By Claire Le Guern
On the Atlantic coast south of Martinique island, FWI, Anse Trabaud is a pristine secluded sandy beach stretching over a kilometer between Pointe d’Enfer and Pointe Baham. Exposed to the winds and the ocean, the beach is often battered by powerful waves that make the place popular with nature lovers and bodyboarders.
Bordered on its entire length by palm, coconut and pine trees, Anse Trabaud is full of shady places conducive to relax and gaze at the natural scenery.
The beach is large and very difficult to access by car or on foot, which limits all the traffic. So much the better! On foot, it takes a good 45 minutes of beautiful steps along the coast and the Savannah of petrifications, from the cove at Plums. By vehicle, a rocky, treacherous dirt, and sandy path must be followed for 20 minutes which ultimately leads to the beach.
By Andrew Cooper
Fire Island, NY is a barrier island that runs east to west on the southern coast of Long Island in New York. Like much of the coast in the area, the island has been heavily modified in an effort to slow the natural erosion and landward migration of the barrier island.
These efforts to slow the natural erosion involve massive fabric tubes filled with sand called geotubes (photo with truck). These tubes are a temporary effort to protect houses that are in danger of being damaged by seasonal storms. The tubes can not be moved when filled with sand, eventually degrade and fall apart over time, and pose threats to wildlife in the water and on land. Another measure used to slow erosion are groins made of concrete and placed in the water (photo with truck). These structures cause accelerated erosion in areas right next to them, often making the situation worse.
This beach is also being nourished in the additional photos. A large ship pumps sand from the ocean bottom to the beach. There, the water runs off and the sand is spread out on the beach by heavy equipment. This disrupts plant and animal life on the beach and makes is a very unpleasant place for a walk! The sand often does not match the composition of the sand that is naturally deposited on the beach as evidenced by different colors and grain size.
Fire Island, New York is an excellent example of a developed barrier island that is experiencing natural erosion. This makes Fire Island Beachcare’s Beach of the Month for July 2009.
By Andrew Cooper
Assawoman Island is in Virginia, USA on the peninsula of land between the Chesapeake Bay and Delaware Bay. Like many of the world’s barrier islands, Assawoman Island has been migrating landward for decades. Evidence for this can be found in the sea shells on the beach, multiple overwash fans (both pictured), and the occurrence of marsh mud balls on the beach.
This overwash fan formed during a storm when a low point in the dune line allowed storm waves to overtop the island and cover the marsh with beach and offshore sand. The process of overwash allows island to migrate towards the mainland by removing sand from the front of the island and adding it to the back.
Examining the seashells on the beach gives another indication that the island is moving toward the mainland. The dominant shell species on the beach are back-barrier fauna, such as oysters. These organisms lived in the estuary behind the island before they were buried by the island migrating toward the mainland. As the island migrates landward, these shells become exposed in the surf zone (where waves break). With each storm that passes, they are churned up and transported onto the beach. The dark colors of the shells indicate that they have not been exposed to the sun for long periods of time.
The large number of shells also highlights the lack of any public access to this beach. Months go by without much human activity at all making it a prime nesting site for the federally threatened piping plover. The pristine condition of Assawoman Island make it Beachcare.org’s June 2009 Beach of the Month.
By Andrew Cooper
Cedar Island, North Carolina, USA is an east – west trending island along the southern rim of Pamlico Sound. It is a fetch limited barrier island and beach, not subjected to open ocean waves. The breakwaters, visible in the photo, protect the landing for the ferry to Ocracoke Island. For more than 50 years there has been a well maintained fence along the road here to keep cattle and wild horses off the parking lot where cars line up for the ferry. As a result of the fence, grazing has been prevented on the western half of the island (in the lower part of the photo) while the eastern half of the island has been extensively overgrazed.
Where there has been no grazing, vegetated dunes have formed and a dark green rim of trees at the back of the island exists. On the overgrazed part of the island there are no dunes, very little forest and the island is almost featureless and flat. The beach on the ungrazed part is narrow and backed with dunes (see photo). The beach where the vegetation has been removed by grazers is wider and more or less merges with the island (shown in the photo of the Canadian Geese).
The normal yellow brown color of modern beach sands in the southeastern US is due to iron staining on shells and on the surface of quartz grains. Here on Cedar Island the sand is white because the iron staining (and the shells) were removed by long weathering in an ice age sand deposit which furnished the sand for the island. Note the double line of surf indicating that there are two offshore bars.
This photo was taken on a March, 2009 flight by Andrew Cooper.