A groundbreaking marine voyage by scientific vessel Tara reveals the disturbing state of the world's plastic-filled oceans.

The Tara just completed a 70,000-mile journey over two and a half years, going from the Mediterranean, the Atlantic, the Indian Ocean, the Pacific and the Antarctic with the goal of studying "planktonic and coral ecosystems in the perspective of climate changes," noting that "Studying plankton is like taking the pulse of our planet." The researchers recorded 1.5 million species of marine micro-organisms, more than previously were thought to have existed.

But what the research team also found in the the Southern Ocean and Antarctica was the frightening, planetary reach of plastic in the world's waters.

"We had always assumed that this was a pristine environment, very little touched by human beings," said Chris Bowler, scientific co-ordinator of Tara Oceans, according to the Guardian. "The fact that we found these plastics is a sign that the reach of human beings is truly planetary in scale."

"It's too late to do much about what's already out there at this stage, as this stuff is going to hang around for thousands of years," said Bowler.