Tuesday, July 12, 2016

Rachel Carson National Wildlife Refuge - Wells, ME

Rachel Carson was a world-renowned marine biologist, author and environmentalist who served as an aquatic biologist and editor-in-chief for the U.S. Fish & Wildlife Service. She has been credited with launching the contemporary environmental movement and awakening the concern of Americans for the environment. See https://www.fws.gov/refuge/Rachel_Carson/about/rachelcarson for more on her life.

The Rachel Carson National Wildlife Refuge in Wells, ME,  was established in 1966 in cooperation with the State of Maine to protect valuable salt marshes and estuaries for migratory birds. Located along 50 miles of coastline in York and Cumberland counties, the refuge consists of eleven divisions between Kittery and Cape Elizabeth. It will contain approximately 14,600 acres when land acquisition is complete. The proximity of the refuge to the coast and its location between the eastern deciduous forest and the boreal forest creates a composition of plants and animals not found elsewhere in Maine. Major habitat types present on the refuge include forested upland, barrier beach/dune, coastal meadows, tidal salt marsh, and the distinctive rocky coast.

The 1 mile walk meanders through the five habitat types with 11 trail markers indicating best places to view important environmental characteristics.








[ 1 ] The Edge of the Marsh

Salt marshes are fragile yet dynamic ecosystems.  Undisturbed coastal wetlands that have natural vegetation along their edges produce dense meadows of grasses and other plants that support abundant wildlife.


[ 2 ]The Edge of the Sea

This view shows all of the parts of this coastal Maine salt marsh.  From critical edge through creeks, salt pannes, marsh grass, beach and ocean, it is a system of soils, water, plants and wildlife that functions as a whole forming a unique and fragile community.



[ 3 ] Run-off

This intermittent stream is one of the obvious links between the forested upland and the salt marsh.  Clean water from the woodland seeps into the ground and then emerges in the stream.  Fresh water flows into the marsh, mixes nutrients with seawater and helps keep the marsh productive.



[ 4 ] The Critical Edge

Critical Edge is the portion of upland that runs along the border of the marsh.  This transition zone is part of the salt marsh system in that it sends fresh water into the marsh, provides food, cover, breeding habitat and travel corridors for wildlife that live in the coastal zone, and protects the marsh from the adverse impacts of human activities.



[ 5 ] Dedication Site



[ 6 ] Joining Rivers

Branch Brook merges with the Merriland River, creating the Little River, which flows to the ocean and reverses on incoming tides.  The tranquil nutrient-rich waters of the tidal rivers and marshes are nurseries for many of our shellfish and finfish.  Mussels, soft-shelled clams, flounder, bluefish and striped bass all depend on this habitat during part of their life cycle.  Abundant insects, worms, clams and fish in the marsh in turn attract flocks of feeding waterfowl, shorebirds, and wading birds.

 (I had help getting the following 4 photos... my Blackberry camera is good but not this good.)

Cranes

Egret (immature)

Lesser Yellow Leg

White Ibis

[ 7 ] Carbon Sequestration

Two grasses are responsible for both building a coastal salt marsh and making it one of the most productive ecosystems in the world.  Smooth cordgrass (Apartina alterniflora), a tall plant with stiff pointed leaves grows along the creek banks and low marsh.  It has special adaptations to get oxygen to its roots when flooded during high tide.  The shorter saltmeadow cordgrass or salt hay (Spartina patens) generally grows above mean high tide and forms broad "cowlicked" meadows of high marsh.  These grasses can produce up to ten tons of plant matter per acre per year - as much as a prime Midwestern corn field.  When these grasses convert sunlight and carbon dioxide into plant material, they lock up (sequester) that carbon dioxide so it is unable to contribute to greenhouse gasses that drive accelerated climate change.



[ 8 ] Salt Pannes

These small ponded areas are another feature of the marsh: salt pannes.  These low spots in the marsh hold salt water as the tide falls.  The water evaporates, concentrating salt in the pannes.  Only specialized saltt-tolerant plants like glassworts and sea-blite can grow here.  The pannes support populations of small invertebrate animals which make these ponds important feeding areas for waterfowl and shorebirds.


[ 9 ] Meanderings

Tidal creeks twist and turn as they wander through a salt marsh.  At any wide turn, or meander, tidal currents erode the outside bank as they build up the inside bank.  As the outside bank erodes the soil slumps into the creekbed.  The creek will slowly carry the soil away, spreading it through the marsh.



[ 10 ] The Tidal Flux

Marshes are flooded and drained twice a day by meandering tidal creeks.  The tides bring sea water into the marsh, mix in fresh water from the upland, and carry organic nutrients from decaying marsh grasses back into the bay.  This continuous exchange of water and nutrients among the upland, marsh and ocean keeps the marsh thriving and helps support a complex marine food web. 

Salt marshes exist in dynamic equilibrium with sea level.  As sea level gently increases, salt marshes can keep pace through plant growth, peat formation, and sediment deposition.  



[ 11 ] Hemlock Hollow

The coastal upland along this part of Maine's shore is evergreen.  White pines and hemlocks dominate, with oaks and maples intermingled and a ground cover of ferns.  Though out of sight of the marsh, this woodland is directly linked to it.  Ground water carries nutrients from the forest's decaying leaves and needles out to the marsh.  Many species of mammals and birds rely on both the marsh and the upland for food, cover, and breeding habitat.  



The 2005 Landslide 














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