It’s now common for the New Hampshire Department of Environmental Services to issue advisories each summer, warning swimmers of bacterial blooms along Northeastern beaches.
Cyanobacteria, which is also known as blue-green algae, has become prevalent throughout the Northeast. Now researchers from Dartmouth, University of New Hampshire, and the Cary Institute of Ecosystem Studies are collaborating with the Lake Sunapee Protective Association to find out why.
David Lutz, a research associate at Dartmouth, is leading the team. He spoke with Morning Edition Host Rick Ganley by phone.
This transcript has been edited lightly for clarity.
So, if I was, you know, visiting a lake here in the Granite State and saw a bloom, what exactly would I be looking at?
You’d be looking at colonies of cyanobacteria, and when conditions are very warm and there isn’t much mixing—so there’s not too much wind to move them around, because they kind of can’t swim by themselves.
Do we find those more often in places where there’s a lot of industrial farming, where there’s large factory farms than we would as opposed to the Northeast?
There’s been an extensive amount of research on farms in the Midwest, or the Southeast or in coasts by cities seeing other types of blooms. Here in New Hampshire, we don’t have those kinds of landscapes as extensively. We’re mostly looking at lakes that are surrounded by forests, or second homes or kind of suburban or rural communities. Yet what we’re starting to see over the past decade or so are more of these blooms showing up. And so now is a really critical time for us to figure out hey what’s going on. We don’t have the same kinds of systems as they do in the Midwest, but we’re having these blooms and we really want to know why.
So you’re trying to find out that data. But we do know that these blooms are more prevalent than they were in the past?
That’s correct. Yeah, there’s been a handful of studies that have really been like going through the records. So yes, absolutely there’s more. I’ll be candid and say that it’s not quite as extensive as it is out in the Midwest, but it’s beginning to happen. And the fear is that unless we start to take action to do something about this, and understand the science of why this is happening, and which lakes are susceptible, we need to do that sooner rather than later, or we’ll have some bigger problems on our hands.
These advisories that come out from state biologists every summer, you know, will say that blooms can cause multiple irritations: vomiting, mild fever, skin rashes. How harmful are they actually to swimmers?
There’s a handful of different species of these organisms, some of which are maybe a little slimy to swim through, but may not toxins that are released. And some of them if you do swim through them, they can cause skin irritations or you’re going to want to go to the hospital and get checked out. The lake advisories are generally when they have identified blooms that are particularly toxic and really harmful. So they’re normally focused on very, kind of life-threatening cases.
So not every bloom is necessarily toxic to people?
That’s right. In any event, even if the blooms aren’t toxic, they do have an effect on people around lakes. So, people don’t generally like to look at them. They have an adverse effect on tourism, on property values because of the aesthetics associated with people looking out on a lake. They generally tend not to want to look out on lakes that are green and covered in kind of goopy cyanobacteria. So all these blooms are problematic.
It has a real economic impact obviously on the communities around the lake as you say.
Yeah, we have so many people who visit our lakes, who have second homes at our lakes, communities around lakes that depend on people coming and visiting. And these blooms really are quite challenging because they really decrease the total numbers of people who go.
What do you hope will come from this research at the end?
As I said, we’re kind of uncertain as to why these blooms are happening in some of these lakes. And one of the main objectives is to say okay well here’s at least a little bit of our understanding of which ones may be more or less impacted and may be more or less impacted in the future, especially as things get warmer, dryer. We have kind of warm spells like we did the past week or so and there were more blooms. We really want to understand which ones are more vulnerable or not. The other part is using drones and satellite technology to help us monitor where these blooms are occurring. Obviously that’s important for issuing advisories, but it’s also important for people who manage lakes. Lake protective associations may be able to use this technology in the future to go around and notify homeowners if there’s a bloom there much more quickly than before.