CRUISE – REPORT 2024_TA_06 DEEP-TRACE 18th to 30th of September 2024.Technical Report No. 134

I Technical report no. 134, 2024 Pinngortitaleriffik, Greenland Institute of Natural Resources CRUISE – REPORT 2024_TA_06 DEEP-TRACE 18th to 30th of September 2024 II Author(s): Zwerschke N., Arboe-Hammeken N., Barnes D., Bax N., de Montety L., Krawczyk D., Lysgård Hammer K., Mathews R., Merz A., Scaramiglia P., Siegstad H., Sinclair D., Sølbeck C., Thompsen F., Vonnahme T., Winding M.H.S., Zinglersen K. Serial title and number: Technical report no. 134 Publisher: Pinngortitaleriffik, Greenland Institute of Natural Resources Date of publication: March 2025 Translation: Financial support: Funded through the Government of Greenland partnership agreement with the European Commission (Green Growth Programme) Cover photo: Mie Winding ISBN: 978-87-94423-07-6 EAN: 9788794423076 Cited as: Zwerschke N., Arboe-Hammeken N., Barnes D., Bax N., de Montety L., Krawczyk D., Lysgård Hammer K., Mathews R., Merz A., Scaramiglia P., Siegstad H., Sinclair D., Sølbeck C., Thompsen F., Vonnahme T., Winding M.H.S., Zinglersen K. (2024) Cruise report for the Deep Trace cruise 2024-TA-06. Technical Report No. 134, Greenland Institute of Natural Resources, Nuuk, Greenland Contact address: The report is only available in electronic format. You can download a PDF-file of the report at this homepage http://www.natur.gl/publikationer/tekniske rapporter It is possible to receive a print of the report here: Pinngortitaleriffik, Greenland Institute of Natural Resources P.O. Box 570 3900 Nuuk Greenland Phone: +299 32 10 95 E-mail: [email protected] www.natur.gl III CRUISE – REPORT 2024_TA_06 DEEP-TRACE 18th to 30th of September 2024 By Zwerschke N., Arboe-Hammeken N., Barnes D., Bax N., de Montety L., Krawczyk D., Lysgård Hammer K., Mathews R., Merz A., Scaramiglia P., Siegstad H., Sinclair D., Sølbeck C., Thompsen F., Vonnahme T., Winding M.H.S., Zinglersen K. Technical report no. 134, 2025 Pinngortitaleriffik, Greenland Institute of Natural Resources IV Summary The Deep-Trace cruise was carried out between the 18th and 30th of September 2024 on board RV Tarajoq. The purpose of the cruise was to better understand environmental conditions and species dynamics in East Greenland, Tasiilaq region along a gradient from coastal shelf along glacially derived trenches towards the continental shelf edge and shelf slope. Geomorphology, benthic biodiversity and community composition, oceanography, sediment chemistry and composition were assessed along three trenches in this region. Eqikkaaneq Deep-Trace ilisimasassarsiorneq RV Tarajoq-mik ingerlanneqarpoq 18.-30. september 2024mi. Ilisimasassarsiornerup siunertaraa Tunumi avatangiisinut tunngasunik paasisaqarnerulernissaq aammalu uumasoqatigiiaat sunneeqatigiittarnerat. Tasiilap eqqaanniit sinerissap qanittuani sermip ilusiligai manissukkuutaarlutik itisiartornerit nunatta qaarsuata imaani killingani innaannarsuup tungaanut misissuisoqarpoq. Qaarsut ilusaat, sananeqaataat aammalu qaatungaat, immap naqqani uumasoqatigiiaat assigiinngissitaarneri aammalu uumasoqatigiiaat aaqqissugaanerat, imarpissualerineq, immap naqqani qaleriiaannerit suussusaallu assigiinngitsuni pingasuni itissutsiniittut tamaani misissuiffigineqarput. Abstrakt Det videnskabelige togt Deep-Trace blev gennemført i perioden 18. og 30. september 2024 om bord på forskningsskibet RV Tarajoq. Formålet med togtet var at få en bedre forståelse af miljøforhold og artsdynamik i Tasiilaq-regionen i Østgrønland. Togtets rute fulgte kontinentalsoklens kant samt transekter herfra og mod kysten henover undersøiske kanaler udgravet af historiske gletsjere. Under togtet undersøgte forskerne havbundens morfologi og sedimenters sammensætning og kemiske forhold, der er grundlag for dyrelivet på havbunden. Ud fra undervandsvideoer og prøver fra havbunden registrerede forskerne det bentiske dyreliv og biodiversiteten og sammensætning af arter. V Acknowledgement We would like to thank the crew of the RV Tarajoq for their invaluable assistance and support during our time on board. The success of the Deep Trace cruise is a is a testament to the enthusiasm, dedication, and exceptional teamwork we experienced throughout this survey. The Deep Trace cruise was funded by the Government of Greenland partnership agreement with the European Commission (Green Growth Programme) Some team members were supported by the EU Horizon funded POMP Project: Grant agreement No.: 101136875 and by the BlueCea Project (Project number: 8014) funded by the Research Council of the Faroe Islands All image copyright by GINR 1 Contents 1. Introduction ................................................................................................................... 3 1.1 Background and Scientific motivation ..................................................................... 3 1.2 Scientific and Ship Personal .................................................................................... 5 1.2.1 Scientists ....................................................................................................... 5 1.2.2 Ship personal.................................................................................................. 5 1.3 Cruise Diary ........................................................................................................... 7 1.4 Survey area .......................................................................................................... 10 2. Geomorphology ............................................................................................................ 11 2.1 Equipment ........................................................................................................... 11 2.2 Summary ............................................................................................................. 11 2.3 Data Storage/Availability ....................................................................................... 14 3. Benthic Ecosystem ....................................................................................................... 18 3.1 Benthic imagery .................................................................................................... 18 3.1.1 Objective ...................................................................................................... 18 3.1.2 Video sledge deployment procedure .............................................................. 18 3.1.3 Preliminary findings ...................................................................................... 21 3.1.4 Data quality notes/problems ......................................................................... 22 3.2 Epibenthic diversity and abundance ...................................................................... 