Ecosystem mapping in the Central Arctic Ocean (CAO) during the SAS-Oden expedition

As a result of global warming, the marine ecosystem around the North Pole, the Central Arctic Ocean (CAO), is in fast transition from a permanently to a seasonally ice-covered ocean. The sea-ice loss is expected to enable summer access to the CAO for non-icebreaking ships, including fishery vessels, in the near future1. However, the lack of knowledge on the CAO ecosystem impedes any assessment of the sustainability of potential future fisheries in the CAO. Taking a precautionary approach, the EU and nine countries in October 2018 signed the Agreement to Prevent Unregulated High Seas Fisheries in the Central Arctic Ocean. This agreement entered into force in June 2021 and a.o. requires the establishment of a joint scientific program to improve the understanding of the CAO ecosystem, including mapping and monitoring. To reduce the existing lack of knowledge, 12 scientists from the EFICA Consortium participated, together with 26 other on-board scientists, in sampling and data collection of ecosystem data during the Swedish SAS-Oden expedition in summer 2021. This report describes the field work performed by the EFICA scientists using water-column acoustics, deep-sea optical observations, and fish, zooplankton, sediment otolith and eDNA sampling for targeting fish, zooplankton and mammals. Further ecosystem data (physical, chemical and biological) were collected by the EFICA scientists in collaboration with other scientists on-board. Together with this report, a metadata database containing lists of all collected samples and data that are relevant for future fish-stock modelling and assessment studies was delivered to the European Commission

In Search of a Field-Based Relationship Between Benthic Macrofauna and Biogeochemistry in a Modern Brackish Coastal Sea

During several cruises in the southern Baltic Sea conducted in different seasons from 2014 to 2016, sediment cores were collected for the investigation of pore-water biogeochemistry and associated nutrient fluxes across the sediment-water interface. Six stations were positioned along a salinity gradient (ranging from 22 to 8) and covered various sedimentary habitats ranging from mud to sand. Integrated fluxes of nutrients in the supernatant water and sediment oxygen consumption were additionally derived from incubations of intact sediment cores. Subsequently, sediment from the pore-water and incubation cores was sieved for taxonomic identification and estimation of benthic macrofauna density. This combined dataset was used to determine the dominant factors influencing the vertical distribution of geochemical parameters in the pore-waters of the studied habitats and to find similarities and patterns explaining significant variations of solute fluxes across the sediment-water interface. A statistical relationship between the thickness of sulfide-free surface sediments, solute fluxes of sulfide, ammonium, and phosphate as well as oxygen consumption and taxonomic and functional characteristics of macrobenthic communities were tested. Our data and modeling results indicate that bioturbation and bioirrigation alter near-surface pore-water nutrient concentrations toward bottom water values. Besides sediment properties and microbial activity, the biogeochemical fluxes can further be explained by the functional structure of benthic macrofauna. Community bioturbation potential, species richness, and biomass of biodiffusers were the best proxies among the tested set of biotic and abiotic parameters and could explain 63% of multivariate total benthic flux variations. The effects of macrobenthos on ecosystem functioning differ between sediment types, specific locations and seasons. Both, species distribution and nutrient fluxes are temporally dynamic. Those natural patterns, as well as potential anthropogenic and natural disturbances (e.g., fishery, storm events), may cause impacts on field data in a way beyond our present capability of quantitative prediction, and require more detailed seasonal studies. The data presented here adds to our understanding of the complexity of natural ecosystem functioning under anthropogenic pressure

Solute Reservoirs Reflect Variability of Early Diagenetic Processes in Temperate Brackish Surface Sediments

