CHARLESTON, S.C. - A summer of high-profile shark attacks has led to a common question: Where do they come from?
The answer: Acombination of shallow estuaries, abundant food and warm waters makes the Carolina coast a prime nursing area for dozens of species of young sharks, from the common Atlantic sharpnose to the fearsome tiger.
In shallow bays and briny river deltas teeming with fish and shrimp, the juvenile eating machines feed and grow until they're ready to brave the open ocean.
"There's a lot of food in sheltered areas," said Chris Jensen, a North Carolina marine researcher. "It's just a great place for sharks."
Still, their numbers in Carolina waters have dropped from two decades ago. And despite the recent attacks, experts say people are still far more dangerous to sharks than the other way around.
Most species won't attack a human unless provoked, and those that do often bite by accident, mistaking people for other prey.
Humans prize sharks, though, for their meat and fins. Biologists estimate that heavy fishing during the 1980s reduced some species by up to 75 percent before federal restrictions were put in place.
Researchers say it's important to understand more about where and how sharks live, both from an environmental standpoint - sharks play an important role in the ocean's ecosystem - and so they can be protected.
Until recently, biologists knew very little about young sharks. So a federally funded study along the Eastern Seaboard is trying to learn more. Already the research has found that several species migrate more than expected, and some juveniles return to the same spot year after year.
The South Carolina portion of the study is headed by Glenn Ulrich, a state biologist who has held hundreds of shark "pups" in his bare hands, punching bright blue plastic tags through their fins.
Three days after a shark killed a Virginia man vacationing on the Outer Banks, Ulrich led a shark-catching expedition into Bulls Bay, north of Charleston.
Two 17-foot boats sliced through the calm waters with five researchers from the South Carolina Department of Natural Resources on board. Their gear was simple: four fishing poles in one boat, a gossamer net the length of 2 1/2 football fields in the other.
Ulrich has had a long relationship with sharks. He's been catching them since 1983, when the South Carolina department received a grant to study the Atlantic sharpnose, the most common species off the Carolinas.
Nowadays he's catching mostly babies and juveniles among the golden-green marsh grass of Bulls Bay and other prime nursing areas, from St. Helena Sound to Charleston Harbor.
Three miles out from the dock, in 10-foot-deep waters, the researchers strung their 780-foot gillnet across the mouth of Five Fathoms Creek. They pulled their boat away and waited.
When a yellow float strung along the net disappeared beneath the surface, it was time to go to work.
'A hard life'
Most sharks are born in the open water. Their mothers, who have carried them for up to a year, lead them to the mouth of a bay or estuary, then leave them to fend for themselves.
"It's a hard life, and it starts early," Ulrich says.
In the Carolinas, researchers have caught newborn sharks in Oregon Inlet, Pamlico Sound, the Cape Fear River, Charleston Harbor, St. Helena Sound and more.
The shallow, murky waters supply the pups with plenty of prey - crabs, shrimp, squid and fish. And they protect them from their main predators: bigger sharks.
The National Marine Fisheries Service, which helps manage shark populations, started studying young sharks in the late 1990s with a project called Coastspan.
The idea is to find shark nurseries in the Atlantic and determine which species use them.
Both Carolinas are active parts of the study, which involves about 20 scientists, including Ulrich. It operates with a budget of less than $50,000 a year, said Wes Pratt, the project administrator. So far, the researchers have tagged more than 4,000 sharks.
Each $1 plastic tag has an identification number and the address of the Coastspan headquarters in Rhode Island. Fishermen who catch a tagged shark are asked to report its length and location. They get a hat in return.
Some of the sharks have been caught as far south as Mexico.
Gathering the catch
Struggling to keep their footing on a boat slick with ocean muck and jellyfish guts, David Smoak and Doug Oakley worked the net, pulling it arm over arm across the bow of the boat.
Their prizes are wrapped in microfilaments, struggling to escape. When a shark hits the net, its head slips through the holes, and the filaments catch behind the gills. Panicked, the fish rolls over and over.
Some bite free, but most only tangle themselves more.
As they pulled each shark onto the boat, the researchers grasped them firmly around the upper body to work them free of the net. The sharks' skin is like rough sandpaper in the researchers' hands, and their bodies thrash with surprising strength.
"You've got to grab them up near the head," Ulrich says. "Otherwise, they'll whip around and bite you."
Ulrich speaks from experience. A few years ago, his wife asked him if he was afraid of getting bitten. He assured her that he knew what he was doing.
"I came back the next night with gauze wrapped around my arm," he said. A 3-foot sharpnose got him just above the elbow.
He still has the scars.
But that's nothing. Last fall, a 4-foot sandbar sank its teeth into the kneecap of Ulrich's graduate assistant and wouldn't let go.
The student didn't scream. He just said, "Oh, s---."
"I thought he had just forgotten to measure it or something," Ulrich said. "I looked over, and it was clamped on his leg."
They had to pry open the shark's jaws. The student needed 42 stitches. The shark was fine.
Nobody gets bitten
Nobody gets bitten on this day - although not from lack of trying. Ulrich had to clamp one 3-footer between his legs to keep it from thrashing free of his grip.
He carried each specimen to the back of the boat, turning it over to check its gender and look for an umbilical scar. That helps him determine age.
He measured each shark, then grabbed a leather punch to put a hole in the dorsal fin for the tag.
Sitting next to him, Catherine Riley recorded the data. Then she clipped a tiny piece off each tailfin and put it in a test tube. Other researchers will use the samples to study shark DNA.
The fish don't spend more than a minute or two out of the water before Ulrich tosses them back. Some stay near the surface for a while to get their bearings, breaking the water with their classic dorsal fins.
This day, the researchers caught mostly finetooths, with their needle-thin chompers. On the second boat, Don Hammond reeled in several young scalloped hammerheads, with their bizarre shovel-shaped faces.
One of the biggest prizes was a 4-foot bonnethead. Ulrich says she's mature - probably with half a dozen pups in her belly.
By next summer, they'll be swimming in the Carolina waters with the summer tourists.
And like their mother, they might wind up in Ulrich's nets.
Facts about sharks
Species known to grow up in Carolina waters include the Atlantic sharpnose, bonnethead, scalloped hammerhead, dusky, finetooth, sandbar, blacktip, spinner and smooth dogfish. Young tiger and bull sharks have also been caught.
Female sandtiger sharks have two uteruses. They may have several pups in each, but only two will be born. The strongest youngsters eat their siblings in the womb.
Most sharks have small litters of half a dozen or so, and they carry their young for up to a year. That makes them vulnerable to overfishing - the populations can't rebound quickly.
In 1999, commercial fishermen caught 3.9 million pounds of shark on the East Coast. That exceeded the federal quota by 38 percent.
Shark fins are prized in Asia, where they're the main ingredient in a popular soup. During the 1980s, fishermen cut off the fins and dumped the sharks back in the water to die. Today, "finning" is illegal in the United States.