24 3.2.1 Introduction & Objectives: ............................................................................. 24 3.2.2 Methodology: ................................................................................................ 24 3.2.3 Preliminary observations: .............................................................................. 26 4. Physical and Biological Oceanography ........................................................................... 44 4.1 Background and objectives ................................................................................... 44 4.2 Sampling strategy and instrument description ....................................................... 44 4.3 Water processing .................................................................................................. 45 4.4 Preliminary findings .............................................................................................. 46 5. Sediment biogeochemistry ............................................................................................ 49 5.1 Background and objectives ................................................................................... 49 5.2 Sampling strategy and instrument description ....................................................... 49 5.3 Specific core fate .................................................................................................. 53 5.4 Organic and carbon content .................................................................................. 55 5.5 eDNA ................................................................................................................... 56 5.6 Biogeochemistry .................................................................................................. 56 5.7 Infauna ................................................................................................................. 59 6. References ................................................................................................................... 60 2 3 1. Introduction 1.1 Background and Scientific motivation Very little is known about the seafloor in Greenland. Commitments by the Government of Greenland to protect 30% of its seas by 2030 and growing pressure to take the impact of demersal fishing on seafloor ecosystems into account for MSC certifications has sparked an increased interest in better mapping and understanding benthic ecosystems around Greenland. Although a benthic bycatch monitoring programme has been implemented by the Greenland Institute of Natural Resources since 2016, information gained here is focused on large epifauna captured in commercial trawls within fisheries zones and often lacks contextual information, such as seafloor morphology, substrata composition, hydrodynamic conditions, nutrient and primary production availability. These parameters are often driving the distribution of benthic species and are instrumental in creating reliable habitat maps. In 2024, the Greenland Institute of Natural Resources received support from the European Union Green Growth fund for a 4 year project (Greenland Seabed Ecosystem Survey) with the goal to improve the ongoing monitoring work, survey understudied areas and provide a better understanding of the Greenlandic seafloor ecosystem. This project is meant to aid pinpointing biodiversity hotspots, areas vulnerable to anthropogenic impact (Vulnerable Marine Ecosystem Indicator Taxa) as well as identify unique and rare ecosystems and provide a better understanding of species distribution across Greenland. Additionally, this project is attempting to consider fairly novel parameters in Marine Spatial Planning, such as potential blue carbon habitats across the Greenland EEZ. The Deep-Trace cruise (18th to 30th of September 2024) on the GINR ship RV Tarajoq was the first scientific cruise carried out as part of the GSES project. The primary aim of this cruise was to trace changes in biodiversity and species composition from the coast along the shelf and into the deep sea of the continental slope, integrating common geomorphological features along the Greenland seafloor such as glacially derived deep trenches on the shelf. The secondary aim was to collect contextual information to help understand shifts in species composition and the tertiary aim was to trace carbon transport from the coast into the deep sea and highlight areas with greater carbon content along the East Greenland Shelf. The large bay in front of Tasiilaq is known to be a biological hotspot with high abundances of different whale species and a comparatively large occurrence of corals found here. Thus, this area was the primary focus on this cruise, with another hotspot for Greenland halibut being surveyed further South. Samples were collected for 4 work packages on each station 1. Geomorphology: Multibeam data was collected continuously throughout the survey area 2. Benthic Ecosystems: video and imagery was collected at all stations, these were followed up with standardised beamtrawl surveys at the coast, the middle of the trough, on the shelf and on the bottom of the continental shelf, in order to ID all species to lowest possible taxonomic resolution and capture small taxa that are not identifiable from video data. 4 3. Oceanographic data: CTD profiles were collected from all realised stations. Water samples were taken throughout the water column and assessed for nutrient and chlorophyll content. 4. Sediment biogeochemistry: Sediment cores were taken where possible using a multicorer. Cores were assessed for oxygen penetration, microbial respiration, chlorophyll content and porosity. Samples were taken for eDNA analysis of macroalgal carbon sources, inorganic and organic carbon content. When possible, sediment cores were sampled for infauna. 11 2. Geomorphology Team: Diana W. Krawczyk ([email protected]) and Karl B. Zinglersen ([email protected]) 2.1 Equipment RV Tarajoq is equipped with a multibeam Teledyne RESON SeaBat 7160 (operating at freq. 44 kHz) and sub-bottom profiler Innomar SES-2000 Medium-100 (operating at freq. 12 kHz); Applanix POSMV OceanMaster. 