The number of loggerhead turtle nests was substantially lower in 2007 than in past years, according to preliminary numbers from scientists statewide.
Scientists found 28,500 nests from 19 surveyed beaches, down from almost 50,000 last year. The number was so low that this could be the lowest nesting year on record for loggerheads, said Blair Witherington, a research scientist with the Florida Fish and Wildlife Conservation Commission. The turtles' nesting numbers have declined in at least four of the past seven years.
Green and leatherback turtles, however, surpassed scientists' expectations and may have made a record number of nests this year on Florida's Treasure Coast.
Scientists aren't sure what's behind the low numbers for loggerheads, but they have some theories. Erik Martin, a biologist who monitors nesting, said the answer could lie in an unknown event that happened 30 years ago when today's nesting females were hatchlings — something like a disease or harmful algae bloom that affected only loggerheads.
A drop in nesting numbers may not correlate to a drop in population, said Pete Quincy, a scientist who monitors nesting for Jupiter Island. "Maybe there is a biological cycle among these turtles that we know nothing about."
Scientists have been tracking nesting for about 30 years.
This year, they counted about 9,450 green turtle nests _ up from the previous high of 7,180 in 2005 — in addition to 517 leatherback nests, up from the previous high of 367 in 2001.