Sandy disrupted sea turtle nesting boom
Loggerhead turtles considered threatened species by federal government and even endangered by some states.
Thu, Nov 08, 2012 at 11:26 AM
As Hurricane Sandy roared up the East Coast, it threatened to disturb the best loggerhead turtle nesting season on record.
Florida, South Carolina and Georgia all reported baby booms, with more nests than ever since the states began tracking turtles in the 1980s. North Carolina had its third highest year, and loggerhead turtles crawled ashore as far north as Maryland to lay eggs. The loggerhead turtle is a federally listed threatened species and is listed as an endangered species by some states.
Sandy's late-season arrival meant most of the tiny hatchlings emerged well before the storm hit. All of South Carolina's nests had hatched, said DuBose Griffin, sea turtle program coordinator for the state's Department of Natural Resources. A record number of sea turtle nests, 4,604, were laid (from all local species) this season on South Carolina beaches.
However, other states had slowly developing or late-laid nests with eggs in the ground when Sandy's storm surge battered the coast.
At Florida's Juno Beach, a nesting hotspot, about 50 endangered green turtle nests were destroyed. In North Carolina, about 12 nests were destroyed, but nearly 50 hatchlings were rescued on the Outer Banks. In Berlin, Md., at the Assateague Island National Seashore, a planned excavation saved two hatchlings and eggs Oct. 26, just before the hurricane's approach. [Tagging and Tracking Sea Turtles]
Storms part of natural cycle
Georgia state wildlife biologist Mark Dodd said the losses from Hurricane Sandy were part of the turtle's natural life cycle.
"Loggerheads and other sea turtle species have evolved nesting on dynamic beaches with periodic tropical events, so their reproductive strategy takes that into account," Dodd told OurAmazingPlanet. "They produce lots of eggs and hatchlings, which in the grand scheme of things aren't expected to survive very well. Ultimately, all they have to do is replace themselves." Dodd coordinates the state's sea turtle program for the Department of Natural Resources.
Loggerheads laid a record number of nests on Georgia beaches, 2,218, for a third summer in a row. The world's most endangered sea turtle, a Kemp's Ridley, also laid a nest in Georgia. The last hatchlings came out of the ground Oct. 22, Dodd said, well before Sandy's waves crashed into the state's beaches and barrier islands. Baby turtles can reach their crèche in the Gulf Stream seaweed beds after about four days of swimming.
Turtles don't nest every year, but when they do "crawl," females produce four to six nests in different spots, each with 100 to 125 eggs the size of ping-pong balls. The eggs hatch after 50 to 120 days, depending on temperatures at the nesting site.
In the United States, hatchlings begin emerging in mid-July and can continue through November. During that time, storms can wash nests from beaches, drown them with seawater, bury them with sand, or expose their eggs to predators by washing sand away.
Surprise inside Maryland nest
As Hurricane Sandy approached the Assateague Island National Seashore, biologists from the National Aquarium in Baltimore evacuated an entire nest. The excavation had been planned before Hurricane Sandy emerged on the radar, to protect the loggerhead eggs from cold temperatures, said Kelly Taylor, a science communicator for the park.
To their surprise, two live hatchlings were in the nest. "When we excavated the nest, we didn't expect any viable turtles," Taylor told OurAmazingPlanet. One turtle died from a pre-existing infection and one survives, Taylor said. The remaining eggs are being incubated at the aquarium, and any surviving hatchlings will be released in spring.
In Florida, no loggerhead turtle nests were left at Juno Beach, said Kelly Martin, a biologist with the Loggerhead Marinelife Center there. The turtles laid 13,000 nests in the sand this season, and the majority of hatchlings were out to sea by the time the storm hit, she told OurAmazingPlanet. But Hurricane Sandy did destroy about 50 green turtle nests, Martin said. The green turtle is a federally endangered species.
This year, surveyors counted 58,172 loggerhead nests along nearly 250 miles (400 kilometers) of Florida's coastline, one of the highest nest counts since monitoring began in 1989, the state Fish and Wildlife Conservation Commission said. Surveyors also counted 6,054 green turtle nests this year.
Matt Godfrey, a biologist with the North Carolina Wildlife Resources Commission, said North Carolina lost about a dozen nests from erosion or overwash from Sandy. "It was not a major loss," he told OurAmazingPlanet.
Rescue on the Outer Banks
On Topsail Island along North Carolina's Outer Banks, volunteers kept a close eye on two of those nests. One began hatching during daytime just before Hurricane Sandy moved into the area, said Jean Beasley, executive director of the Karen Beasley Sea Turtle Rescue and Rehabilitation Center. "The surf was getting pretty angry; there were pretty high waves," Beasley said.
Hospital volunteers try not to interfere with turtle hatchings if possible. (Studies show turtles return within several miles of where they nested, so it's better to let them reach the sea on their own.) In the end, though, the hatchlings were washed back and exhausted, so about 30 were gathered up, to ride out the storm in plastic tubs. The turtle hospital also took in "Scott," a hatchling named in honor of the island resident who braved the height of Sandy's rage to rescue it at the island's northern end, Beasley said. "We don't know where it came from, because it was a larger hatchling than the ones from our nest," she said. [On the Ground: Hurricane Sandy in Images]
The Sea Turtle Rescue and Rehabilitation Center also took in 20 hatchlings from neighbors to the south, at Figure Eight Island. A rescue group grabbed eggs from a nest washed out by waves, and the eggs started hatching as they were hauled inside in a bucket, Beasley said.
Once the weather calms, the rehabilitation group will catch a ride to a protected area in the Gulf and release the turtles. "Every turtle counts," she said.
Reach Becky Oskin at firstname.lastname@example.org. Follow her on Twitter @beckyoskin. Follow OurAmazingPlanet on Twitter @OAPlanet. We're also on Facebook and Google+.
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