Researchers have revealed that plankton in the ocean are responsible for producing half of all the oxygen the world breathes.
After studying plankton for three and a half years, collecting 35,000 samples from 210 sites and traveling 87,000 miles around the world, researchers from the Tara Oceans Consortium were able to determine that the microorganisms don't just function as food for sea creatures. Instead, they actually support all of life on Earth, providing half of the planet's oxygen requirement.
Plankton include microscopic animals (zooplankton) and plants (phytoplankton), viruses, bacteria, fish larvae and other microorganisms drifting in oceans. Like plants on land, phytoplankton produce oxygen through photosynthesis, the process by which plants produce their food.
Since photosynthesis requires carbon dioxide, undergoing the process allows phytoplankton to aid in the fight against climate change by creating a buffer against the growing level of carbon dioxide produced by burning fossil fuels. Phytoplankton bloom the most during spring as they receive an abundant amount of light and nutrients during this time.
Aside from uncovering the plankton's role in contributing to the planet's oxygen supply, the researchers also found that the microorganisms contain about 40 million genes. Compared to the number of genes possessed by a range of organisms in the human gut, plankton have around four times more.
Plankton can be found all over the world, but it turns out they are sensitive to temperature. According to Chris Bowler, a genomics expert from the École Normale Supérieure's biology department, temperature appears to be the most important of environmental factors that determine how plankton communities gather. This also implies that while plankton can do a lot to aid climate change efforts, it can also be easily affected by what's happening in the environment.
Up until around 50 years ago, researchers did not know that the specks they observed in seawater were alive. Now, new research has also shown that not only are plankton alive but they are also constantly interacting with each other. Sometimes, they would be assisting each other to thrive while other times they would be consuming each other for their own survival. This keeps the ecosystem in check, preventing just one species from overrunning the seas.
Future analysis can be expected to let researchers come up with models to help predict activity in plankton communities, such as the way changes in water temperature can affect the level of oxygen produced by the microorganisms as well as the amount of carbon dioxide they are able to absorb.
Photo: NASA Goddard Space Flight Center | Flickr