Following news that microplastics have been found in human stool samples comes word that for the first time plastic microfibers, which are microscopic plastic hairs, have also been discovered in the stool samples of wild animals — namely, South American fur seals.

Determining that the South American fur seal offered an efficient window by which to measure environmental microfiber and microplastic levels, a team of researchers at the University of Georgia examined the waste, or scat, from over 50 female South American fur seals on the isolated Guafo Island in southwestern Chile.

"It's no secret that plastic pollution is one of the major threats to marine ecosystems, but we're learning now just how widespread that problem is," said Dr. Mauricio Seguel, a research fellow at the University of Georgia. "These samples are invisible to the naked eye. We want to understand factors that are driving their distribution and what this means for animals in the Southern Hemisphere."

To determine microfiber and microplastic levels present in the scat, the researchers dissolved each sample’s inorganic material in a solution. Researchers looked at the samples and discovered an abundance of microfibers in 67% of the samples — a finding that had only ever been noted in animals who were held and fed in captivity.

According to researchers, the appearance of microfibers in seals from the remote Guafo Island is due to changing ocean currents, which subsequently introduced the material into the food chain through plankton, then fish, eventually transferring it to the seals.

Though little is known about the impact plastic microfibers have on mammals, other studies have suggested that the microfibers are responsible for morphological changes in fish.

"It's not too late to act to heal our oceans, but one of the first steps is determining how much we have damaged the ecosystem through our activities, like producing and disposing of plastic," said Dr. Kelly Diehl, Morris Animal Foundation interim vice president of scientific programs. "Studies like these will help us learn those answers so we can begin to make better decisions for the health of marine life."

For more on the study, go to the Marine Pollution Bulletin.