A team of marine scientists have discovered up to a million new species of plankton during a 70,000-mile voyage around the world's oceans.


The microscopic sea life was found during  Tara Oceans expedition lasting more than two years and aimed at learning more about the effects of climate change.


The sailing ship's journey took more than two years as it sailed from home in France through the Mediterranean, the Gulf and Indian Ocean to Cape Town.




'It's the first time that anyone's done this expedition looking specifically for plankton life, and that's why we found so many.'

- Expedition leader Chris Bowler




After crossing the South Atlantic, the ship headed into the Antarctic, and then into the South Pacific, reaching Hawaii in September last year and then moving off to its home leg across the North Pacific, through the Panama Canal and across the North Atlantic.


"It's the first time that anyone's done this expedition looking specifically for plankton life, and that's why we found so many," expedition leader Dr Chris Bowler said.


"These planktonic organisms are the life support system of the planet.


"They are the base of the food chain ... if there's no plankton, there's no fish in the oceans. They also, through photosynthesis, generate oxygen -- in fact they generate the oxygen in every second breath that we breathe so they're incredibly important on a planetary scale.


"And they take carbon dioxide out of the atmosphere by taking it into the interior of the ocean where it can be stored for thousands of millions of years so they're an essential buffer against climate change due to carbon dioxide in the atmosphere."


The team also said it found evidence of another of mankind's detrimental effects on the planet - hundreds of thousands of bits of plastic floating in the Antarctic.