Description: Summary The major goal of the RV METEOR cruise M156 to Cape Verdian waters and the Mauritanian upwelling area off West Africa was to contribute to a better quantitative understanding of the effects of mesoscale eddies on CO2 source/sink mechanisms and the biological carbon pump in eastern boundary upwelling areas as well as their effects to the oligotrophic periphery including the deep-sea floor. The cruise M156 (MOSES Eddy Study I) was conducted within the framework of the BMBF funded REEBUS project (Role of Eddies in the Carbon Pump of Eastern Boundary Upwelling Systems) by a consortium of physical, biological (benthic microbiology, bacterial plankton, protists) and biogeochemical oceanographers. Specific aims were i. the quantification of solute and particle fluxes within and at the periphery of eddies; ii. to determine the turnover of carbon species, air-sea gas exchange of CO2, iii. the determination of the protistan and bacterial plankton community structures in the surface layers of an eddy, and iv. to quantify the magnitude and variability of material fluxes to the seabed and turnover in the sediment underneath the eddy passage. To achieve these aims, the cruise had two major observing strategies: i. an intense benthic/pelagic program along the zonal eddy passage at 18°N. Along this corridor ranging from 24°20’ to 16°30’W, five benthic/pelagic stations (E1 to E5) in different water depths and distances from the Mauritanian coast were performed. The motivation for this survey has been to resolve zonal gradients in pelagic element cycling as well as of organic matter degradation and burial in the seabed, which in turn could potentially be linked with changes in eddy induced primary- and export production. ii. the detailed investigation of an individual eddy to investigate physical, biogeochemical and biological processes on meso- to submeso-scales (100km to 10m). Satellite data analysis was performed before and during the cruise to identify a suitable eddy from a combination of sea-level anomaly, ocean color as Chl-a proxy, and sea-surface temperature supplemented with shipboard current velocity measurements. A total of 171 stations were sampled. The water column program consists of 59 CTD casts, 29 MSS and 20 Marine Snow Catcher deployments. For biogeochemical measurements at the sea surface two deployments of a Lagrangian Surface Drifter and one Waveglider deployment were conducted. At the seafloor, we conducted 10 BIGO deployments. Ten seafloor imaging surveys were performed using the towed camera system OFOS, supplemented with 7 Multibeam and 1 Sidescan surveys. In deviation from the cruise proposal, the planned long-term deployment of a Lander, which was planned to record a time series of oxygen fluxes during the passage of an eddy, was not deployed due to a major delay in its design and manufacturing. The planned AUV (Girona 500) deployments at the shallow E5 station close to the Mauritanian coast station did also not take place. Despite moderate weather conditions, all deployments were successful, hence all the data and sample material aimed for has been achieved. It is to expect that as planned all scientific questions can be addressed. Especially in the synthesis of all REEBUS cruises and the consideration of data from earlier cruises (MSM17/4, M107) into this region a high scientific potential can be expected.

Description: In this decade, the amount of (industrial) Internet of Things devices will increase tremendously. Today, there exist no common standards for interconnection, observation, or the monitoring of these devices. In context of the German "Industrie 4.0"strategy the Reference Architectural Model Industry 4.0 (RAMI 4.0) was introduced to connect different aspects of this rapid development. The idea is to let different stakeholders of these products speak and understand the same terminology. In this paper, we present an approach using Digital Twins to prototype different layers along the axis of the RAMI 4.0, by the example of an autonomous ocean observation system developed in the project ARCHES.

Description: Die uns vertraute Grundlage des Lebens ist die Fotosynthese, die Erzeugung organischer Kohlenstoffverbindungen mithilfe des Sonnenlichts durch Pflanzen, Algen und Cyanobakterien (Primärproduktion). Diese Organismen werden als „autotroph" ("sich selbst ernährend") bezeichnet und dienen uns Menschen und anderen heterotroph ("sich von anderen ernährend") lebenden Tieren als Nahrung. In den lichtlosen Tiefen der Ozeane wurden allerdings Ökosysteme entdeckt, die gänzlich anders funktionieren.

