Swimming has resumed at Jones Beach, after a park official said three thresher sharks feasting on bunker fish off the Central Mall caused lifeguards to bar swimming there and at nearby fields shortly after noon on Saturday.
The presence of the predators and their prey at the start of the Labor Day holiday was confirmed by drone, said George Gorman, Long Island regional director of the state Office of Parks Recreation and Historic Preservation.
Cleaner ocean waters and thus increasing schools of bunker and other fish have lured sharks too close to shore to allow swimming on a number of occasions at several Long Island beaches this summer.
Beaches often are especially popular over the Labor Day holiday and Saturday’s fine weather was expected to draw large crowds.
Thresher sharks can live as long as 50 years and grow as long as 20 feet, according to the National Oceanic and Atmospheric Administration.
"Common thresher sharks are aggressive predators that feed near the top of the food chain on schooling fish such as herring and mackerel and occasionally on squid and seabirds," NOAA says on its web site.
NOAA describes their tails as sickle-shaped, adding, “the upper part is extremely long, about half the length of their body.”
Their color may vary from brown to blue-gray to black on the back. They tend to be lighter on the sides.