What it means to have invasive species in your watershed.

Imperial Star Destroyer by Adam Kop.

Picture this, if you will: a tiny pod slips unnoticed into the cargo bay of a ship bound for the Empire’s outer reaches. It travels through the dark unknown, neither seen nor heard by passengers, crewmen, or inspectors. The ship docks, and the hidden passenger disembarks as stealthily as it boarded. The alien port is safe, and welcoming as well–nobody will notice the stowaway here until it is far too late.

This might be a good way to set the scene for an epic of galactic proportions, but it also describes something that’s been happening here on earth for centuries. When seeds, eggs, or breeding pairs of a species from one biome spread to another biome that’s just not ready to handle them, the new invasive species can rapidly cause an environmental disaster.

Ready to feel like we’re talking about aliens again? Take a look at this guy:

Photo via Great Lakes Mapping.

He won’t have any of your loved ones encased in carbonite, but a single sea lamprey will eat over 40 pounds of salmon during its lifetime. This species invaded the Great Lakes in the early 20th century when a canal was deepened; by the middle of the century, it had killed so many salmon that the local fishing industry collapsed. Removing sea lampreys from the Great Lakes is a massive project that costs millions of dollars each year.

The story of the sea lamprey has been repeated in watersheds across the world, and these invaders aren’t just monsters of the week. The Tamarisk has altered the environment of the Colorado River Corridor so extensively that biologists predict the damage to be irreversible. In Minnesota, the round goby competes with native fish for food, wreaking havoc on young smallmouth bass in particular. Meanwhile, the zebra mussel is invading watersheds and disrupting their food systems throughout the Midwest.

Photo by scotto (deviantART).

Stopping the spread of invasive species and fighting infestations of them when they occur is an important part of environmental cleanup. Native species are frequently ill-adapted to compete with their alien technology, so it is difficult to stop the spread of an invasive species once it is established. There are a number of ways to keep invasive species out of your watershed. You can raise awareness of their presence and impact in your community, you can organize and crowdfund efforts to uproot an infestation, and you can keep an eye on your watershed for signs of invasive species. These actions can do a lot to keep your community’s environment safe from species that boldly go to vulnerable biomes.