Nature Notes: Long Island Archipelago

Long Island is the biggest island by far in the Long Island archipelago. This archipelago may not be a true archipelago like the Galapagos in the South Pacific off Ecuador or the Channel Islands off Southern California in the middle Pacific or the San Juan Islands off Washington in the northern Pacific. The status of Long Island as an island has long been in doubt, separated as it is from the rest of New York by the East River. The United States Supreme Court — lawyers, mind you, not coastal geologists or geographers — ruled 9 to 0 that Long Island is not an island but part of New York State’s mainland.

If we just stick to those islands included in New York State’s territorial boundary we have nine of them, not counting those that are part of New York City. If we throw in Block Island — part of Rhode Island, but equally close to Long Island — we get 10. The largest in New York State is Shelter Island, at a little more than 8,000 acres, while Gardiner’s Island is next at 3,308 acres, followed by Fishers Island at 2,224 acres, and trailed by Plum Island at 840 acres and Robins Island at 435 acres. Add up the other five — seven-acre Big Gull, Little Gull, North Dumpling, and South Dumpling, each an acre, and Wicopesset (the easternmost of all) at two acres and you add another 11 acres to the archipelago’s collective land mass. The last eight are in Southold Town. 

But let’s not forget the largest non-island island of them all, Long Island. It is 896,640 acres, or 1,401 square miles. So, the archipelago is 1,424.2 square miles in all, or 1.17 times larger than the State of Rhode Island. As sea level rises and coastal storms hit the archipelago, the very small islands will disappear soon unless protected by revetments, the rest not for centuries, and Long Island, probably never. In the future, based on current rates of loss of land to erosion into Long Island Sound, Block Island Sound, and the Atlantic Ocean, we are looking at a lot of shrinkage, as well as some complete overtopping. For example, Cartwright Shoal, a big sand spit at the south end of Gardiner’s Island, comes and goes with each big coastal storm. while the sand spit at the north end of Gardiner’s linking Fort Tyler with the rest of the island was under water throughout almost all of the 1900s.

Only one of these islands, Plum Island, is not completely in private hands; it is owned by the U.S. government, so Tom, Dick, Harry, or any other interested American citizen cannot take a walk on it without going through a very big length of red tape. Plum Island, part of the Department of Homeland Security, created after Sept. 11, 2001, is off limits to the publicsave for special arrangements.

I was lucky enough to visit Plum Island on Aug. 17. It was quite an experience. Not only were there harbor seals enjoying themselves on the north side of the island, but ospreys flew by with fish in their talons, an occasional turkey vulture drifted by, and the sky was full of tree swallows in the throes of migration, cleaning the air overhead of mosquitoes and other flying insects.

At least 10 monarch butterflies, as well as spicebush and folded-wing butterflies, were in attendance. There were quite a few patches of common milkweeds for monarch larvae to grow up on, but it was equally probable that these were migratory, having island-hopped from Massachusetts, Connecticut, or Rhode Island as they are wont to do when starting to move west-southwest toward that fabulous pine-covered mountainous overwintering spot deep in Mexico more than a thousand and a half miles away from their annual end-of-summer starting point.

I didn’t see a single pitch pine or white pine on the island, but did see a few Japanese black pines of the kind that are forever dying away on the Napeague isthmus in East Hampton Town. There were lots of native oaks, eastern red cedars, black cherries, and other indigenous Long Island tree species, as well as lots of native shrubs including bayberry, groundsel bush, and beach plums, thus the name “Plum Island.” However, for every native shrub, there was also a multiflora rose, Tartarian honeysuckle, or Russian olive to be seen growing next to it. There were native fox grapes in concert with Asian bittersweet, poison ivy with Japanese honeysuckle, not at all an Eden for a Long Island naturalist such as I.

I should have known. After all, the island has a long human use heritage dating back to the Civil War. It’s been a training center and coastal battery for the military for years and years. Then, retired from that duty after World War II, it became a laboratory to study animal diseases from afar that have not yet hit the United States. The place is full of dilapidated old buildings and several newer ones like the laboratories and the center with its elaborate spacious main conference room.

According to our guide, the freshwater wetlands are among the largest on Long Island. And wouldn’t you know it, they are mostly edged with Phragmites australis, that Eurasian reed that has become so well established throughout much of America.

The beaches are comparatively clean; I could find only one or two pieces of plastic in 300 yards of reconnoitering. But, even more amazing, the beaches are practically devoid of shells — no scallop shells, mussel shells, jingle shells, or spider crabs, and only the occasional slipper shell. Puzzling!

The island has a physical geography similar to Montauk. It has eroded bluffs, 15 to 50 feet high on both sides, some small dunes here and there, and typical beaches with some typical beach vegetation — beach grass and saltwart — between the high tide line and the fast land in back of it. Oddly, there is very little seaweed or eelgrass wrack, or even much of a wrack line to mark the flood tide limit. 

Plum Island is a remote part of the Harbor Hill moraine, which is glacial in origin, as is the South Fork. Thus, there are some glacial erratics scattered here and about, but not nearly as many as you might see on a walk in the hills around Sag Harbor. Most that you come across are half submerged in the water; they’ve already been washed out of the coastal bluffs.

Apparently there are no foxes on the island, but there are raccoons and opossums. The feds exterminate any deer that show up. There may be one or two left that they haven’t gotten. I purposely wore shorts and flip-flops to test for ticks. I walked through every tall grassy spot or vegetated edge I could find. Not one tick. But then again, at least two tick species, the black-legged and dog ticks, are in serious decline in some parts of the South Fork while the Lone Star tick takes over the territory.

The hoof-and-mouth disease laboratory is carrying on as it has since the late 1950s, while ground has already been broken for a brand-new one in Manhattan, Kansas. The Plum Island one will wind down in five or six years. What then? The federal government has said it will sell Plum Island to the highest bidder, just as Little Gull Island was recently sold. Our local representative, Lee Zeldin, has introduced a bill that would have the government make the land public in some form of a park or wildlife refuge.

The bill awaits passage in both houses, which may be a long way off, but I can’t imagine the island becoming just another of all those presently in the Long Island archipelago system that are privately owned and off limits to you and me. And such a publicly owned island could serve simultaneously as a nature preserve and a site for generating green electricity, which are compatible if done right.

Wouldn’t it be super if all of those islands and the waters surrounding them would one day become a marine sanctuary of the kind that California has along its coast stretching from Santa Barbara and the Channel Islands north to beyond San Francisco, where commercial and recreational fishing, as well as recreational boating, are allowed, but no oil well rigs or wind turbines are permitted?

Larry Penny can be reached via email at [email protected].