Coastal marine sediments are a hotspot of organic matter degradation. Mineralization products of early diagenetic processes accumulate in the pore waters of the sediment, are subject of biological uptake and secondary biogeochemical processes and are released back into the water column via advective and diffusive fluxes across the sediment-water interface. Seven representative sites in the shallow coastal area of the southern Baltic Sea (15–45 m water depth), ranging from permeable sands to fine grained muds, were investigated on a seasonal basis for their key mineralization processes as well as their solid phase and pore water composition to identify the drivers for the variability of early diagenetic processes in the different sediment types. The sandy sediments showed about one order of magnitude lower organic carbon contents compared to the muds, while oxygen uptake rates were similar in both sediment types. Significantly higher oxygen uptake rates were determined in two near-shore muddy sites than in a deeper coastal muddy basin, which is due to higher nutrient loads and the corresponding addition of fresh algal organic matter in the near-shore sites. Pore water concentration profiles in the studied sediments were usually characterized by a typical biogeochemical zonation with oxic, suboxic, and sulfidic zones. An up to 15 cm thick suboxic zone was sustained by downward transport of oxidized material in which dissolved iron and phosphate indicate an intensive reduction of reactive Fe with the release of adsorbed phosphorus. While the geochemical zonation was stable over time in the muds of the studied deeper basin, high variability was observed in the muds of a near-coastal bay probably mainly controlled by sediment mixing activities. The sediments can be characterized by essentially two factors based on their near-surface benthic solute reservoirs: (1) their organic matter mineralization and solute accumulation efficiency and (2) their redox-state. Benthic solute reservoirs in the pore waters of the top decimeter were generally higher in the muddy than in the sandy sediments as the more permeable sands were prone to an intensive exchange between pore water and bottom water. The three studied muddy sites showed great dissimilarities with respect to their predominating redox-sensitive metabolites (dissolved iron, manganese, and sulfide). Surface-near advective transport like irrigation of permeable sands and rearrangement of cohesive muds had a particularly strong influence on early diagenetic processes in the studied sediments and were probably the most important cause for the spatiotemporal variability of their benthic solute reservoirs

Workshop on Assessing the Impact of Fishing on Oceanic Carbon (WKFISHCARBON; outputs from 2023 meeting)

Rapports Scientifiques du CIEM. Volume 6, nº 12The Workshop on Assessing the Impact of Fishing on Oceanic Carbon (WKFISHCARBON) was set up to provide ICES and stakeholders with a summary of knowledge on the role of fishing in the process of carbon budgets, sequestration and footprint in the ocean. The workshop addressed the potential impact of fishing on the biological carbon pump (BCP), the possible impacts of bottom trawling on carbon stores in the seabed, as well as considering emissions from fishing vessels. The overall aim was to generate proposals on how to develop an ICES approach to fishing and its role in the ocean carbon budget, and to develop a roadmap for a way forward. The main findings were that knowledge of the BCP in the open ocean was reasonably well developed, but that key gaps existed. In particular, information on the biomass of mesopelagic fish and other biota, and of some of the key processes e.g. fluxes and fish bioenergetics. Knowledge is much weaker for the BCP in shelf seas, where the bulk of fishing occurs. In particular, while biomass of fish was often well quantified, unlike the open ocean, the understanding of the important processes was lacking, particularly for the fate of faecal pellets and deadfall at the seabed. There is extensive scientific knowledge of the impact of fishing on the seabed, but what is un-clear is what it means for seabed carbon storage. There have been numbers of studies, which give a very divided view on this. There has also been open controversy about this in the literature. Physical disturbance to the seabed from fishing can affect sediment transport and has the potential to facilitate remineralization, but precise impacts will depend on habitat, fishing métier, and other environmental factors. From this, it is clear that more research is needed to resolve the controversy, and to quantify the impacts from different fishing gears and on different substrates or habitats in terms of carbon storage. There has been much more research on minimizing fuel use by fishing vessels, and hence emissions, but this has mainly focused on fuel efficiency, fuel use per unit of landed catch, and less on the total emissions. Baselines for fuel use are available at the global level, but are lacking at the national and vessel level. There is a need for standardization of methodologies and protocols, and for improving the uptake of fuel conservation measures by industry, as well as for improving the uptake of existing and potential fuel conservation and efficiency measures by industry. Finally, a roadmap was proposed to develop research and synthesis, on the understandings of the processes involved, the metrics and how to translate this into possible advice for policy-makers. To that end, a further workshop was proposed in 2024.info:eu-repo/semantics/publishedVersio

