The bottlenose dolphin (Tursiops truncatus) is the most common marine mammal along the South Carolina coast. These are the dolphins that we see playing and feeding just off our island beaches. They are solid gray on top, with lighter sides and belly, and reach an adult length of between six and twelve feet. Bottlenose dolphins along the Atlantic Coast occur in two forms: those that live near the edge of the continental shelf (offshore form), and those that live within several miles of land (coastal form). These two forms differ slightly in body shape and size. The coastal form may be resident (present year round) or transient (present a few days out of the year as they migrate through our area). A study done in 2002 on the bottlenose dolphins in the Hilton Head Island area estimated that less than 400 individuals were resident here.
The bottlenose dolphins that live in South Carolina and Georgia are unique among dolphins on the east coast in at least one way: they engage in what is called "strand feeding". This is a method of feeding that occurs within a few hours of low tide in the marshes and creeks, and involves one to six dolphins rushing up onto the mudflats, pushing a wall of water in front of them. Fish are also carried along, and when both hit the mud, the dolphins grab the stranded fish. This is obviously a risky technique, as the further up the bank the dolphin lands, the harder it is to slide or wriggle back into the water. Dolphins that participate in this form of feeding also wear down the teeth on the right side of their jaws, as they ingest mud with the fish.
There are several things that you can do to help protect our dolphins:
Be sure all dolphins are clear of your boat before starting the engine; move slowly away from the area.
American Cetacean Society: http://acsonline.org/fact-sheets/bottlenose-dolphin/