The Changing Shape of the Cape & Islands: Cape Poge and North Neck, Martha’s Vineyard

A northwest-facing view of Chappaquiddick’s Cape Poge. Cape Cod can be seen in the background. Photo by Josh Shortsleeve. Inset: 1830 map of Chappaquiddick courtesy of Martha’s Vineyard Museum. Photo by Josh Shortsleeve

At its widest point, the elbow is 250 feet across, but according to Edgartown Harbormaster Charlie Blair, the southern tip has remained stable in recent years as a result of natural accretion and some beach re-nourishment where dredged sediment from the gut has been used to bolster the beach. Blair says the inside delta of the gut was last dredged in 2008, and town officials are considering additional dredging work in the area.

North Neck is another unique topographical feature. The peninsula extends some 2,000 feet into Cape Poge Bay, which is a popular spot for fishing and bird watching. Blair says the area around the neck has also been rather stable. “The current runs hard into the gut, and the sediment is pushed past the neck into the bay,” he says. “In looking at old maps of the area, North Neck looks the same as it did back in 1938.”

Though the neck, which does not face the open ocean, has remained mostly unchanged for at least several decades, the area just outside the gut has a different story to tell. “The bluff has been eroding my whole lifetime, and I’m nearly 70,” says Blair, referring to the coastal area southwest of the channel. “It has been peeling off, putting the houses at the top in serious danger.” Blair estimates that seven or eight homes, in addition to the historic Big Camp building near the Royal & Ancient Chappaquiddick Links golf course, are at risk from erosion. In recent years, property owners have taken some preventative measures, including planting vegetation on the bluff and installing stone bulkheads at its base.

During a 2011 storm, the elbow was breached about 200 yards to the south of a longtime summer camp known as the “windmill house,” where the beach measured just 75 feet across. A temporary channel developed—180 feet across and several feet deep. According to Kennedy, the breach filled in within a few weeks and no breaches have occurred since. This, Kennedy says, is most likely because the elbow is a “cobbled beach,” or one with a granite “spine” just under the surface, making it rather stable. “Often, breaches just happen,” Kennedy says. “It takes the right storm with prolonged winds from a specific quadrant to move the sand. However, the cobbled beach is so fortified that any breach is short-lived.” Though Kennedy says the elbow is relatively stable today, breaches like the one in 2011 could happen again.