Sea turtles are survivors. They've been here since the early days of dinosaurs, and their babies were scampering down beaches long before humans came along.

Yet despite their 100 million-year head start, all seven species now face an existential danger from people. The threat varies by location — from plastic trash and trawl nets to egg poachers and beach development — but the overall pressure has been mounting for decades, raising concerns about the future of these ancient animals.

Thanks to countless scientists, conservationists and volunteers, however, the tide is turning in some parts of the world. It's far from a full recovery, but hints of sea-turtle comebacks are emerging in a variety of habitats, from the honu of Hawaii and the hawksbills of Nicaragua to greens and loggerheads along the U.S. Southeast coast.

And now, just 12 years after their worst year on record, the loggerheads that nest on the coasts of Georgia, Florida and the Carolinas have had their best nesting season on record — again. At least 3,260 loggerhead nests have been counted on Georgia's beaches as of September 7. North Carolina counted 1,628 turtle nests this season — a 25 percent jump from last year and a state record for loggerheads. South Carolina recorded 6,357 nests, also a state record, according to the Winston-Salem Journal, and Florida expects a record, as well.

Georgia loggerhead nest count

2013 had been the fourth record-high year in a row, and 2015 might have been six straight if the 2014 total hadn't dipped to 1,201. Sea turtle nesting can vary widely from year to year, points out Mark Dodd, who coordinates sea turtle conservation at the Georgia Department of Natural Resources, but this recent spate of records still points to a sea change. On average, Georgia's loggerhead nest counts are growing about 3 percent annually.

"We saw this long-term declining trend until the last several years," Dodd says. "Our lowest year was 2004, when we had fewer than 400 nests in the state. We were very concerned; we thought we were losing loggerheads as a species in Georgia."

But just when they seemed doomed, he adds, the turtles began a "dramatic increase" over the next 11 years. "We do have big years and average years, but it's more about the long-term trend. And we have seen an increasing trend that indicates we're in a recovery period for loggerheads in Georgia."

This video explains more about Georgia's efforts to save loggerheads:

Turtle power

Georgia's rebound is part of a broader trend for some Southeastern U.S. sea turtles, especially greens and loggerheads. Florida is the region's traditional epicenter of sea turtle nests, and it too has suffered steep declines. Its loggerhead nests went from a high of nearly 60,000 in 1998 to a low of 28,000 in 2007, while its green and leatherback nests plummeted earlier — greens were below 300 nests in the early 1990s, and leatherbacks didn't reach 100 nests for most of that decade.

But as in Georgia, Florida's sea turtles have enjoyed a "miracle" recovery in recent years. The state's loggerheads laid more than 58,000 nests in 2012, followed by slightly lower, but still 40,000-plus, totals in 2013 and 2014. Green sea turtles returned to a high of more than 25,000 in 2013 (their nesting fluctuates on a two-year cycle, so the total fell below 5,000 in 2014, but the trend is still upward). Leatherbacks also leapt from a low of 27 nests in 1990 to a record 641 in 2014.

Similar patterns are emerging in other states. South Carolina's loggerheads laid nearly 4,600 nests in 2012, their highest total since 1982 — until they laid nearly 5,200 the following year. Biologists and volunteers counted only about 2,100 nests in 2014, but the 2015 count was more than 5,000. And in North Carolina, from a record-low 333 loggerhead nests in 2004, the total rose beyond 1,000 in 2012 and 1,300 in 2013.

loggerhead sea turtle hatchlingsA group of loggerhead hatchlings scramble out of their nest at Core Banks, North Carolina. (Photo: Dawn Childs/USGS)

Life's a beach

All sea turtles in U.S. waters have been protected by the Endangered Species Act since the 1970s; leatherback and green turtles both joined the list in 1978. So why are Southeastern states just now seeing this kind of nesting boom?

It's partly because sea turtles live such slow, lengthy lives. Not only do some individuals survive beyond their 100th birthday, but they can take 20 or 30 years to reach sexual maturity. That means trying to conserve them is a long game, and the recovery seen in recent years has been in the works since the 1980s and '90s.

But how did it happen? One of the best ways to protect sea turtles is to protect the beaches where they nest. After female sea turtles hatch and spend decades at sea, they often return to lay eggs on the same beaches where they were born. If those beaches have since become more polluted, developed or brightly lit — which can lure hatchlings inland instead of seaward — it may spell trouble for their offspring.

