The largest remaining loggerhead sea turtle rookery in the United States is in steep decline, according to the latest Index Nesting Beach Survey compiled by the Florida Fish and Wildlife Conservation Commission.
The analysis shows that nest counts have slumped 22.3 percent from 1989 to 2005. There has been a 39.5 percent decline since 1998.
An average of 14,423 loggerhead turtles nested on Florida beaches between 2001 and 2005.
The index uses nest counts made by hundreds of trained participants who survey turtle tracks and nests at certain Florida beaches, following a rigorous protocol to ensure nest counts reveal unbiased trends. Scientists at the Commission's Fish and Wildlife Research Institute coordinate the counts.
Loggerhead turtle at Florida's Archie Carr National Wildlife Refuge. Only two loggerhead nesting beaches have greater than 10,000 females nesting per year - one is in South Florida (Photo courtesy ACNWR)
Although loggerhead sea turtles nest at many locations around the world, the Commission says nearly 90 percent of the world’s population nests on the beaches of Florida and the beach at Masirah in Oman on the Arabian Peninsula.
Florida accounts for more than 90 percent of loggerhead nesting in the United States. Loggerhead turtles have been federally listed as threatened since 1978.
The U.S. nesting season extends from about May through August with nesting occurring primarily at night. Each loggerhead nests from one to seven times within a nesting season at intervals of approximately 14 days.
A preliminary assessment of data from the 2006 season suggests another poor year for loggerheads, with the second lowest nesting in the history of this program.
David Godfrey, executive director of the Florida-based Caribbean Conservation Corporation, the world's oldest sea turtle conservation group, said, "We have known loggerheads were declining, but this thorough analysis of data dating back nearly two decades paints a far grimmer picture of the status of loggerhead nesting in Florida and the U.S."
"The results are alarming," said Godfrey, "and it is urgent that state and federal agencies strengthen conservation efforts to address the root causes of this decline."
The Commission's report does not identify any conclusive cause of the decline but states that the severe hurricanes of the 2005 season are not to blame.
Loggerheads that hatch on Florida beaches take 20 to 30 years to reach maturity, so recent storm impacts would not be seen in the nesting population for decades, the Commission explains.
Legal and illegal fishing is causing high mortality on loggerhead sea turtle nesting populations of the western north Atlantic region. (Photo courtesy ACNWR) The report suggests that loggerheads are dying before they reach the nesting beaches - drowning in fishing trawls or taken as bycatch by the long line commercial fishing industry in the open Atlantic Ocean.
Once near the nesting beaches, the loggerheads must contend with a booming coastal human population and coastal development.
Artificial lighting on nesting beaches causes hatchlings from nests to crawl inland rather than toward the water, says the Commission. On developed beaches, coastal armoring meant to protect buildings from erosion has resulted in the loss of nesting habitat near natural dunes.
Earlier this month, the U.S. Fish and Wildlife Service announced 70 percent staffing cutbacks at the Archie Carr National Wildlife Refuge, established to protect the most heavily nested loggerhead turtle nesting beaches in the Western Hemisphere.
The refuge occupies a 20 mile section of coastline from Melbourne Beach to Wabasso Beach in Florida. Twenty-five percent of all loggerhead sea turtle and 35 percent of all green sea turtle nests in the United States occur on this stretch of beach where nesting densities of 1,000 nests per mile have been recorded.
According to Godfrey, the federal government appears to be abandoning support for the Carr refuge just when sea turtles are in desperate need of increased protection.
After Hurricane Dennis in 2005, hundreds of sea walls were built along Florida's beaches, affecting turtle nesting sites. (Photo by Richard Fowlkes courtesy Caribbean Conservation Corp.) "These turtles are being hammered in the open-sea fisheries," Godfrey said. "While addressing this serious threat, we must also make sure reproductive turtles find healthy nesting beaches when they return home. Right now, they are returning to find miles of sea walls and new beachfront development."
Loggerhead strandings of dead or debilitated turtles documented by the Florida Sea Turtle Stranding and Salvage Network between 1980 and 2005 have increased over the period from 1989–2005, with the two highest yearly totals occurring in 2003 and 2005.
Throughout Florida waters, the Commission finds that collisions with boats provide the most common identifiable cause of trauma in sea turtles that wash up dead on beaches.
To help protect and manage Florida’s sea turtles outside of Florida waters, the Commission provides nesting data to the National Marine Fisheries Service and the U.S. Fish and Wildlife Service. Both federal agencies have management oversight beyond Florida.
The Commission has also presented this information to an international group of scientists, resource managers, and conservationists, with the hope that threat reduction actions could be identified throughout the multi-national range of Florida’s loggerhead sea turtles.
For loggerhead sea turtle fact sheets visit the U.S. Fish and Wildlife Service.