The scientific objectives of the XL Catlin Deep Ocean Survey are to investigate the state of the deep ocean around Bermuda, Sargasso Sea and the NW Atlantic and create a new standardised methodology for marine scientists around the world to assess the function, health and resilience of the deep ocean.
The research team studied the biodiversity and abundance of marine species across a wide range of depths and locations. The aim is to discover which physical and biological factors affect species distribution and how biogenic structures (i.e. structures created by marine creatures) influence biodiversity and the connectivity of communities. The marine species being studied fall into three main groupings:
- Pelagic & Neustonic: Organisms that live suspended in seawater (pelagic) or on top of the water or just under the surface (neustonic).
- Benthic & Epibenthic: Species that live in or on the deep ocean seabed (i.e. lobsters, sponges, and other tiny organisms that live within the sediments).
- Epifaunal & Infaunal: Epifaunal species live on the surface of submerged rocks, plants or animals (i.e. crabs, mussels, starfish). Infaunal species (i.e. clams, burrowing worms) live in / or burrow in the sediment of the seabed.
The sargassum weed in the Sargasso Sea was also studied. The Sargasso Sea ecosystem is vitally important as a migration route, foraging and spawning ground for threatened and iconic species of whales and sharks as well as several important, but now declining, commercial species including the European freshwater eel and blue-fin tuna.
Across each study location, the scientists identified how the various hydrodynamic regimes (the forces of the sea) interact with underwater features like seamounts, island slopes and canyons. The team investigated how local and more mainstream deep-sea phenomena (everything from localised currents to the Gulf Stream) influence marine communities.
3. Human Impacts
Nekton’s science team studied the risks to the long-term health of the ocean caused by human activity. Areas of scientific study include:
- Abundance, distribution, habitat, diet and impact on local fish communities of invasive lionfish.
- Evidence of disease in coral.
- Level of physical damage caused by fishing, dive-related tourism or other human activities.
- Distribution of and damage caused by large debris and small particulate waste materials (especially microplastics).
- Evidence of contamination from heavy metals, oil, or persistent organic pollutants.
- Levels of suspended sediment.
- Carbonate chemistry which is important in understanding the impacts of ocean acidification.
- Levels of macronutrients (nitrates, nitrites, phosphate, silicate) and any evidence of human influence.