A pioneering experiment by Westcountry scientists to monitor what might happen if carbon dioxide leaked from an underground storage reservoir has been successful.
Carbon capture and storage is one of the methods which is attracting significant international attention and is emerging as one of the front runners for tackling climate change.
The process involves siphoning off carbon dioxide from power plants and industrial sites before it can be emitted into the atmosphere, then pumping it into deep sub-seabed reservoirs for permanent storing.
In a world first, scientists from Plymouth Marine Laboratory are part of a team investigating the environmental impacts through a controlled carbon leak at Ardmucknish Bay near Oban, on the west coast of Scotland.
Project leader Jerry Blackford, from the laboratory, said: "The experiment is going exactly to plan and we are very pleased so far.
"We are now at the stage of collecting detailed data which will enable us to get closer to predicting what might happen if a real leak occurred on an active storage site.
"As well as looking for environmental impacts, the experiment has allowed us to test a range of monitoring equipment in a real-world setting."
The project – Quantifying and Monitoring Potential Ecosystem Impacts of Geological Carbon Storage (QICS) – is being led by Plymouth Marine Laboratory in collaboration with the Scottish Association for Marine Science and four other institutions.
For the last 30 days, carbon dioxide has been supplied from a "pop-up" laboratory and pumped through a bore hole under the sediment to a site 350 metres from the shore and 12 metres below the seabed.
Experiment co-ordinator Dr Henrik Stahl, from the Scottish Association for Marine Science, explained that the drop in pH levels of the seawater on the site caused by the release of the carbon dioxide was having different effects on marine life.
He said: "Some animals, such as sea-urchins living in the sediments, seem to react negatively to the increase in carbon dioxide, whereas others, such as crabs, seem to be attracted or unaffected by the bubbles, so there could be both winners and losers in a real-life situation.
"The next step is to turn off the gas flow and continue to study the recovery of the affected area.
"Even though only a very small area of seabed is being temporarily affected by this experiment, we are confident that it will provide valuable information to help understand the implications of carbon dioxide for marine life, should a leak occur elsewhere."