Something remarkable has happened over the last few years off the coast near Brigantine: A sandbar, or shoal, has emerged into what wildlife officials are calling a 100-acre island complete with lagoon that already is “one of the most critically important areas for birds” in New Jersey.

Officials from the state Department of Environmental Protection and U.S. Fish and Wildlife Service launched a plan this year to manage what they’ve named Horseshoe Island and close it to the public from March 1 to Sept. 30, when nesting is over, for the next five years. The island is about 1,200 feet offshore, just south of Little Egg Inlet off what’s known as Little Beach Islands near Brigantine.

“I don’t think we’re saying it’s going to be permanent, but it’s evolved to where it’s an island now,” said Todd Pover, a senior biologist with the Conserve Wildlife Foundation of New Jersey. “We’re being told by experts it could last a number of years. We certainly don’t have anything like it anywhere else in New Jersey.”

Sandbars are nothing new at the Jersey Shore — coming and going with the tides, and ever shifting their shapes. But Horseshoe Island is different, Pover said, because of its size, location near protected areas, and apparent staying power.

The island, off Little Egg Inlet, now shows up on Google Earth satellite images. And officials say it survived last weekend’s battering nor’easter.

The management plan says Horseshoe Island, so named for its shape, provides habitat for a number of species, including 470 endangered least terns, making it the largest colony of the species in the state. It also provides roosting habitat for 80 red knots, which are federally threatened and state endangered.

It also provides nesting or roosting habitat for other state endangered or species of special concern including six pairs of breeding American oystercatchers, 380 black skimmers, 50 common terns, 24 royal terns, 10 piping plovers, and other species, including brown pelicans, whimbrels, and ruddy turnstones.

“It’s not just that the island is unique,” Pover said, “but it’s become a very important habitat. It has a number of endangered species though it’s a relatively small 100 acres.”

Pover and other biologists from the Conserve Wildlife Foundation of New Jersey had been monitoring the evolution of the sandbar for three years. An article Pover wrote last month about the island attracted the attention of boaters.

As Memorial Day weekend approaches, however, those boaters are angered over the closure. For at least the last few summers, they have flocked to the island to sunbathe, swim, and picnic.

“I understand that people want to protect the environment,” said Michael Gremling, 57, who has been boating in the area for years. “But that thing is a mile or two around. It’s huge, and I don’t see why there couldn’t be sharing of it. … It’s a sandbar, well, really a shoal. It’s not an island. If it disappeared tomorrow, those birds would lay their eggs somewhere else and fly on.”

Where did the island come from?

The island is within an area of Atlantic County noted “as one of the most dynamic ecosystems in New Jersey,” according to the management plan released in April. It includes miles of inlets that intersect with areas of the 48,000-acre Edwin B. Forsythe National Wildlife Refuge, which is managed by the U.S. Fish and Wildlife Service and also designated a National Wilderness Area.

The western side of the Little Egg Inlet is also next to the state DEP’s Fish and Wildlife’s Great Bay Boulevard Wildlife Management Area and is overlaid by the Jacques Cousteau National Estuarine Research Reserve. And parts of Holgate at the southern tip of Long Beach Island are also closed part of the year for birds.

All those surrounding protections have made nearby marshland a major habitat for wildlife over the years.

Shifting sand is common along those protected coastal areas near the Little Egg Inlet, a gap between North Brigantine and Holgate on Long Beach Island. The inlet leads into the Great Bay.

Sand from beach replenishment projects totaling 21 million cubic yards along Long Island Beach, as well as dredging projects, likely drifted south to form the platform shoal that became Horseshoe Island. Wildlife officials say it wasn’t until spring 2018 that the shoal started remaining intact through all tides, leading to the idea it is at least semipermanent.

It’s likely birds started to make homes on the island in 2020, but no one was monitoring because of the pandemic. However, by 2021 biologists confirmed that birds were breeding there and remained until nesting was finished in September. And vegetation has started to grow, officials said.

The island is not easily accessible other than by boat and is surrounded by a maze of marshland and inlets. Its shape remains dynamic.

“The use of this island was truly unprecedented in this part of New Jersey in terms of avian species diversity and abundance, particularly among species of conservation concern,” the management plan states, eventually concluding that now, “Horseshoe Island is one of the most critically important areas for birds in the State of New Jersey.”

Who protected it and why?

The biologists who monitored birds encountered boaters who brought unleashed dogs and jet skis that circled the lagoon. The biologists installed signs to mark off the areas most used by birds.

Sensing an urgency, state and federal officials approached New Jersey’s Tidelands Resource Council, which oversees riparian lands. The council voted 4-2 on Feb. 2 to grant management rights to New Jersey Fish and Wildlife and the U.S. Fish and Wildlife Service, including a seasonal closure of March 1-Sept. 30. One member of the public spoke out against the plan, according to the meeting minutes.

But most boaters say they were unaware of the Tidelands Resource Council meeting.

Larry Hajna, a DEP spokesperson, said state law authorizes the agency “to restrict public access to tidal waters and adjacent shorelines to protect threatened or endangered species and their habitat.”

Hajna noted boaters are still able to travel around but not on the island.

“This type of habitat is very rare along the highly developed New Jersey coastline and may be fleeting, due to the dynamic nature of coastal ecosystems,” Hajna wrote. “In 2021, more than 1,360 coastal birds used the sandbar/island for nesting, foraging, and roosting.”

Champagne Island, a smaller, shape-shifting sandbar near Hereford Inlet, Cape May County, once had a similar management plan that expired and is now popular with beachgoers and boaters.

Why are boaters miffed?

Gremling, who has been traveling to the area since 2010, said Horseshoe Island has become popular because of its “monstrous” size. Boaters tend to stay on the western side of the “shoal” because of winds and waves, he said, but the birds mostly stay on the eastern side. He heads there now on a jet ski.

Boaters who object to the closing of the island call the decision excessive given that the area is already surrounded by tens of thousands of off-limits acres. Boaters say they cleaned up after themselves and respected the areas with posted signs around bird habitat areas.

On weekends, 20 to 30 watercraft might be anchored on the island. On holidays, there were more.

Steve Martinovitch, 55, of Atco, Camden County, said he’s been boating and fishing in the area for years, long before the sandbar began to emerge. He pilots his 19-foot center console boat there from Tuckerton.

“What right do they have to close an island for a couple of birds nests?” Martinovitch asked. “We’ve been going there longer than any birds have been there.”

Rosemary Bunker, 68, from Columbus, Burlington County, portrayed the island as a family-oriented paradise.

“I was shocked when I heard we couldn’t go there anymore,” Bunker said. “It was a place you could enjoy all day, unlike other sandbars that just go away. I don’t know why they are taking it away from the boaters.”

However, protection of the island has supporters, too.

“Fascinating! Great news! Keep the boats out, give the birds a chance,” one commenter, Beth Kovacs, wrote on Pover’s article.