Tour of Sandy Shoreline Habitats
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The shorelines of the world's oceans draw our interest, perhaps because they are the most accessible parts of the ocean. They offer the merest glimpse of the hidden treasures of the ocean. We will divide the shoreline world here into 2 parts, rocky and sandy shores (another shoreline habitat, mangrove swamps, are treated separately). Rocky shores offer a stable base for the attachment of a variety of animals and plants. Sandy shores, with the moving sand particles, offer a very different challenge for animals and plants which would live there.
The Sandy Shore:
On a sandy shore, wave action deposits sand or other sediments and periodically move these sediments around. At first glance, these areas seem devoid of life, but in actuality the life is merely hidden - buried in the sand or even living between the grains of sand.
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The wide beach at Playa Nancite is an ideal nesting site for sea turtles (eggs above), including the endanged Olive Ridley Turtles. Other organisms, such as horseshoe crabs (below) nest on beaches or the shallow water just offshore in huge numbers. |
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| Above - Cavendish Beach on Prince Edward Island, Canada. We visited here as part of a field trip to the Northeast in 1998. More here. Right: Pellicans frolic over the waves at Cocoa Beach, Florida. The Kennedy Space Center is just to the north, for more on that and to see a shuttle launch click here. Bottom right - a beach at Manuel Antonio National Park, Costa Rica. Beaches and rocky shores often lie one right next to the other. Below: the white beach of Sanibel Island, Florida. Barrier islands such as Sanibel form from sand tossed up from the sea. During mild storms they tend to protect the coastline behind them, but in a major storm they can be washed away completely. |
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Left: Fisherman with helper (Snowy Egret, Egretta thula), Captiva Island, Florida. Many fish approach sandy shores to feed on the life hiding in the sands below. These fish, in turn, are the targets of fishermen and their wild counterparts, such as the Osprey (Pandion haliaetus) (below) or the gulls (lower left). |
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Left: The American Oystercatcher (Haematopus palliatus) uses its long, stout bill to probe for its prey. The Black Skimmer (Rynchops niger) uses its unique bill (with the lower jaw loger than the upper) to take its prey on the wing (below, left). The Brown Pelican (Pelecanus occidentalis) dives from a height of 10 meters or more to engulf fish in its greatly expandable throat pouch (below). |
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Sea Oats grow on coastal dunes along the eastern coast of the United States. They help to stabilize the dunes, preventing erosion during storms. Formerly seen as an eyesore limiting tourist access to the beaches, many resorts now protect the sea oats and rope off access routes to the beach. These resorts have come to see the value of plant-stabilized dunes between the expensive hotel and a hurricane.
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Ghost Crabs are common on many beaches - their uncanny ability to run to their holes and disappear is doubtless the source of their common name. The Ghost Crab pictured below, Ocypode quadrata, is getting ready to dive into its burrow on Sanibel Island. The two crabs to the right were on Playa Nancite in Costa Rica. |
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Left: An army of bright red Ghost Crabs met us on this beach in Manuel Antonio National Park in Costa Rica. These crabs always keep their stalked compound eyes perpendicular to the horizon, even when they are being held. |
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Right: Hermit crabs find snail and other gastropod shells and use them as portable protection. As the crab grows, it must find a new shell; in some places shells of the proper size may limit the hermit crab population. This hermit crab was on the beach at Manuel Antonio NP on the Pacific coast of Costa Rica. Below, a Sand Dollar (preserved specimen). Sand dollars are found offshore of sandy beaches. A radical, flattened form of a sea urchin, this echinoderm is commonly found off beaches in the southeastern US.
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The smooth bay shrimp (left) is found in shallow
waters with sandy bottoms.
Below: porpoises of various species are common sights off sandy shores, rocky shores, mangrove swamps, and of course in the open ocean. Some species hunt cooperatively and will drive a school of their prey into the shallow waters of a beach to facilitate catching them These porpoises were photographed at Sea World (Aurora, Ohio and Orlando, Florida) as well as in the Gulf of Mexico. |
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Below - beach sand, magnified. |
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Above: Marshes at Cape Cod and at Scarboro, Maine. Marshes are sandy shores where the sand and sediments have been stabilized by grasses. Ecologically, marshes are very similar to mangrove swamps and tend to occur in places where it is too cold for mangroves to grow.
| Proceed to Coral Reefs | Proceed to Mangrove Swamps |
| Proceed to Coral Reef Fish | Proceed to Sandy Shores |
| Proceed to Coral Reef Invertebrates | Proceed to Rocky Shores |
