Dead fish spotted floating in a canal off the Long Island, New York, on Nov. 14, 2016. (Web pick)

NEW YORK, Nov. 15 (Xinhua) -- An investigation is under way into the tens of thousands of dead fish spotted floating in a canal off the Long Island, New York.

The closing of the Shinnecock Canal at 3:00 a.m. on Monday trapped within the Canal a large, dense school of bunker (Atlantic menhaden) and other bait fish, New York State Department of Environmental Conservation (DEC) said in a statement emailed to Xinhua Tuesday afternoon.

The large school of fish was most likely chased into the canal by other predatory fish, and the fish kill does not suggest any impacts to the health of Shinnecock Bay,around three hours drive east of Manhattan, New York.

Dead fish spotted floating in a canal off the Long Island, New York, on Nov. 14, 2016. (Web pick)

A preliminary field analysis suggested that the fish likely died because of "a lack of dissolved oxygen and the high density of fish," the conservation department added.

DEC staff have collected additional samples for further analysis. The Canal and locks are operated by the Suffolk County Department of Public Works. The canal locks and gates were reopened at 10:00 a.m. Monday, allowing the live and dead bunker to enter Shinnecock Bay.

As a precaution, the Suffolk County Department of Health Services has also collected water samples to test for pathogens, nutrients and pesticides.