BC Rivers Day is just around the corner. As you may or may not know, Lake Windermere is a part of the larger Columbia River. The headwaters are just south of here in Canal Flats, and the emptying point is in Astoria, Oregon. With this in mind, it is extremely important for us to take good care of Lake Windermere. Any impact we have on it at the source will carry down the Columbia River. One of the key areas for a detrimental impact is invasive species. You are probably familiar with Zebra or Quagga mussels, or a variety of invasive plants like Eurasian Milfoil, but did you know some of your household pets can be classified as invasive as well?
A popular household pet or garden pond dweller is the Carassius auratus, also known as the common goldfish. Goldfish make for great pets, they are a good introduction to the responsibility of owning a pet, but they wreak havoc on North American Lakes when introduced. Goldfish are a form of domesticated carp that originated in China, brought to North America in the 1850s.
Similar to other invasive species, goldfish have no natural predators in our lakes, and have been found to only be limited by their environment, allowing them to grow up to 13 inches in size. Goldfish are an omnivorous bottom feeding fish. This is a cause for concern. In addition to out competing native fish species for food, they will also stir up the sediment and increase the turbidity of a lake.
As is the story with many invasive species, once the population has become established eradicating it proves to be a difficult task. The two current methods of removing goldfish are sorting or poisoning. The sorting method requires a team to go in with electro-fishing equipment, send an electric current through the water that stuns all of the fish, and then selectively removing the goldfish. The alternative, poisoning, add the natural pesticide, Rotenone, to the lake which kills all fish species present. Neither method is ideal, one is very financially and time consumptive, while the other damages the entire ecosystem.
There is however a third option, and that is prevention. If we work together to prevent the introduction of Goldfish and other invasive species to Lake Windermere, and all other water bodies, we can prevent these damaging impacts. Prevention comes in many forms, including cleaning, draining, and drying all water based equipment (including boats, and waders), not introducing potentially invasive species to foreign habitats, and by staying informed on threats to your local water bodies!
Feel free to contribute to this conversation on Facebook, Instagram, or Twitter @LakeAmbassadors.
Shannon McGinty, Program Coordinator for the Lake Windermere Ambassadors. Email her at firstname.lastname@example.org or call the office at (250) 341-6898.