POSTED: Wednesday, May 23, 2012 - 1:00am
UPDATED: Wednesday, May 23, 2012 - 1:04am
NBC NATIONAL NEWS — It's low tide in the low country of South Carolina as we board a 20 foot cuddy to cut through the calm waters of Saint Helena Sound.
Our boat is flanked by dolphins and egrets.
On this morning, our guide Kevin Benton, his girlfriend Julie Laney, and their dog "Bizzie Girl" are helping us search for something much more elusive.
"Most people don't even know about it. They think it's a joke," says Benton.
Morgan Island is steeped in mystery and, from a distance, appears to be deserted, but if you journey closer, through the unmarked waterways, you'll hear the rumble in the jungle and see the peering eyes of primates.
"There they are up on the bank. I see 'em," says Benton.
Within moments of our arrival, we are greeted by hundreds of Rhesus monkeys.
With a smile Benton exclaims, "Yeah, there's a bunch of 'em." Fathers, mothers, teenagers and babies call this island home.
"They think we're coming to feed em," says Benton.
Julie Laney says she and Benton come here for entertainment.
"I love it," she says. "I love to just come out here and anchor and watch the family structure of the monkeys."
As we anchor about 15 feet offshore, the monkeys begin to screech and make it clear, we should not get any closer.
Signs warn visitors to stay off the island and not to feed the animals.
Beyond the teenage monkey business and protective parents is a quiet secret.
These tattooed primates are being bred for lab testing and no one wants to talk about it.
In fact, when their caretakers see us, we hear them tell their driver to speed by us and not slow down.
As the workers from Charles River Labs arrive at the dock on Morgan Island, they quickly head on shore to avoid our camera.
Lab workers feed, treat and trap the younger monkeys for research.
Hundreds, each year, are taken by barge to the mainland, then shipped to research facilities across the country.
The colony of monkeys on Morgan Island is owned by the National Institutes of Health.
The NIH would not talk on camera, but did release a statement, saying the monkeys are given "... care in accordance with federal laws, regulations, and policies. No research is conducted on the island."
In nearby Yemassee, South Carolina we discovered more monkeys being raised for research.
Five years ago, Alpha Genesis lost the federal contract to care for the monkeys on Morgan Island.
Outside the gates, we videotape monkeys in cages and quickly discover, primate research is a sensitive business.
As we videotape on public property, an Alpha Genesis employee confronts us to say, "This is private property on the other side of the street sir. Will you please stop videotaping us sir?"
Back on Morgan Island, hundreds of tattooed monkeys are still teeming on the shoreline.
They aren't native to the area.
In fact, they aren't native to this country.
They were shipped here from Puerto Rico in 1979 to test the oral polio vaccine.
Since then, they have flourished.
Nearly 4,000 of them make this the largest colony of free ranging primates in the United States.
"Every time we come out here, there's a lot of babies. So, they're thriving," says Laney.
The monkeys are being used to research bio terrorism agents and find cures for deadly and debilitating illnesses such as AIDS.
Benton has mixed emotions about the testing.
"My mom had cancer. I don't know if they're being used for that or not, but hopefully they're being used to help humans," he says.
As we head home, it's clear, "Monkey Island" is no urban legend.
Three decades after this deserted island came alive, Laney says many locals still don't believe it.
"Well, sometimes you have to pull out a picture to prove it to some people and there's been people who've lived here all their lives and have never yet to see a monkey," she says.
The National Institutes of Health discourages visitors to the area to maintain as wild of an environment as possible.
Despite being owned by the State of South Carolina, visitors are not allowed on the island because of the danger of disease to both the monkeys and people.