British Geological Survey produces seabed geology maps for conservation around Ascension Island
Rafael Sanches for Baird Maratime
Published on:
22 May 2025, 2:45 am
BGS delivers the first marine geology and habitat maps for one of the world’s largest marine protected areas.
The British Geological Survey (BGS) recently completed a programme of high-resolution bathymetry surveys and drop-camera sampling within the nearshore areas of Ascension Island in the South Atlantic Ocean.
The Ascension Island Marine Protected Area (MPA) is one of the largest areas of protected ocean in the world and supports many species that are found nowhere else on earth, a mixture of deep sea and open ocean habitats that remain largely untouched and unexplored, whilst the island itself is home to thousands of nesting turtles and seabirds.
Section of the BGS 1:50 000 geomorphology map of the seabed around Ascension Island. UKRI
The project was funded by the UK Government and utilised both BGS and Royal Navy bathymetry (depth), backscatter (seabed composition), ground-truth sampling (underwater video footage) and many other derived data layers to create the suite of bespoke geological outputs.
The survey team managed to collect data where no other survey had ever been undertaken, which in addition to supporting conservation efforts, will also be used to enable safer navigation in future.
The maps, which include seabed geology (substrate and geomorphology) and habitat, are the first to be created for the island and determine the character, distribution and extent of the nearshore habitats of the MPA.
The geomorphological map revealed a collection of previously unmapped volcanic, erosion-depositional and coastal features including seamounts, submerged lava flows, ridges, submarine landslides and channels.
The substrate map focused on the nearshore areas, composed of sandy sediments and rocky outcrops which are fundamental habitats for the marine communities.
Both maps have enhanced the understanding of seabed processes and geological processes occurring around Ascension Island and enabled the creation of seabed habitat maps which provide insight into the diverse ecosystems present in the surrounding waters.
As part of the project, the BGS Marine team provided training to the Ascension Island Government (AIG) in how to effectively use GIS software to view, edit, query and manipulate the data.
