There's something fishy in Flushing Bay.
Thousands of dead Bunker fish, a type of herring, can be seen floating in the bay, which has turned a milky blue-green color.
John Lipscomb of Hudson Riverkeeper says he believes sewage overflow may be to blame.
"There was a lot of rain on Monday, and in this part of New York City, there are combined sewer overflows when the system can’t handle the volume that occurs in a rain storm combined with the regular sewage the city produces. So, by design, there are hundreds, over 450, discharge points throughout New York City where street water and sewage are discharged into the waters of the harbor."
He says sewage causes algae to bloom and consume oxygen in the water.
This in turn causes the fish to suffocate and die-off.
The city's Department of Environmental Protection says it's too soon to say what killed the fish, as there could be natural explanations for the fish kill.
However, city officials say it has been investing in better ways to handle sewage pollution in the water.
“It would be premature for anyone to announce a definitive cause as this type of incident is rare. However, combined sewer overflows are a historical cause of pollution in local waterways that DEP is investing billions of dollars to better manage and this serves as an important reminder why we must continue our efforts to build curbside rain gardens in neighborhoods such as Flushing and College Point, as both drain to Flushing Bay,” said Edward Timbers, a spokesman for the NYCDEP.