2.2 Summary Multibeam echo sounder (MBES) data were collected continuously throughout the survey (day and night) and during transit to and from harbors. Exception to this were stops at the sampling stations to avoid excess of noise in the water column during drift. The readings and measurements from MBES were the primary source of depth and subsea landscape information to navigators, crew, and scientists during all operations. Sound velocity profiles were periodically collected alongside CTD measurements in the project area to correct the effect of sonar beam refraction due to water density changes. MBES logging was accompanied by sub-bottom profiler (SBP) data recorded at selected stations, where multicorer was deployed to aid the search for soft bottom, as well as to validate the final stratigraphic interpretations. Positioning and movements of the vessel were calculated directly with the Applanix POSMV v5 OceanMaster (SN 11262) receiving data from an Inertial Motion Unit and two Trimble GNSS 540 AP antennas. The Applanix POSMV is the main source of vessel inertia, GNNS (GPS) position and time synchronization information for all sonars. Detailed survey information together with example images of POSMV and GNNS positioning can be found in Appendix 1 (see below). The total area mapped during the Deep Trace cruise is 1941,47937 km2 (Figure 1 and 2.1). 12 Figure 2.1 shows a 2D map and 3D model of multibeam tracks (color grid) of the project area together with all sampled CTD stations (cross symbol). Color scale represents water depth. The total area mapped is 1941,47937 km2. 13 The collected MBES and SBP datasets will deliver new knowledge on seafloor terrain features, underwater landforms, sediment types, and possibly geological units in the area off South-East Greenland. The surveyed project area comprised of 3 transects and spanned from the shallow banks and deep-water troughs to continental slope and deep-sea basin, covering a high topographic complexity and a large variety of benthic habitats. In the coastal region, seafloor data reveal a highly rugged terrain with numerous crisscrossing tunnels suggesting bedrock exposed at the surface (likely Archaean basement) and sculpted by the glacial processes. Further offshore, the landscape transforms into deep-water troughs down to c. 1000 m and continued rugged terrain structure. Streamlined glacial landforms are present particularly in the deeper parts of northernmost and middle transects, reminiscent of past glacial flow (Figure 2.2). Figure 2.2 shows example glacial lineation (crag-and-tails) in transect 1. The middle and southernmost transects displayed a surprising presence of gravelly and rocky sediments in deeper basins and troughs, possibly due to a strong activity of oceanic current, flushing soft sediments. The offshore continental shelf area was comprised of vast plains, which transition into continental slope, characterized by deep canyons (Figure 2.3), most likely carved by glacial meltwater outflow following the Last Glacial Maximum (around 14 20,000 years ago). In addition, some interesting single mounds and crater-like features were found between Iceland and Greenland in deep sea region during transit. Figure 2.3 shows deep canyons off the continental slope off East Greenland. The collected seafloor data will be analyzed in detail for morphological classes and geological features in the area. In combination with other collected data, such as video footage of benthic communities and habitat types, we will produce a spatial benthic habitat model, following the protocol described in Krawczyk et al. (2021) 2.3 Data Storage/Availability All MBES and SBP data collected during the Deep Trace cruide in September 2024 are stored at the GINR database, i.e. multibeam data as .qpd, .xyz, .asc, and .tiff formats, shallow seismic data as .ses3 format. All MBES positional data will be processed against DGPS information from base stations on land using QPS Qinertia or PosPAC MMS 8 for higher accuracy in three dimensions, and to adapt to Mean Sea Level of Greenland on the ggeoid16 geoid from The Danish National Mapping Agency and DTU Space. 15 Automatically and manually processed multibeam bathymetry data will be submitted to the Danish Geodata Agency (Geodatastyrelsen) and they will be further gridded to a 100-meter resolution grid (.geotiff format) and submitted to the International Bathymetric Chart of the Arctic Ocean (IBCAO) under the IHO Nippon Foundation Seabed 2030 for open access. Table 2.1. Survey information of the project area Variable Information Number of MBES files 157 files (25 GB) Number of SBP files 178 files (37 GB) Number of SVP files 23 files Total area mapped 1941,47937 km2 Acquisition software QPS Qinsy 8.4.4 Positioning software Applanix MV-PosView 11.21 Datum Datum : WGS 84 (Greenwich) Spheroid name : WGS 84 Projection Projection name : Universal Transverse Mercator (North Hemisphere) UTM zone number : 24 EPSG: 32624 Mean Water Level Model None Height above draft 5.440 m Geometry TX MBES X (Stbd = Positive): : -0.463 m Y (Bow = Positive): : 6.747 m Z (Up = Positive): : -16.877 m A-priori SD : 0.005 m Heading offset : 1.634 ° Roll offset : -0.085 ° Pitch offset : 1.628 ° 16 Geometry RX MBES - RX X (Stbd = Positive): : -0.461 m Y (Bow = Positive): : 7.730 m Z (Up = Positive): : -16.806 m A-priori SD : 0.005 m Heading offset : 1.224 ° Roll offset : -0.005 ° Pitch offset : 2.038 ° Geometry IMU Lever Arms..: Ref. to IMU Target, 0 0 0, IMU Frame wrt Ref Frame: -0.390, -0.130, 0.040; Target to Sensing centre: 0.000, 0.001, 0.086, Resulting Lever Arm: 0.000, 0.002, 0.086; Ref to P. GNSS Lever Arm: -10.143, 1.226, -12.650 Ref to Vessel Lever Arm: 0.000, 0.000, 0.000 Ref to Centre of Rotation Lever Arm: -16.468, -0.504, 9.331 Other MBES information Beam angle width along : 1.500 ° Beam angle width across : 1.500 ° Maximum number of beams per ping : 512 17 Example image 18 3. Benthic Ecosystem 3.1 Benthic imagery Team: Nadescha Zwerschke ([email protected]), Fletcher Thompson ([email protected]), Ryan Matthews (ry[email protected]), Nanette Hammeken ([email protected]), Alenya Merz ([email protected]) 3.1.1 Objective The majority of knowledge on epibenthic deep-sea communities from Greenland is being derived from the GINR based bycatch monitoring programme. However, this is based on a sampling method designed to assess the health of commercial fish stocks rather than provide an understanding of the benthic ecosystem and often avoids geomorphological complex habitat features. A customised benthic video sledge was used to study benthic communities along a gradient from the coast along a deep trench towards the shelf edge and at the bottom of the shelf slope. This will give better insights into, shallow coastal communities, which are often not part of the traditional fisheries survey, provide information of typical communities encountered across the East Greenland shelf and their geomorphological drivers and improve our understanding of benthic communities on rarely sampled shelf slopes 3.1.2 Video sledge deployment procedure The custom made GINR owned video sledge (design by R. Nygaard) was equipped with two GoPro Hero5 cameras in GroupBinc housings, two GroupBinc GPH2-1750M LED torches, a Marport Trawl Eye Explorer (see Figure 3.1.1 B) and custom-made laser block featuring 4 green Quadro Laser Scale 150 (532nm wavelength). These were arranged in