Off the northeastern coast of Japan, marine scientists have been monitoring the diets of sea turtles for the past 15 years. Live turtles caught as by-catch (mainly loggerhead and green turtles) are brought to the International Coastal Research Center of the Atmosphere and Ocean Research Institute, University of Tokyo, where they are kept in individual tanks for up to 3 months to collect their feces. Sadly, many of the turtles have ingested marine debris, as evidenced by the undigested remains in their feces.
Although the scientists are used to recording plastics in the feces of living turtles, or in the guts of dead turtles, they were shocked by the fecal contents of a young green turtle, caught in their study region on 10 August, 2021. This turtle should have been feeding on a diet of jelly fish, seaweed and seagrass but, instead, its feces contained barnacles, wood chips and plastic – in the form of a disposable face mask. This is the first time that the researchers have direct evidence of the impact of the COVID-19 pandemic on the marine turtles of the area.
The scientists have published their findings on the fecal and gut contents of 76 sea turtles caught in the region over the past 15 years, including the individual that had consumed a face mask. Their report is available online and also in the Marine Pollution Bulletin.
“Face masks had never been found in this survey before the pandemic, and, unfortunately, this is the first detection,” said paper author Takuya Fukuoka, a post-doctoral researcher in the Laboratory of Organic Geochemistry (LOG) at Tokyo University of Agriculture and Technology. “The turtle, in this case, excreted the mask; however, the physical consequences of debris ingestion in many marine species are under discussion.”
And it is not only the physical consequences of eating marine debris that are of concern. Many plastics contain chemicals that can disrupt the normal endocrine (hormone) cycles in the body, thus having far-reaching impacts on individual animals.
The researchers conducted a chemical analysis of the mask, as well as of five other common brands of masks that are readily available in stores. All the masks were made of polypropylene, a plastic with a low density that floats in the water column. This plastic can contain additives that leach into the digestive fluid of marine organisms that ingest it, according to Hideshige Takada, professor in the LOG.
“We detected UV stabilizers in four out of five brands of face masks we tested, ranging from 1.4 to 848 nanograms per gram of material,” Takada said. “This concentration range is similar to those detected in plastic bottle caps, shopping bags and food packaging.” Three of the detected UV stabilizers are known to interfere with the molecules involved with hormone regulation, according to Takada.
“Exposure of marine organisms that ingest PPE waste to the chemicals and the consequential endocrine-disruption are of further concern,” Takada said. “We urgently need to study the ecotoxicological consequences of the ingestion of waste PPE by marine organisms and potential endocrine disruption. As a precautionary action, it is necessary to establish appropriate waste management systems to stop the entry of PPE into the environment and the use of safer additives to PPE.”
Not long ago, sea turtles that had plastic drinking straws stuck in their nostrils became the champions of the movement to reduce single-use plastics and promote the production of non-plastic food containers. It seems that they are again sending humanity a warning that the irresponsible disposal of PPE into the oceans has the potential to harm innocent marine organisms.
Although personal protective equipment (PPE) has been crucial in protecting people from the spread of coronavirus in the past two years, these items need to be disposed of in such a way that they do not enter the marine environment. The researchers plan to continue studying how COVID-19-derived plastic debris enters the environment, as well as how organic pollutants and additives from plastic waste transfer into marine organisms, in efforts to mitigate further harm.
“As the pandemic continues, the usage of disposable personal protective equipment (PPE) continues,” Takada said. “The COVID-19 pandemic affects not only human life, but also marine life through waste management issues. Unless appropriate waste management is instituted, the ingestion of PPE, associated chemicals and microplastics will increase in a variety of marine life very soon.”
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By Alison Bosman, Earth.com Staff Writer