Scientists working in the Antarctic region have discovered a type of seaweed living at depths some 100 metres below the surface.

Researchers hailed the discovery of red alga Palmaria decipiens deep underwater as being “important for furthering our knowledge of Antarctica”.

The seaweed was discovered by a team working at the Rothera Research Station on Adelaide Island, off the south-western Antarctic Peninsula.

Using a remotely operated vehicle (ROV) from a small boat, the researchers found the red alga Palmaria decipiens 100 metres below the surface, and successfully collected samples for further examination.

We now know that seaweeds can live at least down to 100 metres depth in Antarctica. That is quite a lot, but we can’t rule out that they may live even deeper

The research, which was funded by the UK Natural Environment Research Council (Nerc), was a collaboration involving the University of Aberdeen, the University of Southampton, the British Antarctic Survey and the University of Thessaly, Volos, Greece.

With details now published in the journal Polar Biology, Professor Frithjof Kuepper of the School of Biological Sciences at the University of Aberdeen spoke of the “huge role” seaweeds can play in protecting the environment.

Prof Kuepper explained: “We know that carbon capture will be crucial to limiting global warming as we move forward, and seaweeds sequester large amounts of CO2.

“Seaweeds have the potential to play a huge role in protecting the environment by storing carbon at the bottom of oceans when they die and reducing ocean acidification.”

He continued: “Seaweeds are also an important food source to numerous animals and fish and have been eaten by people in many coastal communities in parts of the world for centuries.

“Seaweeds have been used in a variety of cosmetic and pharmaceutical goods and with carbon-neutralising properties it represents a sustainable product.

“Finding Palmaria decipiens at 100 metres depth is important for furthering our knowledge of Antarctica, a continent that is so important to understand for addressing the environmental challenges the world faces today.”

The research team had set out to clarify the maximum depths that seaweed could grow at in Antarctica with Prof Kuepper stating: “We now know that seaweeds can live at least down to 100 metres depth in Antarctica. That is quite a lot, but we can’t rule out that they may live even deeper.”

Ben Robinson, of the British Antarctic Survey and University of Southampton added: “In Antarctica, icebergs scour and remove seaweed from the shallows, leading to lots of loose seaweed at depths where it is no longer attached to the seafloor.

“Due to cold temperatures, it can take many years for these loose seaweeds to even start breaking down, so we could not rely on appearance. Instead, we needed to use an ROV to test and collect seaweed to confirm whether they were attached to the seafloor and to confirm a new depth limit for seaweed.”