Life Found in Darkness: Microbes Thrive Under Antarctica’s Ross Ice Shelf

Overview

Scientists have found thriving microbial communities hundreds of metres beneath Antarctica’s Ross Ice Shelf. These tiny organisms live in complete darkness, cold water, and isolation. They do not use sunlight for energy. Instead, they get energy from chemicals like ammonium and sulfur. The findings were first published in 2022 in the journal  Nature Communications . A follow‑up study in 2024 described a working microbial community in the seawater under the ice. This discovery shows that life can survive in extreme places.

What Is the Ross Ice Shelf?

The Ross Ice Shelf is the largest ice shelf in Antarctica. It is a floating extension of the Antarctic ice sheet. Beneath this ice shelf, there is a cavity filled with seawater. This water is dark, very cold, and cut off from sunlight for a very long time. It seems like a place where life cannot exist. But scientists found that it does.

Which Microbes Live There?

Researchers identified different types of microbes. They include:

• Aerobic lithoautotrophic archaea and bacteria  – These organisms make their own food using chemicals.

• Heterotrophic microbes  – These break down organic carbon for energy.

The community has both primary producers (that make food from chemicals) and recyclers (that break down dead matter).

Where Do They Get Energy Without Sunlight?

Most life on Earth depends on sunlight for energy through photosynthesis. But these microbes use a different process called  chemosynthesis . They get energy from chemical compounds such as:

• Ammonium

• Nitrite

• Sulfur compounds

This allows them to live in total darkness under the ice.

How Did Scientists Study Them?

The environment is very hard to reach. Direct cultivation is difficult. So scientists used advanced methods:

• Metagenomics  – Studying microbial DNA taken directly from water samples.

• Metatranscriptomics  – Looking at RNA to see which genes are active.

These methods helped them identify which microbes were present and what they were doing.

Role of Viruses in This Hidden World

Viruses were also found in the ecosystem. They infect the ammonium‑oxidising and sulfur‑oxidising chemolithoautotrophic organisms. Viral activity helps control microbial populations. It also plays a part in recycling nutrients in the marine ecosystem. Even in this cold, dark place, the cycle of life and death continues.

Why Is This Discovery Important?

The ammonium oxidation rates measured here are as high as those in the winter Antarctic Ocean. This shows that the sub‑ice environment is not dead. It is a functioning ecosystem with its own food web. Understanding it helps scientists learn how life adapts to extreme conditions on Earth – and maybe on other