As a result of heavy rainfall this past spring, Lake Erie is now home to a large — and potentially toxic — algal bloom. The abundant rainfall caused an overflow of phosphorus, which is used in agriculture as a fertilizer, from the Maumee River to flow into the lake. The phosphorus will further stimulate the bloom’s growth during the summer.
Lake Erie suffered a similar bloom in 2014, with the main difference being that the algae had become toxic. Though the large bloom is alarming, Don Scavia, University of Michigan aquatic ecologist, explained a more plentiful bloom does not necessarily correlate to the harmfulness of the algae.
“Forecasts are for the size of the bloom — we can’t predict toxicity,” he said. “The cyanobacteria sometimes become toxic, so we are predicting a large bloom, but we don’t know if it’ll be toxic. The size of the forecast is based on the load of phosphorus coming out of the Maumee River. It’s the primary drive, and we have a high load this year because of spring rains. There is a large flux of phosphorus flowing into Lake Erie this spring, and that’ll drive the large bloom this summer.”
Nathan Manning is a member of Scavia’s forecast team who focuses on determining the size of the bloom. He explains that the forecast team measures the bloom each year by using both satellite imagery and a regression model to estimate bloom size and relate it to the amount of phosphorus from the Maumee River.
“My role is to work on improving the accuracy of the annual empirical Bayesian model,” Manning said. “The model currently uses phosphorus loading to predict the bloom, and we are evaluating if including other environmental factors, like water temperature and wind speed can help improve the model’s accuracy.”
LSA junior Brij Banerji, an environmental science major, explained how understanding the causes of the bloom can lead to more positive outlooks in the long run.
“These massive blooms are a result of human lifestyles — fertilizer runoff from farming and wastewater plants to name two,” Banerji said. “It is important to understand that so moving forward we can be conscientious of the ways in which we affect the environment, and in turn, ourselves. With this understanding we can minimize the impact we have on the natural world that will support us.”
The algal bloom will lead to short- and long-term problems both environmentally and economically if counteractive steps are not taken. Banerji explained the implications that the bloom has on Lake Erie’s ecosystem, saying it could affect both animals and humans more than people expect with hazardous outcomes like low-oxygen zones.
“Algal blooms have the potential to devastate ecosystems and create hypoxic zones in the lakes where nothing can survive,” Banerji said. “The repercussions extend past aquatic ecosystems and affect humans. Drinking water can be compromised due to blooms of cyanobacteria, blue-green algae that produce a toxin, that is harmful to fish and humans alike.”
The decrease in travelers visiting Lake Erie as well as lower shoreline property values due to the murky and uninviting appearance of the lake has the potential to harm both the housing and tourism industries as well.
“The charter captains that bring the people out to fish in Lake Erie suffer because people don’t want to go out when the water looks that bad, so their income goes down,” Scavia said. “Other tourists, people that go to the beach, people that go boating, they’ll all be affected short term. In long term, if this isn’t controlled then shoreline properties will decrease in value. If the bloom becomes toxic, like in 2014, then there’s the risk it’ll impact drinking water.”
Even though Scavia and his team believe surrounding communities are prepared to handle problems associated with purifying drinking water through treatments, it will take a financial toll. The last time an algal bloom turned toxic, the city of Toledo, Ohio, had to instate a ban on using water for drinking, cooking or washing.
“Back in 2014, the drinking water supply folks were not prepared for a toxic bloom — which is why they had to shut down the water supply for three days,” Scavia said. “They’re prepared for it now, so it’s unlikely it’s going to cause a problem with drinking water. However, what happens is that it becomes toxic and they have to add additional treatment to the water, which costs a lot of money.”
Scavia also described the different actions, both locally and federally, that can counteract the bloom’s potential for toxicity.
“Both the U.S. and Canada have agreed to reduce the load by 40 percent, and right now Ontario and the States are developing action plans,” he said. “Two things that students can do is continue to hold Michigan’s feet to their fire to take the action to reduce the loads — and as individuals use less water.”
Banerji agreed, saying the blooms should be a student concern as well as a governmental one.
“This issue should be a concern shared by all people, especially in Michigan because of the proximity issue,” Banerji said. “I believe it would be helpful for the UMich community to push awareness on the issue and get information out to the public about the algal blooms in Lake Erie, their effects on the people, and how they’re caused. Once the public knows about the issue, it can rally together to address the issue as a larger force.”