Giant Virus Feeding on Algae Helps Prevent Damaging Algal Bloom, Shows Potential in Slowing Down Ice Melt in Greenland

Over the years, Arctic sea ice continues to decline at an alarming rate. A team of scientists believe that a giant virus could stop the ice melt.

Protectors of the Ice

Experts from the Department of Environmental Science at Aarhus University in Denmark announced that they have discovered evidence of large viruses living in the snow and ice on the Greenland ice sheet. They believe that these organisms have the potential to reduce some of the effects of climate change.

The newly discovered viruses could be around 1,500 times larger than regular viruses. They are capable of attacking microscopic algae, which makes Greenland's ice darker in color and causes it to melt faster.

In the paper "Giant viral signatures on the Greenland ice sheet," the research team found signs that the giant viruses live on ice and snow, which contain lots of colored algae, indicating a relationship between the two organisms. The team hopes that understanding these viruses can pave the way to naturally control the growth of algae and reduce ice melt.

The experts are still uncertain as to how specific these viruses are and how efficient they could be. They are only classified under the nucleocytoplasmic large DNA viruses (NCLDV) supergroup (phylum Nucleocytoviricota).

Compared to other types of viruses, the giant viruses have lots of active genes which allow them to replicate, repair, transcribe, and translate DNA. They can also be as useful as a way to alleviate ice melt due to algal blooms.

Led by Laura Perini, the team collected samples from red snow, dark ice, and melting holes in various locations on the Greenland ice sheet in 2019 and 2020. Then, they studied the DNA found within the samples to identify their gene sequences that had high similarities to giant viruses.

After analyzing the samples, Perini and colleagues found signatures of active giant viruses in both the dark ice and red snow. This is the first time they have been discovered on surface ice and snow that contain a high abundance of pigmented microalgae.

In the future, Perini and her team plan to conduct more studies to understand the giant viruses and the host that they are infecting. They hope to learn more about their interactions as well as their role in the ecosystem.

Role of Algae in Ice Melt

Algae refers to a photosynthetic organism that is part of a complex ecosystem that also includes fungi, bacteria, and protists. They can exist in various types of environments, such as rivers, oceans, ponds, lakes, brackish water, and snow. They are usually green, although they can also be found in a variety of different colors.

Algae lies dormant in the ice of Greenland. During spring, they bloom and darken parts of the white landscape. Compared to white snow and ice, the darker color of the surface reflects less sunlight. As more heat is absorbed, the melting of ice speeds up.

The highly reflective properties of snow surfaces play an important role in maintaining the balance of energy on Earth. Clean snow surfaces reflect up to 99% of incoming solar radiation, but even a small-scale reduction in snow cover can drastically reduce its protective properties.