East Harbor is a tidal estuary in
Truro, Massachusetts
Truro is a town in Barnstable County, Massachusetts, United States, comprising two villages: Truro and North Truro. Located slightly more than 100 miles (160 km) by road from Boston, it is a summer vacation community just south of the nor ...
that was originally a harbor until it was cut off from
Cape Cod Bay
A cape is a clothing accessory or a sleeveless outer garment which drapes the wearer's back, arms, and chest, and connects at the neck.
History
Capes were common in medieval Europe, especially when combined with a hood in the chaperon. Th ...
to form a salt marsh lagoon, later renamed Pilgrim Lake. It is now within the
Cape Cod National Seashore
The Cape Cod National Seashore (CCNS), created on August 7, 1961, by President John F. Kennedy, encompasses on Cape Cod, in Massachusetts. It includes ponds, woods and beachfront of the Atlantic coastal pine barrens ecoregion. The CCNS includes ...
.
Original Harbor
Until the latter half of the nineteenth century, the East Harbor was a natural embayment deep enough to shelter Provincetown's fishing fleet during the winter, and was connected to Cape Cod Bay through a inlet.
[ This effectively isolated neighboring ]Provincetown
Provincetown is a New England town located at the extreme tip of Cape Cod in Barnstable County, Massachusetts, in the United States. A small coastal resort town with a year-round population of 3,664 as of the 2020 United States Census, Provincet ...
from Truro and other towns on Cape Cod.
Until late in the 19th century, there was not a single road leading in or out of Provincetown – the only way to travel by land to the rest of Cape Cod was to first head north, traversing a series of tall, rolling sand dunes
A dune is a landform composed of wind- or water-driven sand. It typically takes the form of a mound, ridge, or hill. An area with dunes is called a dune system or a dune complex. A large dune complex is called a dune field, while broad, fl ...
, and to then follow the thin strip of beach along the northern shore line, known as the "backshore". A wooden bridge was erected over the East Harbor in 1854, only to be destroyed by a winter storm and ice two years later. Although the bridge was replaced the following year, a traveler using it still had to traverse several miles over a sand route, which, together with the backshore route, would occasionally be washed out by storms.[ Prior to the railroad's arrival in 1873, Provincetown was like an island, in that it relied almost entirely upon the sea for its communication, travel, and commerce needs.]
Back Barrier Lagoon – Pilgrim Lake
The harbor was artificially separated from Cape Cod Bay and cut off from tidal flow in 1868, when a dike was constructed across the inlet to facilitate the laying of track for the arrival of the railroad. The wooden bridge and sand road were finally replaced by a formal roadway in 1877.[
The exclusion of tides changed the harbor into a back barrier ]salt marsh
A salt marsh or saltmarsh, also known as a coastal salt marsh or a tidal marsh, is a coastal ecosystem in the upper coastal intertidal zone between land and open saltwater or brackish water that is regularly flooded by the tides. It is dominated ...
lagoon
A lagoon is a shallow body of water separated from a larger body of water by a narrow landform, such as reefs, barrier islands, barrier peninsulas, or isthmuses. Lagoons are commonly divided into ''coastal lagoons'' (or ''barrier lagoons'') a ...
. In the early 1900s, a real-estate developer named this lagoon "Pilgrim Lake", and the U.S. Geological Survey
The United States Geological Survey (USGS), formerly simply known as the Geological Survey, is a scientific agency of the United States government. The scientists of the USGS study the landscape of the United States, its natural resources, and ...
officially adopted that name in February 1910.[
But it also caused salinity to decline from natural levels of ~25-30 parts per thousand (ppt) to nearly freshwater by the time of the first documented fish survey in 1911. By this time the native estuarine fauna were largely extinguished.]
Over time, the blockage of tides had caused further ecological problems. The lack of tidal flushing deprived the system of salty, nutrient-poor, oxygen-rich Cape Cod Bay water and it became a stagnant freshwater pond. These conditions resulted in midge outbreaks, fish kills, and a proliferation of exotic species.
After almost 140 years of impoundment, no native salt marsh vegetation was left in or around Pilgrim Lake. Instead, the floodplain was taken over by a non-native cattail
''Typha'' is a genus of about 30 species of monocotyledonous flowering plants in the family Typhaceae. These plants have a variety of common names, in British English as bulrush or reedmace, in American English as reed, cattail, or punks, in A ...
species and some highly invasive plants like purple loosestrife
''Lythrum salicaria'' or purple loosestrifeFlora of NW Europe''Lythrum salicaria'' is a flowering plant belonging to the family Lythraceae. It should not be confused with other plants sharing the name loosestrife that are members of the family P ...
(''Lythrum salicaria'') and common reed
''Phragmites australis'', known as the common reed, is a species of plant. It is a broadly distributed wetland grass that can grow up to tall.
Description
''Phragmites australis'' commonly forms extensive stands (known as reed beds), which may ...
(''Phragmites australis'').
Restoration
After an oxygen depletion and fish kill in 2001, the town of Truro and the National Park Service
The National Park Service (NPS) is an agency of the United States federal government within the U.S. Department of the Interior that manages all national parks, most national monuments, and other natural, historical, and recreational propertie ...
began to explore options to restore the estuary. They focused on a drainage pipe connecting Pilgrim Lake to Cape Cod Bay. This ~, diameter culvert had been fitted with clapper valve
A check valve, non-return valve, reflux valve, retention valve, foot valve, or one-way valve is a valve that normally allows fluid (liquid or gas) to flow through it in only one direction.
Check valves are two-port valves, meaning they have ...
s to allow freshwater to drain out of Pilgrim Lake, but prevented marine tides from flowing back into the system.
To restore partial tidal exchange and to improve water quality, they opened the clapper valves, which have remained open continuously since November 2002. Despite limits on tidal exchange imposed by the pipe's small diameter, and the distance that it travels underground, they have observed a substantial response in the recovery of salinity and estuarine biota.
In June 2008, Pilgrim Lake was officially renamed back to its original moniker, East Harbor.
The 720-acre East Harbor system, includes Moon Meadow, Salt Meadow and the East Harbor lagoon.
References
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Ports and harbors of Massachusetts
Truro, Massachusetts
Cape Cod National Seashore
Geography of Barnstable County, Massachusetts
Transportation in Barnstable County, Massachusetts