Preserve Plum Island But Don’t Forget to Manage and Restore Its Habitat

The Town of Southold, on the North Fork of Long Island, passed a zoning ordinance last week that all but guarantees that Plum Island will not be subdivided, carved up and bulldozed for development.

But whether the 840-acre island, which lies at the eastern end of Long Island Sound off the tip of Orient Point, becomes a conservation success is another question.

I visited Plum Island last week, on a tour arranged by Save the Sound, just hours before the new zoning was approved. I left there with my conviction strengthened that Connecticut Audubon Society is taking the right position in opposing large-scale development, but wondering how, if that happens, the island’s intact habitat will actually be conserved and its disturbed habitat restored.

Plum Island is the home of the Plum Island Animal Disease Research Center, a federal government laboratory that works on vaccines and cures for diseases that affect animals such as cattle and pigs.

The research center is clustered on the western end of the island, which is also the site of a lighthouse built in 1869. Scattered throughout are the remains of an abandoned fort from the Spanish-American War era. The pilings of several old piers extend from the shore. Other than that, there’s nothing.

Conservationists are concerned about a mandate by Congress that the federal government move the lab to Kansas and sell Plum Island, which the General Services Administration plans to do at public auction. The worry has been that when the island is sold, hundreds of acres of coastal habitat might be converted into dense coastal development.

But the new zoning is very restrictive.

Research facilities will be permitted on the section of the island on which the laboratory is located now, an area of 160 acres. The minimum lot size in the research district is 125 acres.

The remaining 680 acres can be used for a nature preserve, public park, or an educational museum housed in one of the fort’s historic buildings; or, with a special permit from the town, for “Solar energy generation in excess of that needed to provide power to permitted uses.” The minimum lot size in the conservation district is 350 acres.

If you do the math, it’s easy to see what the Southold Town Board accomplished: no matter how you divide it, the island can have no more than two developable lots – one that is at least 160 acres in the 180-acre research district and another that is at least 350 acres in the 680-acre conservation district.

That ends any worries that Plum Island will subdivided into a housing development. But it doesn’t necessarily ease the concern that it will remain an important component of the many habitats that are part of the Long Island Sound ecosystem, or that its degraded areas will become better habitat.

Most of Plum Island’s 7.5 miles of coastline is deserted and wild-looking. Its dunes and bluffs – similar to those of other glacial moraine islands that stretch from Long Island to Cape Cod. – seem intact. It is within sight of the important tern colony on Great Gull Island. The rich waters of Plum Gut and The Race are nearby.

But limiting development is not the same as conserving critical habitat. The extent of real long-term habitat conservation on the island remains to be seen.

With us on our tour were representatives of the New York State Department of Environmental Conservation, the Connecticut Department of Energy and Environmental Protection, the U.S. Fish and Wildlife Service, the Nature Conservancy and a number of people from Save the Sound and its parent organization, Connecticut Fund for the Environment.

It was a highly restricted and chaperoned visit. Homeland Security agents checked our identification and searched our bags before we boarded the ferry. Plum Island officials accompanied us everywhere and did not allow us to wander anywhere on our own; mostly we had to stay on the bus.

On the occasions when we were let off the bus, we were allowed to look out over the mile and a half of narrow, flat beach facing Gardiner’s Island and Montauk, with dunes behind us and bluffs far to the east (there are shorter stretches of beach on the Connecticut-facing side of the island too).

We peaked at the island’s freshwater wetland, which covers 55 acres and is the drainage point, essentially, for the island’s aquifer. We drove past a huge lawn in the center of the island that used to serve as the fort’s training grounds.

Most of what we saw as we rode slowly through the interior was scrub-shrub fields dominated by invasive plants — bittersweet in particular but poison ivy, phragmites, and multiflora rose as well; there was some bayberry, staghorn sumac and beach rose but not as much as I would have expected.

Given the length of beaches and the fact that nobody uses them, I also would have expected Plum Island to be Piping Plover paradise. This year three chicks fledged from one nest, making it the best year ever recorded for Piping Plovers on Plum.

Great Gull, with its 10,800 pairs of nesting terns, is the next island to the east, and terns fished noisily above the whitecaps of Plum Gut, but no terns nest on Plum Island.

When I mentioned to one of the others on the tour that I found it hard to believe that no terns nest there and only three plover chicks fledged this year, she said she understood that Plum Island has a raccoon problem and that, in fact, the island’s managers have begun a raccoon control program. She suggested that perhaps raccoon predation limits the success of beach nesting birds. It’s also possible that the beaches, which seemed narrow and flat, get inundated regularly by high tides.

As for other wildlife, about a dozen Osprey platforms had active nests this year. We saw small clouds of Tree Swallows about to migrate and, we were told, the bluffs support colonies of Bank Swallows. Seals haul out on east shore rocks in winter. There are no deer – Plum Island’s managers are vigilant about keeping all hoofed animals off the island – and as a result there are no deer ticks (although dog ticks are abundant).

No one knows when Plum Island will go on the auction block. The government plans to move the laboratory to Kansas by 2021. A representative of the U.S. General Services Administration who was on the tour told us that the auction is not imminent.

Connecticut Audubon Society continues to support as much preservation on the island as possible, while recognizing that a large part of the island is already developed and actively used and another large part is dominated by the remains of the fort and the invasive species that have overtaken it.

In other words, Plum Island is ripe for preservation. But it is also ripe for a major conservation management plan and long-term habitat restoration project. – Tom Andersen, director of communications and community outreach