Vincent Saba, a research fishery biologist at NOAA, introduced annual nest counts from Florida and long term climate data in turtle-nesting population models. These models are used to assess observed changes in nest counts and to project future nesting trends in the Northwest Atlantic loggerhead sea turtle population, the largest in the world.
Nearly 90 percent of all loggerhead nesting in the Northwest Atlantic occurs in Florida. Saba’s new research indicates that for loggerhead sea turtles in the Northwest Atlantic, the number of returning nesting females in the population and favorable climate conditions in the year or two prior to the nesting year are strongly related to the number of nests produced by these animals in a given year. Also, in what may be good news for loggerheads, nesting increases since 2008 may be a recovery response in this threatened population.
This study offers a different perspective than earlier work that suggested most of the annual variability in loggerhead sea turtle nest counts in Florida could be explained by climate condition on hatchling survival. The different conclusion is that the annual variability and trends in loggerhead nesting numbers in Florida are associated with long-term survival at sea from hatchling to maturity, combined with climate-driven changes in mature female foraging areas within a year or two before nesting.