The University of Vermont’s research boat was filled with scientists and members of the media Tuesday for a short cruise to explain why problematic cyanobacteria blooms occur each summer and their ongoing research to understand the organisms.
Cyanobacteria blooms have already closed beaches in Burlington on some of the hottest days of the season. Scientists in the region are researching the organisms that can occasionally cause a toxic bloom along Lake Champlain’s shore.
A group gathered beside the ECHO Center for Lake Champlain where the research vessel Marcell Melosira is docked. After receiving safety instructions and donning life vests people boarded.
“Watch your step here.”
And were led to the ship’s interior laboratory by UVM Lake Champlain Sea Grant associate director Kris Stepenuck.
“We need to be in the classroom while we are leaving the dock area.”
As the boat moves past the Burlington breakwater to sail south to Shelburne Bay, scientists provided a primer on their research into the cyanobacteria, or blue-green algae, blooms.
Lake Champlain Basin Program Chief Scientist Matthew Vaughan offered what he called a Cyanobacteria 101 lesson, noting that cyanobacteria and blue-green algae reference the same organisms.
“Cyanobacteria are a large group of primitive bacteria and they’re native to just about every ecosystem on earth. So they’ve been in Lake Champlain since it was formed. And most of the time they exist in the lake and they do not cause harm. So, cyanobacteria are microscopic. So what you’re seeing during a bloom is actually colonies of many, many thousands of cells clumping together. Now one thing I always say is that this is a worldwide issue because humans have altered our ecosystem and are now putting more nutrients like phosphorus and nitrogen into our fresh waterways. So this is something that is a challenge throughout the country and throughout the world.”
When the boat reaches Shelburne Bay, UVM Research Vessel Specialist Eleanor Duva lowers a sample collector, or plankton net, into the water.
“Here we go, down into the water. So, we’ll send it down until we pretty much can’t see it. So that way we’re sampling most of the top layer of water, the photic zone. Alright, coming up and there’s the net in sight again. So we’ve scooped up the plankton that were living at the surface of the lake.”
Duva takes the sample to the lab and places it in a microscope that displays the contents on a large screen. While it doesn’t have much cyanobacteria, an invasive plankton was captured.
“Awesome good stuff immediately. And what we’re catching right here is the namesake of both the spiney and fishhook waterflea. Have this long tail, I suppose, that is barbed. You can see how all this phytoplankton is stuck to this barb at the end of its tail right there. But all of these ones that are moving around on their own are zooplankton.”
UVM Vermont Limnology Laboratory research scientist Katelyn Warner says the samples they take in the summer often detect cyanobacteria.
“We don’t filter out cyanobacteria because we’re curious about the entire phytoplankton community as a whole. So, our lab at the Vermont Limnology Lab is looking at phytoplankton community composition, what environmental drivers are changing these communities and how they kind of shift over time in response to changes in weather patterns and nutrient cycling and all of that. So we really are interested in who’s all here and who all kind of exists together and how those patterns might change over time.”
The severity and even the existence of cyanobacteria blooms vary from lake to lake. Vermont Department of Environmental Conservation State Limnologist Peter Isles says there are numerous factors that lead to more or less cyanobacteria in the water.
“Factors like the size and depth of the lake can have a big impact. Certainly the land use in the watershed draining towards each lake is a major impactor. And then just really the whole shape of the lake bottom. How much shallow area you have versus deep area.”
Back on shore, Stepenuck says they highlighted cyanobacteria because problematic blooms have been occurring over the past few summers.
“It felt like it was the right topic because we knew that they happen and public safety wise we want people to understand it. So, that was the reason for the choice. And because I knew there was a number of different researchers engaged in trying to understand and make recommendations around cyanobacteria. There’s going to be blooms. There’s great research happening and it’s a public safety issue.”
The Lake Champlain Sea Grant and the Lake Champlain Basin Program are planning to conduct a public awareness survey to find out what the public knows about lake and watershed issues.
