Just one piece of plastic enough to kill a turtle, CSIRO finds

Mindy Sparks
September 15, 2018

The first study of its kind sheds fresh light on the risk plastic pollution poses to the world's declining sea turtle populations, especially in coastal surface waters.

Now, a new study out of Australia is trying to catalog the damage.

Scientists have drawn a link between the amount of plastic a sea turtle consumes and its likelihood of death, with an estimated half of all sea turtles having plastic in their gut, according to CSIRO researchers.

Dr Hardesty explained: "Younger turtles tend to drift with currents and feed in offshore waters closer to the surface, which are more likely to be contaminated with large plastic items that can accumulate in the animals" digestive tracts, or cause perforation'.

In one case, researchers found as many as 329 pieces of plastic in the gut of a sea turtle.

Post mortems on nearly 1,000 dead turtles found more than half of the babies - and about a quarter of juveniles - had swallowed plastic, compared to just one in seven adults.

Turtles in the data set which had died of non-plastic related causes had less plastic in their gut than those that died of either indeterminate causes or due to plastic ingestion directly.

But the deaths are hard to pin down. In Uruguay for example, Howarth reports 100 percent of turtles sampled had plastic in their intestinal tracts. Even one small piece of plastic that gets trapped in the wrong place can cause a blockage that leads to death.

The authors of this study estimate that around half of all the sea turtles on the planet have ingested plastic - this rises to 90% among juvenile green sea turtles off the coast of Brazil.


Crucially, those confirmed to have died from plastic ingestion had eaten the most - underlining its threat to sea turtles and other marine life. Because of their anatomy, sea turtles can not vomit up something once they have swallowed it, Hardesty said, meaning it either passes through their gut or gets stuck.

"Let's put a true cost on plastic so they have a similar value to aluminium cans which we don't find lost in the environment, they get picked up and they don't get mismanaged and find their way out into the ocean", she added. It happens at all stages of a sea turtle's lifecycle, and particularly, most frequent at the juvenile stage.

An animal that swallows a lot of plastic might appear healthy, Jones said, but might be weakened by plastic in its gut limiting food absorption.

Mark Hamann, a turtle expert and associate professor at James Cook University in Townsville, Australia, said he hoped that studies like this one would provide a sense of the scope of the problem.

"We know individual turtles are dying, but we don't know yet whether enough turtles are dying to cause population decline, and that's where we're heading to now", Hamann said. "They ate a lot of plastic but it did them no harm", Lynch said of the animals she has examined. "They swallow it and they poop it out". "There's a truly solid bias of their gaze in the direction of very sick, ineffective animals", she stated. "We looked only at live, healthy animals that died because they drowned on a fishhook".

The maximum weight of the plastic was 10.41g (0.4 ounces). A single piece could range from a speck of microplastic to an entire snack bag, she noted.

"In other words, we wanted to know 'How much plastic is too much plastic?' for sea turtles".

While this may sound like an obvious observation, it was previously not known if the plastic pollution in our oceans was actually killing sea turtles, or simply being ingested without significant harm. "Teeth is what's needed", Lynch said. Lynch stated.Dr. Hardesty stated she thinks it's imaginable to in the reduce price of the turtles' publicity to plastic with a unfold of approaches, from incentives to bans for high-impact, continually littered objects."The stuff that ends in the ocean became in someone's hand at some closing date", she stated.

Other reports by Iphone Fresh

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