An inside look at the natural side of Plum Island

Plum Island’s topography was created by the same advancing and receding glaciers that overran Long Island tens of thousands of years ago.

It features VW Beetle-size boulders on the north shore on Long Island Sound, fresh-water wetlands created by glacial runoff and smooth, sandy beaches to the south, which overlook Gardiners Bay. Block Island Sound is east.

“It’s all part of the same [glacial] moraine” that gave rise to the nearby Great Gull Island, Little Gull Island and Fishers Island, said Tom Dwyer, environmental protection specialist for the center, who led the tour.

Unlike much of Long Island, few of the island’s most breathtaking and untamed destinations have names.

Access around the island is via furrowed dirt roads or narrow-tar paths, leading up steep bluffs, through the “lost city” of the former military base known as Fort Terry, past military batteries that dot the coast and a pristine, mile-long south-shore beach.

Many of the island’s outposts are staffed or monitored by armed security guards, who also accompanied the group on a bus around the island.

The undeveloped parts of the island are thickly wooded, covered in underbrush and accented with flora — goldenrod and Montauk daisies were in bloom.

There are no grazing deer on the island — they haven’t been spotted since 2004, and there’s a policy to “cull” any that attempt to swim over from the mainland, to prevent any chance of disease spreading.

Depending on the season, the island is home to 215 species of birds, according to a Plum Island Biodiversity Survey conducted by the New York Natural Heritage Program in 2015, which found up to 111 species and communities of “conservation concern.”

There are mice, voles, turtles and bats, and it’s one of the state’s largest winter resting areas for gray and harbor seals.

Bluffs of varying size bound the island’s north shore, from the western tip at an 1869-era lighthouse overlooking Plum Gut and Orient Point, to the far eastern tip, which faces Long Island Sound and Gardiners Bay.

There’s a 55-acre wetland, which was created by a meltwater channel. Striations in the wetlands were created by a series of dunes that constituted the “old shoreline,” each backfilled with fresh water over centuries, Dwyer said.

Originally sold to settlers for a pittance by the Long Island Montaukett Indians, the island initially was used to graze cattle. In 1897 the U.S. Army bought the eastern end of the island and built coastal artillery batteries to safeguard Long Island Sound during the Spanish-American War.

Although several built-on bluffs have fallen, some batteries remain. The guns were “never fired except in practice,” said Dwyer. There’s also the remains of a facility to remotely detonate mines in waters around the facility. They too were never used.

The island took on its foot-and-mouth disease research role with the Department of Agriculture in 1954. There hasn’t been a U.S. outbreak of the disease since 1929, though research from outbreaks worldwide, including South Korea and the United Kingdom in early 2000s, are closely studied.

The center also developed a foot-and-mouth disease vaccine that can be developed here because it isn’t made from the disease’s antibodies. (In 2007, the lab diagnosed ebola in pigs.) The lab gets 10 to 12 “priority” samples a year.

Forty seven buildings, most abandoned, dot the island, including former barracks, administrative offices and a former disease research facility known as Building 257 that still features a weed-strewn cattle ramp. 

Testing equipment is placed strategically around, such as a large hilltop antenna used to monitor bird movements for a wind-energy turbine study.

There are no grazing deer on the island — they haven’t been spotted since 2004, and there’s a policy to “cull” any that attempt to swim over from the mainland, to prevent any chance of disease spreading. But there is testing equipment such as antennas and other equipment, placed strategically around the island for wind studies, bird movements and other ecological activity.