Irma wipes out half of green turtle nests along Atlantic coast
Still, loss may not affect long-term future of fragile species
Beaches along south Brevard County are a world-class refuge for sea turtles that had a record number of nests just as Hurricane Irma mauled Florida last month.
About half of nearly 16,000 green turtle nests were obliterated in a “devastating” blow to this year’s reproductive efforts of the threatened species, according to scientists.
Remarkably, however, Irma could prove to be a blip in the survival trajectory of green turtles, said Kate Mansfield, director of the University of Central Florida Marine Turtle Research Group.
In an astonishing surge, green turtles progressed from rarely appearing in the 1980s on Central Florida’s Atlantic Ocean beaches to dwarfing the longstanding dominance of loggerhead turtles this year.
Getting significant credit for the trend are laws enacted in the U.S. and other countries internationally that protect nests and eggs, as well as measures that, for example, discourage bright lights on beaches that can disorient the creatures.
“If we keep having these big turtle turnouts on the beach, I think we are going to do all right,” Mansfield said.
A caveat, she and other ex-
“One year’s storm is sad but not a big deal in the big scheme of things.” Simona Ceriani, Florida Fish and Wildlife Conservation Commission
perts noted, is whether the spate of damaging storms continues, from Matthew a year ago to Irma in September.
“One year’s storm is sad but not a big deal in the big scheme of things,” said Simona Ceriani, a research scientist with the Florida Fish and Wildlife Conservation Commission. “It’s the frequency of storms that matters.”
Ceriani said green turtles statewide were having phenomenal success leading up to Irma.
Sea turtles on the state’s east coast, she said, were harder hit by the storm than those along the west coast and the Panhandle.
The state monitors 223 beaches studied by more than 150 groups, many of which won’t provide this year’s numbers until next year.
For more than 30 years, the UCF group has concentrated on the Archie Carr National Wildlife Refuge, spanning 20 miles along south Brevard and north Indian River counties.
Turtle activity there accounts for as much as 35 percent of nesting in the U.S.
Weighing 200 to 350 pounds, loggerheads start nesting in April. Green turtles are heavier at 300 to 350 pounds and show up beginning in June.
Because loggerhead turtle nesting winds down sooner, that species was less troubled by Irma. About a quarter of nearly 10,000 nests were lost.
To an unknowing eye, stretches of Archie Carr appeared this summer as if they were bombed or bulldozed; it’s what happens when loggerhead and green turtles plow up sand for more than 25,000 nests.
UCF turtle biologists have mental maps of Archie Carr beach and have learned to read the jumble of holes, humps and tracks as if they made up a morning report from the reptiles.
“We have GPS, but I’ve been on this beach so many times I don’t really need it,” said Rachel Santulli, a UCF graduate and former intern with the turtle group, which now employs her.
With the morning sun just above the horizon, Santulli stopped her all-terrain vehicle to consider a circuitous adventure by a green turtle on a beach about as wide as a neighborhood street.
“She went up the beach, and there she started pitting,” Santulli said, referring to the initial effort to scrape out a cavity for a nest.
“She started her laying process and decided she didn’t like that spot and came all the way down, went back all the way back over there, back up the dune, and that’s where she nested, which probably took about a good hour, and then came back down,” Santulli said, pointing out the turtle’s track along a giant “S” route meshed with other tracks. “The whole process probably took about two hours.”
The UCF researcher also found where a turtle had nested on top of another nest.
That is a sign of how densely packed Archie Carr beaches are with nests. It has happened this year about 300 times, only a small fraction of all nests, Mansfield said.
Another indication of the intense activity at Archie Carr is what’s missing; the beach does not bear the wood stakes, signs and exclusion-zone ribbons prevalent at other beaches.
If that were done at Archie Carr, the resulting thicket of stakes could obstruct turtles from moving around, Santulli said.
Making sense of tracks and nests is best done while the sun is low and shadows are more pronounced, she said.
A gritty task for her came after the sun was higher and hotter as Santulli dug through a nest where eggs had hatched.
The effort was to document the number of empty shells and the nearly dozen that failed to hatch, including some containing stinking viscous liquid.
Also deeply buried was a living, wiggling hatchling that, unlike its siblings, hadn’t been able to tunnel out of the nest.
“Nothing beats this,” Santulli said, as she carried the hatchling to the surf. “This is definitely one of the best parts.”