Mareano Leg 1 2023 Easter Cruise Report

The following Abbreviations are use throughout this report:

AUV: Autonomous Underwater Vehicle – here it is the Kongsberg Munin +.

CT: Conductivity and Temperature (but not Depth as is normal) – the AUV CT sensor does not collect pressure information that is converted into depth as standard, but it does have an altimeter/depth sensor as part of that navigation system so this data is also available.

CTD: Conductivity, Temperature and Depth sampling rosette

GC1, GC2, etc: Gravity Corer station where there had been requests from the Oil directorate to take gravity corer samples if possible. No sites had suitable sediment to take these samples in the end but the sites are still locations where sampling took place so are logged here.

HI: HavforskningsInstituttet or the Institute of Marine Research as it is called in English.

MBE: MultiBeam Echosounder

NGU: Norsk Geologiske Undersøkelse or the Norwegian Geological Survey as it is called in English.

NSJ-1; NSJ-2: Nord Sjø mapping areas, ames assigned by Mareano but often informed by industry mapping names such as the Sørlige Nordsjø II area which is the official name assigned to an offshore wind licensing area.

SVO: Særlig Verdiful Område – translates to “Especially Valuable Area” and is a Norwegian management region that currently has no protection measures but indicates an area of particular ecological value.

Utsira KB: The Ustira Kyst Belt – another Mareano mapping area name. Utsira is an island in the area and Norway’s smallest municipality.

• Apply Mareano method, generally following the 30 stations/1000 km2 rule (for SVO/very variable environments), with a focus on Video sampling (using the Chimera towed camera rig).

ACHIEVED

• Test AUV (Munin +) for data uses and integration into the Mareano method.

ACHIEVED

• Take 2 x gravity cores at the request of the Oil Directorate in areas with possible natural oil seepages.

CHECKED SITES WITH TOPAZ AND GRABS, NONE SUITED TO GRAVITY CORERS/ SHOWING CLEAR EVIDENCE OF OIL SEEPS, ADVISE RETURNING WITH VIBROCORER

• When there are issues with Chimera/AUV take Boxcores, Multicores, Grabs (in that order) at proposed full stations to reduce the load on the summer cruise.

SOME SAMPLES TAKEN AT FULL STATIONS (DETAILS FOLLOW)

This cruise was focussed on:

• Utsira KB = The coastal belt east of Utsira Nord offshore wind license area (including within the Kystebelt SVO), and

• NSJ-1 and NSJ-2 areas = Multibeam mapped areas which sit alongside the Sorlig Nordsjo II offshore wind license area and overlap with the Tobis SVO and a small corner of the Norskerenna proposed SVO.

• A small amount of additional sampling was performed in Fognafjorden (one of three sites in the fjords around Stavanger where we had applied for, and received, permission from FOH for declassification of the seabed) as a bad weather retreat area where AUV testing could continue while waiting for improved conditions. A CTD was also taken at a second site closer to Stavanger, but that area had too much fishing gear in the way to proceed with AUV/video surveys.

Priority

• Chimera video stations (inc. attached mini grab; Biology, Geology)

• Gravity corer (Geology, Chemistry – at the request of the Oil Directorate)

• AUV testing and data collection (Geology, Hydrography, Biology)

Lower Priority

• Boxcorer (Chemistry, Biology)

• Multicorer (Chemistry, Geology, Biology)

• Grabs (Biology, Geology)

Infrmation about the data collected is here shown in the form of overview maps and a table of stations. More details are available in the day by day overview appendix or can be given upon request. 

The following maps show the overview of the route of this cruise and the sampling stations. A table follows showing all stations, data types collected there and a short description of what was seen on video lines.

Data Collection Overview Tables

Table 1 - Overview of activities in order of R station per area(broken down with more detail in subsequent tables)