The Start of Sea Turtle Nesting

The 2015 sea turtle nesting season is off to a busy start on Little St. Simons Island and along the coast of Georgia. As of June 4 we have already found 35 sea turtle nests on LSSI and 545 nests have been recorded statewide this season.

A loggerhead sea turtle nest

A freshly laid loggerhead sea turtle nest on LSSI. Photo Credit: Elise Diehl

 

Female sea turtles emerge from the ocean to lay nests above the high tide line from May until July. Eggs hatch two months later, and turtle hatchlings crawl from the nest to the ocean under the cover of night. On the Georgia coast, most of the nesting that occurs is from loggerhead sea turtles, but green and leatherback sea turtle nests have also been documented.

On Little St. Simons Island, 123 loggerhead nests were recorded in 2013 and 53 in 2014. These high and low emergence years are normal since loggerhead sea turtles mate every 2-3 years. This year is predicted to be a very active and successful season due to the population rebounding after being protected by the Endangered Species Act and fewer turtles breeding last year (with the mating cycle this should be a higher year).

Elise Diehl is returning for a second season as LSSI’s sea turtle technician. . Elise’s position is part of a long standing, close partnership with Georgia Department of Natural Resources. Sea turtle nesting and hatching has been monitored on LSSI since 1987. Elise bikes the seven miles of beach each morning at sunrise searching for turtle crawls. When a crawl is located she determines if the female turtle laid a nest, or decided to return to the ocean without nesting, known as a false crawl. A turtle false crawls when she feels threatened or does not find the site suitable for nesting. She will often return to the same area within the next few nights to attempt nesting again if this is the case.

Elise marks each nest with a numbered stake, and protective screens to keep predators, like raccoons and ghost crabs, from digging into the nest. If a nest is laid too close to the tide line, Elise relocates it to a higher site to prevent overwashing from tides. Tidal overwash can drown eggs and hatchlings waiting to emerge from the nest.

LSSI's Sea Turtle Technician, Elise Diehl, next to a staked and protected nest.

LSSI’s Sea Turtle Technician, Elise Diehl, next to a staked and screen protected nest.

If you would like to keep track of this season’s sea turtle nesting on LSSI or in Georgia, please visit seaturtle.org. We are hoping for a record year!

-Lauren Gingerella, Ecological Technician

Please like & share:

Naturalist Fact: Leatherback Sea Turtle

Adult leatherback. Photo: Virginia Herpetological Society

Adult leatherback. Photo: Virginia Herpetological Society

The leatherback sea turtle (Dermochelys coriacea) is the largest of the world’s seven species of sea turtles, and in terms of weight is the largest reptile on the planet as well. This impressive animal can reach 6 feet in length and weigh 900-1,000 pounds, with the largest leatherback ever recorded tipping the scale at over 2,000 pounds.

While the most common nesting sea turtle on the Georgia coast is the loggerhead, leatherbacks have nested on nearby islands a few times over the years. Blackbeard, Cumberland, Jekyll, Ossabaw, Sea Island, St. Catherines, St. Simons, and Sapelo have all had leatherback nests in the past five years.

To add to their list of superlatives, leatherbacks are the most widely ranging sea turtle in the world. Leatherbacks’ major nesting sites are in the Caribbean, Central and South America, Africa, southeastern Asia, and the South Pacific Islands, but their migrations can take them over 3,000 miles from their nesting grounds each year.

Leatherback hatchling. Photo: Laura Early

Leatherback hatchling. Photo: Laura Early

The leatherback’s diet consists mainly of jellyfish and other soft-bodied invertebrates, and because of special adaptations, leatherbacks are able to follow their food sources into much more frigid waters than other turtles are able to tolerate. A countercurrent heat exchange system and layers of fat help leatherbacks retain a warmer body temperature in cold waters. Special adaptations in their lungs also enable leatherbacks to dive deeper than any other turtle and most marine mammals—as deep as 4,000 feet, and these dives can last for up to 85 minutes.

The unique nature of their carapace also helps the leatherback complete these long, deep dives. Unlike other sea turtles, the leatherback’s ribs and vertebrae are not fused to create a rigid shell, but instead are integrated into a cartilaginous layer. The layer of skin covering the matrix of bones and cartilage gives the turtle flexibility, hydrodynamics and protection in addition to its common name.

Please like & share:

A rare visitor…

Several days ago I set out with a small group of guests for what I expected would be a routine day of seining and surf fishing. While I pulled the seine net along the shoreline, I expected to bring in an assortment of small fish, crabs, and marine invertebrates.  I was hoping for something special like a bonnethead shark or a large redfish. The last thing I expected to hear when I finally dragged the net ashore were shouts of  “A turtle! A turtle!”

Sure enough, a small juvenile sea turtle was kicking and straining against the net. He was only slightly larger than a dinner plate, making him just a few years old (Loggerhead Sea Turtles can take up to 35 years to reach maturity). Everyone enjoyed an up close look at the very surprised turtle, and I quickly returned it to the water, where it rapidly swam back to deeper water.

Juvenile sea turtles of several species routinely visit Georgia’s inshore waters during the warmer months, foraging in our nutrient rich creeks, rivers, and shoals. It therefore wasn’t a complete shock to find one so close to the beach, but it was still unusual – turtles typically would be expected to shy away from such a slow moving net, and in fact, this was the first time one had been captured in years of seining on Little St Simons Island.

So imagine my surprise when, just a few days later, on another seining excursion, the net was hauled in to reveal another juvenile sea turtle! On closer inspection, it turned out to be the same individual. By now ‘puzzled’ and ‘concerned’ joined ‘surprised’ on the list of emotions running through my head.  Catching the same turtle twice in a short period of time didn’t strike me as a promising sign. A closer look at the turtle revealed several scrapes and cuts on the shell, some of which were still lightly bleeding. I also made a discovery that had escaped my notice the first time around. In my haste to return the turtle to the water, I’d completely overlooked that the little guy was no loggerhead at all, but a rare Kemp’s Ridley.

The Kemp’s Ridley may be the rarest sea turtle in the world. It certainly has the most restricted nesting range – until recently, just a single beach on the Gulf coast of Mexico. As recently as the mid-20th century, they nested in spectacular events called arribadas (Spanish for “arrival”), where thousands of turtles would simultaneously nest in broad daylight. However, as word of the location of the nesting sites spread, poaching of eggs and adults took a toll, leaving as few as 200 adults nesting a year – down from as many as 42,000 in a single day in 1947! Now, the population is slowly recovering, with around 8,000 nests per year.

Unlike our more familiar loggerheads, the Kemp’s Ridley is not know to nest in Georgia, though a handful of nests have been recorded in the Carolinas and Atlantic coast of Florida. The vast majority of the population may never leave the Gulf of Mexico. However, juveniles will often get carried by offshore currents out of the Gulf and into the Gulf Stream, where they arrive in Georgia’s nearshore waters. These young individuals will stay in our area for some time, feeding on crabs and other marine life before returning to Mexico to breed.

Given the condition of the individual in our hands and the overall rarity of the species, we decided to take no chances with its health. Fortunately, nearby Jekyll Island is home to a state-of-the-art sea turtle hospital and research institute. After a couple phone calls, the staff of the Georgia Sea Turtle Center arranged to meet us on St. Simons to take the turtle to their facility. After quick truck and boat rides, the turtle was soon in the capable hands of the Turtle Center.

At last report, the turtle was doing well and seemed to be in good health. He was eating readily and soon should be ready to be returned to the ocean. We’ll keep everybody updated on his status as we hear more from Jekyll!

Photos courtesy of Robin Lacey

Please like & share: