Every spring and summer, one of Earth’s great marvels unfolds on beaches around the world. Sea turtle nesting is one of prehistoric Earth’s last great holdouts, 100 million years in the making, as lumbering amphibious leviathans search out the same beach from which they hatched to lay clutches of eggs just below the sand. All along Florida’s coast, thousands of turtles lay millions of eggs, making the state’s beaches some of the most prolific rookeries in the world. And while Collier and Lee counties are not as productive as Brevard or Palm Beach, the shores of the Paradise Coast represent some of the most important nesting grounds for the Gulf Coast population of loggerhead sea turtles.
Sea turtle nesting season runs from March through October, with loggerheads making their heaviest strides from June to August. Hatchlings emerge as late as October; incubation period is roughly 60 days, with the temperature of the nest determining the hatchlings’ sex. Of the five sea turtle species noted along Florida’s coast, loggerheads are the most frequent visitor to Southwest Florida beaches, reporting 1,091 and 1,315 nests in Collier and Lee counties, respectively, in 2013, according to the Florida Fish and Wildlife Conservation Commission [PDF]. Though this number is low compared to state totals, equating to just three percent of the state’s total loggerhead nests, when parsed for just west coast counties, Lee and Collier are the second and third most prolific loggerhead nesting areas on Florida’s Gulf Coast. Sarasota is first with 4,185 reported nests in 2013; all three of these areas are vital to the survival of the Gulf of Mexico turtle population.
A sharp uptick was seeen in 2012 and 2013 in nesting in Collier and Lee when compared with 2011’s nesting numbers—just 757 nests in Collier and 961 in Lee. “We had a good year last year … the year before was phenomenal, but we did have storms that impacted many nests,” says Maura Kraus, principal environmental specialist with Collier County, who has worked with sea turtles in Southwest Florida for more than 30 years. When asked for a forecast of 2014, Kraus keeps it close to the vest: “It’s pretty unpredictable.”
As of June 17, the beaches Kraus and her team monitor have marked 491 loggerhead sea turtle nests, and the season is still young [get weekly updates here].
Working hand-in-hand with the Conservancy of Southwest Florida, Rookery Bay National Estuarine Research Reserve and Ten Thousand Island Reserve, Kraus and Collier County help cover just about the entirety of Collier County’s coast. Kraus’s office alone conducts daily patrols from Barefoot Beach State Preserve in the north, south to Marco Island, while sharing duties with Rookery Bay on Cape Romano. The Conservancy fills in the gap on Keewaydin Island. “it’s a big chunk,” Kraus quips.
The county’s daily patrols start early, just as the sun begins its ascent, searching for turtle tracks, identifying nests and marking them, both with GPS data points and signage to prevent beachgoers from inadvertently trampling them. Nests are monitored daily throughout the incubation period, ensuring predators and poachers keep their distance. Once hatched, county officials check the nest for unhatched eggs, stranded hatchlings and any anomalies that may be present, all of which are recorded and presented to the state. The information then goes to the federal government, which assimilates this data with projects from all over the eastern seaboard to develop larger population trends and assess the general status of the species as a whole. This information is vital for the agencies writing endangered species acts and for responsible policy management, ultimately helping in the survival of endangered species.
Go to page two for more on the Conservancy of Southwest Florida’s efforts with logerhead sea turtles.
The Conservancy of Southwest Florida currently monitors the beaches of Keewaydin Island nightly, a barrier island just south of Naples that stretches just shy of eight miles. Every night, when a loggerhead is spotted, researchers conduct a series of data collecting and identification procedures: shell measurements; beach activity with GPS location—successful nesting or false crawl; and tag identification—if no tag present, the turtle will receive a flipper and PIT [Passive Integrative Transponder] tag to help with identification. If the encounter happens upon a successful nesting, after the 55- to 65-day incubation timeframe, the nest contents will be documented following hatching, analyzing the number of eggs per clutch and the number of hatchlings. This information proves invaluable to researchers, who have determined that loggerheads, upon reaching breeding age, return to the same beach they hatched at every two to three years, three to eight times per season, to nest. In 2009, the Conservancy began a satellite tagging program to monitor the movement of the loggerhead sea turtles throughout the year. The information gleaned from the transponders is helping researchers locate adult turtles’ foraging areas, and whether the turtles’ movements bring them close to oil and dispersants that still remain in the Gulf from the Deepwater Horizon disaster in 2010.
