The Seashore

Under the gravitational pull of the sun and the moon, the tides come in and out at the seashore twice a day. When the sun and moon are in line with our planet, the gravitational pull is stronger, resulting in the highest and the lowest tides. Waves are caused by the winds; the push and pull of the wind gives the water its rolling and rising motion. When a wave breaks on the seashore, it runs up the beach until its energy is exhausted. Waves crash against the outcrops of metamorphic rock and mica, gradually pulverizing them into smaller and smaller pieces, until they are reduced to particles of sand and are smooth to the touch. Seawater is a great reservoir of heat and profoundly affects climate.

Horseshoe crabs remain at sea, coming to shore only to reproduce, once they are sexually mature, at ten years old. They live for about 20 years. Their blood is blue because of a protein containing copper, responsible for transporting oxygen in their blood plasma. The females release a pheromone to attract the males that fertilize their eggs, sometimes 90,000 per season. They use their tail spikes to steer and right themselves while swimming.

If you see a horseshoe crab on its back on the shore, gently pick it up (holding both sides of the shell, never the tail) and release it back into the water. Saving this species, and the many other species that depend on it is important.¹ Vital to the shoreline ecosystem, their eggs and larvae are an important source of food for many migratory birds, including gulls and terns (Laridae). American horseshoe crabs are only found in North America along the Gulf and Atlantic coasts, from Maine to Mexico. Three other species are found only in Southeast Asia and the Indian and Pacific Oceans.

This harbor has many winter visitors: bufflehead ducks (Bucephala albeola), hooded mergansers (Lophodytes cucullatus), and little bluebills or lesser scaups (Aythya affinis), along with terns (Laridae), and a variety of gulls (Laridae). Mallards (Anas platyrhynchos) can be seen year-round. In the summer months, majestic wading birds, like the snowy egret (Egretta thula) and great blue heron (Ardea herodias), can be seen hunting along the mudflats, stirring the mud with their feet to catch crustaceans or just standing still, watching for a fish to swim by.

Washed up on the seashore are rows of rockweed or bladder wrack (Fucus vesiculosis), red dulse (Palmaria palmata) and a red algae called Irish moss (Chondrus crispus). Seashells, significant to the culture of the Eastern Woodlands tribes, like the ocean quahog clam (Arctica islandica) are found here, as well as the Atlantic jacknife clam (Ensis directus) and the blue (Mytilus edulis) and ribbed mussel (Geukensia demissa). All are brought in on the high tide and stranded in the intertidal zone as the tide recedes. (See History).

All of the islands of the conservancy are natural, although some causeway trails leading out to some of the islands were built by the families living on this property in the 1800s. Although the islands have an elevation of ten feet at their highest, the land is high enough above the saltwater to allow trees to grow, like the post oak (Quercus stellata) and pignut hickory (Carya glabra), stunted by the harsh winds and storms that blow from the ocean. As testament to its North American origins, the name “hickory” derives from words in Algonquian and French. (See History).

On the beach and in rock pools many small, dark-green Asian shore crabs (Hemigrapsus sanguineus) scuttle about. Thought to have been brought in on water used as ships ballast, and then discharged when the ships were loaded with cargo, these opportunistic omnivores may out compete native species, like the fiddler crab.