The first time Mike Overtonsaw the bottlenose dolphins of Hilton Head Island propel themselves out of the water onto marsh banks in perfect unison to feed on fish, he was amazed.
"It is really a miracle in a way, that a creature could be so intelligent that you can watch them harvest their food that way," said Overton, owner of Outside Hilton Head , which leads kayak tours in local waters.
It's called strand-feeding, and it's "unique to only a couple of areas we know of in the southeastern United States," said Stacey Horstman, bottlenose dolphin conservation coordinator for the National Oceanic Atmospheric Administration's Fisheries Service.
The dolphins work in pairs or trios to herd the fish toward land, leap at the same time onto the bank to catch them and then wiggle back into the water, Horstman said. The process is over in a matter of seconds, she said.
Dolphins in other parts of the country also corral fish but eat them underwater, Horstman said.
More recently, however, scientists investigating the Gulf of Mexico oil leak have seen dolphins strand-feeding on Grand Isle, La., she said.
When the dolphins pop out of the water, it can be "explosive," said Marissa McArdle, co-manager of the Schooner Welcome, a touring sailboat on Hilton Head.
"For some people, when they see it ... they're stunned," she said. That's because most people expect only to see "dolphins peacefully cruising through the creek."
But the same visitors who love to watch strand-feeding could be causing the behavior's demise, said Wayne McFee, a NOAA marine biologist.
That's because some boaters feed dolphins, whose upturned faces and reputation for being "playful" lead people to think they might like a hot dog, a hamburger or even a beer, McFee said.
Mothers teach their calves that boaters are an easy food source, creating beggars, he said. Human food also can cause dolphins to become malnourished. McFee fears human-fed dolphins in the Lowcountry could lose their ability to hunt within just a few generations.
That would be a great loss, McArdle said.
"The dolphins on Hilton Head attract people like nothing I've ever seen," she said. "It's the No. 1 requested thing on boat tours.
"People want to know, where are the dolphins?"
How that question will be answered in the future, McFee says, will depend upon how humans treat one of the Lowcountry's favorite animals.