What’s that green stuff on the water? A Blue-Green Algae debrief with Ph.D. Candidate Nathan Wilson
Posted on: November 8, 2020

Would you mind giving us an introduction?

Nathan Wilson out in the field.

My name is Nathan Wilson and I am PhD candidate in environmental biotechnology at Lakehead University. The research I am doing is looking at cyanobacteria in the inland lakes around Thunder Bay that people use for cottaging and fishing as well as a little bit that’s on Lake Superior when it comes time for that. I am headed into my fourth year.

Can you give us an overview of what blue green algae is?

Blue green algae or also commonly known as cyanobacteria is a primary producer in aquatic ecosystems. It is a phytoplankton and there are a ton of different kinds of phytoplankton. They live in the water and they are the first kind of organisms that use up the nutrients and basic elements in the water to provide for the rest of the foodweb. They rely on carbon from the air, phosphorus and nitrogen from the water and then they are usually able to photosynthesize. That is the unique thing about cyanobacteria. They are technically a bacterium, they lack cell organs and there is no cell wall so it is not a plant, but it has the ability to photosynthesize. It gets a little bit more complex; you can divide the cyanobacteria into two general groups. One can fix nitrogen from the air and water and they have specific organelles that allow them to do it that you can identify under a microscope and then the other cannot fix nitrogen. They are important in the ecosystem. They have been around for a very long time. They are thought to be the organism that first started to provide oxygen to the plant and allowed for a big shift from a low oxygen ecosystem around the globe to a higher oxygen ecosystem. If you ever visit Kakabeka you can see at the visitor center stalagmites. They are old rock formations that are actually made by cyanobacteria. They are really old organisms and have been around for a long time. They have become more topical and a problem because of the fact that they can produce toxins. People are still trying to figure out exactly when and why they produce toxins. It’s just a metabolite they produce as they go through life. It’s been determined that the toxins they produce can be harmful to people. The cyanobacteria can produce a  wide range of toxins and they can have a range of effects. Some simpler effects are a contact dermatitis, an itchy rash when you go swimming in the water with a high dominance of cyanobacteria. To some much more complicated neurological toxins that can cause neurological degenerative diseases. There’s a huge range of potential risks associated with the toxins. What’s happening, is that as people start to impact lakes more through what’s called anthropogenic eutrophication. Eutrophication is a slow natural process that takes thousands if not hundreds of thousands of years to transition. People expediate that by cutting trees down, planting and fertilizing lawns, having agriculture systems within the watershed. All this contributes more nutrients than what the natural ecosystem would to the aquatic ecosystem. You see a faster transition up these trophic states. When you see that, one of the biggest things is the dominance of cyanobacteria at certain stages, or blooms. Which are cyanobacteria completely taking over and covering the water. It’s those kinds of changes that have become more and more predominant across the globe recently. It’s getting linked to climate change and peoples impacts across the globe.

Are there other implications that cyanobacteria have on water quality?

Part of the research I am working on now, specifically in this area of North Western Ontario where cyanobacteria aren’t naturally associated to be a problem, we are starting to see it present here. One of the big questions I have been discussing with Dr. Stewart recently is the fact that, if we don’t know when and why they produce the toxins, and they are in the water problem, what is the potential problem of the acute long-term exposure? If it’s in the water and people and people are pulling water from Lake Superior or the inland lakes to do cooking while camping and stuff like that. We’re not aware that cyanobacteria exist in there and when they produce toxins what those human health risks and impacts actually are. It’s an aspect of the ecosystem that I think is still not really understood or well monitored. It’s one of the areas that I can maybe look at in some future research.  The other aspect is that a large portion of the research in academia is currently trying to figure out what other impacts these toxins can have on the ecosystem itself. There has been literature to suggest that cyanobacteria can facilitate other organisms to dominate in the water column once the cyanobacteria have been there and used up the nutrients. They make it easier for other species to come in and also take advantage of those nutrients that they’ve used. There is an additional aspect of that biomagnification or bioaccumulation up the food chain. Zooplankton which are slightly bigger multicellular organisms actually eating the phytoplankton or cyanobacteria can accumulate some of those toxins and pass through to fish and then up to bigger fish and then to humans. It’s kind of split right now. There is no definitive answer as to whether or not that does or doesn’t happen. It goes back to our limited knowledge on the variety of toxins and how they are reacting with the environment; how quickly they degrade, where they are bound within the organisms. There are a lot of unknowns and uncertainties at the moment.

