HAMPTON BAYS, Long Island (WABC) -- Environmental officials are investigating a massive fish kill on Long Island in which tens of thousands of dead fish turned up in a canal Monday.
The New York Department of Environmental Conservation said the Shinnecock Canal in Hampton Bays was closed at 3 a.m., trapping a large and dense school of Atlantic menhaden (bunker) fish. The DEC said it believes the fish died due to a lack of oxygen and a high density of fish in the water.
The DEC said once the Suffolk County Department of Public Works opened the canal locks at 10 a.m., a lot of the fish washed downstream -- some of them still alive.
"The large school of fish was most likely chased into the canal by other predatory fish," the DEC said in a statement.
According to the DEC, the fish kill does not suggest there's pollution in the Shinnecock Bay. Though, a similar die-off happened in Riverhead in June 2015.
Eyewitness News viewer Justine O'Brien snapped photos of the fish kill. This one shows a wider view:
And a video posted on social media shows a different perspective:
As a precaution, the Suffolk County Health Department has collected water samples to test for pathogens and pesticides.
Regional Department of Environmental Conservation spokesman Bill Fonda says fish kills happen when a large number of fish get trapped in a confined area and the oxygen levels go down, leading to suffocation.
Die-offs involving bunkers have become more pronounced. This year, authorities expanded the fisherman's ability to harvest bunkers to five times the normal take.
(The Associated Press contributed to this report.)
Thousands of dead fish turn up in Shinnecock Canal on Long Island