Article & Photo: Katrina Koerting / Hearst Connecticut Media
Reports of items long lost to the depths of the lake being found poured in earlier this summer, as hardware dropped into the waters could finally be seen.
It’s just one of the benefits of this summer’s historic clarity, especially as lakes throughout the country are being plagued by toxic blue-green algae blooms. Connecticut, in general has had a good season, especially compared to the blooms that set up camp on Housatonic beaches this time last year.
“We not only beat the record, we completely destroyed it,” said Sean Hayden, Lake Waramaug Task Force’s executive director.
Visibility measurements were at 6 meters or more for weeks in June and July. The next best clarity was in 2010, but even those were three feet less, Hayden said.
The task force uses several methods to protect the lake, including zooplankton, aerators and a new catch basin study that will help prevent stormwater from entering the lake.
The big concern is cyanobacteria which can release toxins and form the notorious blue-green algae blooms.
Cyanobacteria have been around for 2.5 billion years and are believed to be the reason there’s oxygen in Earth’s atmosphere. A problem has arisen more recently though as blooms have become more frequent. People and animals are in danger if those blooms produce toxins because they can cause serious illnesses if ingested or irritate the skin if they come in contact.
Kelsey Sodul, a research assistant with the task force, said the symptoms in the short term tend to resemble the flu , but they can cause neurological diseases over time. There’s also an economic piece to the problem too.
“If your lake is green, people won’t want to come,” she said.
Businesses and seasonal employees around Lake Hoptacong in New Jersey have reported a big financial hit because the lake has been closed for so long due to the blooms.
“One of the main things for the task force is to make life as uncomfortable as possible for cyanobacteria,” Hayden said. “Everything we do is focused on making it inhospitable for them.”
Some success
Hayden is still studying the lake’s 40 years of data and methods to determine why the lake is so clear. It’s evident the lake is doing better than its days as pea soup in the 1980s, but he’s quick to add the unusually high clarity isn’t a trend just yet.
“I don’t want to count our chickens because I know that one clear summer, does not a trend make,” he said.
Back in the 1980s, the lake was so bad the Secchi disc would vanish before it even hit the water because of all of the green foam.
Hayden and Sodul hope to share any successful strategies with other large lakes and have been given the blessing from the task force to travel out of state and give presentations and help in other ways. Hayden also joined the Connecticut Federation of Lakes Board of Directors to better share information.
At one square mile, Waramaug is the second largest natural lake in Connecticut.
The lake will still have blooms or turn green after a big storm, but Hayden said they don’t last as long as they once did.
“The task force has built up the lake’s immune system,” he said.
Within the lake
A key part of the approach is keeping the cyanobacteria away from their food source of nutrients in the water, especially phosphorus.
Though the cyanobacteria can regulate their bouyancy, they won’t travel to the cold depths of the lake, staying instead in the middle of the water column and rising to the top for photosynthesis. This generally gives the water at that the lowest level a smell similar to low tide at the beach because of all of the sediments trapped down there.
The four aerators throughout the lake help oxidize the lake and trap the iron and phosphorus that enter the water at the bottom because those particles become heavy and sink.
The school-bus size aerators have also helped push the colder layer of water lower in the lake, further keeping that food from the cyanobacteria. They’ve been near the Washington beach for about 15 years and at Arrow Point for about seven years.
Arrow Point is also home to the task force’s zooplankton farm. About a million zooplankton are introduced each week to eat the cyanobacteria. The zooplankton are fed twice a week, with a concoction very similar to the start of a bread recipe: just a half teaspoon each of yeast and sugar and a teaspoon of flour.
The problem is that Waramaug was stocked with alewives years ago in an effort to make it a trophy fishing lake. And while they’re a great food source for the bigger fish, their food source is the zooplankton. Hayden said they saw a big decrease in water quality around the time the alewives were added to the lake.
The task force now stocks brown trout annually to eat the alewives and keep them from going after the precious zooplankton.
“Fisherman are seeing less and less alewives,” Hayden said.
The task force also monitors how the zooplankton are doing during their weekly water quality checks, which use a Secchi disk to check the visibility, measure the temperature and dissolved oxygen at various depths and collect a water sample that might be sent off for testing.
“We like to know where they are and what they’re doing,” Sudol said.
There also hasn’t been as much curly-leaf pondweed, an aquatic invasive plant that the task force has suctioned out of the lake.
“I don’t want to say one year (without it) and we’re done because I’m sure there are beds lurking,” Hayden said.
Around the lake
The fight to protect isn’t done just from the water itself. There’s a key land component, including boat inspections at the Washington boat launch.
Hayden, whose background is in soil testing, just started a years-long study that maps, ranks and inventories all 140 catch basins around the lake to see how stormwater runoff — the lake’s biggest pollution source — is getting in. The task force can then use the study to come up with a treatment plan.
He also checks construction sites around the lake to make sure large amounts of soil isn’t ending up in the water.
“The lake takes a real body blow when a slug of sediments and turbidity goes into the lake,” Hayden said.
It costs about $1,000 to remove a pound of phosphorus from the lake and Waramaug has about 800 pounded already mass loaded. So Hayden is looking to the cheaper option of preventing it from getting into the lake in the first place.
“It’s free to remove phosphorus from stormwater, which is why I want to focus on stormwater,” he said, adding riparian buffers along the shore is an easy and cheap way to do this. “It’s an easy thing to do.”