A killer is stalking the waters of Southcentral Alaska;
lurking in the shadows; ambushing our wild salmon and trout.
Many Southcentral lakes and streams are already empty of everything but the killer -
northern pike.
Soon many of our sport fishing opportunities may be gone.
Northern Pike are a long lived, hardy, voracious species of fish that predates the ice age.
Northern pike can attain lengths of well over 50 inches and weights of up to 40-45 lbs.
Northern pike are a long lived species and can live up to 30 years.
These predators are ambush predators, they’re camouflaged - they hide in the weeds for a while.
Their eyeballs are almost like a dog, kind of facing towards the front.
That’s their mode of operation - they just wait in the weeds and dart out real quick and grab something.
They feed on just about anything that swims and so they would quickly eliminate any native species in the lake,
start eating themselves, and then become stunted to the point where you have a very poor quality fishery.
Northern pike are important subsistence and sport fish in their native range,
but they do not naturally occur in Southcentral Alaska and pose a threat to our native fisheries.
In interior Alaska and western Alaska, wherever there’s shallow slow moving water,
you’re going to find a lot of pike there.
But there’s also a lot of deep, large lake systems and if pike occur there, they’re in the shallow fringes
or in the slow moving waters and there’s a different fish assemblage present in deeper waters.
Essentially other fish can avoid being preyed on by seeking out the deep water refuge.
In Southcentral the places where we have the most problems tend to be areas that are shallow and weedy throughout
and there’s complete overlap of rearing salmonids and the northern pike.
The expansion of northern pike from their native areas is a direct result of illegal introductions during the 1950’s
and their subsequent natural movement following introduction.
Northern pike are established in some of the land locked lakes and pond areas through illegal introductions;
probably anglers that are fishing pike in other areas are bringing pike into those systems and inadvertently
or on purpose releasing pike into those systems.
A lot of people say that northern pike may be introduced to systems by eggs sticking to duck feet
and animals and that type of things, other types of birds, but I don’t really buy into that.
If that were true, northern pike would have been in these systems thousands and thousands of years ago.
About two decades after the initial introduction in the Matanuska-Susitna Valley,
northern pike were discovered on the Kenai Peninsula.
What we found in these lakes like Dirks Lake, Sevena Lake, East and West Mackeys lake -
all these lakes in the Soldotna Creek drainage, is we used to have really good, pretty much trophy, rainbow trout fisheries
in a number of these lakes once we got pike in here it was just within a few years they couldn’t find any rainbow trout at all.
There were large rainbows that would surface and start jumping after flies and what not during the day and
so we would throw down the hammers and grab the fishing rods and go catch a few rainbows
and turn them back and release them.
Well- outrageous (laughs). You couldn’t throw a hook in without having a rainbow on it,
I mean big ones too. This is the last fish, rainbow, I caught in here; went down to catch one for breakfast off the dock.
That’s it - my wife had him mounted for me.
Northern pike not only impact fisheries, they also impact individuals and businesses.
In the Matanuska-Susitna Valley, Alexander Creek is one of the areas hardest hit by the
illegal introduction of invasive northern pike.
Alexander Creek used to be a multimillion dollar sport fish industry supporting 9 lodges,
a good share of 3 or 4 of the major charter operations out of Lake Hood, and now all that’s gone.
The main economy used to be the fishing lodges and when they closed the King salmon season
all of the fishing lodges have closed. So there is essentially no economy left at Alexander Creek.
In the 80’s was the peak of the king fishing for Alexander Creek, business was booming, fishing was excellent
and when the 90’s came… started seeing a big difference. Started noticing - literally in the 90’s
people started catching pike here and there, fishing started to slow down.
Now it’s a…more of a place to go hang out on the weekends more so than a real fishing area, which it used to be.
Like I said there were probably 10 outfitters on the river when it was really good fishing and now there is nobody.
People are trying to sell their places that wanted to run that type of lifestyle -
have either sold their places or just stopped doing business.
There are things that agencies can do to either control or eradicate northern pike populations in Southcentral.
The Fish and Wildlife Service, through its aquatic Invasive Species Program, tries to help in a number of ways
We provide funding to our partners at the Alaska Department of Fish and Game
to implement their invasive pike management plan in Southcentral Alaska.
Well, first and foremost, we’re really trying to get the word out that northern pike are an invasive species in Southcentral and
that introducing them is both illegal and very damaging to our fisheries.
In addition, we’re trying to control populations where we can. The idea is to really drive down the pike population,
try to give the salmon populations a chance to rebound.
And in other cases, we’re actually trying to eradicate entire populations
and we’ve done so successfully in several locations using a chemical called rotenone.
Rotenone has been successfully used around the world with no long-term effect to the environment.
Rotenone is a naturally occurring chemical substance that comes from the roots of tropical plants in the bean family.
It’s been used by fisheries managers since about the 1930’s to remove unwanted and invasive fish.
It is easily absorbed through the thin tissue layer on the gill membranes in fish
and other gilled organisms and that’s why it’s so highly effective with them.
Mammals, birds, humans - we don’t have this rapid absorption route into our blood stream.
Rotenone is used in very, very small concentrations.
Once it’s mixed into a lake it’s at only about 1/20th of one part per million, so that’s a really small amount.
It doesn’t bio-accumulate and it can break down relatively quickly.
The severity of the northern pike problem varies across Southcentral Alaska.
In the Mat-Su, northern pike have been present longer and are more widespread than other areas of Southcentral
where introductions are more recent.
If the question is, “Can we eradicate the pike in the Susitna system up there?” I think the answer would be no.
I think that’s probably too lofty of a goal.
Should we go in and try to control the pike populations to allow continued coexistence
between the salmon and the northern pike? I believe that’s a strategy that can work.
We’ve had adult weirs established in 17 different rearing lakes out of the 24 lakes in the Susitna drainage
and on 11 of those lakes are known to have northern pike in them - 11 out of the 17.
And out of the 11 that have pike in them, we found 5 that have no more adult salmon returning at all
and 4 that have substantially reduced sockeye salmon escapements of less than a 1000 fish.
On the Kenai Peninsula, we believe northern pike can be successfully eradicated
if we prevent further introductions and continue management efforts.
I think on the Kenai Peninsula we’re very fortunate. We’re kind of on a teeter totter right now,
you know when we have 16 or so water bodies that we know that pike occur,
we have an opportunity to assess the situation and to control the pike in areas that we know they occur.
Since Fish and Game has been netting the bigger pike, we now have the ducks and the loons,
but to have trout jumping…
and more of the natural fish in the lake, I think it would…ring it more alive to us.
You can help! If you catch a northern pike in a waterbody where they are not known to exist,
or you observe someone illegally introducing northern pike,
call the Alaska Department of Fish and Game Invasive Species Hotline or go to the web site.