Cape Poge - The Protector
Cape Poge Light has been moved back several times from the edge of the bluff.
At the edges of our lives, the sea pounds upon the shore, and the shore stands guard against the sea's assault. Or does it? The Vineyard littoral has changed repeatedly and significantly over time. It is changing still. The Times asked Jo-Ann Taylor, a coastal planner, to describe and illustrate the changing Island shores, in monthly illustrated installments, of which this is the second.
Cape Poge is a barrier beach. That means a number of things, in terms of its form and function. It separates Cape Poge Pond and Nantucket Sound. It is also the critical outer line of defense for Edgartown Harbor. When it blows hard from the east, or when there is an ocean swell running up Muskeget Channel, it is Cape Poge that bears the brunt of the wind and waves, not the boats in the harbor.
The form of Cape Poge belies its protective function, however. On a map or chart, Cape Poge appears as a delicate ribbon of sand. By no means dainty or delicate, the barrier is composed mostly of unconsolidated (soft) sands, leaving the beach free to migrate with day-to-day longshore transport, and to shift more dramatically under the influence of storm waves. It's easy to observe the day-to-day migration by watching seaweed or other floating objects strike the beach at an angle and then roll straight down to the water. The sand moves in the same manner.
An April 2003 aerial photo of Chappy. Courtesy MassGIS website.
The name Cape Poge was derived from the Wampanoag name "Capoag." Capoag wasn't always a cape. Shortly before the Des Barres chart was made in 1775, Capoag was a little island, not connected at all. A storm pasted the end of the beach onto Chappaquiddick in the mid 1700's.
In Colonial times, Cape Poge was used for sheep pasture, fishing, and hunting. The Poucha Pond Meadow and Fishing Company was formed in 1845 to manage the area for hunting and fishing interests. Hunting and gathering are still important, but more and more as leisure activities. Today, much of Cape Poge is owned by The Trustees of Reservations, which manages the area as a wildlife refuge with considerable recreational use.
If you've been to Cape Poge, you've been there on foot, or by boat, or by 4-wheel-drive vehicle. There are no roads, only soft sand. There are no power lines, no cable TV; just the wild and remote beaches.
After entering Cape Poge by crossing Dike Bridge onto East Beach, the first landscape includes trees, in the area known as "The Cedars," also shown as treed on the 1775 chart. By the mid 1800's, most of Cape Poge had been cleared for agriculture and firewood.
The next landmark is "The Jetties," constructed in an attempt to open and stabilize an inlet to the ocean there, much as they were used to stabilize inlets to harbors and ponds around the Island. The difference, of course, is that this is a barrier beach with no intention of being tamed. The inlet is long gone, and only traces of the stone jetties remain visible. The project turned out to be a monumental waste of money and the stones now remain as a monument to the folly of attempting such a feat.
Just past the Jetties lies Shear Pen Pond, the site of washing and shearing of sheep until the mid 1800's. More recently, the pond has earned the nickname "Shear Pin" Pond, since its shallow waters have claimed many an outboard motor's shear pin, the cotter that helps hold propellers in place.
A map of The Trustees of Reservations' Cape Poge Wildlife Refuge. Map courtesy TTOR
The lighthouse at the northerly tip of Cape Poge is another reminder of its protective role. The lighthouse may be seen from nine miles distant, watching over and lighting the way for boats. It is particularly important for boats sailing between Nantucket and the Vineyard. Erected in 1801, the lighthouse first moved back in 1825 and subsequently moved back again and again, as the ocean claimed more and more of the bluff in front of it; including a historic move in the 1990's, the first time that an entire lighthouse was ever moved by helicopter.
The bluff that stands before the lighthouse, protecting the protector, is clearly erosional, with a bare scarp facing the waves. Erosion at the bluff averages 4.2 feet per year, but the ocean may claim much more in any given year, as it did last year, when a large chunk disappeared. Proceeding west from the lighthouse, the narrow Cape Poge Elbow stretches toward North Neck at the "Gut."
How can this slender barrier protect the lands and waters behind it? Compare the barrier beach to the shear pin of "Shear Pin" Pond fame. The shear pin is softer than the boat's propeller and driveshaft, which it connects. It is designed to give way under strain, saving the more valuable propeller and shaft from damage. A barrier beach like Cape Poge performs in much the same sacrificial manner. The slender barrier rolls with the punches, absorbing the energy of stormy seas and retreating if necessary, keeping its form while rolling back. As evidence, Cape Poge today looks remarkably like Cape Poge in the 1775 chart, but for a small pile of stones reminding us to leave its form alone.
Jo-Ann Taylor studied geology at Smith College and Boston University, earning BA and MA degrees. Her background includes planning, oceanographic research (marine geophysics), small engineering projects, and government administration. For the past 14 years, she has served as the coastal planner for the Martha's Vineyard Commission.