Southeastern states where the sea turtles, listed as threatened, primarily nest report large declines.
By Associated Press
Published August 8, 2004
EMERALD ISLE, N.C. - Scientists have theories but no sure explanation for about half the usual number of loggerhead turtle nests from North Carolina to Florida this season.
"It's one of the lowest nesting years through the last 20," said Larry Crowder, a professor at Duke University Marine Laboratory in Beaufort and member of the Atlantic Loggerhead Sea Turtle Recovery team. "I don't think it's time to say, "Oh my God, loggerheads are going extinct.' It's just a bad year. Obviously that can't go on too long."
Loggerheads have laid about 300 nests in North Carolina and more are expected to lay eggs through August, said Matthew Godfrey, biologist for the state Wildlife Resources Commission Sea Turtle Project. The total will still be far fewer than the 750 nests laid in a typical year.
Other Southeastern states where loggerheads primarily nest - South Carolina, Georgia and Florida - report similar declines. Loggerheads, the most common sea turtle, are listed as threatened, meaning they could become endangered.
Scientists have several theories about the decline, ranging from changes in water temperature that would affect reproduction to climate fluctuations that influence food supply.
Crowder suspects a climate variation.
"That would influence how much food there is for turtles - crabs, shrimp, crustaceans, algal production," he said.
The last time North Carolina had a big dip in nesting was in 1993 when 485 nests were recorded. The following year, there were 1,021 nests.
Female turtles nest every two to five years. If they don't have enough to eat, they store protein for an extra year before nesting.
An upwelling of cold water from the deep ocean last summer settled on the continental shelf and lowered surf temperatures along the Atlantic Coast. That may have reduced the abundance of food, slowed turtles' reproductive processes or both.
"There are a lot of things that might explain what we see," said Blair Witherington, research scientist with the Florida Fish and Wildlife Conservation Commission. "The effect of temperature on the egg production process is pretty profound. "If the water is cold, then the turtles are cold. And if they are cold, they don't do anything very fast, including the metabolic process of making eggs."
He said the nesting decline doesn't necessarily mean there are fewer females.