Safety and efficacy of the ChAdOx1 nCoV-19 vaccine (AZD1222) against SARS-CoV-2: an interim analysis of four randomised controlled trials in Brazil, South Africa, and the UK

Background A safe and efficacious vaccine against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), if deployed with high coverage, could contribute to the control of the COVID-19 pandemic. We evaluated the safety and efficacy of the ChAdOx1 nCoV-19 vaccine in a pooled interim analysis of four trials. Methods This analysis includes data from four ongoing blinded, randomised, controlled trials done across the UK, Brazil, and South Africa. Participants aged 18 years and older were randomly assigned (1:1) to ChAdOx1 nCoV-19 vaccine or control (meningococcal group A, C, W, and Y conjugate vaccine or saline). Participants in the ChAdOx1 nCoV-19 group received two doses containing 5 × 1010 viral particles (standard dose; SD/SD cohort); a subset in the UK trial received a half dose as their first dose (low dose) and a standard dose as their second dose (LD/SD cohort). The primary efficacy analysis included symptomatic COVID-19 in seronegative participants with a nucleic acid amplification test-positive swab more than 14 days after a second dose of vaccine. Participants were analysed according to treatment received, with data cutoff on Nov 4, 2020. Vaccine efficacy was calculated as 1 - relative risk derived from a robust Poisson regression model adjusted for age. Studies are registered at ISRCTN89951424 and ClinicalTrials.gov, NCT04324606, NCT04400838, and NCT04444674. Findings Between April 23 and Nov 4, 2020, 23 848 participants were enrolled and 11 636 participants (7548 in the UK, 4088 in Brazil) were included in the interim primary efficacy analysis. In participants who received two standard doses, vaccine efficacy was 62·1% (95% CI 41·0–75·7; 27 [0·6%] of 4440 in the ChAdOx1 nCoV-19 group vs71 [1·6%] of 4455 in the control group) and in participants who received a low dose followed by a standard dose, efficacy was 90·0% (67·4–97·0; three [0·2%] of 1367 vs 30 [2·2%] of 1374; pinteraction=0·010). Overall vaccine efficacy across both groups was 70·4% (95·8% CI 54·8–80·6; 30 [0·5%] of 5807 vs 101 [1·7%] of 5829). From 21 days after the first dose, there were ten cases hospitalised for COVID-19, all in the control arm; two were classified as severe COVID-19, including one death. There were 74 341 person-months of safety follow-up (median 3·4 months, IQR 1·3–4·8): 175 severe adverse events occurred in 168 participants, 84 events in the ChAdOx1 nCoV-19 group and 91 in the control group. Three events were classified as possibly related to a vaccine: one in the ChAdOx1 nCoV-19 group, one in the control group, and one in a participant who remains masked to group allocation. Interpretation ChAdOx1 nCoV-19 has an acceptable safety profile and has been found to be efficacious against symptomatic COVID-19 in this interim analysis of ongoing clinical trials

Safety and efficacy of the ChAdOx1 nCoV-19 vaccine (AZD1222) against SARS-CoV-2: an interim analysis of four randomised controlled trials in Brazil, South Africa, and the UK.

