On a windy afternoon, Sue Ruoff walks along the shore of Cayuga Lake in Lansing’s Salt Point Park, looking for striped green clumps along the water’s surface.

She is looking for harmful algal blooms, the substances of concern that have appeared in Cayuga Lake and other bodies of water in New York state since the beginning of the summer.

So far this year, more than 500 confirmed cases of harmful algal blooms have been reported nationwide, affecting dozens of bodies of water, according to state data. Although these data occasionally double-count algal blooms that spill into different areas of the same body of water on the same day, the high number remains concerning to environmental advocates.

Harmful algal blooms can cause a range of health problems in humans and animals, from mild rashes to serious illnesses, according to the CDC. When algal blooms occur, authorities close swimming areas for several days or weeks.

The problem is particularly severe in the Finger Lakes region, where several bodies of water have been hit by harmful algal blooms this year. Although the state is investing in keeping the Finger Lakes’ water clean, some advocates say those efforts are not enough to address the severity of the problem.

On Cayuga Lake, Ruoff and other volunteers from the Community Science Institute in Ithaca have documented dozens of harmful algal blooms since the beginning of the summer. Ruoff has been monitoring the lake for algal blooms for four years, but she said the high number of sightings this summer is alarming.

“It seems like they’re getting more frequent and worse,” Ruoff said. “As one of many people just trying to keep an eye on what’s happening on the lake, it was eye-opening and sad.”

A growing problem

Algal blooms have occurred occasionally in the Finger Lakes and other waters in New York for decades. In recent years, however, observations in the Finger Lakes have become more frequent and are occurring earlier in the year, according to monitoring data and reports.

Harmful algal blooms are caused by naturally occurring organisms called cyanobacteria, which can grow uncontrollably in freshwater and clump at the surface. They thrive in high concentrations of fertilizers such as nitrogen and phosphorus, which can enter lakes from farms and other industries.

These nutrients work “like a miracle cure,” says Alyssa Johnson, who leads the Cayuga Lake harmful algal bloom monitoring program at the Community Science Institute.

Johnson said it was important that people do not go into the water when beaches are closed because of an algae bloom, and also not let their pets in the water. She said it was difficult to make people understand the risk, particularly on sunny days when families gather to swim.

“I understand the frustration,” Johnson said. “But it’s such a bad problem across the state.”

Research suggests that climate change could worsen algal blooms. Cyanobacteria multiply on hot days, which are becoming more frequent. They also thrive when there is a lot of fertilizer in the water. As a result of climate change, more intense storms could send more runoff from farms into the lakes.

“It’s just a terrible – but perfect – storm,” Johnson said.

Tackling the problem

Last week, Governor Kathy Hochul announced a $42 million investment to protect and improve water quality in the eastern Finger Lakes region. The funds include money to help farmers reduce water pollution and develop better methods to manage stormwater runoff.

According to the Department of Environmental Conservation, New York has invested more than $428 million in projects to combat the problem of harmful algal blooms in the state. The department is also working on new guidelines for phosphorus levels in freshwater.

But for Walter Hang, head of the Ithaca-based environmental protection and research group “Toxics Targeting,” this attempt falls short.

“New York is currently inundated with these harmful algal blooms,” Hang said. “A little money, even hundreds of millions, will not solve the problem.”

Hang has led a campaign in recent years to introduce stricter and enforceable regulations to limit the amount of nitrogen and phosphorus that can enter waterways. Last year, local environmental groups and officials signed his letter and called on Hochul to impose stricter regulations.

To limit the growth of harmful algal blooms, the DEC recommends that New Yorkers living near freshwater limit their use of fertilizers and opt for low-phosphorus options. Maintaining septic tanks and reducing erosion and stormwater runoff can also help limit the amount of nutrients in the water.

If you think you see a harmful algae bloom on Cayuga Lake, you can report it to the Community Science Institute.

Elsewhere in New York, you can learn more and report an algal bloom on the DEC website.