Toxic Algae from Bottom of Lake Erie, Fed by Rivers

November 21, 2014

Researchers are still trying to figure out more about the thick, pea soup-like algae—known more scientifically as microcystin—on Lake Erie. The blooms caused a water crisis in Toledo, Ohio this past summer, causing thousands to go without drinking water. Justin Chaffin is a researcher with Ohio State University’s Stone Lab. His team studied algae in Lake Erie in 2011, one of the worst years on record.

The Allegheny Front's Jennifer Szweda Jordan spoke with Chaffin about his research. Below are the highlights of his comments from their conversation.

Does the algae look like it's from the science fiction film "The Blob?"

When it's not too thick and you look in the water, the lake will kind of look like there's green cornflakes. And then when it gets really dense it kind of just looks just like green paint on the lake.

On the similarities and differences of other algae problems worldwide

China has a lot of algal problems. They also have microcystis problems. Their third largest lake by surface area, Lake Taihu, in 2007, I believe, their water crisis affected 2 million people, and they were without water for one to two weeks. I'll also say in Brazil in 1996, there was 160 people on a dialysis machine that were poisoned and died due to microcystin. The toxic concentrations in that Brazil water was 19.6 micrograms per liter, whereas Toledo [where many were without drinking water in the summer of 2014] we were between 2 and 4 micrograms per liter.

What is cyanobacteria and microcystis?

Algae is really not a true scientific term. It can refer to any organism living in water, and it photosynthesizes. Now the more technical, correct term is cyanobacteria. They're a natural bacteria. The exact species that we're talking about is microcystis.

On his research findings

We set out to answer two questions. The first question was: Where does the microcystis come from? We know there's some microcystis in the Maumee and Sandusky Rivers, but microcystis also overwinters on the lake bottom. The research showed that the microcystis that's in the Maumee River and in the Sandusky River does not make it out to the lake. And then the microcystis from the sediments was very similar to what we see in the water during the bloom. So this suggests that the bloom is coming from the lake bottom, not necessarily coming from the rivers. I want to emphasize that even though the Maumee River's not pitting microcystis into the lake, it's delivering all the nutrients that feed the bloom, feed the microcystis that's in the lake.

The second question we set out to answer in 2011 was: How does microcystis get transported across Lake Erie? We wanted to know, is the microcystis in Maumee Bay and microcystis off Cleveland, are those one in the same bloom, or are they completely separate blooms with different sources? And what we found is that microcystis that first occurred in July in Maumee Bay, which is near Toledo, was the same microcystis that we saw in October off Cleveland. So it suggests that as the summer progressed, water currents were moving microcystis west to east. And how far east it gets is pretty dependent on the amount of nutrients that get into the lake.

What's the next step?

To keep the nutrients onto fields and in the sewer treatment plants. In the Maumee River Watershed, which is the largest watershed in the Great Lakes by area, and it's all about 80 to 85 percent agriculture, between 60 and 90 percent of phosphorus that enters Lake Erie from the Maumee River is from non-point sources—agriculture, lawn care. So it's not coming from a sewer plant or industry. So the next step is to work with farmers and try to get them to adopt best management practices that are aimed at keeping phosphorus and nitrogen on their land, rather than it being washed away.