News

By Margie Plunkett
    
    Boca Raton counted 1,041 turtle nests along its five miles of beach as nesting season nears its close, bouncing back from 949 last year. But researchers saw an unusually high number of unhatched eggs.
    “Our hatch success is not as high as previous years,” said marine turtle specialist David Anderson of Gumbo Limbo Nature Center, explaining that nests are excavated after hatchlings emerge to inventory hatched and unhatched eggs.
    “It is possibly due to the hot and dry summer we had, as it only began to rain a lot the last few weeks,” Anderson said. “But we really don’t know and we will analyze our data after the nesting season.”
    A full 718 of this year’s nests were made by loggerhead turtles, down from 856 last year. Green sea turtle nests numbered 298, up from 75 in 2014. And there were 25 leatherback nests, rising from 18 last year, according to Gumbo Limbo Nature Center’s end-of-the-season numbers.
    The figures indicate continuing resurgence of the green sea turtle. “Green sea turtles have made an impressive comeback since their populations were decimated from when it was legal to eat and there was a cannery in the Keys,” Anderson said. “The population is recovering after it was almost driven to extinction locally.”
    Green sea turtle nests hit their low here in 2001, when there were only 10. In the years since, the numbers have grown, reaching the highest number recorded — at 331 — in 2010.
    The count alternates from year to year between high and low because the sea turtles nest every two to three years, Anderson pointed out. Meanwhile, sea turtles lay multiple nests, so 1,000 nests may mean 150 to 250 nesting turtles.
    Loggerhead nest numbers had been dwindling here as well, reaching a low of 361 in 2009, although the count has since increased.
    “Nesting numbers may reflect what was happening 20-30 years ago,” Anderson said. “If both green and loggerhead nest numbers are increasing, it could mean conservation efforts over the last couple of decades, along with protection by the Endangered Species Act, have had a positive result.”
    Despite the rising loggerhead numbers, the turtle is still considered a threatened species. And all other sea turtles are listed as endangered, Anderson said. “Neither … is in the clear to be removed from the list anytime soon.”
    The turtles face a long list of threats, such as losing nesting habitat to beach erosion; pollution and plastics in the ocean; being netted with the commercial fishing industries’ catch; and artificial lighting that disorients hatchlings, to name a few.
    While nesting season runs from March 1 to Oct. 31, the Gumbo Limbo numbers are final, Anderson said. “We do not expect any more nests this year.”
    But specialists will continue to survey the beaches after season ends, until the last nest hatches — and that can be well into November, Anderson said. “As of today, we have about 50-60 nests remaining on the beach. We would have more, but the high surf from Tropical Storm Erika offshore washed out over 40 nests.”