The ocean floor is teeming with life forms, many of which are as yet unknown to science. The scientists made the discovery by analyzing DNA samples from deep-sea sediments, Science Advances reports.
Sediment samples were collected from different regions of the globe. The results showed that there are about three times more living organisms at the bottom than previously thought. Two-thirds of them have not yet been identified.
It is known that the deep ocean floor covers more than half of the Earth's surface and is home to the least explored ecosystems. Scientists noted that they have to discover not just new species, but entire evolutionary lines and families. In previous studies, they analyzed DNA samples collected from the water column. Bottom sediment analysis has provided new insights into marine biodiversity.
The research team sequenced DNA from 418 seabed samples collected from all major ocean basins between 2010 and 2016 and compared them with existing data on DNA from the rest of the ocean. They clarified that they identified not individual species, but groups of species, such as families and orders.
It turned out that most of the DNA from the seabed could not be assigned to any known group on the tree of life. Therefore, its owners belong to a category that has not yet been discovered.
The study showed that benthic life is capable of exerting a global influence on the planet, in particular, influencing the climate. So, some communities play a big role in the process of absorption and sequestration of carbon.