What’s the history of blue-green algae in the Thunder Bay area?

That’s a really good question. I can’t say for sure, and that’s part of my big question for my research. I am trying to answer that question specifically. The question comes down to, is this something that’s new, it’s necessarily an invasive species because it’s been around for a very long time and it’s likely been in the lakes since they first formed. Has it been blooming or to the abundance that we’re seeing now, or is it because people are become aware and educated on the problem and what to look for? We are seeing more reports of it and that’s the big shift we are seeing. People are starting to report and are more conscious of the fact that this is something they need to look for so they have begun to report it to the MOE, government institutes, and academics like myself. The government has policies in place to go and sample, people can also sample and bring it to me. We started to see it in 2000, that’s when it started to emerge. I’d say the first public awareness for it was between 2010-2015. That’s when people started to become aware of it in northwestern Ontario. 2015 was the first case I saw was on Cloud Lake, closer to Thunder Bay. There had been reports in the Lake of the Woods area that had been reports of blooms. If you go up to Constance lakes up past Geraldton, there had been reports of cyanobacteria associated with the wood and pulp mill up in that area.

How do you get rid of it? Or do you need to get rid of it?

That’s also a really good question. It’s really tricky, there isn’t a one answer fits all situations. There has been a lot of research looking into it and a lot of it comes from the southern states where they have these higher trophic states into the eutrophic. It’s usually in shallow lakes or ponds where there’s not a lot of depth for the water. The water can warm up nicely and provide a good situation for plants to grow in. Phytoplankton is like a plant, but cyanobacteria is not because it doesn’t have a cell wall. Like any plant, there are more favourable conditions. If it’s warm, sunny, and a good supply of nutrients they grow better. If you’ve had a garden you’ve experienced conditions where plants grow better versus when it’s cooler with less sunlight plants don’t grow as well, it’s the same situation. As you go further south, you get more sunlight and shallower more human impacted lakes. They’ve seen this dominance in those areas, and they have come up with ideas on how to get rid of it. Some of the different methods they’ve looked at are herbicides to develop chemical ways to deal with it. It has to be very specifically dosed, and it doesn’t actually go through and kills everything, it just reduces that specific bloom at that time. Other options people have played around with are ultrasounds. They deploy these buoys into a system where it plays an ultrasonic wavelength through the water and explodes the cell. The problem with that is that you take a cell that may be housing toxins and producing them internally and then you explode that cell and release it into the water and end up making the problem worse. The more extreme side of how to deal with cyanobacteria is actually damming off the ponds and reservoirs that are having problems and actually completely excavating the water and sediment out of the lake and refilling it back in to try to start it over again. It’s massive undertaking and in certain areas like north western Ontario it is impossible to do, but it was their best effort at the time. Work out of ELA and Lake Erie have shown that it is phosphorus coming from humans driving that impact. Scraping out the sediment in the water is great for an immediate fix, but you are not dealing with the watershed issue of people providing the nutrients. It’s a Band-Aid fix for a much larger problem. Most recently what people have been looking at doing, is introducing a fine clay sediment that will bind with the phosphorus. It’s a clay particulate that goes into the water and as it falls to the bottom of the lake it binds with the phosphorus and seals it away at the bottom of the lake where it is not available for plants and cyanobacteria to access. If you want to look into it you can check out Gertrude … She has been running pilot projects on lakes across Canada to see if this is a viable option. That’s probably the best option. But it’s an option for when we’ve gone too far and can’t do anything about it. That has been one of the biggest things I have faced while talking to citizens who live on the lakes this past summer. Their big concern becomes how do we reduce this, how to we revert it, how do we stop it? Most people don’t like to hear that they’re going to have to change their lifestyle. You’re going to need to stop having grass right down to the shoreline, stop fertilizing your lawns, reduce the amount of contamination of human waste and make sure your septic systems is up to snuff. It’s really hard for a lot of people to do because you’re impacting their personal way of life. Sometimes that’s not the easiest way to change. The two best ways to reduce cyanobacteria through lifestyle changes or if the lake is too far gone, doing the clay particulate model.

