The Web of Life (37-8) Intrigue at Organic Lake

 Intrigue at Organic Lake

Viruses are ubiquitous members of microbial communities, and in the marine environment affect population structure and nutrient cycling by infecting and lysing primary producers. Antarctic lakes are microbially dominated ecosystems supporting truncated food webs in which viruses exert a major influence on the microbial loop. ~ microbiologist Sheree Yau et al

The Antarctic is a forbidding place. For those who do manage to live there, existence is made all the harder by being preyed upon.

Organic Lake is a shallow, salty, sulfuric body of water in East Antarctica. The salt was trapped from the ocean when the lake formed 6,000 years ago, when sea levels were higher. The lake would freeze over absent its high salt content.

The density of organic matter within gives the lake’s namesake. This owes to slow decay caused by the salt and cold.

Some very tough algae live in Organic Lake: soaking in the 2 months of summer light and spending the rest of the year as spores. They are plagued by phycodnaviruses: large double-stranded DNA viruses.

The Organic Lake Virophage (OLV) preys on the local phycodnaviruses. In doing so, OLV curtails the damage done by their viral cousins, giving the algae some welcome respite.


Satellite viruses are a compelling argument for considering viruses as alive. It is silly to say that something not alive can interfere with the reproduction of something not alive. Satellite viruses clarify that being alive is not about self-sufficient reproduction, but instead the cunning to reproduce.