Everybody knows Hurricane Irma wreaked havoc on Florida's human population, but it didn't spare one of the state's most precious natural treasures, either. The merciless storm swept away an untold number of sea turtle nests.
Until Irma came along, Florida -- "incubation central" for sea turtles in North America -- was having a good turtle-nesting year -- especially for the endangered leatherbacks, the threatened loggerheads and green turtles.
The New York Times reports that along two stretches of beach south of Cape Canaveral, more than 90 percent of incubating loggerhead nests were destroyed by the storm, representing about 25 percent of the season’s total.
Niki Desjardin, senior project manager at Ecological Associates, Inc. in Jensen Beach, told Sunshine State News many sea turtle nests in the area her facility surveys were impacted by the beach erosion that Irma clawed out. "The storm had a severe erosive impact," she said. "We experienced a huge shift in beach elevation." Beach erosion is always devastating to sea turtles. The creatures take 25 to 30 years to reach reproductive age, and lay their eggs in the open beach, under vegetation or at the base of a dune.
Prior to the storm, Ecological Associates documented approximately 4,500 nests on South Hutchinson Island. As the storm passed Sept. 10, there were about 1,800 viable nests still incubating; of those, 470 were marked with stakes, making it easy to determine reproductive success. By assessing the number of marked nests that washed out, the organization reported it could approximate the actual nest loss due to the storm.
Nest loss was around 88 percent in the St. Lucie County portion of the Hutchinson Island survey area and around 60 percent in the Martin County portion. "Remarkably, some nests still remain on the beach, and we’re continuing to monitor the beach daily."
Green turtles, which tend to nest later into the season, are even continuing to nest on Martin and St. Lucie beaches.
"Sea turtles are resilient and this season’s losses resulting from Irma likely won’t have a large impact on the species as a whole," the organization wrote on its Website.
Kate Mansfield, a marine scientist and sea turtle biologist at the University of Central Florida, agreed. "Sea turtle populations will survive as long as the hits don’t keep coming," she said.
An official statewide picture of the damage to sea turtles won’t be available until Nov. 30, because the nesting season runs through at least the end of this month, Simona Ceriani, a research scientist with the Florida Fish and Wildlife Conservation Commission, told the Times. But it’s clear that nests in many areas of the state were destroyed by Irma, she said.
Ceriani said the northwest Atlantic region is one of the world’s two largest loggerhead nesting areas, and citing a 2015 assessment, she said 89 percent of those animals have been found to hatch in Florida.
At the Archie Carr National Wildlife Refuge just south of Cape Canaveral, more than half of the green turtle nests laid this season and a quarter of the loggerheads were lost as the storm tore up beaches, said Mansfield.
One blessing: Endangered leatherbacks lay their eggs earlier in the season; therefore, none of their nests were lost in the refuge.
Reach Nancy Smith at firstname.lastname@example.org or at 228-282-2423. Twitter: @NancyLBSmith