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​The deep sea is one of the most extreme environments on our planet. Low temperatures, tremendously high pressure, and the long distance from shore create ecosystems that are about as remote as they can get. Areas previously explored are rarely re-visited, mainly due to the high costs of offshore expeditions. The deep sea still poses many mysteries, from the basic biology and ecology of organisms, to the geology and geomorphology of the seabed. The Charlie-Gibbs Fracture Zone (CGFZ), a double transform fault spanning the width of the North Atlantic Ocean, is no exception. 

 

The CGFZ offsets the Mid Atlantic Ridge by almost 370km and influences the warmer waters of the North Atlantic current as well as the sub polar front, creating productive surface waters. This in turn creates a hotspot for charismatic megafauna like cetaceans and seabirds. Very little is known of the benthic ecology of this feature, primarily due to its remote location. 

 

The TOSCA (Tectonic Ocean Spreading of the Charlie-Gibbs Fracture Zone) survey team set out in the summer of 2018 on Ireland’s research vessel, the Celtic Explorer to find out how the underwater mounds in-between the two faults of the CGFZ were formed. They steamed over 1,600km off the West coast of Ireland to reach this remote location of the North Atlantic. The Remotely Operated Vehicle, Holland I, was utilised to collect geological samples and HD video footage of the area. The team also mapped the seafloor using the multibeam echosounder on board the vessel.

 

Aside from the geological discoveries, the videos alone provide a unique glimpse into the benthic ecology of this remote region. Communities of Octocorals and sponges have been observed as well as numerous species of deep-sea fish, sharks and rays, revealing the complex ecosystems of the CGFZ. This project aims to use the observations from the ROV video to identify Vulnerable Marine Ecosystems (VMEs), measure the biodiversity, and determine which environmental factors are influencing the biological community composition. Findings from this project may help to inform future decision making on the protection status of this potentially biodiverse area in the middle of the North Atlantic Ocean.​​

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