Oceanside Meadows
Innstitute for the Arts and Sciences presents:
Discover the Salt Marsh
A
highly endangered habitat
Salt marshes are disappearing at an alarming rate due to a number of reasons. Most significantly, land developers are draining or filling marshes to build housing, factories, and roads. Mosquito control is another factor leading to marsh drainage. Furthermore, these natural habitats are often used as garbage dumps.
Marshes are extremely vulnerable to pollution buildup because of the way particles are recirculated within the marsh. Nutrients carried in from rivers, as well as from the sea, are mixed and constantly cycled in the marsh, forming a nutrient trap. This high concentration of nutrients results in a rich environment many times more productive than wheat fields. However, the marsh can just as easily trap pollutants, thus concentrating toxic chemicals and wastes from detergents, sewage, or agriculture.
Plants and animals cannot survive in such a harmful environment; the marsh, which takes hundreds of years to form, is easily threatened and lost within just a few decades. As awareness of the importance of salt marshes increases, Federal, State, and local governments are taking steps to establish natural preserves and to protect these valuable areas.
The
Formation of a Salt Marsh
A salt marsh forms when incoming tides carry and deposit sediment across low-lying land, resulting in wet mudflats. Saltwater grasses then slowly take hold and spread, stabilizing the land through the growth of root systems. As the plants decay and sediment builds up, peat deposits accumulate, forming a rich habitat that supports the growth of hundreds of diverse organisms.
A salt marsh is thus a place where the land meets the sea, created through tidal action over a span of hundreds of years. This unique habitat is confined to a narrow coastal fringe along shallow, protected bays. A healthy marsh maintains a delicate balance between salt water and fresh water, especially further inland where a salt marsh may merge with a brackish area or a freshwater swamp. Closer to the shoreline, the ebb and flood of daily tides creates zones:
* The Lower Marsh is often submerged under saltwater, and supports the growth of organisms adapted to high salinity and lots of moisture.
* The Upper Marsh is a drier area, where plants tolerate lower salt concentrations.
* The salt pans are small depressions that trap and hold water on a high tide.
* The highest edges of the marsh are only reached by extremely high tides, such as during a storm.
As you walk along the edge of the marsh, observe whether the tide is low or high, and try to identify the various zones created through the action of the tides.
Marsh Birds
Although many bird species feed at the marsh, only some species nest there. Wading birds are fairly common throughout the marsh. Some birds prefer particular zones. For example, among the birds that nest in Salt-Meadow Cord Grass, you may find Nelson’s Sharp-Tailed Sparrows and Saltmarsh Sharp-Tailed Sparrows. Both species are very closely related and have a distinctive orange triangle on the face, a gray crown, and whitish streaks on the back. Willets are large waders with a striking broad white wingstripe that is revealed in flight.
In the Upper Marsh, several species can be
found. The Northern Harrier is a slender raptor with long wings and tail, whose
face resembles that of an owl. It feeds on small birds and mammals.
The Savannah
Sparrow has a small bill, pointed wings, and a short, notched tail. Loud,
bubbling Bobolinks resemble sparrows but are larger, with pointed wings. The
Eastern Meadowlark has a black V-shaped breast band on yellow underparts.
Finally, in the thickets that border the marsh, you may see the solitary, secretive Green Heron capturing fish. It is small and chunky, with short legs, a deep chestnut back and sides, and green upperparts mixed with blue-gray. The Common Yellowthroat is a small and stocky bird with a short neck, round wings and tail, and a pale yellow throat, as its name suggests. The coarsely marked Song Sparrow has a fairly long tail, and its soft, pleasant call consists of a series of trills and clear notes.
Other
Marsh Animals
Detritus, which is carried in by the tides, as well as Cord Grass, provide a very rich source of food for many species of marine animals. Peek into the water and look for crabs and snails. Clams burrow into the mud, feeding on nutrients washed in by the tides. Raccoons, Otters and Muskrat forage for food among the tall grasses, as well as larger mammals such as deer and moose.
Marsh Plants
Different plants are adapted to the various zones of the marsh. The Lower Marsh is dominated by Salt-Marsh Cord Grass, which grows eight feet tall and has eight-inch-long upright spikelets. This grass forms large colonies that bloom from July through September, forcing out other grasses.
The
Upper Marsh has Salt-Meadow Cord Grass, which grows from one to three feet tall
and has one to four-inch-long terminal spikelets. Glasswort is a little plant
that grows about a foot tall with jointed, fleshy, cylindrical stems. Sea
Lavender grows one to two feet tall. It is characterized by minute five-petaled
pale purple flowers that grow on delicate branches. Seaside Goldenrod has
four-foot-tall clusters of tiny yellow flowers that bloom from August through
October. You may also find Orach, a plant with gray-green, trowel-shaped leaves.
Both Glasswort and Orach also grow in salt pans. Look for Seaside Plantain, a two to eight-inch plant with tiny grayish flowers.
At the highest edges of the marsh, observe clumps of Black Grass, a one to two-foot-tall wiry-stemmed rush, with tiny, blackish flowers. Its fruit turns brown quite early in the summer, so you can readily distinguish it from Spike Grass, which remains blue-green through September.
Adaptations:
Some marsh-dwelling organisms have special adaptations to varying amounts of salinity and changes in water levels. For example, Cord Grass contains special glands, allowing it to secrete excess salt. Some crabs have gills that can act as a primitive lung, enabling them to live both inside and out of the water. Other small insects simply move according to the tides, and climb onto higher vegetation when the water level rises.
"Of all the things that General Cobb planned and put into effect, the work on the Dyke Marsh endured the longest… To this day you can trace the broken dykes zigzagging across the marsh. They were kept in repair until gasoline motors took the place of horses and oxen, and many families of the Peninsula still own acres of the dyke land that has gone back to salt grass and to the sea."
- Louise Dickinson Rich, The Peninsula.
Or, nearer home, our steps he led
Where Salisbury’s level marshes spread
Mile-wide as flied the laden bee;
Where merry mowers, hale and strong,
Swept, scythe on scythe, their swaths along
The low green prairies of the sea.
- John Greenleaf Whittier, Snow-Bound
Come hear the sound of the surf...
... at
Oceanside Meadows Inn, the historic bed
and breakfast situated amidst the 200-acre preserve that inspired the guides
above. Visit our information
source page for more information about the inn and its incredible location
on the Schoodic Peninsula.
Oceanside Meadows Inn P.O. Box 90, Prospect Harbor, Maine
04669
Map and Directions to our
Inn
Tel: (207) 963 5557 Fax: (207) 963 5928 Email:
oceaninn@oceaninn.com
All information copyright 2001-02 Oceanside Meadows Innstitute for the Arts and Sciences.
Introductory:
Exploring the Seashore
The Salamander Trail
The Heron Trail
Intermediate:
The Rugged Rocky Shore
Realms of Sand
Discover the Salt Marsh
Life of Ponds and Streams
Wonders of the Sea: