| Lýsing |
Summary
Denmark Strait is the body of water separating Greenland and Iceland. With a minimum width of 290 km and
bisected by the Greenland-Iceland Rise (GIR), it is a region of complex oceanographic settings, where warm
saline Atlantic Waters interact with cold waters of Arctic origin. As a result of these oceanographic processes,
the environmental gradient across Denmark Strait is one of the steepest in the northern hemisphere (Andrews
et al. 2002), with major differences in water mass characteristics, extent of sea-ice cover, and near-bottom
temperature. In addition, the composition of the sea bed in terms of sediments and geomorphic units is highly
variable. These major differences in environmental settings are likely to result in a high diversity of benthic
habitats.
Existing information on the distribution of benthic invertebrates in Denmark Strait is derived from the analysis
of the bycatch during bottom trawl surveys within Icelandic and Greenlandic waters (Ólafsdottir and
Guðmundsson, 2019; Blitcher and Hammeken Arboe, 2017), observations during the BIOICE project within the
Icelandic EEZ (Anonymous2005, Omarsdottir et al. 2013), and underwater video transects carried out in
Icelandic waters by the Marine and Freshwater Research Institute. These observations suggest that the GIR
and adjacent slopes in Denmark Strait may have a high density and diversity of benthic megafaunal taxa,
including the presence of Vulnerable Marine Ecosystems (VMEs). Nevertheless, in general, the composition
and distribution of benthic habitats in Denmark Strait is poorly known.
The BENCHMARK (Benthic Habitats in Denmark Strait) cruise was carried on board the R/V G.O. Sars between
August 1st, and 10th, 2021 (Reykjavik – Reykjavík), with the main objectives of collect underwater video and
photographs to characterise the composition and distribution of epibenthic fauna in the Denmark Strait, with a
particular focus on taxa considered indicators of Vulnerable Marine Ecosystems, and to survey water mass
properties and flow structure across the Denmark Strait. EUROFLEETS+ financed the cost of the vessel
operation, ROV crew, and travel costs for the scientific crew. In addition, it supported the cost of improving
the capabilities of the vessel to transmit live video feed on the internet. Thanks to the professionalism of the
vessel crew and the ROV operators, and aided by excellent weather conditions, we were able to fulfill all the
objectives of the cruise. We complied a rich set of observations that will be analyzed in the coming months,
with preliminary results presented in this report. |
