By LARRY BALLWAHN | Wilton
Soon the most-coveted liquid will not be petroleum; it will be freshwater. The world’s largest freshwater system is the Great Lakes. Over the years, the Great Lakes have served as both a sewer system and a source of freshwater for several cities on its shores. Industrial waste was also discharged there. Only recently have people realized that it was a bad idea. To exacerbate the situation, laws used to govern lake functions must be agreed upon by two countries to be effective. But that is not even the biggest problem.
Though sewage and industrial waste have long been a problem, current awareness and modern treatment methods have curbed what is largely a local problem. In 1959, the St. Lawrence Seaway was completed. This opened the lakes to world-wide shipping; ocean-going ships could now ply the Great Lakes. The freighters used seawater ballast to maintain their stability. When this was replaced by freight, the water was discharged into the lake. Before long, it became apparent that the water was not the only thing discharged. Organisms from around the world had no natural predators in the lakes, thus they became invasive species. The key harmful characteristic of most invasive species is that they drive out the native ones.
Though not a result of ballast water, the first large-scale intrusion were the alewives. By using the Welland Canal to bypass Niagara Falls, they soon propagated the lakes and destroyed the plankton, which was a basic part of the food chain. For a time, the alewives devastated the lakes. But one enterprising fish specialist believed that Coho salmon was a predator that could control the infestation. Not only was he correct, that experiment soon made the Great Lakes a noteworthy fishing destination.
Here’s where the ballast water comes in. When the alewives and trout began to decline, it was discovered that the zebra and quagga mussels were now widespread in the lakes. Making their way from the Caspian Sea, they had the ability to multiply in the millions and stick to any hard surface. In addition to smothering food sources, they clogged intake pipes used in water purification, power generation and anything else that used lake water. And Gobies that feast on the mussels soon proliferated also.
But the St. Lawrence Seaway is not the only entry point for lake problems. To solve a sewage/drinking water problem, Chicago developed a canal system that made a through process between the Mississippi watershed and the Great Lakes watershed. Brought to a Southern fish farm, the Asian and Bighead Carp soon escaped into the wild because of flooding. It proliferated in the South and began to move up the Mississippi. For whatever reason, Asian Carp, in the presence of a boat motor, jump high in the air. Entertaining at first, it soon became apparent that it was extremely dangerous. Bigheads were dangerous for quite another reason. They were big and voracious eaters. Carp are bottom feeders; left to multiply, they wipe out the habitat for all other fish. An effort is being made to block the Chicago canal entry. If the carp reach the Great Lakes, there will be no stopping them. A carp infestation would effectively put an end to efforts to restore the lakes.
If this seems like enough problems for the lakes, there is also the nonpoint farm runoff, fluctuating water levels and widespread toxic algae. And did I mention that since the lakes hold 20 percent of all freshwater there are ongoing efforts to gain access by growing cities out of the Great Lakes watershed? Even so, the author titles the last chapter, “A Great Lakes Revival.” Really?