Kodiak’s own unique invasive pest: crayfish

In the 1940s, Kodiak braced for invasion. Tens of thousands of soldiers and sailors laid infrastructure and built fighting positions, entrenching themselves in preparation for an offensive by the Japanese Imperial Navy that never came.

Some 70 years later, Kodiak is a thriving community that is presently under an entirely different type of invasion. The invading force lives under rocks, attacks under cover of darkness, and tastes delicious. It is the Signal Crayfish, or crawdad as some know it.

The Signal Crayfish is an omnivorous small crustacean, looking a bit like a lobster but smaller than the palm of one’s hand. They have made their beachhead in the Buskin Lake of Kodiak, where they hide in mud and look for things to eat.

Sun’aq Tribe Biologist Matt Van Daele is among the vanguard of the resistance to this invasion. He says that its point of ingress into the island’s freshwaters is not currently known.

“There are a lot of ideas running around. There used to be a pet store in town that sold signal crayfish. And signal crayfish are also really good bait to use in fishing. Maybe somebody had, you know, a crayfish boil and a kid wanted to release some of the crayfish and not eat them. So no one really knows for sure,” Van Daele said.

The Signal Crayfish is unique to Kodiak- you can’t find it anywhere else in Alaska. That’s a good thing, considering that they present an extreme danger to salmon.

“Another behavioral trait of crayfish is that they like to burrow- they’re called ecosystem engineers because they burrow so much and they dig so much. And especially the younger crayfish, the juveniles, the ones that aren’t mature, exhibit a lot more of this burrowing behavior because they’re attempting to escape from other predators- larger crayfish. And so the potential is there for these juvenile crayfish to burrow into a salmon red nest where the salmon lays its eggs, and find this incredible bounty of salmon eggs and gorge itself on salmon eggs. So not only start having negative impacts to the habitat, but also negative impacts to the salmon,” Van Daele said.

This begs the obvious question: are the crayfish going to venture out and infest other waterways? Would they threaten other salmon populations? Unfortunately, according to Van Daele, there is simply no way to know yet. The strategy for now has been to monitor the population, and track its size and behavior. Well, there is another strategy…

“Go crayfishing. Take your family crayfishing, and you know, it’s a lot of fun going after these mudbugs. And they are delicious,” Van Daele said.

There aren’t many species in Alaska that you are encouraged to hunt with reckless abandon. Crayfish are one of them. So long as you’re obeying applicable laws where putting down crayfish pots are concerned, you are encouraged to take as many as you can eat and then some. Just be sure not to let any get back into the water- no matter their size or age.