Faunal biodiversity and food-web structure of organic falls in the deep Norwegian Sea

Kelps are important primary producers found along coastlines throughout the world, and serve as habitat for a variety of shallow-water fauna. Some of the world’s largest kelp beds are found along the Norwegian coast, where the estimated coverage by the kelp species, Laminaria hyperborea, is between 5000 and 10000 km2. Because kelps are very abundant along the Norwegian coastline, and kelp beds export organic matter to other systems, kelp debris is often deposited on the deep-seafloor (as kelp-falls) in many Norwegian fjords. Wood and other forest material is also transported to the seafloor along the Norwegian margin, and large deposits have been documented at the seafloor in many deep Norwegian fjords.

High local energy availability set against an oligotrophic background has been shown to lead to extraordinary faunal diversity, biomass and ecosystem functioning at the deep seafloor (e.g. at whale falls). Because kelp- and wood-falls will increase the local stock of organic carbon by orders of magnitude above background levels in deep-sea environments, they are likely to provide unique ecological opportunities for a variety of novel (potentially un-described) fauna in many deep-sea fjords along the Norwegian margin. Nevertheless, the biodiversity and species novelty at kelp- and wood-falls is poorly known, and we know of no study that has assessed biodiversity, species overlap and ecosystem functioning (e.g., food-web structure) at kelp and wood-falls in Norwegian fjords. This type of research is however urgently needed since many kelp ecosystems around the world are currently under threat, and in Norway alone, approximately 9800km2 (~50%) of kelp forest have so far been lost from the coast.

The PhD studentship will involve deploying 4 seafloor colonisation landers with attached kelp, wood and other organic substrates (e.g., whale bones) in the deep-sea along the Norwegian margin. After 0.5 and 1.3 years, seafloor landers will be recovered and the biodiversity, species novelty and food web structure of the colonising fauna will be assessed. This PhD will form part of a major European H2020 funded project called MERCES (Marine Ecosystem Restoration in Changing European Seas, 2016-2020). The studentship will be based in the Marine Benthic Ecology and In-situ Technology group at the Lyell Centre for Earth and Marine Science and Technology – a new pioneering global research centre set up between Heriot-Watt University and the British Geological Survey (BGS). The student will be required to attend periodic research cruises to the Norwegian deep sea, and research exchange trips to the USA.