Would you say citizen science plays a large role in this issue?

Yea for me that is an issue I am really trying to push. There are a lot of people who live on the lakes who really care about it. As you start to spend more and more time on the lakes, these are the people who are observing it, they’re seeing it on a yearly basis. They’ve hopefully been on the lake for a long time and can say “oh well 5-10 years we didn’t see this, or yes we’ve seen this for a long time” to get a better sense of the local knowledge. This past summer I started a pilot project where we asked, if we can equip citizens with the knowledge and tools to go out and collect samples and make observations and record them, is that a viable way to proceed into the future to make these kinds of observations of how much it is changing year to year. Are we seeing massive shifts? Can we start to look at trends 15-20 years down the road? The water temperature is going up, you’re getting more stratification, you’re getting reduction in oxygen in the water profile, stuff like that. This is all because of the way people have started to impact the area. There are more and more people that are visiting different lakes and going to different regions. It is the job of the MOE to be in charge of monitoring lakes across Ontario. That is a monumental task when you think of the amount of lakes across Ontario. It’s trying to supplement and help them with the work they’re trying to do which is very important. If we can get reliable information, which is the biggest problem with citizen science is trying to figure out how to make it easy enough for people to go out and do it reliably without causing confusion in the data collection that would allow people to say that it is invalid data.

How will climate change affect cyanobacteria distribution?

Given that we currently don’t fully understand the distribution, it’s hard to say how it will be impacted. I would say that the scientific community expects that as temperatures start to increase there are some very key factors that start to effect aquatic ecosystems specifically. One of the biggest things is that when you get warmer winters you get less freezing. Ice on the lake is very important because it allows that water to stay cold and be cold for longer. If you have it exposed where there is no insulation with the ice because the ice allows for there to be insulation between the water and the atmosphere, when there is no ice, you will see that the water warms quicker. When the water warms up quicker, we are back to the garden example. You’re going to see a little bit of vegetation start to grow quicker. It’s the same kind of thing with soils. When they defrost quicker, you can get plants in the ground quicker and the warmer soil will allow the plants to start growing better. This is going to be one of the major impacts. If you start to see warmer winters and less ice on the lakes, you’re going to see that the parameters that allow cyanobacteria and phytoplankton to bloom sooner and become more productive will be there. The other side is precipitation. When you start to see more snow and rain and an earlier spring melt and more flashy events. You’re getting a lot more surface runoff. That’s the natural way that nutrients like nitrogen and phosphorus enter aquatic ecosystems. If you see more populated areas like down in Toronto having those events, you’re getting more and more nutrients picked up from agriculture systems transported into the lakes. When you’re getting larger flashier rain events where the water is landing on something that has been dried for a long time. It is going to run over the surface rather than percolating down to the groundwater. You’re going to have the ability for more nutrients from humans entering the aquatic ecosystems. More nutrients, specifically phosphorus, because it is the limiting nutrient in aquatic ecosystems. The conditions will be right, nutrients will be there, the warm temperatures and sunlight will be prevalent and will allow cyanobacteria to grow and be more dominant in the water. Those are the key factors on how climate change will affect aquatic ecosystems. With climate change, as you go further north, you will see these impacts felt more. One of the other projects I am working on, is trying to get some of this citizen science, into an educational system with some of the First Nations all the way up to Fort Severn with the Severn river watershed. To see what the base lines are and what is this aquatic ecosystem like before we start to see these major changes that some of them are actually starting to see. That’s a stab in the dark at how aquatic ecosystems and climate change may interact.

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