form of a quadrat with all midpoints exactly 15cm apart. The camera taking a continuous video was mounted centrally and at an oblique angle (27°) on the sledge 48 cm above the seabed and parallel to the lasers. This resulted in a laserpoint distance off 334mm vertically and 150mm horizontally, when the sledge sat on the seadbed. The second camera, taking pictures at an interval of 1 second, was placed centrally at an angle of 180° and allowed for top-view pictures of the epibenthos. Customised underwater GroupBinc video lights were placed on either side of the video camera, angled inwards to achieve the most even illumination possible without backscattering caused by particles in the water column. The video sledge was deployed at each site once and towed along the seabed for 20 minutes. Marport data to collect information about pitch and roll, depth, and speed were logged at 2-minute intervals, starting from the moment the video sledge reached the seabed 19 and was fully stabilized. A list of all deployments can be found in table 3.1.1 and Figure 3.1.1 A. Table 3.1.1: Sampling details for each station Even t Nr. Statio n Date Lat. Start Long. Start Lat. End Long. End Depth Start Depth End Bottom Temp. 7 OT1_6 20. Sep 24 64.31 18500 1 37.571 2333 64.315 03334 37.563 36664 731 745 4.3 9 OT1_5 20. Sep 24 64.57 97833 1 38.050 45 64.578 20002 38.061 68333 658 664 4.4 24 OT1_1 21. Sep 24 65.48 93166 5 38.310 16668 65.488 88334 38.301 58332 441 378 4.61 25 OT1_2 21. Sep 24 65.24 355 38.318 63333 65.246 23334 38.315 76665 450 454 4.8 28 OT1_3 21. Sep 24 64.98 27833 2 38.307 54999 64.982 95002 38.300 68334 798 796 4.4 Figure 3.1.1: A) Realised stations, B) Video sledge used for recording epibenthic communities, equipped with two cameras, LED-lights, laser and a Marport for data logging. A) B) 20 31 OT1_4 22. Sep 24 64.77 12166 5 38.276 98332 64.774 91665 38.279 51667 687 682 4.4 35 OT1_7 22. Sep 24 64.15 51833 3 37.024 05 64.155 55 37.018 01667 422 428 4.49 38 OT1_8 22. Sep 24 64.04 87333 3 36.635 46664 64.048 28333 36.625 26665 358 362 4.6 41 OT1_9 22. Sep 24 63.92 83666 6 36.204 6 63.929 50001 36.203 63334 1358 1354 3.5 47 OT2_8 23. Sep 24 63.25 33 39.481 33332 63.256 96667 39.489 78332 1236 1089 3.73 56 OT2_4 24. Sep 24 63.73 85166 8 40.095 16667 63.741 55 40.093 95 932 914 5.1 61 OT2_2 24. Sep 24 63.98 42666 6 40.268 88332 63.987 60001 40.261 11666 1033 1037 5.3 64 OT2_1 24. Sep 24 64.22 34499 9 40.256 81667 64.225 91667 40.244 06667 152 163 2.51 70 OT2_3 25. Sep 24 63.87 83833 2 40.225 73333 63.881 58334 40.222 23333 947 976 5 71 OT2_4 25. Sep 24 64.73 22666 8 40.093 25 64.735 68331 40.095 65 855 879 5.1 75 OT2_5 25. Sep 24 63.66 99499 8 39.958 18335 63.673 46668 39.963 15002 575 599 5.1 76 OT2_6 25. Sep 24 63.56 93499 9 39.754 99999 63.574 06667 39.759 18331 546 548 5.1 84 OT3_6 26. Sep 24 62.21 51 40.418 85001 62.217 18334 40.417 25 1264 1262 3.9 87 OT3_5 26. Sep 24 62.25 70500 1 40.549 60003 62.260 20001 40.545 81668 392 385 5.5 92 OT3_4 26. Sep 24 62.32 27833 4 40.882 78332 62.325 01666 40.891 50003 649 654 5.4 27 Pseudoanthomastus sp (Figure 3.2.4a,b) were found. The latter has a known association with a scale worm, living in the fold of the rim. Pseudoanthomastus sp was collected at stations 43 and 80 and Anthomastus sp at station 80. A stalked crinoid, Rhizocrinus lofotensis has also been collected at station 80 (Figure 3.2.5a,b), as well as a very small ophiuroid, Ophiotjalfa vivipara (Figure 3.2.6a). This is a very small species whose central disk diameter reaches 5 mm. Ophiotjalfa vivipara has been collected for the first time in East Greenland (Martynov & Litvinova, 2008). It has been found at the two deepest stations St. 80 and St. 119. Additionally, at St. 80 an unidentified bryozoa (Cheilostomata, Figure 3.2.6b) has been collected and has been preserved for further identification by experts. Specimen of the stalked crinoid and the ophiuroid have also been fixed in ethanol for the Greenland Institute of Natural Resources collection. Figure 3.2.4: a) Anthomastus sp.; b) Pseudoanthomastus sp. and associated scale worm. Figure 3.2.5: Rhizocrinus lofotensis a) stalk; b) calyx. a b a b 28 Figure 3.2.6: a) Ophiotjalfa vivipara; b) unidentified bryozoa. a b 29 Table3.2.1: Beam trawl stations list Gear Year Ship Trip Station Fix Pos Start latitude decimal Start longitude decimal End latitude decimal End longitude decimal TimeStart TimeEnd Depth1 Depth2 Fishing depth2 Fishing Depth2 T ° BEAM 2024 TA 6 3 OT1_7 64.17031666 37.08835 64.17136666 37.09303333 02:04 02:10 429 431 429 433 4,3 BEAM 2024 TA 6 13 OT1_4 64.7728 38.24290001 64.77020003 38.2467 20:13 20:23 632 639 632 643 4,2 BEAM 2024 TA 6 15 OT1_2 65.24183334 38.31761665 65.24393333 38.31711667 02:43 02:49 453 452 451 453 4,6 BEAM 2024 TA 6 43 OT1_9 63.9278333 36.26855001 63.92606665 36.27038333 02:06 02:12 1038 1048 1038 1048 3,8 BEAM 2024 TA 6 49 OT2_7 63.38788335 39.56781667 63.38658333 39.57049999 18:25 18:31 404 402 400 404 4,9 BEAM 2024 TA 6 52 OT2_4 63.70900002 40.16648334 63.70913334 40.16748333 02:30 02:37 752 762 751 762 BEAM 2024 TA 6 65 OT2_1 64.23568333 40.22516667 64.23723334 40.22303333 20:14 20:20 151 156 150 156 1,8 BEAM 2024 TA 6 80 OT2_8 63.20249999 39.75708332 63.20423333 39.75543334 21:16 21:22 1287 1293 1282 1293 3,7 BEAM 2024 TA 6 97 OT3_3 62.42283335 41.25503333 62.42489999 41.22183334 22:05 22:11 517 514 514 517 5,2 BEAM 2024 TA 6 98 OT3_1 62.58056666 42.02905 62.57999999 42.02496667 02:16 02:22 274 271 271 275 3 BEAM 2024 TA 6 109 OT3_5 62.24371667 40.5699 62.24536667 40.57186667 19:51 19:57 406 408 404 408 5,5 BEAM 2024 TA 6 112 OT3_6 62.18388333 40.41378333 62.18503334 40.41001666 01:43 01:49 1410 1409 1409 1412 3,5 30 Table3.2.2: List of taxa identified during the cruise, for all the beam trawls with classification and frequency of encounter. AphiaID_ accepted Scientific Name accepted Kingdom Phylum Class Order Family Genus Subgenus Species Freq 130081 Euphrosine borealis Animalia Annelida Polychaeta Amphinomida Euphrosinidae Euphrosine borealis 1 157381 Euphrosine cirrata Animalia Annelida Polychaeta Amphinomida Euphrosinidae Euphrosine cirrata 1 129285 Euphrosine Animalia Annelida Polychaeta Amphinomida Euphrosinidae Euphrosine 1 967 Lumbrineridae Animalia Annelida Polychaeta Eunicida Lumbrineridae 2 965 Onuphidae Animalia Annelida Polychaeta Eunicida Onuphidae 2 157181 Aphrodita hastata Animalia Annelida Polychaeta Phyllodocida Aphroditidae Aphroditella hastata 1 129844 Laetmonice filicornis Animalia Annelida Polychaeta Phyllodocida Aphroditidae Laetmonice filicornis 8 129300 Goniada Animalia Annelida Polychaeta Phyllodocida Goniadidae Goniada 1 129370 Nephtys Animalia Annelida Polychaeta Phyllodocida Nephtyidae Nephtys 1 130745 Eunoe nodosa Animalia Annelida Polychaeta Phyllodocida Polynoidae