Soaking up viruses like a sponge

-March 31, 2020. The smallest creatures on earth are also incredibly numerous. A single drop of seawater contains hundreds of millions of viruses. As we have known for some time, viruses need a host to reproduce. What's more, they generally don't survive long outside of this host organism.

Researchers from the NIOZ (Royal Netherlands Institute of Sea Research) have now conclusively proven that marine animals such as sponges, crabs and cockles consume enormous amounts of viruses. As it turns out, these creatures unintentionally play a key role in controlling virus populations.

The term unintentional refers to the fact that they merely filter viruses from the water, rather than actively scouring for them. Marine animals such as sponges and cockles are referred to as filter feeders, and filter sea water to extract oxygen and food particles. Experiments have now shown that some of these filter feeders are capable of drastically reducing the amount of viruses. NIOZ researchers published the results of their experiments in Scientific Reports last week.

Sifting sea-life

Sponges are in a league of their own. These primitive marine animals consumed 94% of all viruses in the surrounding water over the course of a three-hour experiment. In fact, the sponges even continued to filter the water when new viruses were added at several stages of the experiment.

Aquatic assistance

The researchers have identified aquaculture as a potential short-term application. Some types of fish and shellfish are increasingly being cultivated in water compartments connected to the open sea to eliminate the need for fishing. This type of aquaculture is often criticised for the fact that contagious disease outbreaks can easily be transferred to species in the wild. Based on the outcomes of this research project, sponges and other marine life could be added to aquacultures to mitigate the potential danger of viral infections.

A healthy balance

Until now, the scientific community was unaware that marine animals had such a significant impact on virus populations. Nevertheless, viruses remain the most numerous type of oceanic life. That can only be a good thing, as they in turn play a key role in controlling bacteria populations. As this research confirms, each group of organisms plays an important role in the complex oceanic food chain.