Scientists hopped on the sailboat Tara to conduct the first-ever global survey of ocean viruses, uncovering nearly 200,000 marine viral species in the ocean.
It's a far cry from earlier surveys that placed the number at just 15,000.
Hundreds Of Thousands Of Ocean Viruses
In a study published in the journal Cell, researchers collect 145 marine samples from multiple expeditions on the Tara between 2009 and 2013, identifying 195,728 different viral populations. The team didn't just collect viral samples from water samples, but also from microbes and other living organisms.
The existence of such large viral populations mean that they likely have an impact on many environmental issues, such as climate change and evolution.
"Viruses are these tiny things that you can't even see, but because they're present in such huge numbers, they really matter," said senior author and microbiologist Matthew Sullivan in a press release on Eurekalert.
According to Gizmodo, these populations are classified into five distinct ecological zones: Arctic; Antarctic; deeper than 6,500 feet (2,000 meters); 490 to 3,300 feet (150 to 1,000 meters); and temperate or tropical waters with depths of 0 to 490 feet (0 to 150 meters).
Furthermore, while one would expect a higher concentration of viruses near the equator, it turns out that latitude is not indicative of viral diversity. In fact, the researchers discovered a hotspot in the Arctic Ocean.
The Significance Of The New Discoveries
Findings from the new study could have a great impact on scientists' approach to climate change.
Previous research has shown that half of the oxygen come from marine organisms and that half of the carbon dioxide from the atmosphere are absorbed by the ocean, according to Sullivan. He adds that while more carbon dioxide at the ocean's surface causes it to acidify, the gas can instead be converted to organic carbon and biomass, so it becomes particulate and sink under the surface.
"That's a good result for helping mitigate human-induced climate change--and we're learning that viruses can help facilitate this sinking," Sullivan explains. "Having a new map of where these viruses are located can help us understand this ocean carbon "pump" and, more broadly, biogeochemistry that impacts the planet."
With a complete working map of marine viral distribution, scientists can figure which viruses to focus on in future studies. Future efforts at collecting samples can also eventually answer questions about microorganisms' levels changing through time as an effect of climate change and seasons.
