Dave Fanslow stands with GLERL’s fluoroprobe.

Dave Fanslow is a GLERL biologist of 25 years. He’s basically done it all, but these days he takes care of the lab’s fluoroprobe – a special instrument that measures different types of algae using light beams. Read our interview with Dave to learn more about the fluoroprobe, along with a decades-old scientific mystery that still haunts him and a fear he had to overcome on the job.

How would you describe your job?

My job is to support the principal investigators with technical know-how in the laboratory. I spend a lot of my day working on instruments right now – the flowcam and the fluoroprobe — which are both used to assess and describe HABs, or harmful algal blooms.

The fluoroprobe is a new device that uses LED lights that trigger a response from the algae, which have unique pigments in them that respond to very distinct wavelengths – so it’s able to distinguish between types of algae simply by flashing an LED light as you pull it through the water. It first came out in about 2014. We had one of the first here at GLERL.

What is the most interesting thing you’ve accomplished in your job?

The most interesting thing that I worked on was actually an unresolved question, the disappearance of the Diporeia from Lake Michigan. There was an amphipod organism called Diporeia that is still present in tiny numbers but used to be really common, and was the basis for the lower food web in Lake Michigan prior to the expansion of quagga mussels. In the mid-90’s, those organisms plummeted from numbers of around 10,000 per square meter down to practically zero in the large majority of the lake.

There was some assumption of effect by zebra mussels and quagga mussels, but we never did really figure that out. The change in the food web was occurring anyway, where quagga mussels were going to take over and dominate the system…so the exact reason for the disappearance of the Diporeia didn’t really matter in the ultimate outcome. But, it was a mystery that piqued my interest and I wish we had been able to describe it. It may have been relevant for some other instance. If it was a disease, if it was an invertebrate disease that was introduced by some other invasive species, that’s a form of microbiological pollution, and it would’ve been nice to nail that down and figure that out.

What do you feel is the most significant challenge in your field today?

The hardest part about doing what we do is the disconnect that I sometimes feel exists between policymakers and scientists. And, I know that’s something that scientists and researchers have struggled with forever, it’s not new, and it’s an ongoing problem to communicate the issues and hope that policymakers make good decisions based on good information.

Where do you find inspiration? Where do your ideas come from in your research or other endeavors in your job?

Most of my inspiration comes from encounters with the public, family and friends who are invariably enthusiastic and concerned about the Great Lakes. People in Michigan in particular, it’s part of our identities, and so that’s where I get my motivation because I know people care.

Dave Fanslow explains some data coming from the fluoroprobe.

There’s a fun story about a fear you had to overcome to do this job. Can you tell us about that?

When I first got the job interview, I was told that they wanted me to do scuba diving to collect zebra mussels. This was at the very beginning of the zebra mussel invasion in 1992. I wasn’t super comfortable with swimming and the water, but I thought I would check it out. So I did my research, read about it, went to the pool and practiced, and said yeah I’ll take the job. Then I got trained at NOAA diving headquarters in Seattle where they have retired Navy Seals conducting the training. Then, I conducted over 500 dives over the next 6 or 7 years, mostly related to collecting zebra mussels and then also in the early stages of the Thunder Bay Marine Sanctuary, observing some of the wrecks and establishing moorings up there.

How would you advise young people interested in science as a career path, or someone interested in your particular field?

My general advice would be that they be flexible in terms of not narrowing down their discipline too much until they get out in the field and discover what the opportunities are. I know that in my career, what I have worked on, the area of technical expertise has ranged wildly over the 25 years I’ve been at GLERL. From picking bugs initially, to measuring lipid content, to measuring enzyme content in mussels and Diporeia…to now I’m working with electronic instruments. So, be flexible.

What do you wish people knew about scientists or research?

Well, one thing I think that people tend to assume about scientists is that they’re eggheads who are narrowly focused on their own work to the exclusion of the rest of the big questions about what’s going on in the environment and in society in general. So, scientists are well-rounded and multi-dimensional people too.

What do you like to do when you AREN’T sciencing?

When I’m not at the lab I have raced my bike a lot over the years, starting when I was an undergraduate. I am now kind of transitioning into middle age and doing other things like gardening and canoeing and fishing. Usually it involves being outside in the environment and making observations about the plants and the bugs and the weather and the things that are around me. We have a place on Lake Superior, and just being there and seeing the change in the weather from day to day and hour to hour is a blast; it’s one of my favorite things.

It can be tempting to think of the Great Lakes as 5 big bathtubs – 5 uniform masses of water that each face one set of problems, or are each home to one list of fish no matter where you’re dropping a line. But, the Great Lakes cover nearly 100,000 square miles, span a full 10 degrees of latitude and range 1,300 feet in depth. Any environmentalist working on polluted runoff or any fisherman worth his or her (non)salt will tell you: The problems and possibilities in one section of a lake aren’t the same ones you’ll find 50 miles north or 10 miles offshore.

