|
The Blue Belt RRS Discovery expedition has departed the Ascension Island Marine Protected Area (MPA) and is now journeying to St Helena.
The six-week long expedition is surveying the marine environments of Ascension and St Helena, growing scientific understanding and conducting research in areas never previously explored.
From discovering new seamounts to collecting unique deep-sea specimens for research, catch up on the work of DY159 so far below.
 The new seamount, discovered in the north-west of Ascension's MPA
Within the Ascension MPA, the Discovery team have been conducting bathymetry surveys to map the seafloor, often around 3000m below the surface. This works by sending large numbers of acoustic ‘pings’ from the ship to the seafloor, and by measuring the time they take to return, mapping the shape of the seabed.
Very little of Ascension’s offshore areas have been mapped by ships, and only limited data is available from satellite-data based maps. Excitingly, in the north-west of the Ascension MPA, a substantial new seamount was discovered on day one as Discovery travelled over its position.
Around 2600m at its highest point, 1200m above the surrounding seafloor and 84km2 in size, the seamount was previously unknown. Seamounts are important as they often create areas of biodiversity and seabed habitats such as cold-water coral reefs.
Discoveries such as this highlight how little is known about the deep-sea, and how expeditions such as DY159 can expand our knowledge of marine ecosystems, improving our understanding and better informing protective measures.
 Cold water coral, photographed using the deep-sea camera
One of the most effective tools on DY159 for exploring areas of the seabed is the deep-sea camera system.
Multiple camera surveys have taken place across the Ascension MPA, allowing us to study the incredible habitats and ecosystems present in the deep. Lowered to depths of around 1000m, a wide variety of coral and fish species have been recorded – from stony and black coral (which can live over 2000 years!) to six-gill sharks.
Camera surveys like these allow us to test computer models which predict what type of deep-sea habitats may be present on the seafloor. Using the deep-sea camera, we can test the accuracy of these predictions, better informing the models and ultimately predictions of larger areas of seabed habitats.
 Galapagos shark, photographed using the BRUVS
Baited Remote Underwater Video Systems (BRUVS), have been deployed at offshore research stations within the Ascension MPA. These cameras float around 10m under the surface, collecting information on the biodiversity present in the area.
On the Grattan seamount site in the south of the MPA, the BRUVS recorded high numbers of Galapagos sharks, as well as other fish species such as rainbow runners.
The data collected from all sites, once analysed by project partners Blue Abacus, will contribute to the local management and protection of the MPA by the Ascension Island Government. This data will also contribute to the data collected by Blue Belt Programme’s Global Ocean Wildlife Analysis Network – the global network of BRUVS deployed across the UK Overseas Territories.
 Whiplash squid
Throughout Discovery’s time in Ascension, we have been collecting specimens of deep-sea marine biodiversity for analysis and study. These little studied areas of ocean provide an exciting opportunity to gain a better understanding of the species present and how they interact within these remote marine ecosystems.
So far across Ascension, specimens collected include the joint largest wing-finned snaggletooth fish on record, and a whiplash squid. Many of these specimens will be added to the collection at the Natural History Museum (UK), where they will be available for research.
 James Bell, Molly Meadows (Cefas), James Maclaine (Natural History Museum)
After a busy few days of deployments and analysis across the Ascension MPA, the DY159 team were excited to be able to get onto the island before departing for St Helena.
The DY159 scientists delivered a presentation on the work of the expedition to the local community, and how it supports the on-island marine conservation team in their work.
The scientists also provided a video of them answering questions from the Ascension Island Youth MPA committee, who had sent questions in advance for the team to answer about the deep-sea!
To follow live updates from Discovery during its time in St Helena, follow on social media using #DY159!
 DY159 scientific crew, including colleagues from Ascension Island Conservation
|
