GAS-ABSORBING deep sea bacteria are soaking up carbon dioxide – and mining could create major problems, Scots scientists say.

As many as 16 contractors from countries including the UK, Germany, France and Korea have secured exploration rights to the Clarion-Clipperton Fracture Zone (CCFZ) in the Pacific Ocean.

However, the Lyell Centre for Earth and Marine Science and Technology at Heriot-Watt University in Edinburgh has produced findings that suggest full scale mining could “significantly” impact ecosystems there for “decades”.

Until now, scientists believed dead fish, plankton and other material sinking to the lowest depth was the main source of seafloor biomass.

However, the team has shown bacteria are the main source, consuming carbon dioxide and fixing millions tonnes of the gas every year.

Professor Andrew K Sweetman said the discovery was “completely unexpected”.

Calling for caution over industry, he said: “If mining proceeds in the CCFZ, it will significantly disturb the seafloor environment.

“We need to know much more about abyssal seafloor biology and ecology before we even consider mining the region.”

He went on: “Now that we have shown that novel carbon cycling processes are happening on the seafloor in this region, which may be very significant in terms of the carbon cycle, authorities should insist that hopeful mining contractors study these processes in baseline surveys, impact assessments and monitoring, so that mining-related changes in this important ecosystem process can be identified and tracked.”

The findings were published in the journal Limnology and Oceanography.