The most well-known species-based conservation tool is the International Union for the Conservation of Nature (IUCN) Red List of Threatened Species. The current coverage of species in the Red List is known to under-represent benthic marine species. Cold-water corals (CWCs) are increasingly recognised as key to deep-water biodiversity and integral to protected vulnerable marine ecosystems (VMEs), but no deep-sea coral species w...

Despite its remoteness, the deep sea is not spared from the impact of human activities. The emergence of industrial-scale deep-sea mining of polymetallic nodules on the abyssal plains (4-5 km depth) of the Clarion-Clipperton fracture zone in the equatorial Pacific is potentially the most threatening undertaking at present time. A primary aspect that must be comprehensively assessed in order to safeguard these abyssal benthic c...

The focus of the present study was on arcturid isopods occurring in the subarctic region around Iceland. Data from two decades of sampling with an epibenthic sledge (EBS) during numerous expeditions of the BIOICE (Benthic Invertebrates of Icelandic Waters; 1992–2004) and IceAGE (Icelandic marine Animals: Genetics and Ecology; 2011—ongoing) projects were incorporated into an integrative taxonomy approach. This approach linked d...

The Greenland–Scotland Ridge is a submarine mountain that rises up to 500 m below the sea surface and extends from the east coast of Greenland to the continental shelf of Iceland and across the Faroe Islands to Scotland. The ridge not only separates deeper ocean basins on either side, that is, the North Atlantic and Arctic oceans, but also forms a geomorphological barrier between the cold arctic water masses of the Nordic Seas...

Cold-water corals build up reef structures or coral gardens and play an important role for many organisms in the deep sea. Climate change, deep-sea mining, and bottom trawling are severely compromising these ecosystems, making it all the more important to document the diversity, distribution, and impacts on corals. This goes hand in hand with species identification, which is morphologically and genetically challenging for Hexa...

Correct identification of species is required to assess and understand the biodiversity of an ecosystem. In the deep sea, however, this is only possible to a limited extent, as a large part of the fauna is undescribed and the identification keys for most taxa are inadequate or missing. With the progressive impact of climate change and anthropogenic activities on deep-sea ecosystems, it is imperative to define reliable methods...

The crustacean marine isopod species Haploniscus bicuspis (Sars, 1877) shows circum‐Icelandic distribution in a wide range of environmental conditions and along well‐known geographic barriers, such as the Greenland‐Iceland‐Faroe (GIF) Ridge. We wanted to explore population genetics, phylogeography and cryptic speciation as well as investigate whether previously described, but unaccepted subspecies have any merit. Using the sam...

Paralicella tenuipes Chevreux, 1908 and Paralicella caperesca Shulenberger and Barnard, 1976 are known as widely distributed deep-sea scavenging amphipods. Some recent studies based on genetic data indicated the presence of high intraspecific variation of P. caperesca suggesting it is a species complex. Based on published molecular data from the Pacific and Indian oceans and new material obtained from the North and South Atlan...

In the deep sea, the phylogeny and biogeography of only a few taxa have been well studied. Although more than 200 species in 32 genera have been described for the asellote isopod families Desmosomatidae Sars, 1897 and Nannoniscidae Hansen, 1916 from all ocean basins, their phylogenetic relationships are not completely understood. There is little doubt about the close relationship of these families, but the taxonomic position o...

During RV MS Merian expedition MSM75, an international, multidisciplinary team explored the Reykjanes Ridge from June to August 2018. The first area of study, Steinahóll (150–350 m depth), was chosen based on previous seismic data indicating hydrothermal activity. The sampling strategy included ship- and AUV-mounted multibeam surveys, Remotely Operated Vehicle (ROV), Epibenthic Sledge (EBS), and van Veen grab (vV) deployments....

Aim The deep waters around Iceland, known as the North Atlantic Gateway, constitute an ideal location to investigate deep‐sea ecological hypotheses. We constructed a comprehensive deep‐sea macroecological dataset of the North Atlantic Gateway region and investigated the controlling factors of large‐scale, deep‐sea species diversity patterns. Location Sub‐polar North Atlantic Ocean. Time period Modern. Major taxa studied Ostrac...