Eunoe nodosa 4 129491 Harmothoe Animalia Annelida Polychaeta Phyllodocida Polynoidae Harmothoe 1 939 Polynoidae Animalia Annelida Polychaeta Phyllodocida Polynoidae 6 985 Sabellidae Animalia Annelida Polychaeta Sabellida Sabellidae 5 131025 Placostegus tridentatus Animalia Annelida Polychaeta Sabellida Serpulidae Placostegus tridentatus 2 988 Serpulidae Animalia Annelida Polychaeta Sabellida Serpulidae 3 982 Terebellidae Animalia Annelida Polychaeta Terebellida Terebellidae 5 31 129220 Notomastus Animalia Annelida Polychaeta Capitellidae Notomastus 1 130277 Chirimia biceps Animalia Annelida Polychaeta Maldanidae Chirimia biceps 1 175027 Golfingia (Golfingia) margaritacea Animalia Annelida Sipuncula Golfingiidae Golfingia Golfingia margaritacea 1 136025 Phascolion Animalia Annelida Sipuncula Golfingiidae Phascolion 1 101958 Haploops tubicola Animalia Arthropoda Malacostraca Amphipoda Ampeliscidae Haploops tubicola 1 101447 Haploops Animalia Arthropoda Malacostraca Amphipoda Ampeliscidae Haploops 1 102152 Paramphithoe hystrix Animalia Arthropoda Malacostraca Amphipoda Paramphithoidae Paramphithoe hystrix 1 102945 Pardalisca abyssi Animalia Arthropoda Malacostraca Amphipoda Pardaliscidae Pardalisca abyssi 1 1135 Amphipoda Animalia Arthropoda Malacostraca Amphipoda 1 107581 Acanthephyra pelagica Animalia Arthropoda Malacostraca Decapoda Acanthephyridae Acanthephyra pelagica 1 107021 Hymenodora Animalia Arthropoda Malacostraca Decapoda Acanthephyridae Hymenodora 1 107563 Pontophilus norvegicus Animalia Arthropoda Malacostraca Decapoda Crangonidae Pontophilus norvegicus 5 107568 Sclerocrangon boreas Animalia Arthropoda Malacostraca Decapoda Crangonidae Sclerocrangon boreas 1 107316 Dorhynchus thomsoni Animalia Arthropoda Malacostraca Decapoda Inachidae Dorhynchus thomsoni 1 107166 Munida tenuimana Animalia Arthropoda Malacostraca Decapoda Munididae Munida tenuimana 1 106835 Munida Animalia Arthropoda Malacostraca Decapoda Munididae Munida 1 158351 Atlantopandalus propinqvus Animalia Arthropoda Malacostraca Decapoda Pandalidae Atlantopandalus propinqvus 3 107649 Pandalus borealis Animalia Arthropoda Malacostraca Decapoda Pandalidae Pandalus borealis 2 32 158351 Atlantopandalus propinqvus Animalia Arthropoda Malacostraca Decapoda Pandalidae Pandalus propinqvus 3 107678 Pasiphaea tarda Animalia Arthropoda Malacostraca Decapoda Pasiphaeidae Pasiphaea tarda 1 107521 Lebbeus polaris Animalia Arthropoda Malacostraca Decapoda Thoridae Lebbeus polaris 4 106989 Lebbeus Animalia Arthropoda Malacostraca Decapoda Thoridae Lebbeus 1 118814 Aegiochus arctica Animalia Arthropoda Malacostraca Isopoda Aegidae Aegiochus arctica 2 118831 Aegiochus ventrosa Animalia Arthropoda Malacostraca Isopoda Aegidae Aegiochus ventrosa 2 119930 Gnathophausia zoea Animalia Arthropoda Malacostraca Lophogastrida Gnathophausiidae Gnathophausia zoea 3 134654 Pseudopallene brevicollis Animalia Arthropoda Pycnogonida Pantopoda Callipallenidae Pseudopallene brevicollis 1 134669 Colossendeis proboscidea Animalia Arthropoda Pycnogonida Pantopoda Colossendeidae Colossendeis proboscidea 1 134686 Nymphon elegans Animalia Arthropoda Pycnogonida Pantopoda Nymphonidae Nymphon elegans 1 134690 Nymphon hirtipes Animalia Arthropoda Pycnogonida Pantopoda Nymphonidae Nymphon hirtipes 6 134711 Nymphon stroemi Animalia Arthropoda Pycnogonida Pantopoda Nymphonidae Nymphon stroemi 2 134591 Nymphon Animalia Arthropoda Pycnogonida Pantopoda Nymphonidae Nymphon 3 1566 Nymphonidae Animalia Arthropoda Pycnogonida Pantopoda Nymphonidae 1 106182 Arcoscalpellum michelottianum Animalia Arthropoda Thecostraca Scalpellomorpha Scalpellidae Arcoscalpellum michelottianum 1 1424477 Weltnerium stroemii Animalia Arthropoda Thecostraca Scalpellomorpha Scalpellidae Ornatoscalpellum stroemii 2 235385 Novocrania anomala Animalia Brachiopoda Craniata Craniida Craniidae Novocrania anomala 1 104040 Terebratulina Animalia Brachiopoda Rhynchonellata Terebratulida Cancellothyrididae Terebratulina 2 33 104062 Macandrevia cranium Animalia Brachiopoda Rhynchonellata Terebratulida Zeilleriidae Macandrevia cranium 1 104046 Macandrevia Animalia Brachiopoda Rhynchonellata Terebratulida Zeilleriidae Macandrevia 1 110831 Cystisella Animalia Bryozoa Gymnolaemata Cheilostomatida Bryocryptellidae Cystisella 1 110835 Porella Animalia Bryozoa Gymnolaemata Cheilostomatida Bryocryptellidae Porella 1 111230 Caberea ellisii Animalia Bryozoa Gymnolaemata Cheilostomatida Candidae Caberea ellisii 2 110866 Scrupocellaria Animalia Bryozoa Gymnolaemata Cheilostomatida Candidae Scrupocellaria 1 111268 Cellepora pumicosa Animalia Bryozoa Gymnolaemata Cheilostomatida Celleporidae Cellepora pumicosa 1 110873 Cellepora Animalia Bryozoa Gymnolaemata Cheilostomatida Celleporidae Cellepora 1 110875 Celleporina Animalia Bryozoa Gymnolaemata Cheilostomatida Celleporidae Celleporina 1 110911 Flustra Animalia Bryozoa Gymnolaemata Cheilostomatida Flustridae Flustra 1 111373 Sarsiflustra abyssicola Animalia Bryozoa Gymnolaemata Cheilostomatida Flustridae Sarsiflustra abyssicola 2 465722 Serratiflustra serrulata Animalia Bryozoa Gymnolaemata Cheilostomatida Flustridae Serratiflustra serrulata 1 986944 Terminoflustra barleei Animalia Bryozoa Gymnolaemata Cheilostomatida Flustridae Terminoflustra barleei 8 110765 Myriaporidae Animalia Bryozoa Gymnolaemata Cheilostomatida Myriaporidae 2 110956 Reteporella Animalia Bryozoa Gymnolaemata Cheilostomatida Phidoloporidae Reteporella 8 110836 Rhamphostomella Animalia Bryozoa Gymnolaemata Cheilostomatida Umbonulidae Rhamphostomella 1 110722 Cheilostomatida Animalia Bryozoa Gymnolaemata Cheilostomatida 1 110993 Alcyonidium Animalia Bryozoa Gymnolaemata Ctenostomatida Alcyonidiidae Alcyonidium 1 111032 Crisia Animalia Bryozoa Stenolaemata Cyclostomatida Crisiidae Crisia 1 111723 Hornera lichenoides Animalia Bryozoa Stenolaemata Cyclostomatida Horneridae Hornera lichenoides 5 34 111041 Hornera Animalia Bryozoa Stenolaemata Cyclostomatida Horneridae Hornera 7 470799 Diplosolen intricarium Animalia Bryozoa Stenolaemata Cyclostomatida Plagioeciidae Diplosolen intricarium 2 111052 Idmidronea Animalia Bryozoa Stenolaemata Cyclostomatida Tubuliporidae Idmidronea 4 146142 Bryozoa Animalia Bryozoa 3 103456 Didemnum Animalia Chordata Ascidiacea Aplousobranchia Didemnidae Didemnum 6 103439 Didemnidae Animalia Chordata Ascidiacea Aplousobranchia Didemnidae 1 103624 Eudistoma vitreum Animalia Chordata Ascidiacea Aplousobranchia Polycitoridae Eudistoma vitreum 1 103434 Aplousobranchia Animalia Chordata Ascidiacea Aplousobranchia 1 103483 Ascidia Animalia Chordata Ascidiacea Phlebobranchia Ascidiidae Ascidia 2 103488 Ciona Animalia Chordata Ascidiacea Phlebobranchia Cionidae Ciona 1 103509 Molgula Animalia Chordata Ascidiacea Stolidobranchia Molgulidae Molgula 1 103531 Dendrodoa