Nathan Wilson is a PhD candidate at Lakehead University. Infosuperior conducted the following interview with Nathan to learn more about his research on nutrients and cyanobacteria in Northwestern Ontario lakes before he gets started out in the field this Summer.

What is the main question that you are trying to answer with your PhD research?

The main question, at this point, I am looking to answer for my PhD would be, Have cyanobacteria (a known toxic producing phytoplankton) existed in Northwestern Ontario lakes historically? On lakes that currently have cyanobacteria have they increased since people have settled the shore? This is somewhat of a basic or simple question that has some very important information within it. Understanding if cyanobacteria have been in Northwestern Ontario’s oligotrophic lakes historically or not will provide an insight into how best to move forward with managing this possible future problem.

Little is currently known about the distribution and abundance of cyanobacteria in Northern Ontario lakes because they are assumed to be cold, clean, oligotrophic lakes buffered against problems such as phytoplankton blooms. I am looking to better understand what the phytoplankton community composition on lakes in this region is/was. By understanding what phytoplankton communities currently and previously existed on a lake it is possible to better manage a lake if it starts to change beyond what would be expected for that lake. An example would be for lakes where development, cottages, or mining, is being proposed. Having the predevelopment community composition allows us to monitor resulting disruptions in the phytoplankton community that may result. 

What made you interested in this question?

What sparked my interest in this topic, work from my Master’s. I was looking at a lake just south of Thunder Bay when we observed cyanobacteria blooms. The more I looked into this problem the more I realized how much this topic was an emerging issue and how little was known or understood outside the major lakes like Winnipeg, and Erie.  

The main focus of my research is to raise awareness regarding lakes and phytoplankton in Northwestern Ontario. 

What are phytoplankton and what types of phytoplankton do you expect to find in a Northwestern Ontario Lake?

Phytoplankton are microscopic plants that live and grow in water. They contain chlorophyll and require sunlight to grow and live. You can think of them as the grasses of the water. They take in nutrients from the water and use photosynthesis to supply themselves and, just like plants on land, they are the base of the food chain. There are several kinds of phytoplankton – green algae, brown algae, golden algae, dinoflagellates, diatoms, cyanobacteria, and many more. Many phytoplankton can be found in both salt and freshwater systems. It is fairly likely that I will find a number of green algae, dinoflagellates, diatoms, and I expect to find at least a few cyanobacteria. 

Your research also looks at internal loading with relation to cyanobacteria. Can you explain this concept and how it relates to lakes in Northwestern Ontario?

Internal loading refers to the resuspension of biologically available phosphorus into the water at the bottom of a lake. Most phytoplankton is unable to access this very important nutrient. Unfortunately, cyanobacteria is able to regulate its buoyancy and therefore it is able to access this nutrient and outcompete other less harmful or problematic phytoplankton. Internal loading also poses a major issue when addressing the management of human-induced eutrophication because the cyanobacteria are not limited by reductions of external phosphorus inputs.

The initial plan to combat the major issues of anthropogenic eutrophication came from work done at the Experimental Lakes Area by Kenora, Ontario. The research there showed that increases in phosphorus in the lake water resulted in more phytoplankton and specifically more cyanobacteria blooms. The immediate management approach of lakes experiencing problems was to address the sources of phosphorus that were entering into the lake. Lake Erie is an example of this problem.

Strict regulations were put in place for water treatment and industrial water and the removal of phosphorus from that water before it was allowed back into the lake. This approach worked initially and there was a reduction in the size and distribution of cyanobacteria blooms on Lake Erie. However, as most know Erie is still experiencing problematic blooms. This is because of a number of additional factors that we can not account for as easily. One of which is the continued development of anoxic bottom water which is associated with internal loading and allows cyanobacteria to out-compete other phytoplankton and dominate the community composition. Therefore, despite the limiting of external phosphorus, cyanobacteria are able to proliferate and bloom due to internal loading of phosphorus. 

These factors are very important for Northern Ontario as currently, the accepted knowledge is that Northern Ontario lakes do not experience internal loading. If they do or have the potential to experience internal loading, this is very important for the management of lakes. It will help better understand the number of camps/cottages a lake can have on it without overloading, and if a lake is already overloaded, it will help better understand the best options to protect that lake from further human impacts (as we see in other parts of Canada and the world). 

I am hoping my research will be able to provide information that can be used to better understand internal loading specifically within Northern Ontario Lakes. I am hoping to do this through the examination of sediment cores and monitoring current lake conditions and phytoplankton communities. Lakes in Northwestern Ontario are usually thought to be Oligotrophic (low nutrients, clean, cold water lakes). 

Fieldwork for your research begins this summer, what questions will you be focusing on? What type of data do you need to collect and how will it be collected?

For this season I am focused on collecting data that provides a baseline of the current conditions for the lakes I have selected. To do this I will be focusing on collecting data that tells me about the current state of the lakes. Things like temperature and dissolved oxygen profiles, secchi depth, some basic water chemistry like nutrient composition, and most importantly phytoplankton samples. I will also be taking sediment cores from the bottom of the lakes to gain data about how the lake has changed in the last few decades.

Most of this data is relatively simple to collect using a boat to get on the water so I can measure the temperature, dissolved oxygen and secchi depth. Collection of water samples for both chemical analysis and phytoplankton requires sample bottles to and a preservative to keep the phytoplankton from degrading or losing small identification features like their flagella. The sediment samples are a bit more tricky. Using a long rod with a tube on the end I will push the tube into the sediment in the deepest part of the lake. A one-way valve on the top of the apparatus causes a seal with the sediment in the tube, this has to be pulled out. Trying to do this from a boat can be rather difficult. Usually, cores are taken during the winter when the lake is frozen and you can stand on the ice for more leverage. The analysis of all this data is more difficult.

Infosuperior is grateful to Nathan Wilson for sharing some more information about his research. Nathan Wilson studies various aspects of lakes and lake management through the environmental biotechnology program at Lakehead University, working with Dr Carney Matheson and Dr Rob Stewart. His focus is on examining lakes within Northwestern Ontario to better understand nutrients and cyanobacteria.

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