Invading the Waterways
FISH TANKS TO FISHERIES: HOW AN INVASIVE SPECIES COULD CHANGE THE CULTURAL LANDSCAPE IN ALASKA.
Up to my chest in frigid bog water, I cling tightly to my waders, hoping not to flood them, as I trudge through thick clay that covers the bottom of the ponds. “Where is the elodea?” I ask one of the members of the Alaskan Forest Service as I look down into the murky water. “Everywhere,” she says.
Elodea is a seemingly unassuming plant. It is small and narrow with flat, leafy segments that snake down to the roots. The aquatic plant floats peacefully in ponds, lakes, and bogs but the Forest Service is in the process of killing the plants, which have the potential to wreak havoc on Alaska’s thriving salmon fishing industry.
Elodea is not a native plant to Alaska and was first discovered in 1882 at Eyak Lake, Cordova. Since then, it has been documented in several other locations including Fairbanks, Anchorage, and even farther away in Germany which shares a similar climate. The theory most scientists subscribe to is that elodea came to Alaska in an aquarium. A popular plant to stock fish tanks with, elodea could have easily been dumped into the water system. It is an incredibly durable plant and is able to survive even through ice. As long as the plant has a viable fragment and doesn’t completely dry up, it can survive up to 24 hours outside of the water and begin to grow a new colony. Because it is such a tough plant, it can be distributed on the soles of shoes, on the bottoms of float planes, and on fishing equipment. In Alaska, elodea is not as harmless as it may appear.
Elodea has become an invasive monoculture type species in the region and has the ability to change the complexity of aquatic ecosystems, which are important to the economy and culture in Alaska. It can overcrowd or outcompete native vegetation which can change the distribution and richness of the native plant species. These minute changes could have cascading effects in the food web, water quality, and fisheries. On the flip side, the herbicide used to kill elodea – fluridone – has been called into question. 2016 will be the first year the treatment has been implemented in Cordova, and if the control experiments go well, the Forest Service is looking to treat 75 acres of wetlands.
Fluridone is not known to be harmful to fish directly, but experts worry that changes in the aquatic plant density may change oxygen levels and create an anoxic environment where fish cannot survive. A few species of native plants including milfoils, coontail, duckweeds, and lilies are expected to die after application, but the other side effects won’t be fully understood for two years after careful observation.
My experience with the Forest Service came from a trip to Cordova with the Science and Memory Team where I had the privilege to learn about complex environmental issues, such as the elodea problem. Alaska is one of the last few places left in the United States that is still predominantly wild. The skyline alone will take your breath away, and the sense of community that surrounds the fishing industry is an undeniably essential part of culture there. The Alaskan people genuinely care about the diverse environmental systems down to the smallest leafy, aquatic plants, so much that the Forest Service cared enough about it to drag me along through frigid bog water so I could tell the story of this tiny plant with such large implications.