Scientists recently studied seven species of turtles across three different oceans and found that all individuals – every single one – had microplastics in their guts.
Over 5 trillion pieces of plastic are lurking in the seven seas, all of which are the direct result of human-made pollution. Recent years have also brought the idea of “microplastics”, defined as plastic particles smaller than 5 millimeters, into the public eye. While their precise effects on biological life are still unclear, this new study adds to the mass of evidence that points towards an overwhelming problem.
It's fair to say that eating hundreds of microplastic particles won't ever be considered a cornerstone of a nutritious diet for any biological being.
A collaboration between scientists from the University of Exeter in the UK, Plymouth Marine Laboratory, and Greenpeace Research Laboratories found evidence of microplastics in all of the 102 turtles studied. In total, over 800 synthetic particles were discovered in their digestive tracts, an average of eight pieces per turtle. However, since they only fully tested a small portion of each turtle's gut, they estimate that the real figure could be higher.
"Our society’s addiction to throwaway plastic is fuelling a global environmental crisis that must be tackled at source,” Louise Edge, plastics campaigner at Greenpeace, said in a statement.
"While this study has been successful, it does not feel like a success to have found microplastic in the gut of every single turtle we have investigated,” added Dr Penelope Lindeque of Plymouth Marine Laboratory.
"From our work over the years we have found microplastic in nearly all the species of marine animals we have looked at; from tiny zooplankton at the base of the marine food web to fish larvae, dolphins, and now turtles."
As reported in the journal Global Change Biology, the research looked at all seven sea-dwelling species of turtle, known collectively as Chelonioidea, in the Atlantic and the Pacific Oceans, as well as the Mediterranean Sea. All of the turtles died as a result of either stranding or becoming accidental bycatch. After their bodies were discovered, they were subjected to an autopsy and gut content analysis, which involved a specialized enzymatic digestion technique to identify the contents of their stomachs.
As mentioned, 102 out of 102 individuals contained microplastics.
"The effect of these particles on turtles is unknown," said lead author Dr Emily Duncan of the University of Exeter.
"Their small size means they can pass through the gut without causing a blockage, as is frequently reported with larger plastic fragments. However, future work should focus on whether microplastics may be affecting aquatic organisms more subtly. For example, they may possibly carry contaminants, bacteria or viruses, or they may affect the turtle at a cellular or subcellular level. This requires further investigation."