Seaweed found living 100m below Antarctic ice shelf

Researchers say the discovery of red algae is 'important for furthering our knowledge of Antarctica'

A remotely operated vehicle (ROV) being used to find seaweed in the Antartic. Photo: University of Aberdeen/PA

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

Researchers hailed the discovery of red alga Palmaria decipiens deep under water 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 100m below the surface and successfully collected samples for further examination.

The research, funded by the UK Natural Environment Research Council, 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, Prof 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.

“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.”

Prof Kuepper 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 100m 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 100m 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 sea floor.

“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 sea floor and to confirm a new depth limit for seaweed.”