Researchers say they have discovered the highest density of trash in the world on a tiny, remote island in the middle of the Pacific Ocean. According to a report this month in The Proceedings of the National Academy of Sciences, an estimated 38 million pieces of trash have washed up on Henderson Island.

How could this happen? Here & Now's Robin Young speaks with Enric Sala (@Enric_Sala), National Geographic explorer-in-residence and marine ecologist. Sala was not involved in this particular study, but has visited the island through his work with the Pristine Seas project.

Interview Highlights

On whether he knew how much trash was on the island prior to a 2012 visit

"Yes, it's difficult not to notice. The whole beach was covered in fishing lines and buoys, flip-flops, plastic bottles. It was atrocious. But, there are other places that have not been reported in the scientific literature that are as bad. There are beaches in Mumbai in India, a beach in Singapore. And all this plastic in the ocean kills hundreds of thousands of sea birds, sea turtles and marine mammals every year."

On the importance of being able to trace trash back to its country of origin

"In this particular study in Henderson, most of the identifiable trash came from China, Japan and Chile, and this clearly shows that trash from all over the world is transported all over the ocean. And we have to think that 80 percent of the trash in the ocean comes from the land."

On how trash winds up in the ocean

"It could be the plastic bag from the supermarket that the wind takes away, or the microfibers that come out when I wash my polar fleece, in my washing machine at home. The ocean is downstream of everything, so all this plastic that doesn't end up on a landfill ends up in the ocean."