Sonya Colberg NewsOK.com on Tulsa World 9 Apr 09;
Imagine gulping down a gelatinous blob of toxic tentacles and discovering that instead of a delicious jellyfish, you just swallowed plastic.
That’s what happened to almost 34 percent of big sea turtles studied by researchers at three Canadian universities.
Floating plastic bags look like dinner to the giants of the oceans.
"Jellyfish are a very common sea turtle prey item,” said Elizabeth Griffin, a marine wildlife scientist with Oceana, a marine conservation group. "If you can imagine what a plastic bag floating in the water looks like, it looks very similar to a jellyfish.”
Researchers studied autopsy reports of 408 sea turtles from 1885 to 2007. A total of 138 turtles had ingested plastic, according to the study by researchers N. Mrosovsky with the University of Toronto, Geraldine D. Ryan with University of Guelph and Michael C. James with Dalhousie University.
Nine percent of the turtles’ deaths were specifically tied to plastic that had bound their digestive tracts. Other causes of sea turtle death mentioned were catches in fishing gear, collisions with boat propellers and development on nesting beaches.
Researchers concluded that, conservatively, about a third of adult leatherbacks have swallowed plastic.
"We have to look out for them,” said John Money, curator of the Oklahoma Aquarium in Jenks, where two sea turtles live.
Money said visitors who see the captive loggerheads make the connection to the wild sea turtles that face the risks of mistaking plastic for jellyfish. He thinks many visitors become determined to recycle to help increase the chances of sea turtles living out their 100- to 125-year lifespan in the wild.
"I think that everyone should be aware that everything that we put in the water, especially plastic, has a tendency to look like other things,” Money said. "These animals have developed habits over thousands and thousands or maybe even millions of years, and they aren’t changing.”
The Jenks aquarium’s 18-year-old loggerhead turtles paddle around gobbling down whatever is in their path, Money said.
"They’re kind of programmed to survive, to eat anything out there,” Money said. "That’s one of the challenges in captivity — making sure that the inside of the tank is safe for them.”
By SONYA COLBERG NewsOK.com
Study finds plastic 'diet' in leatherback turtles
Necropsy reports show a third of specimens had it in their digestive system
Emily Sohn msnbc.msn.com 9 Apr 09;
Leatherback turtles are ancient creatures with a modern problem: Plastic.
A new study looked at necropsy reports of more than 400 leatherbacks that have died since 1885 and found plastic in the digestive systems of more than a third of the animals. Besides plastic bags, the turtles had swallowed fishing lines, balloon fragments, spoons, candy wrappers and more.
Plastic was probably not the cause of death in most cases. Nevertheless, the study is an important wake-up call for a growing garbage problem.
"Eating something that is plastic can't be good for you, whether it leads to death or not," said Mike James, a marine biologist at Dalhousie University in Halifax, Nova Scotia. "It's not what they should be eating. And it's kind of scary that it is showing up in their diet to the extent that it is."
Leatherback turtles are critically endangered and highly charismatic creatures. They are big, weighing 1,000 pounds or more, with shells that can measure more than 6 feet across. These peaceful creatures have had the same basic body plan for 150 million years.
Leatherbacks are also popular for what they eat: namely, large quantities of jellyfish. The problem is that plastic bags look a lot like jellyfish, and plastic often ends up in the oceans, piling up in areas where currents -- and turtles -- converge. That led James to wonder how much often the turtles were swallowing plastic in their hunt for yummy jellyfish.
Collecting the data was a painstaking process. James and colleagues spent two years searching far and wide for turtle necropsy reports. They scanned the literature, and they asked people to dig up old field-notebooks. For every report found, they had to make sure that a complete necropsy had been performed and that the entire GI tract had been opened.
The researchers ended up with a sample size of 408 turtles, stranded at some point during the last 125 years. Of those, 138 -- or 34 percent -- contained plastic. Alongside the rise in plastic production, there has been a sharp rise in plastic-containing turtles since the 1950s.
That finding isn't surprising, given the leatherback's jellyfish-based diet, said Christopher Sasso, a research fisheries biologist with the National Marine Fisheries Service in Miami.
But the numbers are alarming. Plastic can block a turtle's gut, causing bloating, interfering with digestion, and leading to a slow, painful death. "I can't imagine it's very comfortable," he said. "Their guts weren't designed to digest plastic."
There are vast fields of trash floating in the world's oceans, Sasso added. And leatherback turtles travel thousands of miles each year, giving them even more opportunities to come in contact with it.
"This is an animal that has survived many extinction events," James said, "And now it's got all these anthropogenic hazards to face."
That's where people come in. Simple choices -- like putting balloons and picnic supplies in the trash and using canvas instead of plastic grocery bags -- can help leatherbacks and other marine creatures survive long into the future.
"Of all the problems the environment faces, this one is not impossible to address," James said. "We don't need to have everything packaged in plastic. There are alternatives."
© 2009 Discovery Channel
