As endangered turtles wash ashore, scientists get a rare glimpse

By Christopher Baxter
Globe Correspondent / July 24, 2008

CUTTYHUNK ISLAND – Seagulls, strangely absent from this quaint summer getaway, feasted Monday along the rocky shoreline, and Carrie DeArmond and her daughter, Jordan, knew something was amiss.

“There were five or six and then another and another,” DeArmond said. “And then I said, ‘Oh, my God, would you look at that.’ “

Lying in a patch of mud-colored seaweed was one of the ocean’s largest, most mysterious reptiles: the leatherback turtle.

“But she smelled,” Jordan said. And it was dead, the third of the rare and endangered species to wash ashore in Massachusetts in the past three weeks. Researchers typically see one or two each year.

“You could be a marine biologist for a long time and not come in contact with a leatherback,” said Tony LaCasse, a spokesman for the New England Aquarium. “And we could go another couple years without seeing another.”

Word of the 500-pound turtle spread quickly through the island community and among scientists eager to study the carcass for clues about the life of the leatherback. New England Aquarium researchers headed to the island yesterday morning to examine the turtle.

Distinguished by its unusual shell, a soft, vinyl-like skin over laying tiny interlocking bones, with seven ridges running front to back, the leatherback has roamed the world’s oceans for about one hundred million years.

Adults can measure as long as 6 1/2 feet and weigh up to 2,000 pounds, and are thought to live for more than 100 years. They spend much of their life close to the ocean surface, feeding on jellyfish, but have been spotted more than 4,000 feet underwater, LaCasse said.

Boat propellers, fishing lines, and beach development contributed to the leatherback’s rapid decline between the 1950s and 1980s, LaCasse said. Only an estimated 34,500 females existed worldwide in 1996, according to a report last year by the National Marine Fisheries Service and US Fish and Wildlife Service. The most recent population estimate for the North Atlantic alone ranges between 34,000 and 94,000 adult leatherbacks, the study said.

More than 40 sightings have been recorded in the waters of Nantucket Sound and Vineyard Sound this year, said Connie Merigo, director of the Marine Animal Rescue program at New England Aquarium. But some of those may be the same turtle, Merigo said, and “we don’t have an exact number.”

This year’s first dead turtle was spotted July 3 on Popponesset Beach in Mashpee. The second came ashore July 13 on Ricketson’s Point in Dartmouth, and the latest washed up here earlier this week. Researchers say the turtle was probably killed by a boat propeller, but they don’t know for sure.

Residents struggled to prevent full-moon tides from reclaiming the leatherback, DeArmond said, and it took seven people tugging at the turtle to keep it from washing away Monday night.

The turtle was eventually tied to an anchor about 20 feet inland and restrained with a small, green net.

The aquarium team had about an hour to analyze the turtle yesterday and collect samples before high tide made work impossible. The leatherback was significantly decayed: Its left side was split open, seagulls had pecked away the eyes, and much of the skin on its back had peeled away.

“It’s in pretty bad shape in terms of what we can learn,” said Sheila Sinclaire, an aquarium biologist. “We can’t even tell for sure whether it’s male or female.”

Tags on the turtle’s front flipper indicate the leatherback originated from the Caribbean, near Trinidad. It appeared to be a young adult, Sinclaire said, but an electronic tag found implanted in its muscle may lead to more information.

Leatherbacks live throughout the world, but this one probably nested in the tropics and followed migrating jellyfish up the US Eastern Seaboard, LaCasse said.

Unlike other cold-blooded animals whose internal temperature changes with their surroundings, the leatherback can moderate its heat and swim into colder waters. And had it not died, it would have returned south, possibly to the same beach where it was born, researchers speculate.

Instead, it landed on the shores of Cuttyhunk, and residents flocked to watch the team of scientists collect samples.

“I’ve seen sea turtles, but nothing like this,” said Ben Snow, 11, who was sitting in a line of friends as biologist Adam Kennedy examined a flipper.

“There was a sense of protectiveness on the island about it,” said Kathleen Patton, a summer resident from Milton who questioned researchers about what may have killed the turtle. “We almost wanted to have a little service for it.”

Advertisements

~ by Digory Kirke on August 1, 2008.

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s

 
%d bloggers like this: