Sep 10 2010

Dolphin Encounters

Captain Anton DuMars, a coastal geologist and 30-year Folly Beach Resident, captured dolphin echolocation clicks off Folly with his hydrophone. Click the ‘play’ icon below to listen.


As an Eco-tour guide, I know a trip into the salt marsh almost always includes a dolphin encounter.  Next come the smiles and the wows.  Dolphins enchant us- all of us.  After spending almost 3 decades casually observing dolphins, I started paying a bit more attention to our tidal creek neighbors.  I began to see the same animals over and over again, often in the same bend in the same creek.  Using my iphone, I record dolphin geographic positions and numbers per pod, hoping to establish some patterns.  Taking a picture of these guys is like trying to take a picture of lightening- their next 2-second surface could happen anywhere.  So, in lieu of photographing subtle distinguishing dorsal fin features, I sketch them into my logbook instead.

In Folly Creek, I usually see “Saw fin” among a large dolphin pod, including juveniles and infants.  Apparently, dolphins segregate themselves like 3rd graders on a playground- girls over here and boys over there.  Girls work together to rear the little ones, while males swim alone, or with one or two other partners in crime.  Saw fin must be female, I conclude. I’ve seen “Prop fin”, a big male, working with other big boys, chasing mullet onto the bank at Morris Island.  “Tip” and “Flat top” make random appearances in their resident areas of the creeks. Some Dolphin sport numbers on their dorsal fin, apparently assigned by dolphin scientists.  I’ve recorded the position of “866”, “860”, and “854”- yet to find “007”.

All this above-the-water surface observation had me wondering what goes on below the surface.  We know dolphins make noise- anyone who’s seen “Flipper” knows this.  Intrigued, I bought a hydrophone and digital recorder from Cetacean Research Technology, Inc. out of Seattle.  My first deployment of the hydrophone captured dolphin echolocation clicks.  “Holy Crap!” I screamed, mildly impressing my passengers.  Since this initial recording, I’ve amassed over 50 dolphin recordings.  I’ve heard clicks, pings, pops, and oscillating whistles.  I even captured a strand feeding “charge” command, given just before two dolphins simultaneously exploded onto the creek bank chasing fish.  Other noises heard include snapping shrimp, grunting fish, and boat propeller sounds.  Bill Roumillat, a fish scientist with the South Carolina Department of Natural Resources knows a red drum from a spotted sea trout by voice.  He told me the best time and place to listen- I’ve got to do that!

My ultimate fantasy dolphin-recording goals include recognizing some language patterns.  Generic signals among dolphins must exist.  They work as groups to feed and raise young.  They also encounter dolphin from outside their pod who likely share the language, if it exists.  We all recognize the urgency when someone yells “fire!”  Maybe dolphins recognize that same urgency when one of them yells “boat!”  Seeing these animals thrills us.  Hearing them adds an entirely different dimension.

Captain Anton DuMars, a coastal geologist and 30-year Folly Beach resident, owns and operates Tideline Tours, LLC.  To contact Anton, please call 843-813-2497 or visit



Bob Hart Author

Plan Your Next Visit

Search Folly Beach Vacation Homes

Book Now