The U.S. has focused on setting aside vital habitat for sea turtles, including federal refuges like South Carolina's Cape Romain, Georgia's Cumberland Island and Florida's Archie Carr, each of which hosts a major portion of its state's nest count. Regulations on beach development and outdoor lighting have also helped, as have laws against disturbing turtles or their eggs. But getting humans to share such prime real estate with reptiles is always a struggle, Dodd says, regardless of who was there first.

"All our coastal communities have beachfront lighting ordinances," he says. "But once you get development on the beach, it's just something you have to deal with on an annual basis. Even if you get all the lights straight one year, someone might decide the next year, 'Oh, we need more lights on this beach.' So it's just an ongoing thing."

sea turtles warning signA sign warns drivers in Fort Lauderdale, Florida, that street lights are kept off during nesting season. (Photo: Serenethos/Shutterstock)

Net benefit

Farther offshore, the Southeast's turtle recovery may also be linked to low-tech life-savers known as turtle excluder devices, or TEDs. Sea turtles are prone to being snared in shrimp nets, so TEDs filter shrimp into one part of the net while keeping larger animals, namely turtles, in a separate compartment that has an exit.

TEDs became mandatory for the U.S. shrimping industry in 1989, and they're now credited with reducing the number of adult sea turtles killed by human activity off U.S. coasts and elsewhere. "The primary source of adult mortality is commercial fishing, specifically shrimp trawling," Dodd says. "TEDs were contentious for a few years, but now they're standard."

While saving beaches and curbing bycatch is obviously good for sea turtles, the exact reasons for these nest counts remain unclear. Georgia wildlife officials are happy about their record loggerhead season, Dodd says, even if they can't fully explain it.

"That's the million dollar question," he says. "Our first nest protection project started over 50 years ago, on Little Cumberland and Blackbeard islands. We spent lots of time protecting nests from predators, improving nest success. We also put a lot of effort into reducing mortality of juveniles and adults at sea. So it's probably a combination. We kind of did everything at once. We threw everything we could at the problem, so it's hard to sort out which were the most important measures."

adult loggerhead sea turtleLoggerheads' typical life span is unknown, but they reach sexual maturity at around 35 years old. (Photo: Polly Dawson/Shutterstock)

Slow and steady

Despite their recent success in a few U.S. states, plenty of man-made dangers still plague sea turtles overall. Aside from habitat loss, light pollution and bycatch, one of the most pervasive problems is now ocean plastic, which can entangle their flippers or clog their digestive systems. Some species now ingest twice as much plastic as they did 25 years ago, according to a 2013 study, and not just the bags that notoriously resemble prey such as jellyfish. For instance, scientists in Costa Rica rescued an olive ridley turtle that had a plastic straw stuck in its nostril.

Then there's climate change, which threatens an array of marine life via ocean acidification — including sea snails that loggerheads eat, coral reefs where many turtles forage and plankton at the base of the food web. A recent study also suggests sea levels may be rising too rapidly for some turtles to adjust their nesting sites.

Turtles swimming offshore face more localized risks, too, ranging from boat motors to oil spills. (In Texas, researchers are investigating whether the 2010 BP oil spill is related to drops in nest totals and survival rate of the critically endangered Kemp's ridley.) People also still poach adults and eggs in many places, and some even lash out at other humans trying to stop them. Poachers attacked a group of volunteers in Costa Rica in July 2015, for example, the same month a 72-year-old former U.S. Marine was shot and injured in Florida by a man who explained "I hate sea turtle people."

Still, even a small nesting boom is reassurance that we can save sea turtles from ourselves. Just by protecting a patchwork of beaches and making small changes to shrimp nets, the Southeastern U.S. seems to have averted a disaster — at least for now. And while co-existing will be a long-term struggle, Dodd says it's worth pausing to appreciate what we've helped sea turtles accomplish so far.

"It's a single year, but it's a continuation of an increasing trend," he says of Georgia's 2015 nest count. "So that is pretty exciting. We have volunteers who help us monitor turtle nesting, and some of those people have been out on the beaches for 50 years. They're finally seeing this turnaround, and it's especially rewarding for them."

Editor's note: This story has been updated since it was originally published in August 2015.

Russell McLendon ( @russmclendon ) writes about humans and other wildlife.