How toxic algae in Lake Erie affects aquatic life and the people relying on it

Looking out onto Lake Erie, it is hard to miss the algae out on the water. With your toes in the water, the moment you take them out, a green goo gets stuck in between your toes. Sides of boats become greener day after day as they are coated in the algae.

Joseph Ortiz is a professor and assistant chair in the department of geology at Kent State University. Using methods that he used in the past to study climate, Ortiz transformed these methods to create a way to study harmful algae blooms. Earlier this week, Ortiz discussed the presence of algae in Lake Erie, how it affects the environment around the lake and what we can do about it.

Q: How many different types of algae are in Lake Erie?

There’s probably hundreds of types of algae that are in Lake Erie, and so I should be clear on that that we can’t identify, for the most part, algae down to the individual species level. What we’re able to do is to see different divisions of algae, a division of algae is equivalent to a phylum.

We can see broad groups and with the tool that we’re using, we can differentiate the green algae and diatoms as one group from cyanobacteria and cryptophytes, which are the three dominant groups of algae that we pick out. As side predictions with that method, we also are able to look at different types of sediment and the degradation products of the different pigments in the algae. That’s the trick, the way that we identify the algae is not based on their genetics or something, it’s based on what color they are. So different algae have different types of pigments. By looking at lots of different channels or bands across the visible, we can figure out the different types of pigments and from that make inferences about the type of algae that are probably associated with it.

Q: Is there algae throughout the entire lake?

There are some algae found throughout the lake. But the amount of algae that that forms depends on the amount of nutrients that are available. They need nutrients in particular proportions. Just like when you feed your lawn or the plants in your garden you give it a fertilizer that has a particular ratio of nutrients. Different types of algae need different amounts of nutrients. The most nutrient-rich water in Lake Erie is coming in from the Maumee river or the Sandusky river — any of the rivers that feed in through the agricultural areas. So, what happens is rain falls on the farm, some of that soil and nutrients get washed into the streams. The streams then flow into Lake Erie, and that nutrient now is fertilizing Lake Erie instead of fertilizer in the fields where we want it.

Q: What does it mean for aquatic life?

These blooms can be very massive, so these thick mats of microcystis that form in the western basin as they float up to the surface can be so thick that they can be 11 to 16 centimeters thick. When we were doing work in 2015 on the western basin, we were pulling an instrument along constant line at a constant rate. And when we sailed into the thickest part of the of the bloom it actually caused the boat to slow down by a quarter of a knot. And that was only a five or six-centimeter-thick layer at the time. So, that can have impacts on organisms that are living there and how it competes and blocks out the sunlight for many different types of algae that are in the water.

Q: What are dead zones?

When the dead algae sinks to the bottom of the lake. The bacteria that they chew it that’s their food. And in the process of doing that, they consume oxygen, and give off CO2. And so, the consumption of the oxygen creates these so-called dead zones.

Q: What does these toxic algae mean for people who rely on Lake Erie?

It’s a challenge because there’s a potential threat to your water supply. And there’s the possibility that the sports fisheries in the area, won’t be active because the fish are dead. There’s a possibility that the fish might concentrate some of the toxins and that has negative impacts on people’s health, negative impacts on tourism dollars and makes it a less pleasant place to live. Standing on the shore of Lake Erie you’d like to be able to go in and swim rather than be concerned about whether it’s a toxic bloom that you’re going to come to contact with.

Q: What is the amount of nutrients needed?

The nutrient ratio of nitrogen to phosphorus in the western basin at the beginning of the bloom can be as high as 1200 to one. So, 1200 nitrogen atoms for each phosphorus atom and that’s really high. Typical surface water is at 10 of nitrogen, relative to the phosphorus. And in fact, the critical number is something like 16 to one. So, once the bloom gets down or once the water column gets down to less than 16 to one nitrogen to phosphorus, then the bloom can’t grow anymore because it doesn’t have enough nitrogen. When we started out at 1200 to one right and those blooms by the end of the season, we’ll drop it down to 16 to one or less. So, [they] use up all of the available nutrients that are present in the water column.

Q: What does this mean for the future of Lake Erie?

Those are all the challenges, but the good news is that there are lots of groups that are working on trying to find solutions to this. There’s a group in Cleveland called the Cleveland Water Alliance that works as a consortium between companies, academia and government to try and work on solutions. Kent State is a partner of that partnership.

They’ve worked on a number of different technologies to remove the nutrients from the water column to try and minimize the blooms. They work on monitoring and putting in instruments to tell people where the bloom is so that we can figure out how to avoid it or contain it or address the problems associated with it.

The legislature has taken some action to try and address some of the root cause of the problem. Meaning reductions in nutrient levels and so, they banned practices like placing fertilizer or manure on farms before the spring fall.  

Q: What can we personally do to fix this issue?

One of the things you can do is to educate yourself on what the issue is, the second is to vote. Probably the most important thing you can do is to vote for state representatives and senators and a governor who will support addressing these kinds of problems. There are folks in the legislature that trying to work on that now. The governor has put together the Ohio h2o program to try and fund methods to reduce nutrients and so on. Realize that the choices that you make when you fertilize your lawn are going to have an impact on potentially nutrients that get into the stream and so think about how to do that responsibly.