Green turtles are more likely to swallow plastic that resembles their natural diet of sea grass, new research suggests.
Published in the journal Scientific Reports, the study found that turtles strongly favour narrow lengths of plastic in natural colours like green and black, rather than debris of other shapes and colours.The researchers examined the guts of turtles found washed up on beaches in Cyprus. Plastic was found in all turtles whose full gastrointestinal tract could be examined, with one found to contain 183 pieces.
"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 favour plastic of certain sizes, shapes and colours," said researcher Emily Duncan from the University of Exeter in the UK.
"Compared to a baseline of plastic debris on beaches, the plastic we found in these turtles suggests they favour threads and sheets that are black, clear or green.
"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.
The study found that smaller turtles tended to contain more plastic, possibly because they were less experienced and therefore more likely to eat the wrong food or because diet choices change with age and size.
Of the 34 turtles examined, the researchers were able to examine the full gastrointestinal tracts of 19. All of these turtles contained plastic, with the number of pieces ranging from three to 183."Research like this helps us understand what sea turtles are eating, and whether certain kinds of plastic are being ingested more than others," said Brendan Godley, professor at University of Exeter.