Nature Notes: A Watery Grave

We’ve just suffered through another northeaster, but fortunately missed Hurricane Joaquin, which went out to sea after bombarding the Bahamas and Bermuda. After a long lull between 1962 and 1983, we’ve had a plethora of costly coastal storms beginning with the March northeaster of 1984 and culminating with Sandy at the end of October 2012.

What God giveth, he can take away. He’s been doing that to Long Island ever since he and his glaciers created it more than 15,000 years ago. Barring a return glaciation in the next 15,000 years, Long Island will get smaller and smaller and eventually waste away to an elongate shoal, a tortuous bump in the water between the Long Island Sound and Atlantic Ocean.

Up until the 1950s, as calculated by annually measuring the distance between Montauk Point’s actual tip and the Lighthouse since its construction just after the turn of the 18th century, the South Fork was shortening at a rate of about a foot a year — some 200-plus feet gone by 1960.

Now the erosion rate in many places along our south and north shores is on the order of five or more feet per year. Long Island’s famous Atlantic Ocean barrier beach, stretching from Southampton Village to the Rockaways is similarly shrinking. If it weren’t for Georgina Reid’s tremendous volunteer efforts towards stabilizing the Lighthouse’s bluff followed by the Montauk Historical Society’s continued caretaking over the years lead by Greg Donahue, a “student” of Reid’s, the Lighthouse would be gone and the Point would have receded another 100 feet or so to the west.

Montauk’s north shore west of the inlet to Lake Montauk, once the largest freshwater pond on Long Island, but a tidal harbor after its permanent opening to Block Island Sound around 1926, is receding to the south at a rate of more than 3.75 feet per year since 1933, when the United States Coast and Geodetic Survey published a series of Long Island coastal survey maps. Areas downdrift of jetties constructed perpendicular to the run of the coast accelerate beach erosion and since the longshore current trends westerly from Montauk Point, that stretch of beach has been retreating at an accelerated rate ever since.

Once loosened by erosion, the very large glacial erratics that are partially responsible for Montauk’s rugged coastal aspect, roll down the coastal bluffs to the beach and stay there. The gigantic ones rising out of the water populated by seals and sports fishermen in season show vividly the course of such wearing away of the fastland over the years. Ultimately, Split Rock in Hither Woods, almost 100 feet above sea level and about as inland as you can get in the hamlet of Montauk, will become one of those offshore rocks. Enjoy it while you can.

Increasingly frequent coastal storms and steadily rising sea level will eventually reduce Montauk to a rock pile. Fort Pond, notwithstanding the barrier presented by the railway berm immediately to its north, Big Reed Pond and Oyster Pond east of it, and Fresh (or Hidden) Pond in Hither Woods will all drop into the sea in the same way that the pond above Cavett’s Cove and ones to the east and west of it went over the bluff at the beginning of the new millennium.

Brushy Island in the northwest corner of Fort Pond (Long Island’s second largest freshwater pond after Lake Ronkonkoma) and Star Island in Lake Montauk are barometers of the future. Brushy island was populated by tupelo trees as late as 1995. Twenty years later a few snags remain but the island is completely under water. Sea level’s rise has accounted for most of that; less dense freshwater on top of underlying denser seawater rises accordingly with sea rise. Brushy Island is already a ghost. The same fate awaits Star Island, unless of course fill is brought in to keep up with sea-level rise.

Both Lake Montauk and Fort Pond used to be seapoosed by the Montauketts and colonists, we are told. The evidence for seapoosing is markedly obvious on an 1892 U.S. coastal map of Montauk. That is how, undoubtedly, Fort Pond got its freshwater mussels. Big Fresh Pond in North Sea also has them. Alewives carry the larvae in their gills while at sea, and when they enter freshwater to spawn, the larvae drop off and become miniscule bivalve shellfish. Alewives are no longer in Fort Pond; they were cut off by the building of the railroad at the turn of the century, but Lake Montauk still gets them, and both Big Reed Pond and Stepping Stones Pond on the east and west sides of the lake with surface water connections to it have had breeding populations in the past.

Yes, we can cap carbon emissions, but it’s already too late to save Montauk and most of the rest of Long Island from an ultimate watery grave. In the meantime let’s cherish what God gave us and enjoy the sea and its biological riches. Anyone up for a little mahimahi washed down with some delicious Long Island wine?

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