“Welcome to paradise,” beckons the Cocos Keeling Islands’ Visitor Center. The island chain is popular with vacationing Australians, and it’s easy to see why.
Photos from the chain of 27 islands, of which only two are inhabited, feature oceans that are nothing but swirls of translucent turquoise, cobalt and cerulean, and sandy beaches so pristine they feel untouched.
But a 2017 survey by researchers from the University of Tasmania and Victoria University, both in Australia, found the islands covered in some 414 million pieces of plastic weighing a total of 238 metric tons (roughly the same weight as a blue whale). The results were published this month in the journal Scientific Reports.
The use of plastics, especially single-use plastics, has skyrocketed since the 1990s, according to Jennifer Lavers, a research scientist at the Institute for Marine and Antarctic Studies at the University of Tasmania and the lead author on the study. “That plastic has to go somewhere, and a lot of it is ending up, unfortunately, in countries where waste management can’t deal with it. And it ends up in our rivers and into our oceans,” she said.
The ocean’s plastic problem is twofold: There’s a lot of it — the study authors estimate that there are more pieces of plastic in the ocean than there are stars in the Milky Way — and it kills marine life.
Fish, birds, sea turtles and marine mammals can become entangled in plastic soda-can rings and discarded fishing nets, or can choke on the debris if they eat it. And studies suggest that some marine life do not just accidentally eat plastic — they seek it out. That is because over time, marine plastic can absorb aquatic odors, making them smell uncannily like food to some fish and bird species. When these animals eat the plastic instead of real food, they also get a dose of chemicals such as PCBs and heavy metals that the plastic absorbs from the environment.
A separate study released in the journal Communications Biology found that plastic in the oceans also harms prochlorococcus, the marine bacteria responsible for producing 10% of the world’s oxygen.
Lavers chose these islands for the study because their relatively isolated location means that there are relatively few sources of local pollution and not much human activity such as beach cleanups. This enabled the team to see how much plastic from the world’s oceans ended up deposited on the islands.
Some of the plastic the researchers found was easily identifiable: toothbrushes, food packaging, straws and plastic bags. Single-use plastics made up roughly 25% of the material the researchers found.
But some 60% was microplastics, or bits that break off when a piece of plastic is buffeted around. These microplastics can be as small as .08 inches, or roughly half the size of a grain of rice.
“It should serve as yet another warning that yes, our local actions can have long-distance effects,” Thomas Ballatore, a teaching fellow at Harvard University who has studied plastic pollution and was not involved in this study, said by email.