NORWALK, Conn. -- Something is in the water in Norwalk, and it's not pretty.
The water in Norwalk Harbor, especially around South Norwalk Boat Club, does not look like it used to.
"Green pea soup, 'Exorcist'-type," Norwalk resident David Mott said.
"I don't want to go in it," Norwalk resident Susan Mott said.
Side-by-side photos reveal the change.
"It looks like ... the stuff they spread on the fields, the liquid manure," Redding resident Richard Friese said. "I think it's the sewage plant."
"No smell to this, though?" CBS2's Vanessa Murdock asked.
"No, I haven't noticed a smell," Friese said.
"Boaters have not been feeling very comfortable about it," said Glenn Perschino, marina chairman of the South Norwalk Boat Club.
Perschino reached out to CBS2.
We reached out Reza Marsooli, assistant professor at Stevens Institute of Technology, to get his expert opinion.
"It looks like a brown tide, which is excessive gross of certain microscopic algae," he said.
Marsooli says brown tide is most common when the water is warm and overloaded with nutrients, especially following a heavy rain event; recall May 20, when over 2 inches fell.
"When you say nutrients, what type of nutrients are we referring to?" Murdock asked.
"Nitrogen. What we see in fertilizers," he said.
Sewage overflow can also be the root cause.
"Is it dangerous?" Murdock asked.
"It's not dangerous for humans directly," Marsooli said.
Marsooli says if it covers a wide swath and lasts long, it can have an impact on marine flora, cutting off light, and subsequently marine life, when oxygen levels drop. But the water quality already looks better than it did, according to Perschino.
"When people talk about brown tide, what do you think?" Murdock asked Copps Island Oysters owner Norman Bloom.
"Food. Food ... Not for me, food for the oysters," he said.
Bloom says a little color in the water means good eatin'. His bivalves feed off of algae of any color. Bloom beds are blooming, the haul impressive.
Is brown tide unsightly? Yes. But is it bad? Consensus says not this time.
Marsooli says preventing brown tide is challenging, but it can be mitigated with better controls of stormwater runoff.
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