ALBERT

Description: Innovation and improvement report on the extension of capabilities to measure emerging EOVs including metagenomics across different observational platforms with links to MicroB3 best practice.

Description: Arctic Ocean surface sea-ice conditions are linked with the deep sea benthic oxygen fluxes via a cascade of interdependencies across ecosystem components such as primary production, food supply, activity of the benthic community, and their functions. Additionally, each ecosystem component is influenced by abiotic factors such as light availability, temperature, water depth, and grain size structure. In this study, we investigated the coupling between surface sea-ice conditions and deep-sea benthic remineralization processes through a cascade of interdependencies in the Fram Strait. We measured sea-ice concentrations, a variety of different sediment characteristics, benthic community parameters, and oxygen fluxes at 12 stations of the LTER HAUSGARTEN observatory, Fram Strait, at water depths of 275–2500 m. Our investigations reveal that the Fram Strait is bisected into two long-lasting and stable regions: (i) a permanently and highly sea-ice-covered area and (ii) a seasonally and low sea-icecovered area. Within the Fram Strait ecosystem, sea-ice concentration and water depth are two independent abiotic factors, controlling the deep-sea benthos. Sea-ice concentration correlated with the available food and water depth with the oxygen flux. In addition, both abiotic factors sea-ice concentration and water depth correlate with the macrofauna biomass. However, at water depths 〉 1500m the influence of the surface sea-ice cover is minimal with water depth becoming more dominant. Benthic remineralization across the Fram Strait on average is � 1 mmol Cm

Description: The need to cover established and emerging Essential Ocean Variables (EOVs) as defined by the Global Ocean Observing System (GOOS) calls for the development and refinement of the available sensors and samplers, specifically for biogeochemical and biology/ecosystem observations. For several of these EOVs as well as for microplastics as a relatively novel variable of particular societal concern, technological progress has been made as part of AtlantOS. This involves the samplers and sensors and the platforms to use them from as such as well as the required methodologies for obtaining relevant and well-validated results and disseminate data according to the FAIR principles. For biological observations, a main focus was on automated sampling of particles and water samples. While active, pump-based samplers for particles in the water column have been available for many years, it turned out that they were not yet fully mature for operational sampling of zooplankton, microorganisms (e.g., bacteria, archaea, phytoplankton and other eukaryotic unicellular organisms), and microplastics. AtlantOS partners joined forces with manufacturers to overcome limitations with respect to quantitative filtering without leakage, avoidance of plastic contamination and the option for preservation with appropriate agents. Technical solutions were identified and partly tested but could not in all cases be fully implemented in the time frame of the project. Technologies for automated water sampling proved to be more mature and samplers could already be successfully included in observation programs. For both water and particle samples only very few manufacturers offer off-the-shelf solutions which slows down innovation and adaption to user’s needs and may impede successful implementation of appropriate instruments on a larger scale. Particle traps are well-established and operational passive samplers of sinking particles that are widely used for phytoplankton and particulate matter observations based on microscopic sorting and chemical analyses. Using legacy samples collected in the Arctic it could be demonstrated that the same samples can also be used for omics-based observations allowing to address the emerging EOV ‘Microbe biomass and diversity’ and also contributing to the ‘Phytoplankton biomass and diversity’ EOV. Applied to legacy samples also from other sites, this holds the potential to assess past microbial communities of the Atlantic that could serve as a baseline for comparisons to recent communities that are subject to global change. Significant progress was achieved in building capacities for the implementation of omics-based observations of marine organisms into recent and future observation programs. The feasibility of samplers and different preservation agents was tested and a comparison of different methods for omics-based investigations of microbial communities was conducted. The Global Omics Observatory Network (GLOMICON) was established to better connect the institutes and initiatives that are active in the field. As part of GLOMICON, solutions were implemented that allow for a registration of omics observatories and for the sharing of protocols and bioinformatics code. Irrespective of these achievements, major steps still need to be taken to consolidate and standardize approaches in this rapidly evolving field and to establish operational and well-integrated omics-observations as part of an Atlantic Ocean Observation System. For biogeochemical observations, the focus was placed on sensors for oxygen and marine CO2 system parameters (pCO2, total alkalinity) and their readiness for integration into classical as well as emerging biogeochemical observation platforms. For oxygen, the situation is very favourable as the oxygen optode technology and the best practices routines developed around it can be considered fully operational. There are no obstacles for the D3.17 „OceanSITES Innovation Report“ 5 integration of oxygen optodes into the full range of autonomous ocean observation platforms (mooring, drifter, glider, wave gliders, floats, voluntary observing ship etc.). For marine CO2 system parameters, work carried out in AtlantOS focussed the CO2 partial pressure (pCO2) and total alkalinity (TA). With respect to pCO2 it can be stated, that the membraneequilibration sensors with NDIR detection have clearly matured to a level that they can be used routinely on a range of platforms (mooring, wave glider, voluntary observing ship) with an accuracy of ~1% under well-constrained operation conditions and with rigorous data processing routines. Major limitations still exist, however, for this sensor technology on moving platforms (long sensor response time) and platforms with stringent payload and energy limitations (float, glider etc.). In contrast, the pCO2 (as well as pH) optode technology, in which significant hopes lie, has not been forthcoming and existing products still do not meet the quality requirements for open ocean applications. For TA, our intensive testing both in the laboratory and in the field has led to significant improvement of the commercially available system, which now can be considered operational. It allows high-quality autonomous bench-top measurements (e.g., on voluntary observing ships). Ideas for a submersible version of the system are in early stages and would need significant design and testing efforts. With respect to the possibilities of oxygen and carbon measurements from novel autonomous observation platforms, our work in AltantOS has shown very promising applications on profiling Argo floats, submersible winch systems with upper ocean profilers as well as wave gliders. On all these platforms, we were able to successfully implement oxygen and carbon measurements for high-quality observations.

