One of our favorite perks of life in the Milwaukee area is easy access to the shores of Lake Michigan. We moved here in 2006 from land-locked Champaign-Urbana and soon formed a habit of visiting the lake, sometimes daily, to dip our feet in the water at Bradford Beach or walk along the shore at Klode Park in Whitefish Bay in search of sea glass and cool rocks.
Despite our love of the gorgeous expanse of Lake Michigan shoreline, we rarely wade further than our knees into the great lake's waters. Very few locals swim in the ice cold lake – partly because, well, it's freezing, and partly because of the unimaginable things one might find in the water. Like blobs of algae, garbage, maybe human and pet waste (really). Never mind the unseen poisons in the water thanks to industrial dumping by BP in Indiana and others.
At a recent trip to a Milwaukee beach, we confronted all of the above pollutants – including pet waste (someone's unleashed dog trotted by and peed in the sand right in front of us). But the most memorable pollutants were dozens of shiny little fish baking on the shoreline.
When we first arrived, we found a decent spot in the sand and watched our three girls run to the icy water to wade. Almost immediately, one of them was able to catch a fish with her bare hands. She brought her prize to us and I suggested that she temporarily place the small silver fish in a plastic cup lying in the sand so she could study it (the cup was one of many pieces of trash laying on the beach). She placed the fish in the cup and watched it float, belly-up. "It looks dead," I said, wondering if the process of being captured was too much for the creature to handle. She dumped the fish into the water. Then, a few moments later, she caught another fish. And then another. "Why are these fish so easy to catch, and why do they all look half-dead?" my husband and I wondered. We speculated that the "living" fish our girls caught were sick and about to join their dead brethren on the shore.
Of course, given the local lore about Lake Michigan pollution, our first thought was that the fish were dying because of something in the water. We grew increasingly squeamish watching our girls play in what we assumed to be a polluted lake. The longer we sat, the more the odor of the dead fish, along with sea gull feces, overwhelmed us. To make matters worse, biting flies surrounded us. Then that dog trotted along and peed. The dog pee was the last straw. We packed up and moved our party to Alterra on the Lake.
We were perplexed for days about the dead fish, wondering what caused this phenomenon. Any time creatures die en masse, humans speculate. Were the fish deaths caused by industrial waste dumped into the water? By global climate change? Is it an omen? My overactive imagination gravitated toward the worst.
Then came an answer to why this seemingly mysterious phenomenon is occurring. We learned from a WISN report that the fish are called alewives (Alosa pseudoharengus), a smallish, invasive herring. According to the report, alewife deaths are common this time of year. The die-offs are probably caused by temperature fluctuations in the water. Still curious, I did some googling and found a few articles on the subject of the alewife die-off, including a recent piece by the Associated Press and WISN's web coverage. Both reports claim that the deaths are a normal phenomenon that occurs with this invasive species every so often.
But isn't Lake Michigan so polluted as to be deadly to some of its fish? This is a popular assumption on the part of many beach-goers, myself included. I asked the DNR's Southern Lake Michigan Fisheries Supervisor Bradley Eggold about pollution and whether it harmed the alewives. His answer? It is "very, very remote" that water pollution is a factor in the alewife deaths. "Alewives are very sensitive to changes in water temperature, especially at this time of year," he said. "These water temperature changes occur every year. Other major reasons why these alewives die-off every year include 1) they are native to the Atlantic Ocean and therefore live in saltwater. They can have trouble regulating their salt/water in their bodies, 2) spawning stress and 3) low food availability."
Harvey Bootsma, Associate Professor of the School of Freshwater Sciences at the University of Wisconsin-Milwaukee, agrees that pollution is "highly unlikely" to be a cause in alewife deaths. "This is a common occurrence on the great lakes, and it's almost always due to changing physical conditions in the early summer."
Temperature fluctuations, says Bootsma, are normal, and not necessarily caused by global climate change. "Alwives have been doing this ever since they entered the great lakes."
Regardless of what is causing the alewives to die, the fact remains that our beaches can sometimes feel as dirty as the nearby public restrooms (if you've been at the public restrooms by the lake shore on a busy summer day, you know what I mean). That goes for both the shoreline and the water itself. Although pollution may not be the cause of alewife deaths, it certainly contributed to an unpleasant beach experience. The amount of litter on the beach alone bordered on disgusting. All that filth on the shore made me wonder how clean the water is.
I asked Dr. Bootsma whether pollution in Lake Michigan is a problem. "The water itself is quite clean," Bootsma said. "There are some areas where there are localized problems, called 'areas of concern'. You can read more about them at http://www.great-lakes.net/envt/pollution/aoc.html." An Area of Concern (AOC), according to Environment Canada, "is a location that has experienced environmental degradation." This map indicates that in MKE the Milwaukee Estuary is an AOC, due to "significant contributions of toxic substances to the Milwaukee Estuary AOC from upstream sources" (e.g. the Menomonee River).
The bottom line is that it's fairly safe to swim in Lake Michigan water if you're not in an AOC – that is, if you can stand the cold. And it's probably not a big deal for kids to be catching half dead alewives in the water, as long as they're not handling the ones that have been dead for a while. But many of our beaches are filthy -- there's no doubt about it. The sand is littered with waste, as well as bacteria from the feces of abundant sea gulls who gorge themselves on our garbage.
What might we do about our filthy beaches and our AOCs? While some of these issues are perhaps too deeply rooted for us to change on an individual level, Bootsma suggests a few things average citizens might do to help clean up Lake Michigan: "1. Mercury comes from coal burning power plants and other industrial (and natural) sources…reducing energy consumption helps, and people should also be careful how they dispose of hazardous waste; 2. Some near-shore problems are caused by excessive phosphorus loading to the lake. Some of this comes from urban runoff, so if people apply fertilizer (or any herbicides or pesticides) to their lawns, they should do it sparingly. A video that highlights some of the work we have done in this area can be viewed at http://www.mefeedia.com/watch/29499314; 3. Water quality is sometimes affected by overflows of storm sewers or sanitary sewers, so water conservation methods (using rain barrels; disconnecting sump pump drains from the ditch) can be helpful; 4. Be careful about what we flush down the drain. Unused pharmaceuticals, chemicals, and paint should be disposed of properly; 5. One of our websites has more useful information on beach water quality: http://www.glwi.uwm.edu/documents/non-pointdweb.pdf."
Seems to me that the simplest thing any beach-goer can do is to pick up trash off the shore. That and avoid feeding the gulls.
Beyond these measures, the DNR's Bradley Eggolt says it can be helpful to get involved through education and activism. Educate yourself by seeking out a range of sources on these issues. Then look for opportunities to become active. "The best advice I can give is to get involved," Eggolt explained in a recent e-mail. "Whether it is because you are a beach goer and want clean beaches or you are a fisherman and you want to catch salmon and trout, read and learn about the issues and attend meetings where these things get discussed… It could be a local fishing club, environmental group, nature center, etc. With that said, you would not have to join a group or go to those meetings, just read and get involved in whatever way that person feels comfortable doing."
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