Simcoe County is famous for its many lakes and rivers, but the pristine water hides a deadly element. Now, a team of researchers are trying to do something about it. Aboard the research vessel Neeskay in Parry Sound, they are serious about water. The scientists on board are on a five-year mission to learn as much as they can about mercury in the waters of the Great Lakes. “Even a small amount of mercury in the system can result in toxic levels of mercury in fish,” said Ben Peterson, School of Freshwater Sciences, University of Wisconsin-Milwauke. Scientists say a lot of mercury was dumped into the Great Lakes during the Industrial Revolution, and while much less is entering the water these days, what is already there remains a problem. “You have these beautiful, clear waters. You wouldn’t really expect contaminants to be a problem there,” added Peterson. Mercury lasts virtually forever until bacteria transform it into a form that can be absorbed by plants and animals. Without any way to eliminate the heavy metal, it becomes increasingly concentrated as bigger fish eat smaller fish. Neeskay’s captain, Maxwell Morgan says, “With top predators, you can’t eat them more than once a month or so. That’s a shame because they’re very healthy fish otherwise.” The journey through the mercury study Exactly how mercury moves through the water column and the food web is what the researchers are studying. “Mercury analysis is very difficult, and it’s not a trivial thing to come out here and measure it,” said Peterson. The team uses a pump to collect water from different depths, straining samples of plankton, sediment and water to analyze a host of characteristics. They do this at dozens of locations throughout Georgian Bay to get a complete picture of what is happening in the water. “If we don’t have a good understanding of what’s happening in the water and with the organisms themselves, then we have no hope of predicting whether or not mercury in the fish is going to go up or down,” added Peterson. And while the first step is preventing any more mercury from entering the water, the long-term goal is much more ambitious. “If we can understand how mercury moves through the system, then we can potentially stop it and break that cycle. That would be quite amazing,” Morgan concluded.
