Scientists keep close eye on sea turtles

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When environmentalists with Florida’s Sea Turtle Conservancy tagged a leatherback turtle named Dawn with a satellite tracking device off the coast of Panama, they thought their major goal would be identifying her migratory routes.

Dawn soon became the face of a much broader ecological crisis, as they nervously watched her swim right up into the northern Gulf of Mexico during the height of the BP oil spill.

“The turtle became kind of a poster child for the fact that the oil spill wasn’t just affecting what we think of as Gulf wildlife,” said David Godfrey, executive director of the Sea Turtle Conservancy.

The conservancy tagged Dawn in June 2010 and followed her movements for 153 days, nearly 3,000 miles from the coast of Panama to just off the coast of Louisiana and across the panhandle of Florida before she stopped transmitting.

One third of the leatherback turtles the conservancy has tracked from Panama have migrated into the Gulf of Mexico.

Turtles freely roam the oceans, but females usually return to the beach where they were born lay their own eggs. Dawn had just laid her eggs in Panama when she was tagged.

With sea turtle egg laying season under way a year after the oil spill, ecologists will be monitoring the effects on some of the spill’s most fragile victims, sea turtles and their hatchlings.

“If these turtles have been exposed to lots of oil, eating things with oil or dispersants on them, it’s conceivable their health has been affected and reproductive functions to make viable eggs may have been affected,” Godfrey said.

“We’re cautiously optimistic we won’t see drastic changes, but that is where you can see the lingering effects of such a massive spill.”

Last year, the conservancy and other environmental groups upped the hatchlings’ odds of survival, moving nests to the Atlantic coast for fear the oil washing ashore would harm them.

This year will be a litmus test for the health of turtles born along Gulf Coast beaches impacted by the spill.

“In terms of the physiological impact of the oil on the hatchlings themselves, are they born with deformities, we don’t know that yet,” Godfrey said.”It would be irresponsible to speculate that’s happening but it’s possible and it’s something we need to monitor.”

After they hatch, young turtles live in patches of sargassum weed, a type of sea weed that floats along the ocean’s surface. Godfrey says the sargassum weed rebounded from the spill better than expected, creating a safe place for hatchlings to nest and grow.

“After the spill was capped, I went out on a NOAA research vessel into the major spill zone. We spent all day examining the habitat. I expected to see remnants of oil but we found very healthy sargassum mattes,” he said.

“For the most part, we think if the hatchlings are healthy and aren’t compromised by their mothers being exposed to oil, they will emerge and find a decent habitat when they move into the gulf.”

Where his concern lies is with the older turtles, which forage in deeper waters.

“Juveniles and larger adults that feed on the bottom, those are the ones we have more concerns like ‘What is that bottom habitat like? How polluted are those food sources?'”

Turtles already impacted by the spill should receive the best in treatment. Through money funneled down from BP after the spill, the conservancy distributed more than $1 million to twelve turtle rehabilitation facilities in Florida.

“We were able to fairly substantially improve the capacity of those facilities around Florida, nearly doubling the capacity for the number of turtles that can be held and expanding the quality of care they can receive by providing state of the art equipment,” Godfrey said.