In a new global expedition looking at waters from all the oceans, the Arctic Ocean has emerged with a surprisingly high level of viruses. From about 200,000 viruses found in total, 42% of these were from the Arctic waters exclusively. The results of this global survey done by Tara Oceans global oceanographic research expedition are reported in Cell.
Analyzing the World’s Oceans
For the study, water samples were taken from all the oceans in an expedition running between 2009 and 2013. A sailboat known as Tara was used. Over the period of the expedition, 145 samples of water were taken from dozens of locations around the world. These were dropped off at Tara. The water samples were taken from the ocean surface to depths of up to 4,000 meters.
Naturally, the water samples often contained many different particles. Filtration was used to isolate the viruses, and these were then analyzed and identified. The results show that 12 times more viruses were found this time around compared with a previous study that was conducted on a smaller scale.
A Hot Spot for Viruses
Interestingly, of the 195,728 virus species identified in all five global regions, the second highest diversity was in the Arctic where 42% of these species were found. The most diverse ocean regions were the tropical and temperate shallow waters.
Microbiologists are saying that the high numbers of viruses in the oceans should not be a cause for concern for people. Most of the viruses found were bacteriophages, and these kinds of viruses target bacteria and not humans. In fact, such viruses kill about 20% of the ocean’s bacteria daily. This causes carbon in the bacteria to be quickly recycled back into the ocean for use by other marine micro-organisms. Scientists are now pondering on the possible impact of this carbon recycling on the grander scale of things, and in particular, on climate change.