Visit the Conservancy of Southwest Florida for an up-close encounter with sea turtles at the Dalton Discovery Center. At 1 p.m., daily, Conservancy staff conducts a sea turtle presentation, which discusses this ancient species’ importance on the marine ecosystem and perilous state in which the turtles live today.
- For more information, visit conservancy.org.
Little is known about the time between hatching and adulthood, collectively known as the “lost years” by marine biologists, though some theories of turtles making their way into the Gulf Stream and into the Sargasso Sea formed by the North Atlantic Gyre has begun to gain some credence. On March 5, a research team from the University of Central Florida reported in the Proceedings of the Royal Society B that they may have cracked a mystery that has been routine for thousands of years. Affixing juvenile turtles with tags small and flexible enough to keep from impeding the turtle’s ability to swim, and not constrict the animal’s rapid growth, researchers were able to track turtles as they cruised the Gulf Stream. Findings show that the turtles did not just passively traverse the current, but made a beeline for the Sargasso Sea, while temperature sensors discovered the seaweed mats that collect within the Sargasso create a microenvironment ideal for growing turtles. With a temperature a few degrees warmer than surrounding seas, this not only helps in the function of growth, but the mats also act as a means of protection and navigation. Though these findings are new, the importance of the Sargasso Sea can scarcely be overstated in terms of the protection and proliferation of future sea-turtle generations.
The findings from this study do not necessarily mean that the hatchlings from the Collier County nesting population are making their way to the Sargasso Sea, or the Gulf Stream for that matter, but we do know that tagged adults have made it out that far east. “Our population goes everywhere,” says Kraus, speaking of the tagged population from the Conservancy, “We actually watch them on the computer every day to see where they are. They do migrate. There are some that have gone up to Mississippi, some around the Florida Panhandle, some in the Bahamas, some off the coast here, and a couple off Sanibel Island. They head to these areas to feed and hopefully the tags stay on long enough to see them return.” [Click here to see an interactive map of the Conservancy of Southwest Florida’s tagged turtles].
Sea turtles have the remarkable ability to sense magnetic fields and can recognize the scent of mud, helping them return to the same beach from which they hatched in order to nest themselves. But making it to adulthood is no easy task for sea turtles. Each nesting turtle lays roughly 100 eggs per nest, and returns between three to seven times to nest per nesting season. By law of averages, each turtle lays 500 eggs per season (loggerheads tend to nest every two to three years), and with a 40 percent hatching success, in 2013, more than 192,000 eggs remained in the dunes to feed shore mice, crabs and the hardy, slow-growing vegetation of the dunes. These numbers may seem large, but like everything with the sea, survival is a numbers game. It’s posited that only one in 1,000 sea-turtle hatchlings survives to adulthood, so for 2013, for a hypothesized 48,000 hatchlings that breached their sandy nests in Collier and Lee counties and made it to the water, just a scant 48 will survive to the age of 15, when they will return to nest on these same beaches (assuming, of course, all are females—males, once in the water, will spend the rest of their lives out at sea). This means each and every nest is necessary for the survival of the species, and why the work headed up by Collier County, the Conservancy and partnering agencies and organizations is so important.
Public awareness for sea turtles and their nests has become the norm in Collier County. Kraus says, “rarely do we have issues.” But it is important to keep the beaches clean and prepped for the nighttime nesters. Some quick tips for the beachgoer to keep the beach nesting ready is to fill any hole you may dig (nesting turtles and hatchlings can get trapped), and remove all beach furniture and trash, both of which can scare an emerging turtle and deter her from nesting. The best rule of thumb: “Leave only footprints.”
If you come across a stranded sea turtle or disoriented hatchlings, contact the Conservancy at 239-262-2273.