Australian researchers have estimated that a turtle which eats just one piece of plastic can die 20 percent of the time. Consuming 14 pieces raised the risk level to 50 percent.
Furthermore, their calculations suggest that younger turtles are much more likely to die from plastic exposure. This puts into question the long-term viability of certain species.
Sea turtles are one of the most famous marine animals that are threatened by the plastic pollution that constantly enters and fills the oceans. They either get tied up in plastic rubbish and end up drowning, or they mistake dangerous, toxic plastics for food and eat them.
The latter condition is harder to ascertain. The Commonwealth Scientific and Industrial Research Organisation (CSIRO) researchers believe that perhaps 50 percent of the sea turtles on Earth have eaten at least one piece of plastic.
Among young green sea turtles that live near Brazilian coastlines, this increases to a staggering 90 percent. (Related: Are bioplastics really as eco-friendly as they’re touted to be?)
The CSIRO researchers investigated sea turtles in Queensland, Australia. They took a look at post-mortem reports and archived data pertaining to stranded animals.
Based on their analysis, an animal was not going to survive if it consumed at least 200 pieces of plastic. The fewer the plastics involved, the better the chances of survival.
Study author Dr. Britta Denise Hardesty explained that sea turtles cannot vomit out anything dangerous or poisonous that they have swallowed. If it's canal is blocked by a plastic piece, the animal would eventually starve to death.
Hard and rough pieces of plastic would also cut up the soft internals of the turtle. The resulting internal bleeding could also lead to its premature demise.
To make matters worse, the new generations of sea turtles are much more vulnerable than their parents. Only 16 percent of all adults have mistaken plastic garbage for a delicious jellyfish, but 23 percent of the juveniles and 54 percent of the babies were more than happy to bite off what they aren't supposed to chew.
Hardesty warned that baby turtles like to go with the flow of the great currents that traverse the world. It so happens that many of the smallest and lightest of plastics also take that path of least resistance.
"We think that small turtles are less selective in what they eat than large adults who eat sea grass and crustaceans," she said. "The young turtles are out in the oceanic area offshore and the older animals are feeding in closer to shore."
Sea turtles can live for up to eight decades. They remain fertile for much of their lifetimes. However, they have been subjected to many threats in recent times, such as poaching and loss of home environments.
Given how deadly plastic pollution is, the CSIRO researchers are worried for the long-term survival of species like the green sea turtle. If fewer baby animals survive their perilous journey, the breeding population of turtles will be greatly depleted, which in turn decreases the number of new births.
Hardesty and her teammates are hoping that their findings can inform both consumers and politicians. They urge better solutions to the plastic pollution that is killing off sea turtles and other marine wildlife.
See for yourself how you can help save sea turtles from plastic pollution at Environ.news.