Plastic creates 'evolutionary trap' for young sea turtles

Olive ridley sea turtle. This is a species in the superfamily of sea turtles. Credit: Thierry Caro/WikipediaNew research shows that plastic pollution is an evolutionary trap for sea turtles young.The University of Exeter led the study that found plastic in small juvenile turtles on both the East (Pacific) as well as West (Indian Ocean), coasts of Australia.Sea turtles hatch on beaches and then travel on currents to reach the open ocean.These currents have accumulated large quantities of plastic, and many young turtles eat it.Murdoch University, Murdoch University and the Department of Environment and Science (Queensland), and the Department of Biodiversity Conservation and Attractions were part of the research team.Dr. Emily Duncan of the Centre for Ecology and Conservation at Exeter's Penryn Campus in Cornwall said that juvenile turtles evolved to thrive in open oceans, where predators are scarce.Our results show that their evolved behavior now leads them to a trap, bringing them into polluted areas like the Great Pacific Garbage Patch."Juvenile sea Turtles eat almost anything. Our study shows that they don't have a specialized diet.We don't know yet what plastic intake has on juvenile turtles. However, any loss at these early stages could have a significant effect on the population.Researchers examined the juvenile sea turtles, from hatchlings up to 50cm in length, that were accidentally or intentionally caught by fishermen off the Australian coasts.The study involved 121 sea turtles representing five of seven species around the globe: flatback, green, hawksbill and loggerhead.The Pacific coast had a much higher proportion of plastic-containing turtles: 86% of the loggerheads, 83% greens and 29% olive ridleys.Plastic was found on the Indian Ocean coast in 28% of flatbacks, 21% loggerheads, and 9% green turtles.On either coast, no plastic was found in hawksbill Turtles. However, only seven hawksbills could be found so the sample was very small.The plastic found in the Pacific turtles consisted mainly of hard fragments. These could have come from a wide range of products, while Indian Ocean plastics were mostly fibres, possibly from nets or fishing ropes.Turtles in both oceans ingest the most polymers, which were polyethylene (and polypropylene)Dr. Duncan stated that these polymers are used so often in plastic products, it is impossible to trace the probable sources of the fragments found."Hatchlings typically contained fragments of between 5mm and 10mm in length. The turtles' sizes increased with increasing particle sizes."The next step in our research is to determine if and how plastic intake affects the survival and health of these turtles."This will require close cooperation with researchers and veterinarians across the globe."The Sea Life Trust and National Geographic Society funded the study.The paper was published in Frontiers in Marine Science and is entitled "Plastic Pollution and Small Juvenile Marine Turtles: A Potential Evolutionary Trap."Learn more Green turtles eat plastic similar to their foodFurther information: Emily M. Duncan and colleagues, Plastic Pollution and Small Juvenile Turtles: A Potential Evolutionary Catch, Frontiers of Marine Science (2021). Information from Frontiers in Marine Sciences Emily M. Duncan and colleagues, Plastic Pollution and Small Juvenile Turtles: A Potential Evolutionary Catch, (2021). DOI: 10.3389/fmars.2021.699521