Algae blooms threaten Long Island wildlife and waterways

LONG ISLAND - Harmful algae blooms are popping up in multiple bodies of water across Long Island.

The bays, lakes and ponds are not as clean and clear as they need to be - this according to an annual assessment of water quality report. 

"We had a record number of dead zones in 2024 with oxygen levels of less than 3mg oxygen per liter. Ideally, our coastal waterbodies will have 4.8mg oxygen per liter," said coastal ecologist Dr. Christopher Gobler at Stony Brook University. 

The cause, according to Gobler, is excess nitrogen that seeps into the water from outdated septic systems and fertilizers. In turn, it promotes algae and algal blooms. 

"These are harmful because these blooms make biotoxins," he said. "They’re consumed by organisms in the pond and dogs go in the water and get sick." 

It’s not only dogs that are impacted. Fish are dying by the dozen. 

Environmentalists question whether climate change is a factor. Record-high temperatures cause lower levels of oxygen in the water. 

"Another symptom of climate change is changing rainfall patterns," Gobler said. "The northeast U.S. is experiencing a 71% increase in a number of these rainfall events."

Suffolk County residents can vote on Proposition 2, which would fund expanded sewers and grants to homeowners for nitrogen-removing septic systems by raising the sales tax about a tenth of a percent. The fund is expected to raise nearly $3 billion over 50 years.

"It means we need to treat our sewage here in the year of 2024," said Adrienne Esposito, who is the executive director of Citizens Campaign for the Environment.  

There is hope, according to researchers who say improvements in the wastewater treatment systems in the city helped nitrogen levels in the Sound.