Animalia Chordata Ascidiacea Stolidobranchia Styelidae Dendrodoa 1 103893 Kukenthalia borealis Animalia Chordata Ascidiacea Stolidobranchia Styelidae Kukenthalia borealis 2 1839 Ascidiacea Animalia Chordata Ascidiacea 1 100954 Hormathia nodosa Animalia Cnidaria Hexacorallia Actiniaria Hormathiidae Hormathia nodosa 1 1360 Actiniaria Animalia Cnidaria Hexacorallia Actiniaria 3 117093 Eudendrium Animalia Cnidaria Hydrozoa Anthoathecata Eudendriidae Eudendrium 1 117246 Stylaster Animalia Cnidaria Hydrozoa Anthoathecata Stylasteridae Stylaster 1 22805 Stylasteridae Animalia Cnidaria Hydrozoa Anthoathecata Stylasteridae 1 744825 Aglaophenopsis bonnevieae Animalia Cnidaria Hydrozoa Leptothecata Aglaopheniidae Aglaophenopsis bonnevieae 1 35 744828 Aglaophenopsis cornuta Animalia Cnidaria Hydrozoa Leptothecata Aglaopheniidae Aglaophenopsis cornuta 1 117293 Cladocarpus formosus Animalia Cnidaria Hydrozoa Leptothecata Aglaopheniidae Cladocarpus formosus 1 117294 Cladocarpus integer Animalia Cnidaria Hydrozoa Leptothecata Aglaopheniidae Cladocarpus integer 2 117000 Cladocarpus Animalia Cnidaria Hydrozoa Leptothecata Aglaopheniidae Cladocarpus 1 117103 Halecium Animalia Cnidaria Hydrozoa Leptothecata Haleciidae Halecium 3 117692 Grammaria abietina Animalia Cnidaria Hydrozoa Leptothecata Lafoeidae Grammaria abietina 1 117809 Nemertesia antennina Animalia Cnidaria Hydrozoa Leptothecata Plumulariidae Nemertesia antennina 2 117195 Nemertesia Animalia Cnidaria Hydrozoa Leptothecata Plumulariidae Nemertesia 1 158196 Thuiaria laxa Animalia Cnidaria Hydrozoa Leptothecata Sertulariidae Thuiaria laxa 1 117237 Thuiaria Animalia Cnidaria Hydrozoa Leptothecata Sertulariidae Thuiaria 1 1614 Sertulariidae Animalia Cnidaria Hydrozoa Leptothecata Sertulariidae 4 125269 Alcyoniidae Animalia Cnidaria Octocorallia Malacalcyonacea Alcyoniidae 2 146941 Drifa glomerata Animalia Cnidaria Octocorallia Malacalcyonacea Capnellidae Drifa glomerata 1 146940 Drifa Animalia Cnidaria Octocorallia Malacalcyonacea Capnellidae Drifa 1 290873 Pseudodrifa groenlandica Animalia Cnidaria Octocorallia Malacalcyonacea Capnellidae Pseudodrifa groenlandica 1 267775 Pseudodrifa Animalia Cnidaria Octocorallia Malacalcyonacea Capnellidae Pseudodrifa 1 125285 Anthomastus Animalia Cnidaria Octocorallia Scleralcyonacea Coralliidae Anthomastus 1 135282 Atolla wyvillei Animalia Cnidaria Scyphozoa Coronatae Atollidae Atolla wyvillei 2 123213 Novodinia Animalia Echinodermata Asteroidea Brisingida Novodiniidae Novodinia 1 36 123796 Icasterias panopla Animalia Echinodermata Asteroidea Forcipulatida Asteriidae Icasterias panopla 2 123896 Leptychaster arcticus Animalia Echinodermata Asteroidea Paxillosida Astropectinidae Leptychaster arcticus 1 123915 Ctenodiscus crispatus Animalia Echinodermata Asteroidea Paxillosida Ctenodiscidae Ctenodiscus crispatus 1 123276 Henricia Animalia Echinodermata Asteroidea Spinulosida Echinasteridae Henricia 11 124002 Tremaster mirabilis Animalia Echinodermata Asteroidea Valvatida Asterinidae Tremaster mirabilis 1 124020 Ceramaster granularis Animalia Echinodermata Asteroidea Valvatida Goniasteridae Ceramaster granularis 2 125170 Poraniomorpha (Poraniomorpha) hispida Animalia Echinodermata Asteroidea Valvatida Poraniidae Poraniomorpha Poraniomorpha hispida 7 124155 Crossaster squamatus Animalia Echinodermata Asteroidea Valvatida Solasteridae Crossaster squamatus 2 123336 Crossaster Animalia Echinodermata Asteroidea Valvatida Solasteridae Crossaster 1 124163 Solaster glacialis Animalia Echinodermata Asteroidea Valvatida Solasteridae Solaster glacialis 1 124167 Solaster syrtensis Animalia Echinodermata Asteroidea Valvatida Solasteridae Solaster syrtensis 2 124126 Myxaster sol Animalia Echinodermata Asteroidea Velatida Myxasteridae Myxaster sol 1 124128 Diplopteraster multipes Animalia Echinodermata Asteroidea Velatida Pterasteridae Diplopteraster multipes 1 124135 Hymenaster pellucidus Animalia Echinodermata Asteroidea Velatida Pterasteridae Hymenaster pellucidus 1 124147 Pteraster militaris Animalia Echinodermata Asteroidea Velatida Pterasteridae Pteraster militaris 1 124151 Pteraster pulvillus Animalia Echinodermata Asteroidea Velatida Pterasteridae Pteraster pulvillus 3 124223 Heliometra glacialis Animalia Echinodermata Crinoidea Comatulida Antedonidae Heliometra glacialis 1 124229 Poliometra prolixa Animalia Echinodermata Crinoidea Comatulida Antedonidae Poliometra prolixa 5 43 New Species Bivalvia 1 2 New Species Holothuroidea 1 3 New Species Holothuroidea 2 1 New Species Ophiuroidea 1 1 New Species Polychaeta 1 2 New Species Porifera 1 8 New Species Porifera 2 3 New Species Porifera 3 2 New Species Porifera 4 1 New Species Porifera 5 1 44 4. Physical and Biological Oceanography Team: Tobias Vonnahme, Mie Winding, Katharina Hammer, Pia Scaramiglia 4.1 Background and objectives The overall aim of the pelagic sampling of this cruise was to characterize the oceanographic setting of the sampling sites which may be key drivers for the benthic ecosystem and carbon sequestration potential. The main objective was to identify different water masses, and to quantify biological biomass and productivity and their drivers. The transect from the coast towards the shelf is typically characterized by meltwater outflow from the fjords leading into the East Greenland current on the shelf, and the Irminger current feeding Atlantic water along the shelf break. In areas with deep troughs, such as along the selected sampling transects, Atlantic water may reach across the shelf affecting coastal processes. Understanding the presence of Atlantic vs coastal water is important since Atlantic water is typically enriched in nutrients, which may lead to higher primary production and higher carbon sequestration potential. Pelagic primary production is a key source of carbon to the seafloor, where it can feed benthic ecosystems and may eventually be buried below the oxygenated layer, where it gets sequestered. Thus, primary production and chlorophyll a (Chl) biomass was measured, and the diversity and potential drivers (nutrients, light, stratification) were sampled. Due to the strong seasonality of pelagic production and biomass the data measured on this cruise will also be used for ground truthing of remote sensing products. 4.2 Sampling strategy and instrument description Samples were taken in Southeast Greenland, where the Irminger current transporting Atlantic water along the shelf slope meets the cold and low salinity coastal water of the East Greenland current flowing along the shelf. Samples were taken along three transects from the coast, across the continental shelf, to the shelf break. All three transects followed troughs, which have the potential for deep water exchange (e.g. Atlantic water inflow across the shelf) and accumulation of sediments in the trough basin. 