The oceans conceal all sorts of secrets and unknowns in the depths – like the 195,728 viruses scientists found lurking underwater, during a voyage of a pole to a pole carried out to test sea life. According to the researchers, the vast majority were never seen.
Before that, we knew only about 15,000 of these ocean viruses – so this study is a huge deal for understanding our planet.
The findings can teach us more about everything from the evolution of life on the planet to the potential consequences of climate change.
The study is based on samples collected between 2009 and 2013 by a team on Terra, a tool that spends more than a decade on water exploring ocean science and the hints it can give us about how our world evolves.
"Viruses are the tiny things you can not even see, but because they are present in such huge numbers, they are really important," says one of the teams, microbiologist Matthew Sullivan of Ohio State University.
"We developed a distribution map that is the basis for anyone who wants to learn how viruses manipulate the ecosystem. There were many things that surprised us about our findings."
Despite the large number of viruses discovered and the vast complexity of the world's ocean regions, the team was able to split the viruses into five different ecological zones – all the Arctic and Antarctic depths, and three different depths of the world and the tropics.
In fact, the Arctic Ocean – where researchers did not expect the greatest diversity – was discovered as an unexpected life. All this adds to our understanding of how viruses get around the planet.
Scientists estimate there are tens of millions of viruses in the ocean, many of which may exist outside the water, even in our bodies. Being able to recognize more of them can teach us more about life itself, not just about underwater life.
For this study, as well as detection of new viruses found in deep water samples of up to 4,000 meters (13,123 feet), the researchers also identified new strains from other bacterial analysis and living organisms that built the house in the oceans.
The completeness of the new study is also important because it helps scientists more accurately calculate the oxygen balance and carbon carbon in the atmosphere – the marine organisms help to recycle oxygen, while the oceans absorb and store a large amount of CO2.
Additional life below the surface of the water means more CO2 converted to organic carbon biomass, stored deep in the sea – instead of CO2 oxidation of the oceans, killing marine life along the way. It is a delicate and complex set of mechanisms.
"Using a new map of the presence of these viruses can help us understand the oceanic carbon pump and, more specifically, biogeochemistry that affects the planet," says Sullivan.
"Previous models of ocean ecosystems usually ignore bacteria, and are rarely included in viruses, but we now know that they are an essential element to include."
The study was published in cell.