BACKGROUND: A safe and efficacious vaccine against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), if deployed with high coverage, could contribute to the control of the COVID-19 pandemic. We evaluated the safety and efficacy of the ChAdOx1 nCoV-19 vaccine in a pooled interim analysis of four trials. METHODS: This analysis includes data from four ongoing blinded, randomised, controlled trials done across the UK, Brazil, and South Africa. Participants aged 18 years and older were randomly assigned (1:1) to ChAdOx1 nCoV-19 vaccine or control (meningococcal group A, C, W, and Y conjugate vaccine or saline). Participants in the ChAdOx1 nCoV-19 group received two doses containing 5 × 1010 viral particles (standard dose; SD/SD cohort); a subset in the UK trial received a half dose as their first dose (low dose) and a standard dose as their second dose (LD/SD cohort). The primary efficacy analysis included symptomatic COVID-19 in seronegative participants with a nucleic acid amplification test-positive swab more than 14 days after a second dose of vaccine. Participants were analysed according to treatment received, with data cutoff on Nov 4, 2020. Vaccine efficacy was calculated as 1 - relative risk derived from a robust Poisson regression model adjusted for age. Studies are registered at ISRCTN89951424 and ClinicalTrials.gov, NCT04324606, NCT04400838, and NCT04444674. FINDINGS: Between April 23 and Nov 4, 2020, 23 848 participants were enrolled and 11 636 participants (7548 in the UK, 4088 in Brazil) were included in the interim primary efficacy analysis. In participants who received two standard doses, vaccine efficacy was 62·1% (95% CI 41·0-75·7; 27 [0·6%] of 4440 in the ChAdOx1 nCoV-19 group vs71 [1·6%] of 4455 in the control group) and in participants who received a low dose followed by a standard dose, efficacy was 90·0% (67·4-97·0; three [0·2%] of 1367 vs 30 [2·2%] of 1374; pinteraction=0·010). Overall vaccine efficacy across both groups was 70·4% (95·8% CI 54·8-80·6; 30 [0·5%] of 5807 vs 101 [1·7%] of 5829). From 21 days after the first dose, there were ten cases hospitalised for COVID-19, all in the control arm; two were classified as severe COVID-19, including one death. There were 74 341 person-months of safety follow-up (median 3·4 months, IQR 1·3-4·8): 175 severe adverse events occurred in 168 participants, 84 events in the ChAdOx1 nCoV-19 group and 91 in the control group. Three events were classified as possibly related to a vaccine: one in the ChAdOx1 nCoV-19 group, one in the control group, and one in a participant who remains masked to group allocation. INTERPRETATION: ChAdOx1 nCoV-19 has an acceptable safety profile and has been found to be efficacious against symptomatic COVID-19 in this interim analysis of ongoing clinical trials. FUNDING: UK Research and Innovation, National Institutes for Health Research (NIHR), Coalition for Epidemic Preparedness Innovations, Bill & Melinda Gates Foundation, Lemann Foundation, Rede D'Or, Brava and Telles Foundation, NIHR Oxford Biomedical Research Centre, Thames Valley and South Midland's NIHR Clinical Research Network, and AstraZeneca

Partikeldynamik in den Sedimenten der westlichen Ostsee

High variability of bioturbation on different spatial scales with regard to the distribution and intensity of local and non-local transports with an increase of non-local biotubration towwards the east was estimated. The depth distribution of the macrozoobenthos within the sediment explained these bioturbation patterns, determined key species and gave evidence for the superior role of the fauna on particle transport. Food supply and local transports corrleated negatively and non-local processes depend on the number of gallery-biodiffusors.Die hohe Variabilität der Bioturbation auf verschiedenen räumlichen Skalen bezüglich Verteilung und Intensität der Local- und Non-local-Transporte mit einer Zunahme der Non-local-Bioturbation gen Osten wurde nachgewiesen. Die Tiefenverteilung des Makrozoobenthos im Sediment erklärte diese Bioturbationsmuster, bestimmte Schlüsselarten und bewies die übergeordnete Rolle der Fauna am Partikeltransport. Nahrungsverfügbarkeit und Local-Transporte korrelierten negativ und Non-local-Prozesse hängen von der Anzahl der Gallery-Biodiffusoren ab

