Oceanography | June 2022
High-Stakes Mudbank Chase
AT LOW TIDE, US SOUTHEAST DOLPHINS “BEACH” THEIR PREY
BY CHERYL LYN DYBAS, PHOTOS BY ILYA RASKIN
Captain Sam’s Spit, a sandy inlet at the
southern end of South Carolina’s Kiawah
Island, moves with the winds, the waves,
the tides. Sand grain by sand grain, it
erodes and accretes, erodes and accretes.
The spit’s shifting beaches and mud-
flats are important to species like piping
plovers, diamondback terrapins, and
Atlantic bottlenose dolphins. And to the
dolphins’ prey, mullets. The fish leap out
of the water in straight, clean slices to
escape their predators.
Mullets aren’t the only animals jump-
ing at Captain Sam’s Spit. The inlet is a
showcase for a low-tide bottlenose dol-
phin behavior called strand feeding. It
starts when two or more dolphins work
together to herd a school of mullets into
shallow water and toward the shoreline, in
this case the muddy banks of the Kiawah
River that runs between South Carolina’s
Kiawah and Seabrook islands.
It’s early November when Captain Jake
Feary, assistant director of outdoor pro-
grams at the Kiawah Island Golf Resort,
ferries us in a Boston Whaler to a spot just
off Captain Sam’s Spit. Slowing to an idle,
we quietly bob in small waves, waiting for
the display to start. Pelicans glide over-
head, alerting us to fish below. Where pel-
icans go, so, too, go the dolphins.
Just off the starboard bow, water sud-
denly splashes in all directions. Fins
appear, swirling in tighter and tighter
circles. “The show is about to begin,”
announces Feary. “The dolphins are
herding the fish into a ball they can drive
ashore, then they’ll surge onto the mudflat
right behind them.”
Dolphins corral the fish in a circle of
bubbles left in their wakes, pushing their
prey ever closer to the shore’s edge. All
at once, the dolphins rush the mudbank,
forcing the flopping fish ahead of them. A
wave of water from the lunging dolphins
carries the fish forward.
The dolphins are right on their tails,
heaving as much as two-thirds of their
bodies onto the mudflat. Their prey is
now stuck on the bank, unable to escape.
When almost every fish has become the
dolphins’ breakfast, lunch, or dinner, they
shimmy back into the shallows, there to
search for another school of fish to strand.
ONLY IN THE LOWCOUNTRY
Kiawah residents and visitors are lucky
to witness the spectacle, Feary says.
Dolphin strand feeding happens only
in the Lowcountry and a very few other
places around the globe. Captain Sam’s
is the sole location where strand feeding
doesn’t require a boat to spot. Depending
on the time of day and therefore tide, peo-
ple can watch by walking out to flats along
the Kiawah River.
“Along the East Coast, strand feeding can
be observed only in the tidal creeks and
marshes of South Carolina and Georgia,”
writes Cara Gubbins in The Dolphins of
Hilton Head.
In South America, dolphins strand feed
in Ecuador’s Gulf of Guayaquil. There,
strand feeding occurs at very low tides
in the interior channels of mangroves.
Extreme low tides, such as those at the
full moon, uncover wide mudflat beaches,
creating good conditions for strand feed-
ing, report Pedro Jimenez and Juan Jose
Alava in the Latin American Journal of
Aquatic Mammals.
“Groups of bottlenose dolphins, ranging
RIPPLE MARKS: THE STORY BEHIND THE STORY
Oceanography | June 2022