10, 7 and 6 samples for CTD and water sampling were taken along the three transects (Figure 4.1). A CTD (Conductivity, Temperature, Depth) profile was taken using a Seabird SBE19Plus CTD profiler with additional sensors for fluorescence (proxy for Chlorophyll), oxygen, PAR, and turbidity. CTD profiles were taken at a speed of 30-60 m/min from the surface until 10 m over the bottom. A MARPORT system was used to measure the actual depth during the deployments to ensure that the CTD was at the desired depth. CTD profiles were taken from all stations. During the cruise, data for CTD profiles were uploaded from the CTD using the SEatermV2 software and processed using the SBEDataProcessing software. The data were further used for multibeam calibrations and analyses in R. 45 Water samples at 1, 5, 10, 15, 20, 30, 40, 50, 60, 100, and 60m over the bottom were taken using a Niskin Rosette (Multiwater Sampler MWS12, Hydrobios Apparatebau, Kiel Germany) with 10 L Niskin bottles as described in the operation manual (ed 1/21). The trigger depths were preprogrammed (pressure triggered) using the Hydrobios OceanLab Software. CTD profiles and the Niskin bottle closing depths were recorded during the deployment and exported using the OceanLab Software. The Niskin rosette was also equipped with a MARPORT to ensure that the trigger depths were reached. Water samples were transferred into 5 and 10 L canisters or 50 mL Duran bottles and processed immediately as described below. Water samples were taken from all stations except OT1-4, due to time limitations. Figure 4.1: Map of realised stations for CTD (blue) and Water (red) samples 4.3 Water processing Water samples were processed for measurements of chlorophyll a (Chl, all depths), particulate organic carbon and nitrogen (60 m, bottom), bacteria cell counts (all depths at OT1; 1, 5, 20, 60, bottom, ChlMax at OT2 and OT3), phytoplankton communities (5 m, 20 m, Chl max), DNA (Chl max, Bottom), primary production and photophysiology (1-60 m), and Nutrients (all depths). The chlorophyll max was defined after fluorescence measurements on a PhytoPAM II (Walz). The PhytoPAM II measures various photophysiological parameters and estimates primary production as electron transport rates based on the variable fluorescence of chlorophyll under dark and light conditions using the PhytoWin3 (Walz) Software. The Phytopam II can also differentiate photophysiological parameters of different algae groups (blue algae, green algae, brown algae, cyanobacteria). The gain of the instrument was set automatically (most samples between 22 and 23) and blanked using a filtered sample (0.45 µm syringe filter). 46 The yield of photosystem II indicates the stress level of the phytoplankton and was measured on dark adapted (at least 15 min) samples. Chlorophyll was then measured for the 4 algae groups, but the values are biased to specific reference cultures and additional Chl measurements of extracted samples are still necessary (see below). Primary production was estimated as electron transport rates under various light intensities. Samples from 5 m, 20 m, and the Chl Max were measured in triplicates, while all other samples with sufficient Chl concentrations were measured once. All measurements were done in the cold room at 7°C. For chlorophyll measurements, 500 or 300 ml water was filtered onto 25 mm GF/F filter using a vacuum pump (max 0.3mbar underpressure) in the dark. The filters were folded and transferred into 11 mL plastic vials before adding 5 mL 98% ethanol and storage at -20°C until measurements on a fluorometer at the GINR in Nuuk. For POC/PON samples, 5L water was filtered onto 47 mm pre-combusted (450°C) and preweighed GF/F filters before storage in petri dishes at -20°C. Nutrient samples were prefiltered into 11 mL plastic vials using a 0.45 µm syringe filter and stored at -20°C. For each depth two samples were prepared, one for external measurements of nitrate, nitrite, silicate, phosphate, and ammonium on a nutrient analyser. The other sample will be used for nitrate and nitrite measurements using colorimetric methods at the GINR. The samples measured at the GINR will allow early data access for a master thesis, while the samples measures on the nutrient analyser provide a broader spectrum of different nutrients. For bacteria cell counts, 1.8 mL water was transferred into cryovials before adding 40 µL 25% Glutaraldehyde and storage at -80C. The samples will be analysed using a flow cytometer. Water samples for phytoplankton communities were taken in 100 mL grown borosilicate glass bottles and fixed with 1-2% neutral Lugol solution. The samples will be counted under a light microscope and identified at the GINR. DNA samples were taken by filtering 2-5 L water onto 0.22 µm Sterivex filters using a peristaltic pump. The filter will later be used for metabarcoding analyses of 16S rRNA (bacteria and archaea) and 18S rRNA (protists) marker genes. 4.4 Preliminary findings While most samples will be analysed after the cruise, data from the CTD profiler are already available and allow a first insight into the oceanographic setting of the sampling sites. While the transects show some differences in the extent of Atlantic and coastal water masses, the overall structure is comparable and the transect of OT1 is shown below (Figure 4.2). Atlantic water masses of the Irminger current are characterized by high temperature and salinity, and low oxygen concentrations, while coastal water masses of the East Greenland current are characterized by low temperature and salinity, and high oxygen concentrations. 47 In all transects the AW was abundant at the shelf break, and coastal water close to the coast. However, AW intrusions into the trough were observed at all three transects. While the transects followed the troughs, there is no clear gradient of AW form the shelf break towards the coast, instead patches of AW appear in single stations on the shelf. This indicates that the AW can enter the trough along a different route, but it also shows that AW can cross the shelf and potentially reach the fjords introducing heat and nutrients onto the shelf, which will affect primary production and plankton communities. Fig 4.2: Cross transect of A) Oxygen (O2), B) Salinity (S), and C) Temperature (T°C) along transect OT1 (D). The added fluorescence sensor on the CTD can gives a first impression of Chlorophyll concentrations across the transects. At all transects the highest fluorescence is found along the shelf slope, which may be due to the typically higher nitrate concentrations in Atlantic water, but which may also be associated to shelf break upwelling, or advection of old blooms with the Irminger current. To some degree, a second fluorescence maxima can be found close to the coast, which may be fuelled by coastal processes such as coastal or subglacial upwelling. Some of the fluorescence maxima at the shelf slope are below 30 m, which is below the depth that satellites can detect, indicating some upcoming challenges in using remote sensing data to estimate the annual productivity of the study area. 48 Fig 4.2. Fluorescence profiles (proxy for Chl) along the three transects from the shelf slope (0km) to the coast. A) OT1, B) OT2, C) OT3. 