When it comes to local ponds, the scum search is always on.
The Association to Preserve Cape Cod (APCC) is contracted by Barnstable County and the Cape Cod Commission to monitor 50 ponds, seven times per year, through 2025. Staff and volunteers are constantly testing water for cyanobacteria, which can harm us and our pets.
Morning Edition host Patrick Flanary spoke with Sophia Feuerhake, the APCC's freshwater science coordinator of the Cyanobacteria Monitoring Program and the Cape Cod Pond Monitoring Program.
Patrick Flanary How often are you monitoring ponds on the Cape, and how many?
Sophia Feuerhake About 130 ponds on a biweekly basis, from mid-May to sometimes late October.
PF I'm picturing a team at each pond, on hands and knees and taking samples into little beakers and bottles.
SF That's pretty accurate. Staff and interns collect the samples out at the ponds every morning, and we monitor up to 30 ponds a day.
PF I was surprised to read that there are about 900 ponds on Cape Cod.
SF Yes. There's an incredible amount of freshwater ponds on Cape Cod now.
PF Devil's advocate: Why can't you cover them all? Do you just not have enough time?
SF We're limited in resources. We collaborate with the towns, and we try to get to the priority ponds where there's a lot of recreational activity or poor water quality.
PF We've got a lot of people from out of town and out of state. What's the first order of business? Walk me through a typical day of monitoring.
SF We collect up to four different types of samples, and we take photos of the water. If there's a scum present, we'll collect a sample of that. We collect a toxin sample, and then we collect two different types of water samples, one of the water column and one more concentrated sample of any plankton that's in the surface water. And if there were any scum samples collected, we'll look at those under the microscope and determine whether they are cyanobacteria and what genus is dominant. We look at two different types of pigments: chlorophyll and fecal.
PF I think people hear "cyanobacteria," and know it's bad just by the sound of it. But sometimes you can't see it because of its life cycle.
SF That's correct. We focus on scums near surface water because that's where most of the recreation happens. And that's where the most vulnerable groups usually are, which are children and pets, because they're most likely to inhale or swallow water. Certainly there could be a cyanobacteria bloom present that's less visible to the eye, tiny little dots in the water. Or, like you said, in deeper waters where it's just not as visible to us.
PF Phosphorus is the enemy of freshwater. A lot of that's coming from runoff, from when it rains, and it's draining into the ponds.
SF Exactly. Freshwater ponds are phosphorus-limited. There's plenty of nitrogen. And when there's plenty of phosphorus as well, that's when blooms can happen because there's all these nutrients available in the water. And, like you said, phosphorus can come from stormwater runoff fertilizers or outdated septic systems.
PF So how is this summer compared to summers past? Are you closing more ponds more often these days than you were last year, or five years ago?
SF It is still quite early in the season, so it's a little hard to say. It really depends. Maybe three or four years ago, we had a year with far more blooms and we think that might be due to the drought conditions at the time. And this year has been a lot cooler and wetter, which has led to a slight decrease in cyano blooms. But we have still seen several this season.
PF How do you address a habitual pond here when it comes to cyanobacteria? Is there any way to finally just eradicate it?
SF Cyanobacteria are naturally occurring in the water. They've been around for a really long time. They're the first oxygen producers on Earth. When you try to eradicate one species frequently, what happens is you eradicate a lot more of them. So there's no way to specifically target cyanobacteria. Update your septic systems; that's something that we can do.
