The voyage of the schooner Tara shows that plankton produce 50% of the oxygen on our planet.
The thousands of species of microorganisms that inhabit the surface waters of the oceans, and which collectively form plankton, produce the same amount of oxygen as the Earth’s forests. And they do it in exactly the same way: through photosynthesis.
The data comes from the schooner Tara which between 2009 and 2013 sailed 140 thousand kilometres from Alaska to Antarctica, collecting samples of 35 thousand microscopic marine creatures.
These microorganisms, in addition to producing 50% of the oxygen on the planet, are a valuable carbon trap, affecting the climate and are at the base of the food chain that supports the larger fish and marine mammals.
The scientists who participated in the project (over 500 from 40 nations) studied the genetic material, completing a DNA sequencing that has never been done in ocean sciences: ‘The analysis has revealed about 40 million genes, most of them completely new, suggesting much wider plankton biodiversity than previously thought,’ explained Patrick Wincker of Genoscope, an institution that took part in the Tara Oceans expedition.
The researchers also discovered how environmental factors such as water temperature, pH levels and the presence of nutrients, affect plankton and determine the distribution and interactions of species that inhabit the oceans.
The impact of climate change, global warming and rising sea temperatures, as well as marine pollution, can undermine the ocean ecosystems and, consequently, our very survival.