Life in the Saltmarsh - Part 1

 

Sunrise over the saltmarsh at low tide.
Huntington Beach State Park, South Carolina.

Sometimes our travels take us to saltmarshes along the southeast Atlantic coast.  One of our favorite locations is Huntington Beach State Park in South Carolina.  The park has extensive saltmarshes with numerous access points that allow easy exploration of this unique ecosystem.   

Smooth Cordgrass, Spartina alterniflora at high tide.
Huntington Beach State Park, South Carolina. 

Saltmarshes appear simple, just one species of plant for acres and miles.  But look a little closer and all manner of life can be found.  The plant that predominates southeastern saltmarshes is Spartina alterniflora or Smooth Cordgrass.  

This remarkable grass not only lives but thrives in a very harsh environment.  Twice a day the tide rolls in.  As seawater partially submerges the Spartina plants they experience dramatic changes in salinity and temperature.  These environmental fluctuations prevent other plants from growing in the marsh, so Spartina provides the basis for the saltmarsh food chain.  

Marsh Periwinkle (Littoraria irroata) on Spartina.
Huntington Beach State Park, South Carolina. 

One of the most abundant animals in the saltmarsh is the Marsh Periwinkle (Littoraria irrorata). This small snail grazes on algae in the marsh mud and on dead Spartina. Amazingly, these lowly creatures also practice a primitive form of agriculture.  Marsh Periwinkles make wounds on living Spartina stems that become infected with a fungus.  Snails that eat the fungus grow more rapidly and have a better survival rate than those without access to the fungus.  

Marsh Periwinkle on mud at low tide. 
Huntington Beach State Park, South Carolina. 

Marsh Periwinkles are preyed upon by many animals including the reclusive Clapper Rail (Rallus crepitans).  These shy, chicken-like birds are more often heard than seen.  Clapper Rails walk the marsh mud and between the stalks of Spartina where they catch not only Marsh Periwinkles but also crustaceans, small fish and insects. Clapper Rails are dark brown with fine barring on the sides, a turned up white tail and a strong beak.  When viewed from the rear, Clapper Rails look like they have been squeezed.  They are as thin as a rail.  This compressed body shape allows the Rails to slip between the Spartina stems and quickly disappear.   

Clapper Rail (Rallus crepitans) dashing across the mud at low tide.
Huntington Beach State Park, South Carolina. 

Clapper Rail about to disappear into the Spartina.
Huntington Beach State Park, South Carolina.  

Fish are abundant in the tidal creeks of the saltmarsh and are fed upon by many wading birds.  Great Blue Herons (Ardea herodias), Great Egrets (Ardea alba) and Snowy Egrets (Egretta thula) impale fish with their long, pointed beaks. White Ibises (Eudocimus albus) and Wood Storks (Mycteria americana) work their open bills through the shallow water and snap up any prey they encounter.

Great Egret (Ardea alba) and 
Great Blue Heron (Ardea herodias) fishing at low tide.
Huntington Beach State Park, South Carolina. 

Snowy Egret (Egretta thula).
Huntington Beach State Park, South Carolina. 

Snowy Egret with a fish.
Huntington Beach State Park, South Carolina. 

White Ibis (Eudocimus albus).
Huntington Beach State Park, South Carolina. 

Wood Stork (Mycteria americana).
Huntington Beach State Park, South Carolina. 

Wood Stork feeding.
Huntington Beach State Park, South Carolina. 

Double-crested Cormorants (Phalacrocorax auritus) dive in the tidal creeks and catch fish with their hooked beaks. These relatives of pelicans are found in large numbers along the coast, on inland lakes and rivers.

Double-crested Cormorant (Phalacrocorax auritus).
Huntington Beach State Park, South Carolina. 

Double-crested Cormorant with a fish.
Huntington Beach State Park, South Carolina. 

Ospreys (Pandion haliaetus) are large birds of prey and have a most dramatic fishing style.  They dive from heights, plunge into the water feet first and snatch swimming fish.  Ospreys then lift off from the water carrying their catch in their sharp talons. 

Osprey (Pandion haliaetus).
Huntington Beach State Park, South Carolina. 

Roseate Spoonbills (Platalea ajaja) have a unique feeding style.  These pink waders sweep their spatulate bills through the mud catching fish and invertebrates they encounter.     

Roseate Spoonbill (Platalea ajaja).
Huntington Beach State Park, South Carolina. 

Roseate Spoonbill feeding.
Huntington Beach State Park, South Carolina. 

Saltmarshes are remarkable places.  Despite their apparent simplicity they are quite diverse and are a key to the coastal ecosystems. Saltmarshes teem with life and serve as a bulwark against hurricanes. So much is going on here, this blog will continue exploring saltmarshes in the next installment. 

Saltmarsh.
Huntington Beach State Park, South Carolina.