49 5. Sediment biogeochemistry Team: David Barnes ([email protected]), Tobias Vonnahme ([email protected]), Duncan Sinclair ([email protected]), Narissa Bax ([email protected]), Ryan Mathews ([email protected]), Pia Scaramiglia ([email protected]) 5.1 Background and objectives Short core samples (1m) were collected to investigate sediment geochemistry, biogeochemistry and ecology in the SE Greenland continental shelf. These cores were preserved to allow laboratory determination of variability in seafloor organic material, organic carbon, inorganic carbon, nutrients, and biota along three different transects (Table 5.1). The cores were sliced at specified intervals to facilitate comparison with wider polar data (e.g. those taken by Changing Arctic Oceans cruises in the Barents Sea and ICEBERGS along the West Antarctic Peninsula (Sands et al., 2018; Zwerschke et al., 2022). One core was taken for respiration measurements on board. 5.2 Sampling strategy and instrument description The sampling strategy and sites for the Deep Trace scientific cruise of RV Tarajoq were planned along three transects across the SE Greenland continental shelf (Figure 1). These transects spanned from coast to the continental slope just beyond the shelf break and were designed to incorporate some areas likely to be formed of soft sediment types. Approximately eight days of sampling time was organised such that attempts at sediment capture would predominantly occur during the night and alternate with other apparatus deployments, such as beam trawl and video-sledge. All sediment cores were collected using a multi-corer at the approximate location of predetermined sites (Figure 5.1). In each case a decision whether, and exactly where, to deploy was based on prior consideration of both multibeam and sub-bottom profiling data (and sometimes time and weather constraints). The instrument used to capture sediment was a KC Denmark Multicorer 70,000 (model) fitted with six Perspex core sleeves (800mm length, 105mm diameter). This is an ideal instrument to sample the upper 50 cm of sediment, overlying bottom water and usually intact sedimentwater interface. Before deployment, core sleeves were loaded into the instrument and the spring closing mechanism was locked open using pins. The instrument was lifted slightly on the deck to remove the two safety bars (which prevent it triggering when away from the seabed). It was then manoeuvred over the side of the vessel and lowered to the seabed using a side gantry winch. As the six round feet of the multicorer frame land on the seabed, the middle section containing the six core tubes penetrates into the sediment, pressed down by the onboard weights. The corer was left to settle on the seabed for 1-2 minutes and then pulled up slowly, triggering the release pins and allowing the trap doors to snap shut, sealing the sleeves and retaining any captured sediment within the tubes. 50 The protocol for using the multicorer was adapted throughout the cruise. Initially 120 kg of weights were fitted, which was increased to 240 kg and eventually 360 kg. Initial descent speed was 60m per minute, decreasing to 20m per minute on approach to the seabed (approximately 50m above), and then slowing to 5m per minute in the final stages. However, due to concerns regarding the instrument being lifted off the seabed through pitch, roll and drift of the ship the 5 m descent portion was removed and a final descent of 20 m per minute continued until the deployed wire length was at least 20 m greater than the depth of seabed. The bottom time duration was increased in later deployments from 1-2 minutes to 4-5 minutes. Initial lifting speed was 20 m per minute later increasing to 30 m per minute. The winch auto-spooler required truing on a couple of occasions and occasionally the winch wire slipped in spooling and the winch had to be stopped and reversed to achieve smooth spooling. The path of the multicorer to and from the hydrography hanger to outboard requires tight navigation around the deck railing, not all of which can temporarily fold away (Figure 5.2). 51 Figure 5.1: Realised multicore stations 52 Figure 5.2 Deployment of multicorer through the side gantry on RV Tarajoq and successful recovery of multicorer 59 Figure 5.6.2: Set-up for A)micro profiling and B)porewater collection 5.7 Infauna Team: David Barnes, Ryan Mathews, Laure de Montety, Alenya Merz Cores available for infauna estimation were gently washed over a 1 mm sieve to remove all sand and mud. Pebbles were removed by hand. Small delicate infauna such as worms were picked out of the sample and stored in ethanol. The remaining sample was stored in a ziplock bag and frozen at -20°C. This was not always possible, owing to time constraints. In this case the whole sample was frozen at -20°C for later sorting and identification. Preserving all samples in ethanol was unfortunately not possible, owing to a lack of ethanol on board. B) A) 60 6. References Krawczyk, D. W., Zinglersen, K. B., Al-Hamdani, Z., Yesson, C., Blicher, M. E., Arboe, N. H., Jensen, J. B., Wagnholt, J. N., Hansen, F., & Rödel, L.-G. (2021). First High-Resolution Benthic Habitat Map From the Greenland Shelf (Disko Bay Pilot Study). Journal of Geophysical Research: Oceans, 126(11), e2020JC017087. https://doi.org/10.1029/2020JC017087 Martynov, A. V., & Litvinova, N. M. (2008). Deep-water Ophiuroidea of the northern Atlantic with descriptions of three new species and taxonomic remarks on certain genera and species. Marine Biology Research, 4(1–2), 76–111. https://doi.org/10.1080/17451000701840066 Sands, C. J., Annett, A., Apeland, B., Barnes, D. K. A., Bascur, M., Bruning, P., Costa, M., Dadd, G., De Lecea, A., Ensor, N., Featherstone, A., Flint, G., Goodger, D., Guzzi, A., Howard, F., Hunter, D., Jenkins, S., Kender, S., Lincoln, B., … Zwerschke, N. (2018). Cruise Report RRS James Clark Ross JR18003 [Cruise Report]. British Antarctic Survey. Zwerschke, N., Sands, C. J., Roman-Gonzalez, A., Barnes, D. K. A., Guzzi, A., Jenkins, S., MuñozRamírez, C., & Scourse, J. (2022). Quantification of blue carbon pathways contributing to negative feedback on climate change following glacier retreat in West Antarctic fjords. Global Change Biology, 28(1), 8–20. https://doi.org/10.1111/gcb.15898 61