Unintended consequences endanger peninsula salmon

Jun 20, 2018

On the Kenai Peninsula, salmon are king. Whether they’re king salmon or one of the other species of salmonid that populate our fresh waters. And that’s why when there’s a biologic danger to their existence, people go into high gear to try and protect them.

Take invasive species for example. About 20 years ago, northern pike were illegally introduced into Kenai Peninsula lakes by persons unknown. And they thrived, just like they do elsewhere in Alaska where they naturally occur. But here on the Kenai, the pike’s success came at a cost - the lives of baby salmon.

John Morton, the supervisory biologist at the Kenai National Wildlife Refuge, said the invasive northern pike and two plant species, elodea and reed canary grass, have come to plague the Central Peninsula’s salmon rearing grounds.

“They were all introduced initially because they were being used for a useful purpose. Whether it was an aquarium plant, or somebody wanted to fish pike, or in the case of reed canary grass as a forage or as an erosion control plant, right? They all have positive properties. The problem is they have these unintended consequences that we think are more injurious than any of the benefits could ever be.”

Morton was speaking about invasive species with two others, Jennifer Hester of the Kenai Watershed Forum’s Adopt a Stream program, and Rob Massengill, a fisheries biologist with the Alaska Department of Fish and Game, both of whom are working on invasive species eradication as well.

Massengill said invasive species often share traits that make them especially suited for their role as the new apex predators in town.

“They’re often opportunistic, they often have really high reproductive potentials, they generalists they often can live in a lot of different types of habitats. So they’re very successful, and that what makes them a threat, either through predation, or through out-competing or smothering out. They’re highly successful species and they’re outside the niche they developed in and can really run amok.”

Massengill said there actually are some people who would still like to see the hard-fighting pike in some lakes, but nevertheless, he appreciates when other residents tip him off of such illegal practices.

“The ones that pick up the phone that call when they’re worried about a new critter they’ve seen or plant they’ve seen. And I just encourage people to be the eyes and ears for us. I think people’s mindsets have changed. I’ve seen it just in the last 10- 15-years that people do see what’s at risk, what the potential loss could be if we don’t do our best to contain these problems.”

Morton said that when he speaks with property owners about the need to do an invasive species eradication in a pond or lake on their land, he has a way of making them see the big picture.

“The reality is, what we’re talking about here is 4,000 lakes on the Kenai Peninsula. It’s not about a single lake. At the end of the day, it’s about what happens to the rest of the peninsula. And if the stuff gets out of control and goes in a different direction that we can’t stop it, then we have put 4,000 lakes at risk.”

The prerecorded conversation with John Morton, Rob Massengill and Jennifer Hester about efforts to identify and eradicate invasive species on the Kenai Peninsula will be featured on a future Kenai Conversation.