Pioneering deep-sea research marks 40 years at Atlantic observatory

A major scientific expedition led by the UK’s National Oceanography Centre (NOC) set sail on 30 May from Southampton aboard the Royal Research Ship James Cook, marking four decades of groundbreaking research at one of the world’s most significant deep-ocean observatories.

The 25-day voyage is focused on the Porcupine Abyssal Plain Sustained Observatory (PAP-SO), located about 800km south-west of Land’s End in the north-east Atlantic Ocean. Established in 1985 at a depth of 4,850 metres, PAP-SO is home to the world’s longest-running study of life on an abyssal plain – vast seafloor regions between 4,000 and 6,000 metres deep – and one of the most enduring records of deep-ocean environmental data.

This year’s expedition (JC278), supported by the UK’s Natural Environment Research Council (NERC) through the AtlantiS programme, combines traditional scientific methods with a new generation of autonomous technologies. Together, these tools are helping researchers to monitor long-term changes in ocean health, assess climate impacts and understand the deep ocean’s role as a carbon sink.

Testing miniaturized sensors

“Science undertaken at PAP-SO has significantly advanced knowledge of the remote deep-ocean realm and beyond,” said Dr Andrew Gates, NOC principal scientist and leader of the expedition. He noted that early research at the site overturned assumptions about the abyssal seafloor being unchanging. “Early insights revealed that the deep-sea floor, thought to be a very stable, constant environment, is in fact subject to seasonal change.”

A major feature of this 41st expedition to PAP-SO is the testing of new technologies developed through the Horizon Europe-funded GEORGE project. These include miniaturized sensors and samplers mounted on two underwater gliders and an uncrewed surface vessel. “This is an important opportunity to deploy our new technology at an open ocean site where we have long-term data to compare with the new measurements,” said Dr Socratis Loucaides, NOC’s lead GEORGE scientist.

The mission also includes the deployment of hydrophones to capture the deep-ocean soundscape for an entire year, as well as the recovery of Bathysnap, a time-lapse camera that has spent the past year recording seafloor life. Scientists are also trialling a camera system that images microscopic organisms from seawater samples every 30 minutes – with plans to enable real-time AI identification.

As Dr Gates remarked: “The PAP-SO is more than a research site – it’s a test bed for new technologies that advance ocean science.”