Description: In this paper we provide an overview of new knowledge on oxygen depletion (hypoxia) and related phenomena in aquatic systems resulting from the EU-FP7 project HYPOX (“In situ monitoring of oxygen depletion in hypoxic ecosystems of coastal and open seas, and landlocked water bodies”, www.hypox.net). In view of the anticipated oxygen loss in aquatic systems due to eutrophication and climate change, HYPOX was set up to improve capacities to monitor hypoxia as well as to understand its causes and consequences. Temporal dynamics and spatial patterns of hypoxia were analyzed in field studies in various aquatic environments, including the Baltic Sea, the Black Sea, Scottish and Scandinavian fjords, Ionian Sea lagoons and embayments, and Swiss lakes. Examples of episodic and rapid (hours) occurrences of hypoxia, as well as seasonal changes in bottom-water oxygenation in stratified systems, are discussed. Geologically driven hypoxia caused by gas seepage is demonstrated. Using novel technologies, temporal and spatial patterns of watercolumn oxygenation, from basin-scale seasonal patterns to meter-scale sub-micromolar oxygen distributions, were resolved. Existing multidecadal monitoring data were used to demonstrate the imprint of climate change and eutrophication on long-term oxygen distributions. Organic and inorganic proxies were used to extend investigations on past oxygen conditions to centennial and even longer timescales that cannot be resolved by monitoring. The effects of hypoxia on faunal communities and biogeochemical processes were also addressed in the project. An investigation of benthic fauna is presented as an example of hypoxia-devastated benthic communities that slowly recover upon a reduction in eutrophication in a system where naturally occurring hypoxia overlaps with anthropogenic hypoxia. Biogeochemical investigations reveal that oxygen intrusions have a strong effect on the microbially mediated redox cycling of elements. Observations and modeling studies of the sediments demonstrate the effect of seasonally changing oxygen conditions on benthic mineralization pathways and fluxes. Data quality and access are crucial in hypoxia research. Technical issues are therefore also addressed, including the availability of suitable sensor technology to resolve the gradual changes in bottom-water oxygen in marine systems that can be expected as a result of climate change. Using cabled observatories as examples, we show how the benefit of continuous oxygen monitoring can be maximized by adopting proper quality control. Finally, we discuss strategies for state-of-the-art data archiving and dissemination in compliance with global standards, and how ocean observations can contribute to global earth observation attempts.