Cape Cod National Seashore

Cape Cod National Seashore

Natural World


Cape Cod is a large peninsula extending 60 miles into the Atlantic ocean from the coast of Massachusetts. Located on the outer portion of the Cape, Cape Cod National Seashore's 44,600 acres encompass a rich mosaic of marine, estuarine, fresh water, and terrestrial ecosystems. These systems and their associated habitats reflect the Cape's glacial origin, dynamic natural processes, and at least 9,000 years of human activity. Geomorphic shoreline change, ground water fluctuations, tidal dynamics including rising sea level, and atmospheric deposition are among the many physical processes that continue to shape the Seashore's ecosystems. Marine and estuarine systems include beaches, sand spits, tidal flats, salt marshes, and soft-bottom benthos. Freshwater ecosystems include kettle ponds, vernal pools, sphagnum bogs, and swamps. Terrestrial systems include pitch pine and scrub oak forests, heathlands, dunes, and sandplain grasslands. Many of these habitats are globally uncommon and the species that occupy them are correspondingly rare.


Cape Cod National Seashore harbors a diverse array of terrestrial, wetland, aquatic, and marine plants that are uniquely adapted to life in the coastal environment. More than 800 species comprise the vascular flora of the seashore, which are associated with a number of landscape features. For example, heathlands, grasslands, dunes, woodlands, forests, vernal pools, kettle ponds, salt marshes, freshwater marshes, intertidal zones, and seagrass beds are among the different community-types that can be distinguished by their own special kinds of plant life. Past human activities on Cape Cod have played a major role in shaping the Seashore's vegetation. In fact, land-clearing practices by early European settlers gave rise to the seashore's extensive heathlands - a habitat that has since become globally rare. However, many plant communities within the Seashore are being negatively impacted as a result of human pressures on the environment. Sea-level rise, acid rain, ozone, groundwater withdrawal, nutrient enrichment, and invasions of exotic species are just a few of the threats that pose serious risks to plant diversity and ecological function across the landscape. We are developing techniques to effectively monitor plant communities and determine how they are changing in time and space. Armed with this kind of information, we can then devise well-informed management strategies that will help protect this resource.


Over 450 species of amphibians, reptiles, fish, birds, and mammals, and a myriad of invertebrate animals, depend on the diversity of upland, wetland, and coastal habitats found at Cape Cod National Seashore. Depending on the species, the park may provide habitat year round, or only during nesting season, migration, or the winter time. Park wildlife includes marine mammals and turtles; the familiar gulls, terns, and waterbirds of beaches and salt marshes; and a great variety of animals that inhabit the park's woodlands, heathlands, grasslands, swamps, marshes, and vernal ponds. Twenty five federally-protected species occur in the park, most prominently the threatened piping plover. The Seashore is a significant site for this species with roughly 5% of the entire Atlantic coast population nesting here. Cape Cod National Seashore also supports 32 species that are rare or endangered in the state of Massachusetts. Some of these, such as the common tern, are conspicuous; far less noticeable is the elusive spadefoot toad which spends most its life buried in the sand, emerging only on warm nights with torrential rainfall.

While Cape Cod National Seashore provides significant protection to wildlife and their habitats, there are concerns. For example, changes due to sea level rise or fire suppression may alter habitats, making them less suitable for some species. Disturbance, development, and road mortality may also take its toll on park wildlife. With a program of long-term inventory and monitoring, knowledge of park wildlife continues to grow, and with it, efforts to ensure its survival.

Estuaries and Salt Marshes


Herring River, Wellfleet:

Herring River Tidal Restoration Project Conceptual Restoration Plan

Herring River Groundwater Effect Report, 2007

Link to Town of Wellfleet Herring River Restoration Project Update website

Sedimentation Concerns Associated with the Proposed Restoration of Herring River Marsh, Wellfleet, Massachusetts

Herring River Groundwater Effect Report, 2004

Tidal Restoration Alternatives for Wellfleet's Herring River

A Wide-Culvert Alternative for Herring River Restoration, February 2005

East Harbor, Truro:

Annual Report on Estuarine Restoration at East Harbor (Truro, MA), Cape Cod National Seashore, September 2006

Hatches Harbor, Provincetown:

Estuarine Habitat Restoration at Cape Cod National Seashore: the Hatches Harbor Prototype (high-resolution pdf - large file)

Environmental Factors

From the air, outer Cape Cod appears to be a flooded landscape - a narrow arm of glacial outwash and moraine thrust 60 miles into the North Atlantic Ocean; fringed by thousands of acres of tidal marshes; peppered with over 30 freshwater ponds. Hydrologists call it "the sand pile in the ocean" because this image best describes the Cape's permeable soils infiltrated by seawater from both Cape Cod Bay and the Atlantic Ocean. Atop this saline groundwater floats a thin lens of freshwater sustained solely by precipitation that falls on the land surface. Fresh surface water resources, kettle ponds, dune ponds, vernal pools and the low-salinity upper reaches of estuaries, depend on fresh ground water. For the past 18,000 years of the Cape's post-glacial existence, the sea has dominated the local environment. Strong winds and salt spray stress even the hardy pitch pines and bear oaks, with a clear gradient of decreasing plant height and vigor as one approaches the Atlantic bluffs. The proximity and influence of the ocean is even evident in the ionic composition of the Park's kettle ponds, essentially containing very dilute seawater. The dominant vegetation of outer Cape Cod's forests, mostly pitch pine and black oak, has changed little over the past 9000 years, with the very important exception of almost total deforestation by European settlers from 1650 to 1900. Surviving artifacts of the extensive deforestation include globally rare heathland plant communities. These original pine-oak forests burned frequently, creating a mosaic of open and wooded habitats. Over the past 100 years much of the upland forest has grown back, especially on National Seashore lands which are protected from housing development. However, with fire suppression, the seashore's current forests are much less diverse than the prehistoric forests. Besides early deforestation, more modern human activities have altered the environment in various ways: suppressing natural fires, restricting tidal flow into coastal salt marshes, potentially loading surface waters with polluting nutrients and, from more distant pollutant sources, even changing the chemistry of precipitation. However, water quality to date remains high in freshwater ponds, estuaries and seashore beaches. Seashore staff monitor park terrestrial and water resources intensively in an effort to understand change and avoid or mitigate human-caused damage. The Park is also active in the restoration of human-disturbed habitats.