Description: Bottom contact trawling from commercial fishing activity can have profound impacts on the sea floor, as trawling gear can both resuspend the surface sediments and shift sediment to the sides of the gear, forming furrows and mounds. This disturbance can thus have profound impacts on the benthic biogeochemistry, as these surface sediments generally contain the most labile organic matter, and the porewaters can be elevated in dissolved redox-sensitive metals (Fe and Mn). Disturbance can thus mix these Fe- and Mn- rich porewaters with oxygenated bottom waters, which can reoxidize and form particles, potentially making their distribution more heterogeneous and acting as a substrate for sorption processes. As these particulate iron oxy(hydr)oxides and manganese oxides can be reduced by the sulfide produced by microbial sulfate reduction, the distribution of these phases has profound implications for the habitability of surface sediments by modifying sulfide concentrations and related toxicity for higher life. Here, we report on a research endeavor in Fehmarn Belt, an extensively fished region in the Southern Baltic Sea, Germany. Inside of this area, we collected sediment cores from a variety of sites ranging from undisturbed (due to a nearby shipwreck and boulders) to heavily trawled. From these cores we analyzed a suite of porewater parameters (including: dissolved sulfide, Fe, Mn, SO4, nutrients, and 13C-DIC), solid phase parameters (including: Hg, TIC, CNS, reactive Fe, and reactive Mn), as well as rates of sulfate reduction (SRR). Due to the addition of an ultra-short baseline acoustic positioning system (USBL) on our multicorer (MUC), we are able to relate these parameters not just to coarse estimates of areal trawling density, but also obtain a fine (about 1 m) estimate of the MUC location in relation to specific trawl marks. Thus, we are well equipped to broaden our understanding of the impact of bottom contact trawling on benthic biogeochemical element cycling.

Description: The AL561 cruise was conducted in the framework of the project APOC (“Anthropogenic impacts on Particulate Organic Carbon cycling in the North Sea”). This collaborative project between GEOMAR, AWI, HEREON, UHH, and BUND is to understand how particulate organic carbon (POC) cycling contributes to carbon sequestration in the North Sea and how this ecosystem service is compromised and interlinked with global change and a range of human pressures include fisheries (pelagic fisheries, bottom trawling), resource extraction (sand mining), sediment management (dredging and disposal of dredged sediments) and eutrophication. The main aim of the sampling activity during AL561 cruise was to recover undisturbed sediment from high accumulation sites in the Skagerrak/Kattegat and to subsample sediment/porewater at high resolution in order to investigate sedimentation transport processes, origin of sediment/POC and mineralization processes over the last 100- 200 years. Moreover, the actual processes of sedimentation and POC degradation in the water column and benthic layer will be addressed by sampling with CTD and Lander devices. In total 9 hydroacoustic surveys (59 profiles), 4 Gravity Corer, 7 Multicorer, 3 Lander and 4 CTD stations were successfully conducted during the AL561 cruise.

Description: Carbon capture and storage (CCS) is a key technology to reduce carbon dioxide (CO2) emissions from industrial processes in a feasible, substantial, and timely manner. For geological CO2 storage to be safe, reliable, and accepted by society, robust strategies for CO2 leakage detection, quantification and management are crucial. The STEMM-CCS (Strategies for Environmental Monitoring of Marine Carbon Capture and Storage) project aimed to provide techniques and understanding to enable and inform cost-effective monitoring of CCS sites in the marine environment. A controlled CO2 release experiment was carried out in the central North Sea, designed to mimic an unintended emission of CO2 from a subsurface CO2 storage site to the seafloor. A total of 675 kg of CO2 were released into the shallow sediments (~3 m below seafloor), at flow rates between 6 and 143 kg/d. A combination of novel techniques, adapted versions of existing techniques, and well-proven standard techniques were used to detect, characterise and quantify gaseous and dissolved CO2 in the sediments and the overlying seawater. This paper provides an overview of this ambitious field experiment. We describe the preparatory work prior to the release experiment, the experimental layout and procedures, the methods tested, and summarise the main results and the lessons learnt.