat in the lakes. They long ago devoured all the native fish in the lakes, and now are reduced to surviving on leeches and insect larvae.

McKinley did a brief autopsy on one of the fish pulled from West Mackey lake. After cutting open the 20-inch fish's stomach, he pointed to a small glob of black, slimy dragonfly nymphs.

"That's the biggest fish for the day, too, and that's what he's eating," McKinley said.

However, just because there's slim pickings in the lakes, doesn't mean the fish won't look elsewhere for food. McKinley said he remembers cutting open one large pike to find a partially digested duckling.

"That was something," he said.

The fact that pike will eat just about anything they can get their mouths around is what worries McKinley and other area biologists. If the fish are able to move into area river systems, they could easily have an impact on salmon runs. McKinley said juvenile coho salmon, which spend much of their time in the same slow, shallow habitat as pike, are the most vulnerable. Although pike likely would find the fast, silty Kenai River unsuitable habitat, he said the fish would have no problem using the river as a way to get into more lakes.

"They move through the Yukon River, and that's a lot bigger than the Kenai," he said.

In addition to netting the Mackey Lakes, McKinley also has been setting nets on Stormy Lake in North Kenai. Although there are fewer pike in that lake, it's a concern because a popular salmon stream is nearby.

"The Swanson River is only a quarter mile from Stormy Lake," he said.

Pike have yet to be documented in the Swanson River, and McKinley said he'd like to keep it that way. In addition to setting hoop nets in the lake which are used because they don't harm the lake's native fish McKinley also has installed a fish barrier at the outlet of the lake. So far, he said the barrier appears to be keeping the Swanson pike-free.

"We don't think they're there. There's enough fishermen in there where if they were there at all we'd know about it," he said.

McKinley said he'll continue the netting project at the Mackey Lakes through the winter, although not at Stormy Lake. As long as he's got funding to continue, he said he'll keep fighting the pike. However, with state money tight, he's got to rely on grants and volunteers to keep the project afloat.

For the current netting project, McKinley said the department got a $25,000 grant from Fish America. A previous project to assess the population in the lakes was funded by the U.S. Fish and Wildlife Service's Coastal Grant program. As long as he's got nets and money to continue killing pike, McKinley said he's going to make the effort to eradicate as many of the peninsula's pike as possible.

"If we can get them out of here, if we still have time and funds, we would pursue eradicating them in some of the landlocked lakes as well," he said.

He said the department has considered using chemical agents to help eliminate the fish, but for now he'll stick with the netting. Eventually, though, McKinley said he'd like to see the program end permanently.

"It's not out of the question to try and get rid of all of them down here," he said. "It won't be easy."

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