But the consequences of opening a nautical freeway into the Great Lakes for globe-roaming freighters proved disastrous — at least 56 non-native organisms have since been discovered in the lakes, and the majority arrived as stowaways in freighter ballast tanks.Insofar as the volume of water-borne commerce is so slight, there's a very simple way to protect the upper Great Lakes from any more invasive species.
Building a barrier to protect the upper Great Lakes from Seaway invaders would actually be simpler than restoring the natural watershed divide at Chicago. In fact, such a barrier already exists.Meanwhile, the international ships have brought in a predator for the mussels: the round goby. The Erie Island water snakes have an appetite for gobies. Whether they can be introduced elsewhere in the Lakes remains to be seen.
It's called Niagara Falls.
Perhaps when the infrastructure known as the St. Lawrence Seaway crumbles, the best policy response is ... let it.