Tuesday, July 3, 2012

Sapelo Island beaches

Nanny goat beach

A road leads directly from the Reynold's Mansion to Nanny goat beach.   The road passes through the marshes and ends at a parking area behind the dunes.  A boardwalk arches over the wind blown dunes to the beach.  Sun rise at the beach is a magical time.  The quiet warm glow of the sun turns the sky and sand pink.  

Ghost crabs (Ocypode quadrata) seem to fly across the beach from twilight until dawn foraging among the wrack.  As the sky brightens they head for cover. Their burrows are tucked beneath arching stalks of Sea oats (Uniola paniculata), among lengths of pennywort (Hydrocotyle sp.) and morning glory (Ipomoea sp.) that reach down from the dunes to the beach.  The area around an active burrow entrance is covered with numerous foot prints.

The dunes are formed by an accumulation of wind blown sand.  The loose sand of newly formed dunes is easily blown or washed away.  Older dunes, stabilized by plants, shift and move more slowly.  The extensive roots and runners of the beach plants help them stay anchored on the shifting sand.  As the plants grow they form a mat that traps more sand making the dunes more stable.

It may not look like it, but the surf zone is alive with worms, crabs, snails and clams.  You just may not notice them.  Their presence is known by all the burrow holes and trails.   By following the large trails in the sand we uncovered Shark's eye Moon snails (Neverita duplicata) and a Lettered Olives (Oliva sayana).  Both of these snails are active hunters who prey on smaller clams and snails.  Shells moon snails have fed on have a small round tell-tale bore hole.

There are traces of other animals on the beach too.  The Plume worm (Diopatra cuprea) cements shell and other debris to its tube.  Pieces of the tubes covered in Dwarf Surf clam (Mulinia laterals) and small Tellin shells were found washed up on the shore among the very colorful Coquina clams (Donax variables).  Numerous empty Coquina shells were scattered along the beach, the living clams are just at the waters edge.  Small breathing holes betray them.  If you look for them you can find clams washed out by the waves rapidly burrowing back in the sand.

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