‘Our lakes are sick’: Upward trend of cyanobacteria blooms troubles residents, experts

By: - December 6, 2021 5:53 am
An algae bloom on a lake

Cyanobacteria occurs naturally, but when there are too many nutrients in the water the growth can get out of control. Here, a bloom on Phillips Pond in Sandown in a photo taken in September. (Courtesy of the New Hampshire Department of Environmental Services)

This story was updated on Dec. 6, 2021, at 10:28 a.m. to correct the name of the nonprofit NH LAKES.

Kirk Meloney first started going to Lake Kanasatka in Moultonborough as a boy. He remembers the crystal-clear water in the small lake – you could see straight to the bottom, even in parts of the lake that were 12-feet deep.

Meloney spent the formative years of his childhood at his grandparents’ lake camp, and it was the lake in large part that drew him to later make New Hampshire his permanent home in the mid-1970s. But in the past two years, Meloney has watched with dismay when the lake changes – a bright green film the color of Gatorade starts to grow across its surface, the clear water turning into pea soup as potentially toxic cyanobacteria blooms cloud the once-clear water.

A couple years ago, Meloney started volunteering for the Lake Kanasatka Watershed Association; now, he’s been its president for three years, and cyanobacteria blooms – a type of bacteria that lives in the water – is one of the major problems he’s trying to tackle.

“I want my lake, little Lake Kanasatka, to be as crystal clear as it was when I was a child for my grandchildren, who are 3 and 5. And the way things are going, that’s not going to happen,” he said.

Cyanobacteria occurs naturally, but when there are too many nutrients in the water – driven by human development and runoff – the growth can get out of control, and the blooms can be toxic, making humans and animals who come into contact with the water sick. A one-time exposure can cause a rash or nausea, but continual exposure even at low levels can cause respiratory, liver, and neurological issues. And it’s not just a problem for Lake Kanasatka: Health advisories and alerts have been rising in recent years throughout the state. This past year alone, the state issued 32 health advisories and over 40 alerts – a record-breaking year for observed blooms.

A chart showing the rise in cyanobacteria blooms in NH lakes
(Source: New Hampshire Department of Environmental Services)

Experts say the increasing reports may reflect a worsening problem, but some of the increase may also be driven by growing awareness of the issue. As people learn what cyanobacteria is, they can recognize it and report it to the state more frequently. Still, it’s cause for concern.

“Our lakes are sick, and they’re making us sick, too,” said Andrea LaMoreaux, president of the nonprofit NH LAKES. LaMoreaux said the nonprofit has been hearing reports of people and animals getting sick if they go in the lake. Lake Kanasatka was effectively shut down to recreation for more than three weeks in each of the past two summers. When tourists learned they couldn’t go in the water, some tried to cancel their plans and get their money back, Meloney said.

“It’s definitely impacting our way of life. And it has huge ripple effects on our economy,” LaMoreaux said.

Cyanobacteria is a priority for the nonprofit, which is tracking legislation that could help tackle the problem. House Bill 1042, for example, would require rental properties to provide information about state health advisories to renters who might not know where to look for it.

Blooms are also being observed later and later in the season, with waters warming as a result of climate change. In the 20 years LaMoreaux has been working on lakes in New Hampshire, she’s never seen blooms occur this late in the season. There were blooms being reported even in the last week of November this year.

LaMoreaux said warmer winters are part of the problem, as the time lakes are covered with ice has diminished by one to two weeks on average, allowing for a longer growing season.  

Amanda McQuaid, who runs the state Harmful Algal and Cyanobacterial Bloom Program at the Department of Environmental Services, said warmer water is just one of the factors that can affect cyanobacteria.

“The warmer it gets, the more nutrients there are. The more extreme weather events, the more blooms we’re going to expect to have,” McQuaid said.

An extreme weather event – such as the heavy rains climate scientists predict in the Northeast – carry a lot of nutrients from the soil into lakes, and those nutrients fuel cyanobacteria growth.

Outdated septic tanks on lakefront properties that are leeching into the groundwater can also contribute to the problem. McQuaid said the pandemic has played a role as well, as people flocked to rural lake houses that were seen as a haven. With an increase in rental properties through platforms like Airbnb, some septic systems that were designed for four people might have been getting used by eight people. 2020 was a difficult summer for lakes in New Hampshire, McQuaid said, and her department – charged with responding to more and more reports – was also understaffed.

On Lake Kanasatka, Meloney says some residents haven’t updated 65-year-old septic systems.

“Chances are all it is is a 55-gallon drum in the ground and people have been using it for 60-plus years. And over time, those systems fail,” he said. That failure means sewage is getting into the groundwater, and in turn flowing into the lake.

Meloney and the watershed association are doing what they can to address the problem – such as working to raise $85,000 to create a watershed management plan. But there are limitations to what the volunteer-run association can accomplish on its own. Meloney thinks the state needs to step in to solve this problem by mandating that residents have a functional septic system.

House Bill 1066 would create a study commission to analyze the human and animal health impacts of cyanobacteria. Michelle Davis, the policy and advocacy program manager at NH LAKES, said if this bill becomes law, it would be a good chance for the Legislature to take a more comprehensive look at addressing the problem.

Other lake associations – like the Lake Winnipesaukee Association – are concerned about the economic impact of worsening cyanobacteria blooms. A recent study found that Lake Winnipesaukee is worth more than $17 billion to New Hampshire’s economy, and $16 billion of that worth came from property values.

Bree Rossiter, the conservation program manager of the Lake Winnipesaukee Association, said growing concern over cyanobacteria is one of the reasons the organization decided to have the economic study done.

“We’re hoping that policy makers can see the importance of the lake to the entire economy of the state, and not just to the towns around Winnipesaukee,” she said.

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Amanda Gokee
Amanda Gokee

Amanda Gokee reported on energy and environment for New Hampshire Bulletin. She also previously reported on these issues at VTDigger. Amanda grew up in Vermont and is a graduate of Harvard University. She received her master’s degree in liberal studies, with a concentration in creative writing, from Dartmouth College. Her work has also appeared in the LA Review of Books and the Valley News.