After decades of foul-smelling and toxin-producing algae blooms, Ford Lake has enjoyed several bloom-less years. In this week’s “Issues of the Environment” David Fair talks to the man who figured out how to prevent the blooms. Listen to the conversation with Dr. John Lehman, professor in the University of Michigan’s Department of Ecology and Evolutionary Biology, about his work to improve water quality on the 975-acre, man-made lake.
Overview
· Ford Lake in Southeast Michigan has suffered from nuisance algal blooms since Henry Ford built the dam on the Huron River that created the impoundment in the 1930s.
· Cyanobacteria (aka blue-green algae), can pose a human health concern. Although most blue-green blooms are not toxic, some blue-green algae produce nerve or liver toxins. Toxicity is hard to predict in part because a single species of algae can have toxic and non-toxic strains. Also, a bloom that tests non-toxic one day can turn toxic the next day.
· Dr. John Lehman, a professor in the University of Michigan’s Department of Ecology and Evolutionary Biology, and his research team discovered that phosphorus that is trapped in the lake sediment is released and stirred up when the lake mixes. When this occurs during a period of low oxygen in the lake, cyanobacteria (aka blue-green algae) are propagated.
· Dr. Lehman discovered in 2006 that by manipulating when and how water is discharged by the dam, the conditions that lead to nuisance algae could be prevented. In 2012, due to an unusually dry summer, the dam could not be used to selectively churn the water, and the algae returned—despite local phosphorus discharge ordinances that led to lower levels in the Huron River.
· Starting in January 2012, a new Michigan Law, Public Act 299 of 2010, took effect. It prohibits the application of fertilizers containing phosphorus to turf grass (with exceptions).
· Blooms of toxic algae occur are most common in late summer or early fall. Dr. Lehman says that, in August of 2017, conditions that could have produced cyanobacteria were possible, but due to pro-active management with the dam and the presence of diatoms, he expects the water to be transparent and free of a significant outbreak for this year.
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— David Fair is the WEMU News Director and host of Morning Edition on WEMU. You can contact David at734.487.3363, on twitter @DavidFairWEMU, or email him at dfair@emich.edu
