When the glistening dorsal fins first sliced through the water, Debra Iannelli thought they belonged to sharks.
Ms. Iannelli instantly felt a “fear factor” — after all, she was six feet away on a paddleboard and, at a full 300 yards out into Long Island Sound near Orient Point, she was in their territory.
Luckily, however, Ms. Iannelli then noticed the fins were too curved to be those of sharks. Instead, they belonged to a pod of about 60 bottlenose dolphins, splashing around in Friday’s late-afternoon sunlight, searching for food.
“I was afraid at first, but then when I realized what they were, it was absolutely the most amazing paddle of my life,” she said.
Residents and boaters across Long Island reported seeing dolphins over the weekend, from Orient Point to spots as far west as Hempstead Harbor. The aquatic mammals received something of a celebrity reception for their presence in the Sound.
“It was majestic,” Ms. Iannelli said. “I was in heaven. I can’t even describe my euphoria.”
As if her paddleboard experience wasn’t enough, Ms. Iannelli then saw the dolphins Saturday morning from her house in the Orient by the Sea neighborhood.
The dolphins’ appearance here, while not unheard of, is still somewhat rare. This past weekend’s multiple sightings were thanks to “a combination of good things happening,” said Kim Durham, rescue program director at the Riverhead Foundation for Marine Research and Preservation.
In the past, bottlenose dolphins have tended to venture no farther up the coast than New Jersey, Ms. Durham explained. But as their food, sometimes called “bait fish,” moves farther north and closer to shore, the dolphins follow.
“The waters are full of [bait fish] right now, and it’s leading to some amazing dolphin encounters,” she said.
Alyssa Montellesse, a part-time Wading River resident, spotted dolphins while out on her boat with her family around 3 p.m. Saturday near Wildwood State Park.
“A jetskiier came by and said ‘There are dolphins down there!’ı” she recalled. “We went out there and we started looking for them. What we saw was dolphins coming fully out of the water. It was incredible. I would say there were at least 100 dolphins, cruising along, jumping out of the water and diving back down.
“It was a once-in-a-lifetime experience.”
Tom Hartnett, a professional hockey player from Westchester County, had one such experience at around 1 p.m. Friday. While on a boat just east of Plum Island, he saw close to 15 dolphins “putting on a little show.”
“It was very surprising,” he said. “I didn’t know that they even come close to Long Island Sound, so for a little bit, I was in disbelief. They were very energetic, splashing around.”
Mr. Hartnett estimated that the dolphins came within 30 feet of the boat; it was the first time he had ever seen dolphins in the wild.
“That’s why there was a lot of disbelief: The first time I saw dolphins, it wasn’t in Florida — it was in the Long Island Sound,” he said.
Five facts about bottlenose dolphins
• Bottlenose dolphins tend to inhabit temperate and tropical waters, though they can sometimes be found as far north as the southern tip of Norway and as far south as New Zealand.
• Like other dolphin species, the bottlenose uses echolocation when hunting. The process works similarly to sonar: Dolphins emit a series of clicks, which send sound waves into the water around them. The sound waves bounce off fish and, based on the speed and direction, dolphins are able to locate their prey.
• They sometimes use an outrageous practice called “fish whacking” to catch their prey. Like circus performers, the dolphins strike fish with the ends of their tails, called flukes, often launching the fish straight up out of the water.
• The bottlenose dolphin has been immortalized in American popular culture. A fictional dolphin named Flipper — played by a variety of real dolphins — starred in movies in 1963 and 1996 and in a spinoff television series from 1964 to 1967.
• Homosexual relations between bottlenose dolphins, especially between young males, are fairly common. In a decade-long study of a dolphin population, conducted from 1989 to 1999, researchers found that “half of all socio-sexual events were homosexual.” The researchers speculated that such activity is done to form bonds or alliances.
Sources: National Oceanic and Atmospheric Administration
Although Ms. Iannelli remembers seeing only adult animals, Greenport resident Jamie Droskoski saw several dolphin calves off the eastern coast of Gardiners Island between 10 and 11 a.m. Saturday.
“The little ones were clearing the water,” she said. “The bigger ones would jump around a little bit, but they weren’t getting way out of the water like the little ones were.”
Ms. Droskoski was struck by their behavior: All at once, she said, the dolphins would dive underwater for at least 20 seconds. Then they would resurface, sometimes as close as 25 yards from the boat.
Altogether, she estimated there were 40 dolphins — the most she has ever seen in one group.
“Seeing that many at once was one of the coolest wildlife experiences that I’ve had,” she said. “I’ve never been up close and personal with dolphins in the wild ever before … Seeing that number of them all together was fascinating.”
Ms. Durham was particularly encouraged to hear that the dolphins appeared to be healthy. In 2013, bottlenose dolphins along the East Coast began dying rapidly from a naturally occurring virus that left them emaciated, discolored and covered in lesions.
“This virus was pretty horrific,” Ms. Durham said. “It really destroyed a lot of animals and we were getting a lot of sickly bottlenose dolphins washing up on our shore. I’m quite happy to get the reports that these animals are flourishing again.”
Unfortunately, onlookers must keep their distance from the seemingly friendly creatures, despite living in a culture in which dolphins are glorified as guardians and in which almost every Caribbean resort offers a chance to swim with them.
Although they are neither endangered nor threatened, Ms. Durham explained, bottlenose dolphins are a protected species under the Marine Mammal Protection Act of 1972. Therefore, it is illegal to swim with or feed them.
“We’re just encouraging people to enjoy it and to enjoy it safely from their vessels,” she said. “Give those animals a lot of space.”