Researchers have found an estimated 414 million pieces of plastic trash at a distant archipelago in the Indian Ocean called the Cocos (Keeling) Islands, showing the scale of the danger posed by plastic debris to the world’s oceans and marine life. The group of islands is located 2,750 km (1,708 miles) from Perth, Australia.

Most of the debris consisted of single-use bottle caps, straws, shoes and sandals, said Jennifer Lavers, the lead author of the study. Some 93 percent of the debris remains underground, exposing the dangers of plastic menace, added the researcher.  

Describing the findings as "conservative," she said the team had managed to sample to a depth of 10 cm only, and couldn't visit some beaches, considered as debris "hotspots." Jennifer said her group studied these low population islands as most of the debris directly came from the ocean.

Plastic pollution is now threatening oceans globally, and remote islands are the best places to study the severity of the problem, said the researcher, explaining the rationale behind selecting the islands for the study.

Before undertaking this study, the team had previously studied a remote, uninhabited island in the South Pacific called Henderson Island and found that it had the highest density of man-made plastic debris in the world. United Nations has listed Henderson Island as a World Heritage site, recognizing its international importance and ecological value due to its geographical isolation from human presence. This island is unique for the 10 plant and four land bird species endemic to it.

Recently, a team of divers had found plastic waste on the seafloor at the world’s deepest point, the Mariana Trench, which is nearly 11 km (seven miles) under the ocean. 

It is estimated that every year up to 14 million tons of plastic garbage enters the oceans. Some 40 percent of this is "single-use plastic," which means it enters the seas within the same year of manufacture.