The appearance this week of numerous Portuguese man-of-war on ocean beaches from Montauk to East Hampton Village has created a sort of "Jaws" moment for local officials. They have not added up to a call to close beaches, as in the 1975 film about a killer great white shark, but officials have urged beachgoers to be cautious.
According to John Ryan Jr., the chief lifeguard for East Hampton Town, more than 30 have washed ashore. "A dozen were found in Montauk today," Mr. Ryan said on Tuesday, adding, "The majority of the man-of-war that we've found have been in Montauk. We've been checking the beaches every morning on the high-tide line."
The invertebrate, which is often mischaracterized as a jellyfish, is actually a colony of different organisms, called polyps. They become so specialized that they need each other to survive.
Portuguese man-of-war are generally found around the world in the ocean close to the equator, but strong currents sometimes pull them out of their range. "The recent southwest swell that has caused all of this surf has pushed them up the Gulf Stream. The water is five degrees warmer now," Mr. Ryan said.
"They have a tendency to stay in warmer waters, so the ongoing change in water climates is probably causing this problem," East Hampton Village Mayor Paul F. Rickenbach Jr. said. However, seeing these faux-jellies off Long Island is not so uncommon, according to Mr. Ryan. They were last spotted here after a storm in 2006.
Man-of-war are typically 12 inches long, 5 inches wide, and their tentacles can be up to 165 feet long. Their bodies and tentacles are covered in venom-filled nematocysts, which paralyze and kill prey such as small fish, and can pack a powerful sting. However, they are not as dangerous as one might think.
"People misunderstand them. There are cases where people have been severely affected, but it only will happen if you are allergic. If you get stung, you're not going to die," Mr. Ryan said.
Regardless of whether one is allergic to them, the sting is extremely uncomfortable. The tentacles can stick to the victim's skin and leave large, painful welts. Even after washing ashore, when they look dead, they can sting when touched.
There are ways to reduce the pain and swelling when stung. "Man-of-war stings are treated differently from a normal jellyfish sting. Remove the tentacle and rinse with cold fresh or salt water. But make sure you don't apply vinegar. That will make the pain worse," Mr. Ryan said. "But this is definitely one of the reasons why people should swim in protected areas."
Sounding relieved that no one had been stung, at least by Tuesday, Mr. Ryan confirmed that there was no plan to close the beaches. "We are looking for them. If we see a lot floating in a certain area, we would call people out of the water," he said.
"The village government and the local business owners want everybody to enjoy everything the town has to offer, including the beaches, on this very busy weekend of the summer," Mayor Rickenbach said.
Additional photograph: Jack Graves