Sea turtles that eat 14 pieces of plastic have 50 per cent chance of dying, CSIRO study finds
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.
The CSIRO said it was previously unclear how much plastic could kill sea turtles and whether they could ingest it without significant harm.
A study, published today in Scientific Reports, has found that once a turtle had 14 pieces of plastic in its gut, it had a 50 per cent likelihood that it would cause death.
Principal research scientist Chris Wilcox at the CSIRO in Hobart said they estimated 52 per cent of sea turtles had plastic in their stomach.
“What we found was that when the turtle eats the first piece of plastic, it has about a 20 per cent chance of dying due to that one piece of plastic and as they eat more plastic, the chance that they die goes up,” he said.
“We find hundreds of pieces of plastic in some turtles, everything from thin film to rope to fishing line, anything you see in your daily life we see in a turtle.”
Dr Wilcox said they were previously unsure about the impact plastic had on sea turtles.
“It’s really widespread but it might have been that the turtles can live with plastic in their gut no problem,” he said, “It might be that it’s relatively deadly.
CSIRO research assistant Qamar Schuyler said they studied nearly 1,000 turtles found dead and washed up on beaches around Australia.
“In one tiny little flatback turtle we did find whole apple stickers, the stickers that come on fruit,” she said.
“We find a lot of soft plastics in the older animals, it could be plastic bags it could be lolly wrappers.”
Dr Schuyler said the next step was to estimate the impact plastic had on turtle populations.
“Now that we know how much plastic it takes to kill a turtle, we can combine that with previous work that we did which looked at the probability of ingestion of plastic by turtles,” she said.
“We can come up with a global mass mortality estimate of how many turtles globally are being killed by plastics.”
Animal ecology lecturer at the University of the Sunshine Coast Kathy Townsend said sea turtles in different parts of the world had varying amounts of debris in their gut.
“It really depends upon what part of the world you’re looking at,” she said.
A recent study in Uruguay found almost 100 per cent of the sea turtles had marine debris in their gut.
“We’re not talking little bits, we’re talking hundreds of pieces,” Dr Townsend said.