The massacre was recorded Thursday at 7 a.m. by Sean Donohue at the 106th street beach, and uploaded the same day to YouTube.
Early morning beachgoers evacuated the shallow surf, according to the Barnegat-Manahawkin Patch.
They could be seen looking on in horror as multiple dorsal fins swirl and cut through the roiling, crimson waters only a shell’s throw from the sand.
Unconfirmed reports said the dolphin was originally injured by a boat propeller and the bloody wound attracted the maneaters.
Dolphins are generally able to defend themselves by using their long, hard snouts to ram into the soft underbellies of threatening sharks, and usually travel in pods that help them gang up against predators. But this this dolphin did not have a swimming buddy, and appeared to be compromised.
Certain types of sharks do occasionally prey on dolphins — great white, bull and tiger sharks — but it is unusual for such an encounter to occur so close to shore.
Researchers were unable to find the dolphin’s remains afterward, so bite marks could not be used to determine what kind of sharks were involved.
The Post reported last week that as many as five great-white sharks have been satellite-tracked in the ocean off Long Island and New Jersey. But scientists said this is normal and that the apex predators pose far less danger to humans than the drive to the beach.
The 106th street beach has been reopened, and there has not been any sign of sharks close to shore.