Tales from the Great Lakes: Big waves, clear water, and research on killer bacteria

You can’t swim slowly through waves. Approach the churning water timidly, and it will slam against your face, choke you, and push you backwards towards the land. Neither can you swim over a wave or around a wave. The only path is through.

The trick is to swim hard until you get past the break. Tuck your head under, reach, pull, and plow through the water until you finally reach the place where frothy whitecaps give way to rolling hills. Then, you can relax your stroke a bit. Find the rhythm of the water and let it carry you.

Last weekend, I traveled to Door County, Wisconsin for an ultra-relay triathlon on Washington Island. There, Lake Michigan reminded me of her ever-changing temperament. Sometimes the lake was calm and warm, other times it churned with angry waves and cold, grey water. In the final hours of our race, I found myself challenged to swim five quarter-mile loops through churning water, roiled by an overnight storm, to help bring our team to the finish. The waves bucked and broke in a dozen different directions and I tucked my head and swam.

Swimming in Lake Michigan at the Washington Island Ultra Triathlon.

While riding the ferry from Washington Island back to the mainland, I was reminded of a conversation I had years ago while traveling. I had met two girls – one from the east coast and one from the west coast – neither of whom had ever visited the Great Lakes. “Is this what they are like?” they asked one day, as we sat perched on a rock, overlooking a bay. “No,” I replied. “They are much, much bigger. When you look out across them, you can’t see the other side.” Incredulous, they asked, “Not even if you stood on top of a tall rock while you looked out? What if you used a pair of binoculars?” I went on to explain how the lakes were like the ocean – big enough to have waves and even shipwrecks – and yet different because they are filled with cold, fresh water instead of salt. I told them about the rocky shores of Lake Superior and the towering sand dunes along Lake Michigan.

On the eastern side of Lake Michigan, enormous sand dunes tower above Lake Michigan at Sleeping Bear Dunes National Lakeshore.

The Great Lakes — Superior, Michigan, Huron, Erie and Ontario — cover more than 94,000 square miles and hold nine-tenths of the U.S. supply of fresh surface water. These lakes provide drinking water for more than 48 million people in the U.S. and Canada, generate more than 1.5 million jobs, and are home to 3,500 plant and animal species. Lake Superior, the greatest of the greats, has the largest surface area of any freshwater lake in the world and contains enough water to fill all four of the remaining Great Lakes, plus three additional Eries. Lake Michigan is the second largest by volume and has the largest freshwater sand dunes in the world. An estimated 3000 ships have gone down in Lake Michigan over the years, and many can still be seen almost perfectly preserved in its frigid waters.

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Split Rock Lighthouse is an iconic destination along the North Shore of Lake Superior.

In addition to their size, Lakes Superior and Michigan are known for their ultra-clear water. Most smaller lakes contain more nutrients and have softer, mucky bottoms, which help them to support a higher density of aquatic plants and animals. However, the suspended sediment and algae in these smaller lakes also impacts water clarity. In contrast, I was able to see all the way to the bottom of Lake Michigan with ease, even when I was swimming far from shore in choppy water.

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The deep waters of Lakes Superior and Michigan are known for being clear and cold.

Lake Erie, the smallest of the Great Lakes by volume, is shallower and has been most heavily affected by pollution from surrounding farms and cities. (Lake Erie has an average depth of 62ft, 210ft at its deepest, while Lake Superior averages 500ft deep and is an astounding 1,332 feet at its deepest!) Researchers at Sea Grant and the Great Lakes Environmental Research Laboratory are studying harmful algal blooms in the Great Lakes, and particularly Lake Erie, to help understand how to protect humans and wildlife from these toxin-forming bacteria. Locally, the St. Croix Watershed Research Station (SCWRS) in Marine on St. Croix is conducting similar research on lakes in Minnesota to help understand when, where, and why harmful algal blooms happen. As part of this project, the SCWRS worked with MinuteEarth to produce a short and very fun video that helps to explain how “the bacteria that made life on Earth possible are now killing us.”

According to the Great Lakes Commission, our five mighty lakes support a $5 trillion regional economy in the U.S. and Canada, and generate more than $52 billion annually from recreation alone. People flock to the shores of the Great Lakes for scenic driving, agate hunting, sailing, fishing, dining, camping, wading and relaxing.

Also, there are waves in the lakes. Yes, there are definitely waves.