Halloween 'Witch's Finger' Found in Turtle's Gut

Dead sea turtles have been discovered with a vast array of plastic waste inside their bellies, with one unlucky reptile having swallowed a rubber witch's finger.

Of a total of 135 loggerhead turtles found dead off the coast of Cyprus, over 40 percent of the animals contained plastics larger than 0.2 inches, known as macroplastics.

There were 492 chunks of plastic found in the guts of these turtles, with a single turtle containing 67 pieces of plastic, according to a new paper in the journal Marine Pollution Bulletin.

It is the latest study to show how pieces of plastic, produced by humans, can affect the health of marine animals and how common they are throughout the oceans.

"The journey of that Halloween toy—from a child's costume to the inside of a sea turtle—is a fascinating glimpse into the life cycle of plastic," paper author Emily Duncan, a researcher at the Centre for Ecology and Conservation at the University of Exeter's Penryn Campus in Cornwall, in the U.K., said in a statement.

Loggerhead turtles are one of the largest species of sea turtles, usually weighing between 180 to 440 pounds, and growing to lengths of between 2.5 and 3.5 feet. These turtles migrate immense distances, traveling thousands of miles between their nesting beaches and foraging grounds. Female loggerheads return to the beaches where they were born to lay their eggs, typically during the nesting season, which varies depending on the location. They dig nests in the sand and lay over 100 eggs, which they then cover with sand before returning to the sea.

They are listed as a vulnerable species by the International Union for Conservation of Nature Red List, due to them facing numerous threats, including habitat loss, pollution, climate change, accidental capture in fishing gear, and poaching of eggs and adults.

The turtles examined in the paper were found either washed up dead on the beaches of northern Cyprus, or were accidentally caught as bycatch in fishing nets, between 2012 and 2022. Four of these 135 turtles were post-hatchling young turtles. The study found that of the 131 adults, 57 contained macroplastics inside their bodies, equating to 42.7 percent. It's not clear if the plastics contributed to the deaths.

Certain types of plastic were more commonly found inside the turtles, mostly including clear or pale sheets of plastic.

"The plastics we found were largely sheetlike (62 percent), clear (41 percent) or white (25 percent) and the most common polymers identified were polypropylene (37 percent) and polyethylene (35 percent)," said Duncan.

This indicates that the turtles may be attracted to eating plastics that look a certain way, perhaps because they resemble the turtles' natural food sources.

"These turtles feed on gelatinous prey such as jellyfish and seabed prey such as crustaceans, and it's easy to see how this item might have looked like a crab claw," Duncan said. "It's likely that turtles ingest the plastics that mostly closely resemble their foods."

Eating plastics can be terrible for the health of sea creatures like turtles, as it can cause internal injuries, blockages in the digestive system, and abrasions in the throat and digestive tract. Sharp edges or points on plastic items can puncture internal organs, leading to infections or death.

Additionally, when turtles consume plastic, it fills their stomachs without providing any nutritional value. This can lead to malnutrition and starvation, as the turtle feels full but is not getting the necessary nutrients from its actual diet. Plastics in the marine environment can also absorb and accumulate harmful chemicals from seawater, such as persistent organic pollutants and heavy metals, which can poison an animal that consumes it.

"We still don't know the full impacts of macroplastic on turtles' health, but negative effects could include causing blockages and limiting nutrition," Duncan said.

The study found that the numbers of macroplastics found within the turtles did not increase across the 10-year study period, remaining at a stable rate. There was also no difference in the amount of plastics found within turtles that had been discovered dead on beaches and those killed as bycatch.

It is hoped this study will inform scientists of the degree of plastic pollution in the Mediterranean, and the impact that this plastic has on wildlife. However, more research is needed into how other species of turtle are affected, which will give a more comprehensive view of the impacts of macroplastics.

"Much larger sample sizes will be needed for loggerheads to be an effective 'bioindicator' species, and we recommend studies should also include green turtles—allowing a more holistic picture to be gathered," paper co-author Brendan Godley, a professor of marine biology at Exeter University, said in the statement.

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