Thursday, August 19, 2010
Panhandle now safe for turtles
Florida wildlife officials say they now feel that a portion of Panhandle beaches are safe enough for loggerhead and other sea turtle nests to hatch naturally.
As a result they have modified a controversial relocation project that took sea turtle eggs from their nests in the Panhandle and moved them to beaches along the East Coast. But while the threat from the spill has diminished significantly, wildlife officials say they will continue sea turtle nest excavations along beaches west of the St. Joseph Peninsula, which is southeast of Panama City.
The question now is what long-term impact the relocations will have on hatchlings and the ecology of the Panhandle. By relocating some eggs, biologists may have altered nesting protocols that have been in place for hundreds of thousands of years. Will the displaced hatchlings return to their traditional beaches when they are old enough to lay eggs? Or will they, instead, establish their nests on the East Coast? And if that happens, what will be the impact on birds and animals that depend upon the annual nesting to feed?
At this point, no one knows for sure, and the answers may be a long time in coming.
Robbin Trindell, a Florida Fish and Wildlife Conservation Commission biological administrator and sea turtle expert, said since it may take 20 or more years for surviving females to mature to the point where they are laying eggs, the answer to that question will have to wait.
In the wake of the Deepwater Horizon well blowout that spewed oil into the Gulf and onto northern Gulf beaches, the FWC decided to dig out and relocate sea turtle eggs in the Panhandle to beaches along the East Coast. The eggs were packed in coolers and shipped to the East Coast.
The decision to move the eggs was not taken lightly, Trindell said.
"It was very much a balancing act,' Trindell said, suggesting that the desperate situation caused by the spill demanded desperate measures in response. Once the decision was made, the relocation process was carefully thought out to cause as little disruption as possible to the eggs, officials said.
The researchers waited until late in the incubation process, for example, before digging out nests, and then packed the eggs with sand from their nests, Trindell said.
According to an FWC report, 209 nests, primarily those made by loggerhead sea turtles, were excavated along the northwestern Florida coast. Of those, 148 came from Gulf and Franklin counties, which are prime sea turtle nesting sites. Since July 10, more than 6,000 hatchlings collected from Northwest Florida and Alabama beaches were released into the Atlantic Ocean.
A few endangered Kemp's ridley turtle and green sea turtle eggs also were relocated to the East Coast.
State biologists say they now believe that hatchlings in Franklin and Gulf counties can emerge from their nests naturally. FWC officials reported that they made that decision after examining the results of airborne inspections of the region. Inspection teams were looking specifically for patches of sargassum, the floating seaweed that provides the primary habitat for the hatchlings that make it from the nests to open water.
Once those patches were found, FWC researchers evaluated samples of the sargassum and discovered no visible signs of oil.
Locally, sea turtle nesting season begins in May and lasts until October. State researchers estimate female turtles deposit up to 100 eggs into their nests buried on beaches. The females can nest multiple times in a season and nest every two or three years.
The eggs generally take two months to incubate and temperatures can affect the gender of the hatchlings - warmer temperatures typically produce more females, while cooler temperatures typically produce more males. The 2-inch hatchlings emerge from their nests as soon as they break free from their eggs and immediately head to open waters. Researchers suggest only one in 1,000 hatchlings survives to adulthood.
Scientists believe the female sea turtle embryos become imprinted with the beach upon which they hatch, and that they will return there to lay their eggs.
Trindell said researchers have been able to determine through DNA testing that subpopulations of sea turtles nesting in the Panhandle aren�t the same as those nesting on Manasota Key and elsewhere in the state.
The turtles also are known to have crystals in their brains that can detect - and are directed by - magnetic fields, Trindell said. That may lead them to their traditional nesting spots no matter where they first went into the sea, she said. The hatchlings also may pick up other cues, she said, that lead the females back to their home beaches.
Besides addressing the nests, Trindell said the FWC and other agencies captured 134 turtles alive in the oil-polluted waters of the northern Gulf. Of those, she said, 42 were unaffected by the spill and immediately released. One dead turtle was recovered.
The good news is that, despite the oil well blowout, loggerhead sea turtle nest numbers are up around the state, compared to the declines seen in nesting over the last few years, she said.
Manasota Key, too, has seen higher numbers in sea turtle nests. So far this year, volunteers have documented 1,585 nests on the key, compared to the 1,489 nests laid there in 2009. While sea turtle nesting season ends in October, nesting already has started to slow down this month.
For more than 20 years, Zoe Bass, president of the Coastal Wildlife Club, and other volunteers have documented sea turtle nesting on the key. In the 1990s, Bass said the "very, very best year" saw nearly 3,000 nests. But since the late 1990s, she said the numbers have declined, with 2009 registering the lowest numbers of counted nests.
This year, Bass said wildlife state officials asked turtle patrol volunteers to be especially vigilant due to the oil spill.
To learn about the local sea turtle documentation efforts, visit www.coastalwildlifeclub.org.
By STEVE REILLY
Staff Writer
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