This can be hard for scientists, who need to compare similar regions to get answers to important questions. Are a certain species of fish not thriving because of a nearby source of pollution? Or is it because the habitat isn’t right? You can’t study the effects of pollution in one area, 10 feet deep and near a river mouth, by comparing it to an unpolluted area that’s miles offshore.

So, what can be done? All parts of Lake Erie’s western basin, for example, don’t provide similar habitats. BUT, one part of Lake Erie’s western basin might look a lot like an area in Saginaw Bay. If only one of these similar areas is being impacted by a certain pollutant, that’s a good setup to study the effects of that pollutant, because other factors (like depth or temperature) are being held constant.

Scientists and resource managers have been making this leap for ages – finding areas in the Great Lakes that are relatively alike and comparing them – everything from fish stocking efforts to the spread of invasive species. But now, there’s a tool to make it easier. Scientists have developed what is basically an atlas of ecologically similar areas in the Great Lakes.

Researchers have developed a classification system for the Great Lakes that groups regions with similar characteristics. Credit Lacey Mason/GLAHF

Based on four main variables (depth, temperature, motion from waves and currents, and influence from nearby tributaries) researchers from multiple institutions (including NOAA Great Lakes Environmental Research Laboratory) organized the Great Lakes into 77 Aquatic Ecological Units (AEUs). The classification system took 6 years to create and incorporates multiple NOAA datasets, including depth, temperature patterns and circulation patterns throughout the lakes.

Each AEU is a chunk of the lakes with its own unique combination of those four variables. The idea is that scientists and conservation professionals working within one type of AEU will be comparing apples to apples.

Ecosystem classification isn’t new – it’s been applied to land and ocean environments before. But, this is the first classification system developed for the Great Lakes.

Catherine Riseng, a researcher with the University of Michigan’s School for Environment and Sustainability, is lead author on the paper. She tells us the work “simplifies a complex ecosystem”.

“It can be used by researchers to help describe and explain existing ecological patterns and by resource managers to facilitate inventory surveys, evaluate the status and trends, and track the effects of human disturbance across different types of ecological units”, she says.

The work was done as part of the Great Lakes Aquatic Habitat Framework (GLAHF), which is “a comprehensive spatial framework, database, and classification for Great Lakes ecological data.”

The classification data will soon be available for download at https://www.glahf.org/classification/. For now, you can interactively explore the AEUs and related datasets at https://glahf.org/explorer/.

As the winter months begin, they bring the phenomenon that every Great Lakes resident knows (and either loves or hates): lake effect snow.

Lake effect snow happens while the Great Lakes are still unfrozen and relatively warm. Cold air (usually from Canada) sweeps over them, picking up moisture and warmth on the way. It then drops the moisture as snow downwind.

This might sound a little confusing — how could “warm” lake water result in snow? Well, the warmth from the lakes is only enough to get the moisture from the surface of the lake into the atmosphere. Once the moisture is up in that mass of cold air, it turns into snow and then falls — usually about the time it’s passing over whatever freeway you use for your afternoon commute.

Check out this map of the United States: you’ll notice that things generally get snowier the farther north you go, but that the really dramatic snowfall (average of more than 8 feet annually) occurs in two places: high mountain elevations and land adjacent to the Great Lakes. Many areas in the Great Lakes basin average at least 4 feet annually. You can thank lake effect snow for this.

Map showing average annual snowfall in the contiguous United States.

Notice that the western shore of Lake Michigan and Southeast Michigan/Northwest Ohio are somewhat spared — wind patterns have a lot to do with this. It is not enough to just be next to a Great Lake — the wind has to be blowing your way.

The GIF below shows lake effect snow in action. The black arrows represent wind speed (length) and direction, and the color scale shows snow accumulation. This is model output re-creating a lake effect snow event from December of 2016.

Model output for a lake effect snow event back in December of 2016. Arrows show wind speed and direction and color scale shows snow accumulation.

Researchers at the NOAA’s Great Lakes Environmental Research Laboratory, along with partners from the Cooperative Institute for Great Lakes Research (CIGLR), are working on a model that can indirectly improve predictions of lake effect snow through the expected latent heat flux from the lakes. “Latent heat flux” is fancy terminology for that warmth, and associated water, moving from the lakes to the air that we talked about earlier. So, if the latent heat flux is predicted to be high (lots of moisture and warmth being transferred from the lake to the atmosphere), there’s a greater chance of a lake effect snow event.

You can see that model output here, although for now it’s a “nowcast” — a re-creation of the last 5 days. However, forecast data (and data for more lakes) is on the way!

Since 1990, GLERL scientists have been measuring temperature in the middle of southern Lake Michigan (at approximately 42.68, -87.07). They’ve been using a vertical chain of instruments that measure temperature from top to bottom. This is one of the longest vertical temperature records in existence anywhere in the Great Lakes, and it reveals some interesting patterns about lake temperature and the seasons. We’ve created a static infographic as well as an interactive chart that allows you to zoom in on the data and get individual measurement values.

Below, check out our infographic explaining seasonal temperature profiles in Lake Michigan.

Click here to interactively explore Lake Michigan temperature data.

Lake Michigan temperature data infographic.