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The whale shark.

Plastics were first synthesized about a century ago. Since then, their unnaturally durable structures have persisted in the environment even beyond their intended usage. Particles are found in the biggest lakes, the most remote parts of the Pacific Ocean and even in tap water worldwide.

Whales and other filter-feeding marine life are ingesting tiny fragments of plastics at an alarming rate – and potentially being poisoned by the toxins within the substances, according to a new study in the journal Trends in Ecology and Evolution.

The analysis, led by PhD student Elitza Germanov at Murdoch University, concludes that hotspots of plastic pollution in the world’s oceans are impacting endangered species like the whale shark (Rhincodon typus).

Finding the actual impacts of the ever-present plastic particles is not easy – especially since stomach analysis is invasive for the threatened animals. The latest method by the international team of scientists is to sample small amounts of tissue, like in skin biopsies.

“We are using non-lethal sampling of small amounts of tissue, which we are testing for chemical tracers using sophisticated and sensitive analytical tools,” said Germanov, in a statement released by Murdoch.

Using such a methodology, a previous study that appeared in September in the journal Comparative Biochemistry and Physiology Part C: Toxicology & Pharmacology indicated that whale sharks in the Gulf of California were swallowing about 170 pieces of plastic each day. The biopsies were assessed fpr key compounds indicating digestion of plastics, including organochlorines like PCB and DDT, polybrominated diphenyl ethers, other plastic additives, and biomarkers indicating system responses, like CYP1A.

Other “hotspots” of microplastic pollution include the Gulf of Mexico, the Mediterranean, the Bay of Bengal, and the Coral Triangle off the coasts of Southeast Asia.

Understanding what the ingested plastics is doing to the whales is another question. Germanov said she is working with the Separation Science and Metabolomics Laboratory to better understand the link between the plastic traces and the biomagnification of pesticides and industrial chemicals in the impacted species.

Germonv wrote in a blog post last month that there was some reason to hope the world was taking notice of the growing problem – and may be able to turn the tide.

“The silver lining is that world now seems to have pricked up its ears to microplastic pollution and plastic marine debris in general,” she wrote. “This year we saw two major world ocean meetings… focus on plastic marine debris. Encouragingly, Indonesia pledged to reduce the plastic waste it contributes to our oceans (currently number 2 spot on the naughty list) by 70 percent by 2025.”

Plastics continue to pile up in the world’s oceans. Their mass in the world’s oceans will outweigh all fish by the year 2050, according to a report released in 2016.

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