The Fate of Mud Nourishment in Response to Short-Term Wind Forcing

<jats:title>Abstract</jats:title><jats:p>In this study, results from a realistic 3D hydrodynamic and sediment transport model, applied to a channel in the Dutch Wadden Sea, are analyzed in order to assess the effect of short-term wind forcing, the impact of fresh water effects, and the variability induced by the spring-neap cycle on the transport of suspended sediment. In the investigated region, a pilot study for sediment nourishment, the so-called Mud Motor, is executed. This project aims for the beneficial re-use of dredged harbor sediments through the disposal of these sediments at a location where natural currents are expected to transport them toward a nearby salt marsh area. The model results presented in this study advance the understanding of the driving forces that determine sediment transport in shallow, near-coastal zones, and can help to improve the design of the Mud Motor. In the investigated channel, which is oriented parallel to the coastline, tidal asymmetries generally drive a transport of sediment in flood direction. It was found that already moderate winds along the channel axis reverse (wind in ebb direction), or greatly enhance this transport, up to an export of sediment over the adjacent water shed (wind in flood direction). The most beneficial wind conditions (moderate westerly winds) can cause an accumulation of more than 90% of the initial 200 tons sediment pool on the intertidal area; during less favorable conditions (northeasterly winds), less than a third of the dumped sediment is transported onto the mudflat. On-shore winds induce a transport toward the coast. Surprisingly, sediment pathways are only sensitive to the exact disposal location in the channel during wind conditions that counteract the tidally driven transport, and freshwater effects play no significant role for the dispersal of sediment.</jats:p&gt

Demersal fishery Impacts on Sedimentary Organic Matter (DISOM): A global harmonized database of studies assessing the impacts of demersal fisheries on sediment biogeochemistry

Marine sediments are one of the largest carbon reservoirs on the planet and play a key role in the global cycling of organic matter. Bottom fisheries constitute the most widespread anthropogenic physical disturbance to seabed habitats, andthis has prompted NGOs and governments to act on regulating mobile bottom contacting fishing gear. However, the scientific evidence of the effects of bottom trawling on sediment biogeochemistry are highly diverse and present contrasting results. Here we present a global harmonized dataset of 71 independent studies that assess the effects of demersal fisheries on sedimentological (i.e. grain size, porosity) and biogeochemical (i.e. organic carbon, phytopigments, nutrient fluxes) properties: Demersal fishery Impacts on Sedimentary Organic Matter (DISOM) database (Paradis, 2023; https://doi.org/10.3929/ethz-b-000634336). We establish protocols to report metadata that will allow a better comparison of the results in order to improve our understanding of the effects of bottom trawling on the seafloor on a global scale. With this harmonized database, we aim to allow researchers to explore the effects of demersal fisheries in variable environmental settings to deconvolve the effects ofthis disturbance and provide efficient management strategies

Sediment Bulk Density Effects on Benthic Macrofauna Burrowing and Bioturbation Behavior

Benthic macrofauna are a key component of intertidal ecosystems. Their mobility and behavior determine processes like nutrient cycling and the biogeomorphic development of intertidal flats. Many physical drivers of benthic macrofauna behavior, such as sediment grain size, have been well-studied. However, little is known about how sediment bulk density (a measure of sediment compaction and water content) affects this behavior. We investigated the effect of bulk density on the burrowing rate, burrowing depth, bioturbation activity, and oxygen consumption of bivalves (Limecola balthica, Scrobicularia plana, and Cerastoderma edule) and polychaetes (Hediste diversicolor and Arenicola marina) during a 29-day mesocosm experiment. We compared four sediment treatments consisting of two sediments of differing grain size classes (sandy and muddy) with two bulk densities (compact and soft). Overall, bulk density had a strong effect on benthic macrofauna behavior. Benthic macrofauna burrowed faster and bioturbation more intensely in soft sediments with low bulk density, regardless of grain size. In addition, L. balthica burrowed deeper in low bulk density sediment. Finally, we found that larger bivalves (both C. edule and S. plana) burrowed slower in compact sediment than smaller ones. This study shows that benthic macrofauna change their behavior in subtle but important ways under different sediment bulk densities which could affect animal-sediment interactions and tidal flat biogeomorphology. We conclude that lower bulk density conditions lead to more active macrofaunal movement and sediment reworking