Autonomous Techniques for anthropogenic Structure Ecological Assessment (AT-SEA)

With a growing number of decommissioning projects worldwide, as ageing structures reach the end of their life cycle, AT-SEA has addressed the urgent need for efficient, cost-effective, and regulator-approved survey methods, without setting foot on a boat.

Decommissioning offshore infrastructure requires thorough environmental assessment and monitoring to understand ecological changes and mitigate any unexpected impacts. Advances in autonomous monitoring of the marine environment around offshore installations offer significant improvements in efficiency, yet these approaches remain largely untested—until now.

A Revolutionary Approach

AT-SEA successfully conducted the first fully autonomous environmental monitoring of multiple decommissioning sites without the aid of a support vessel. The team tested the feasibility of using a shore-launched, long-range Autonomous Underwater Vehicle (AUV) to survey decommissioned oil and gas sites in the North Sea. Over 21 days, the AUV, affectionately known as Boaty McBoat face, travelled more than 1,000 km, collecting millions of seabed images and detailed environmental data at the decommissioned North West Hutton and Miller platforms, and the Braemar Pock Marks special area of conservation. One of the key successes of AT-SEA was its ability to operate with minimal energy consumption. The AUV used just 21.3 kWh of energy—roughly equivalent to 2 litres of diesel—while standard vessel-based imaging surveys would have required at least three days of ship time, a large crew, and thousands of litres of fuel. 

Professor Daniel Jones and team with the AUV Boaty McBoatface. Image credit: National Oceanography Centre (NOC), Southampton.

Objectives

To trial the use of autonomous vehicles, to monitor offshore decommissioning sites, and demonstrate what the future of decommissioning could look like – a first look at a future where ships and people are needed far less.

Achievements and Findings

AT-SEA successfully conducted the first fully autonomous environmental monitoring of multiple decommissioning sites without the aid of a support vessel. The project combined seafloor visual imagery, mapping, and water column sensor-based measurements to produce comprehensive environmental assessments. The data collected autonomously was directly compared with conventional vessel-based survey methods, and it was found that autonomous approaches can enhance data quality and quantity while significantly reducing costs.

Images taken by Boaty McBoat Face using the BioCam  system (developed as part of the NERC Oceanids project). During its time at offshore sites, the AUV surfaced periodically to send data quality indicators to the AT-SEA team, so they could monitor and make any necessary adjustments.

The Future of Offshore Monitoring

This autonomous approach proved scalable, efficient, and resilient, even in the challenging waters of the northern North Sea, where hazards such as shipping and fishing activities were successfully managed through careful planning. As adoption increases, technological advancements and economies of scale will further enhance cost efficiency and operational capabilities.