Why a sudden spike in the temperature of the Great Lakes has scientists worried

The Great Lakes are getting much hotter according to a professor with the Great Lakes Institute for Environmental Research at the University of Windsor. Aaron Fisk explains why temperatures are on the rise and what that means for the Great Lakes and the things that live in it.

'Yeah, I am worried. And I am an optimist'

New data shows the Great Lakes is warming at an usually high rate. (Google Maps)

The Great Lakes are getting hotter, seeing a rise in some parts of three degrees.

Aaron Fisk, a professor with the Great Lakes Institute for Environmental Research at the University of Windsor, spoke with the CBC's Julianne Hazlewood about why temperatures are on the rise and what that means for the Great Lakes and the things that live in it. You can read an abridged and edited version of the interview or listen to the full audio interview by hitting the play button below.

The Great Lakes are getting much hotter according to a professor with the Great Lakes Institute for Environmental Research at the University of Windsor. Aaron Fisk explains why temperatures are on the rise and what that means for the Great Lakes and the things that live in it. 7:17

Aaron Fisk, Great Lakes Institute for Environmental Research 

How significant is this three degree increase?

Three degrees is pretty big. We see a variation from year to year of half a degree or .2 of a degree. Three degrees is a pretty significant jump.

Where is the temperature change most acute?

The coldest, most northern lake, Lake Superior, is seeing the biggest changes and that fits global change. We tend to see most warming around the planet as we approach the poles and the Antarctic and the Arctic.

What does this warmer water mean for the lakes and the species that inhabit them?

Temperature is one of the most important drivers of aquatic systems and terrestrial systems as well. It sets up the types of animals you can have there. Animals and fish like a particular temperature. They have evolved to live in that temperature. We also see a lot of seasonal chances with the algae and the zooplankton that are in the water. When you change the temperature you force animals to move to places they don't want to be and also fish are a cold blooded species. They are the temperature of their water. When water gets warmer it means their metabolism is higher which means they need to eat more. It just adds to a general stress on the system. 

Is there one species that is most affected? 

We are starting to see very rapid changes both in the Great Lakes and around the world.- Aaron Fisk, Great Lakes Institute for Environmental Research 
Right now most of the changes we are seeing in the Great Lakes are more surface. The fish that you find on the edge of the lake like bass are the ones that have to change their habitat the most. The more surface and near shore species are probably a little bit more vulnerable in the beginning but it does cascade through the environment so it's an implication for the entire ecosystem.

Were you surprised by the three degree increase?

Yeah. It's a really significant change in temperature. Much beyond anything you would normally expect over the last 60, 70, 80 years. 

How is all of this tracked?

We have a system of temperature loggers and buoys throughout the Great Lakes. The U.S. has more than we do. Some of it's real time. It uplinks and goes into databases. You can look at it if you want. We collect that data for a whole bunch of reasons. The most important part is for climate models. All that data is tracked and archived and followed. 

Are there any positives to warmer Great Lakes?

It makes for better swimming, I suppose. However, that usually leads to greater E coli breakouts and harmful algal blooms. Certain species like warmer water. In Lake Erie we are seeing very positive Walleye and Yellow Perch recruitment. We have a very large recreational and commercial fishery worthy hundreds of millions of dollars. But, a word of caution, the trends we're seeing and the recruitment — which is how well they're reproducing — is good right now but it's a little out of whack with what we know historically with that system. It may be wearing down the system and there may be problems down the line. 

How does what we're seeing now compare to the Great Lakes of past decades?

If you look at any of the Great Lakes there's a warming trend since the '50s and '60s but this recent jump is consistent with a lot of other data. We are starting to see very rapid changes both in the Great Lakes and around the world. That's the concern. Are we moving into a phase of much larger changes and a lot more variability?

Is there something we can do?

Well, the Great Lakes were in bad shape in the '50s, '60's and '70s. We did a lot of really positive things. We controlled nutrient release. We started looking at pollution. We started studying how to reclamate ecosystems. I think the Great Lakes are probably in better shape than they were fifty, sixty years ago. The problem with temperature is that this is a global phenomenon. We should all try to help and make changes with climate change. But it's so global I don't know what we can do in the Great Lakes to try and mitigate this. It's almost beyond the region. I think that's what is quite worrying about these trends.

Are you discouraged?

As a scientist we have to be objective in our research and we all try to do that. We have to be careful about being an environmentalist. It's something I've been thinking about for the last couple years. I think ecologists and environmental scientists are often afraid to say this because they want to be objective. There is a general depression and worry amongst all of us.

Even the people who have been working on the Great Lakes for a long time, people who have seen it all, are all saying 'wow, things are really changing.' Yeah, I am worried. And I am an optimist. We have ignored climate change for much too long. It might be too late. We are already living with the ramifications of climate change.  

About the Author

Conrad Collaco

Producer

Conrad Collaco is a CBC News producer for CBC Hamilton with extensive experience in online, television and radio news. Follow him on Twitter at @ConradCollaco, or email him at conrad.collaco@cbc.ca.

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