Pollution is affecting marine on a chemical level, scientists have confirmed, after finding high concentrations of plastic in the muscles of loggerhead sea turtles.
Researchers analysed the remains of 44 turtles found washed up dead on coastlines in eastern Spain — finding traces of plastics in each one.
Marine animals like sea turtles often fall foul to fishing nets, waste in the oceans, and other plastics that they can end up eating — often with fatal results.
Loggerhead sea turtles are listed as ‘endangered’ in the Red List of the International Union for Conservation of Nature.
Pollution is affecting marine on a chemical level, scientists have confirmed, after finding high concentrations of plastic in the muscles of loggerhead sea turtles (like that pictured)
The study — led by chemist Ethel Ejarrat of the Spanish National Research Council — focussed on 44 loggerhead sea turtles, or ‘Caretta caretta’, that were found dead on the Catalan coast and in the Balearic Islands between 2014–2017.
The turtles, whose diet mainly consists of jellyfish, sardines and squids, also consume such waste as plastic bags, bottle tops and fragments of floating plastic.
‘There was a clear presence of those additives in the muscles of the analysed turtles,’ Dr Ejarrat, 51, told Real Press.
‘There were higher levels of plastic in the turtles from the Balearics and we believe turtles living along the Algerian coast have a higher presence of plastic waste than those along the Catalan coast,’ she added.
‘The research shows that plastic waste not only affects them on a physical level — when the turtles get stuck among the waste or it ends up in their digestive system — but also on a chemical level.’
The team analysed 19 additives used in plastics that are known to disrupt the hormone-regulating endocrine system, are neurotoxic or even carcinogenic.
These included organophosphorus compounds, or OPCs, which are added to plastics to improve their flame retardant properties and were found in all the turtles.
Analysis revealed the presence of plastics in all the turtles, with concentrations ranging between 6 and 100 nanograms per gram of muscle.
These levels are similar to those found in previous studies on OPCs such as polychlorinated biphenyl or Dichlorodiphenyltrichloroethane — commonly known as DDT — which, as Dr Ejarrat notes, ‘was banned years ago for being toxic’.
‘When eating sea waste voluntarily, [turtles] often mix it up with real food (such as jellyfish),’ said biologist Luis Cardona of the University of Barcelona.
‘Turtles are one of the groups of animals most exposed to contamination from plastic additives, although we do not fully understand the real impact of that yet.’
Researchers analysed the remains of 44 turtles found washed up dead on coastlines in eastern Spain — finding traces of plastics (pictured) in each one
The study — led by chemist Ethel Ejarrat of the Spanish National Research Council — focussed on 44 loggerhead sea turtles, or ‘Caretta caretta’, that were found dead on the Catalan coast and in the Balearic Islands (pictured) between 2014–2017
Doctor Ejarrat also said that the plastic compounds they detected could be affecting the turtle’s fertility — and have been linked to cancer cases in the marine reptiles.
“The toxic effect is not acute, but chronic toxicity,’ she told Real Press.
‘The fact they are exposed daily to these contaminants could cause problems for their whole life.’
Furthermore, loggerhead sea turtles may be more susceptible to the chemical additives linked with the plastics than other marine creatures.
‘[They] take in more plastics than whales or dolphins. For example, when whales filtrate water, they take in microplastics, but the levels of contaminants in the microplastics are lower than the macroplastics taken in by turtles,’ Dr Ejarrat said.
If loggerhead sea turtles are suffering from these effects, it stands to reason that humans could also be exposed, Dr Ejarrat also warned. Pictured: a sea turtle on a beach after spawning
If turtles are suffering from these effects, it stands to reason that humans could also be exposed, Dr Ejarrat also warned.
‘We are incorporating these compounds in our diet through fish as well as in the air while breathing so we are absorbing it and, depending on each one of us, our organism and metabolism can be affected sooner or later.’
The full findings of the study were published in the journal Environmental Pollution.