Vanishing Viruses

For anyone who’s ever had a cold, the flu, or any other illness caused by a virus, getting rid of viruses might sound like a good idea. But many viruses play important roles in the environment. That includes marine viruses. They recycle nutrients, and can help control other microscopic organisms. So it’s good to keep them around.

But in the northwestern Mediterranean Sea, viruses are disappearing in a hurry. The drop corresponds to changes in the sea caused by Earth’s warming climate.

Marine scientists have been keeping tabs on Blanes Bay since the early two-thousands. It’s on the coast of Spain, about 40 miles from Barcelona. An observatory there monitors the temperature, salinity, and clarity of the water. And it samples the water once a month. Lab work reveals the amounts of nutrients and other compounds in the water, along with the populations of bacteria and viruses.

Scientists recently used several techniques to analyze the observations from 2005 to 2022. The work showed that the virus population remained steady until about 2011. But since then the population has gone down dramatically. At the same time, the water has gotten warmer. That suggests the viruses are being thinned out by climate change.

Reducing the virus population could impact the amount of nutrients in the water, making the region less productive. That could hurt the fishing industry. So the lack of viruses could actually harm the people along the Mediterranean coast.