Forget flying saucers and crop circles. We’ve got proof that alien invasions are taking place this very moment – and they’re closer to home than you might think! Alien species, are non-native species that have wound up in our own backyards and been able to thrive. For the most part, alien species aren’t threatening to native species, and in some cases they can even be beneficial. It’s when they turn invasive that you need to worry.
You can’t help but notice the invasive species in your own backyard – like the tent caterpillars noshing on your apple trees – but what about the invasive species making themselves at home in our waterways? Every 10 years, 15 alien species set up their “Home, Sweet, Home” signs in our salt and fresh waters. Aggressive species can spread quickly, changing the very make up of their new habitat and driving out native species. In the last two centuries, 163 non-native aquatic species were introduced to the Great Lakes alone.
So, how do they get here? Well it’s certainly not as simple as hollering, “Beam me up, Scotty!” Aquatic invasive species have seven major pathways for getting from one place to another:
Shipping is the primary avenue through which alien species are introduced into our waters. Approximately 75 per cent of alien species in the Great Lakes region were introduced via ballast water in ships (water that is taken on in foreign ports and released in Canadian waters).
While you’re off painting the town, your cruise ship is sitting pretty and attracting invasive species. Ships that stay in harbours for long periods of time are vulnerable to aquatic species that grow and collect on their undersides. When the boat gets moving again, those species move with it and find new homes at the next port – sometimes becoming invasive.
Hook, Line and Sink ’er
A fishing weekend with the guys may seem innocent enough, but if you’re using live bait to catch your fish, you might be introducing new species into our rivers and lakes.
Here Fishy, Fishy!
Primping your pond with pretty plants is a must, but be wary of the plants you introduce to your water garden. You might be introducing an invasive species that will quickly turn your haven into a headache.
Plenty of fish species are imported live for culinary purposes, but if they are released into the wild they can become invasive.
The Great Escape
You heard it from Sesame Street first: One of these things is not like the other, One of these things just doesn’t belong. Releasing fish species into water bodies that aren’t their native homes can really damage an ecosystem, as they might settle in and actually adapt the makeup of the ecosystem as a whole.
Building canals and water diversions is another way in which alien species are introduced, as it allows new species to move from one body of water to another.