<p>After a near two-year "Microbiome" mission around the world, scientists said on Saturday they had gathered thousands of samples of marine micro-organisms in a bid to better understand ocean plankton and pollution.</p>.<p>The survey was carried out by the 33-year-old Tara research schooner, which returned to her home port of Lorient on France's western coast at the weekend.</p>.<p>From Chile to Africa, via the Amazon and the Antarctic, nearly 25,000 samples were collected over the 70,000-kilometre (43,000-mile) route.</p>.<p>"All this data will be analysed," Tara Ocean Foundation director Romain Trouble told at a press conference.</p>.<p>"Within 18 months to two years we will start to have the first discoveries from the mission," he said.</p>.<p><strong>Also Read |<a href="https://www.deccanherald.com/science-and-environment/over-200-stranded-pilot-whales-die-on-pacific-oceans-remote-pitt-island-1152572.html" target="_blank"> Over 200 stranded pilot whales die on Pacific Ocean's remote Pitt Island</a></strong></p>.<p>At the base of the food chain, micro-organisms were the "invisible people of the sea, accounting for two-thirds of marine biomass, they capture atmospheric CO2 (carbon dioxide) and supply half of the oxygen we breathe." said Trouble.</p>.<p>Trouble said the mission sought to find out how it all works. "How do all these marine viruses, bacteria, micro-algue manage to interact to produce oxygen? And how will that change tomorrow with climate change and pollution?"</p>.<p>The Tara team paid particular attention to the impact on the oceans of the River Amazon, which has a water flow rate of 200 million litres (53 million gallons) per second.</p>.<p>They wanted to test a theory that deforestation and the spread of agriculture has increased nitrate fertiliser discharge, leading to an abundance of toxic algae along river banks and coasts, particularly in the Caribbean.</p>.<p>The 22-month odyssey also sought to trace the sources of plastic pollution at river mouths, to understand distribution and the types of material involved.</p>.<p>The mission was Tara's 12th global journey and involved 42 research institutions around the world.</p>.<p>Next spring, Tara sets off to research chemical pollution off European coasts.</p>
<p>After a near two-year "Microbiome" mission around the world, scientists said on Saturday they had gathered thousands of samples of marine micro-organisms in a bid to better understand ocean plankton and pollution.</p>.<p>The survey was carried out by the 33-year-old Tara research schooner, which returned to her home port of Lorient on France's western coast at the weekend.</p>.<p>From Chile to Africa, via the Amazon and the Antarctic, nearly 25,000 samples were collected over the 70,000-kilometre (43,000-mile) route.</p>.<p>"All this data will be analysed," Tara Ocean Foundation director Romain Trouble told at a press conference.</p>.<p>"Within 18 months to two years we will start to have the first discoveries from the mission," he said.</p>.<p><strong>Also Read |<a href="https://www.deccanherald.com/science-and-environment/over-200-stranded-pilot-whales-die-on-pacific-oceans-remote-pitt-island-1152572.html" target="_blank"> Over 200 stranded pilot whales die on Pacific Ocean's remote Pitt Island</a></strong></p>.<p>At the base of the food chain, micro-organisms were the "invisible people of the sea, accounting for two-thirds of marine biomass, they capture atmospheric CO2 (carbon dioxide) and supply half of the oxygen we breathe." said Trouble.</p>.<p>Trouble said the mission sought to find out how it all works. "How do all these marine viruses, bacteria, micro-algue manage to interact to produce oxygen? And how will that change tomorrow with climate change and pollution?"</p>.<p>The Tara team paid particular attention to the impact on the oceans of the River Amazon, which has a water flow rate of 200 million litres (53 million gallons) per second.</p>.<p>They wanted to test a theory that deforestation and the spread of agriculture has increased nitrate fertiliser discharge, leading to an abundance of toxic algae along river banks and coasts, particularly in the Caribbean.</p>.<p>The 22-month odyssey also sought to trace the sources of plastic pollution at river mouths, to understand distribution and the types of material involved.</p>.<p>The mission was Tara's 12th global journey and involved 42 research institutions around the world.</p>.<p>Next spring, Tara sets off to research chemical pollution off European coasts.</p>