On the Invasion Front: The Pesky Problem of Invasive Species

Photo by ABEL Lab | McMaster University

Globalization has had many obvious, yet controversial benefits. Check your clothing tags, or where your computer was made. It’s likely that at least one of those things wasn’t made in North America. It’s likely that most of us wouldn’t have these items if it weren’t for the rapid expansion of the global market. However, we now know that the transportation of goods across the globe isn’t exactly a zero-emission process. But did you know that globalization has also led to the introduction of invasive species?

Invasive species, simply put, is an organism that traveled from one area to another, and was able to rapidly expand its population in its new environment. The most important part is that more often than not, these species had a human vector. Someone (or some people) brought the species from point A to point B, allowing the species to proliferate. Often, this species is next to impossible to remove from the population.

Some of the human vectors are accidental. Some aren’t. Often, fish species get moved from lake to lake due to fishing. A fisher may catch something, put it in a bucket of water, and then dump the fish out at another site.

Ballast water, or the water that ships intake and expel when travelling, is often another source of invasive species. Zebra mussels, which are now rather common in the Great Lakes at the Canada-US border, came from ballast water. Round gobies, an invasive fish which I conduct research on, also came from ballast water.

The problem with these species lies within their persistence. These organisms adapt really well to their new environment and can survive a wide range of change. For round gobies, they can survive temperatures from 5 to 30 degrees C, and they can have nests of up to 2,000 eggs large. This means that despite the temperature of the water, they can reproduce very quickly.

The solutions are as complicated as the problems themselves. Each situation is about a different ecosystem, and so, different solutions may need to be applied across a variety of sites. For example, zebra mussels and round gobies are both rather common in the Great Lakes, but within my study site (Hamilton Harbour, in Lake Ontario), there is a high degree of contamination – thus giving a much more complex situation than other sites.

As depressing as this may sound, there are measures you can take in order to reduce the spread of invasive species. If you’re fishing, putting the fish back where you captured it is essential. Also, you can prevent the spread of invasive plants by ensuring that you don’t carry seeds, burrs, or anything of that sort to a new place. Above all, knowing about the invasive species in your area is of the utmost importance, and I encourage you to do some online investigations to figure out how you can help your community in preventing the spread of these pesky intruders.