BENCHMARK Benthic Habitats in Denmark Strait

Scientific Discipline: Marine Biology, Physical Oceanography

Work Area: Denmark Strait, between Iceland and Greenland (between 65-67°N and 25-31°W)

Research Vessel/Equipment: G.O. Sars & ROV Ægir 6000

PI Name and Affiliation: Dr Julian M. Burgos, Marine & Freshwater Research Institute, Iceland

Date: August 1 – August 10, 2021

Citation from PI: Our objective for this cruise is to increase the knowledge on benthic habitats on the Denmark Strait and the Greenland-Iceland Rise (GIR), focusing on Vulnerable Marine Ecosystems (VMEs). The environmental gradients in Denmark Strait are among the strongest in the northern hemisphere. The high variability in depth, near-bottom temperature, salinity and current speed, it is likely to have a great influence in the distribution of benthic fauna, including in species that are considered VME indicators. Although information from different sources indicate that there is a high diversity of benthic habitats in this area, there are few direct observations, in particular in the deeper areas of the Icelandic EEZ and within Greenland waters. With this cruise we will obtain baseline data to characterise seabed habitats in this area.

Abstract & Main objectives: Our primary objective is to 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. We aim to carry out dives using an ROV (Remotely Operated Vehicle) in 20 stations located along three transects running in a NW-SE direction across the Denmark Strait.

Planned Transects

Specific aims of the project are:

1) Obtain baseline information on the distribution and composition of benthic ecosystems (including biota and sediment types), contributing to the mapping of benthic habitats on Greenlandic and Icelandic waters in general, and to the identification of potential Vulnerable Marine Ecosystems in particular.

2) Validate predictive distribution models of VME indicator taxa obtained by the NovasArc project (Burgos et al. 2020).

3) Obtain new records of VME indicator taxa to allow the fitting of high-resolution predictive models of VME indicator taxa in Denmark Strait.

4) Survey water mass properties (temperature, salinity, nutrients) and flow structure across the Denmark Strait, contributing to the characterisation of currents in Denmark Strait and providing baseline information to understand the distribution patterns of benthic taxa.

5) Collect high-resolution bathymetry and backscatter data using a multibeam echosounder in selected locations.