Invaders of the Great Lakes

No science fiction here. With the spring thaw around the corner, some in Toronto are asking for the latest news on invasive species in the Great Lakes and Lake Ontario in particular. It's been about 20 years since the infamous zebra mussels arrived, so what's happening with that anyway?

This was the focus of a recent get together of the Hart House Underwater Club, where Dr. Nicholas Collins (a biologist with U of T Mississauga), reported on the current situation.

The good news is that a more recent arrival, the round goby, eats zebra mussels and is flourishing, likely to drive the zebra population down. The bad news is that both are almost certainly here to stay and the round goby populations are ridiculously dense in many of the great lakes, including Lake Ontario.

Oh and the scary stuff? You may have heard of the Asian Carp that have spread throughout much of the southern US river system. Well, they aren't here yet, knock on wood, but we're relying on the efforts (such as electric barriers) of our southern neighbors to keep them out of Lake Michigan. If they do make it up here they are likely to become the top predator in the lake (and most abundant). Things might look something like this.

The Hart House Underwater Club occasionally puts together events like these but its main focus is organizing various trips and activities around underwater diving. It has a very active summer dive schedule open to experienced divers and also offers basic and advanced diver courses.

Photo: "Lakescape" by blogTO Flickr pooler Dave MacIntyre.