Plastic pollution is having a huge economic impact on society, but for sea creatures, the devastating effects are much worse.
Hungry green turtles are being fooled by plastic that looks like their natural diet, new research suggests. The plastics, which are often green, black or clear in colour, look like seagrass to the turtles, a staple of their diets.
When researchers examined the guts of green turtles found washed up on the beaches of the Eastern Mediterranean island of Cyprus, the pieces of plastic they found were long and thin.
Scientists from the University of Exeter and the Society for the Protection of Turtles (Cyprus) dissected 34 turtles, but were only able to examine the full gastrointestinal tracts of 19 specimens. Researchers found plastic pollution in the guts of all 19. One turtle's intestinal tract revealed 183 pieces of plastic debris.
The turtles mostly died after getting caught in fishing nets. Scientists were unable to determine whether or not plastic consumption played a role in the deaths. Green turtles are classified as endangered.
In addition to getting caught in fishing nests, adults are hunted. Their eggs are also targeted by poachers. Human activities also threaten the species' preferred nesting sites.
"Previous research has suggested leatherback turtles eat plastic that resembles their jellyfish prey, and we wanted to know whether a similar thing might be happening with green turtles," Emily Duncan, researcher at the University of Exeter, said in a news release.
"Sea turtles are primarily visual predators -- able to choose foods by size and shape -- and in this study we found strong evidence that green turtles favor plastic of certain sizes, shapes and colours."
The survey of turtle intestines suggests green turtles tend to target plastic that is grass-like and black, green or clear.
"The sources of this plastic might include things like black bin bags, and fragments from items such as fishing rope and carrier bags," Duncan said.
Younger turtles tended to contain the highest concentrations of plastic, possibly because they are less experienced and therefore more likely to eat the wrong food, scientists said. This also might be because diet choices change with age and size.
Plastic is now everywhere in the world's oceans. Studies suggest even deep sea creatures are ingesting plastic. Sea birds have also been found to eat plastic debris resembling their prey.
"It's important to know what kinds of plastic might be a particular problem, as well as highlighting issues that can help motivate people to continue to work on reducing overall plastic consumption and pollution." said Brendan Godley, professor of marine sciences at Exeter.
Results of this latest study, published this week in the journal Scientific Reports.
