Description: Currently, the ocean carbon sink annually removes about a third of anthropogenic fossil fuel and industrial CO2 emissions, reducing therefore climate change damages and CO2 abatement costs. While the land sinks have entered climate policies, the ocean sink has not—for good reasons since the former stores carbon within the boundaries of a state while the ocean removes carbon from the atmosphere rather in its property as a global common. However, the question remains what is the value of the ocean carbon sink and should it be differently attributed when comparing a coastal state with a large exclusive economic zone (EEZ) compared to landlocked state. Here, we demonstrate different approaches to value the ocean sink, comparing a climate-change damage-based approach with an abatement, market-based approach. We use a high-resolution carbon flux dataset (0.25x0.25 degree) to estimate the ocean carbon sink and source in coastal areas. We assign a net sink of 1.72 GtC proportional to countries with negative carbon fluxes in their EEZ. In our calculation the annual value of the global ocean sink ranges from 61.19 B USD (Std 31.80), equivalent to the 2021 GDP of Slovenia, to 1433 B USD (Std 94.30), equivalent to the 2021 GDP of Spain (World Bank data) for the abatement cost-based assessment approach (assuming full emission trading and low ambition levels in the national determined contribution) and for the climate-change damage-based assessment approach relying on an upper value of the social cost of carbon in our investigation. By breaking down the carbon sink by nations EEZ we estimate which countries are the largest donors of ocean carbon wealth and which countries would be affected the most if a weakening of the ocean sink would need to be compensated by higher emission reduction levels.

Description: Several legal frameworks exist that are important for states conducting ocean observing activities or for which it would be relevant to include the necessity of ocean observing activities and development of ocean information products. Existing hard and soft law frameworks and mechanisms will be analysed to enable adequate adaptation of ocean observing system design at a regional and global level, with a focus on supporting sustained ocean observing and fit-for-purpose ocean information products.

Description: This document presents the results of simulations that include glider profiles assimilation. Simulations are performed with the Marine Copernicus operational biogeochemical model system of the Mediterranean Sea. The deliverable shows that the assimilation of BGC-glider is feasible in the contest of biogeochemical operational systems and that it is built upon the experience of BGC-Argo float data assimilation. Different configuration of the assimilation of glider data have been tested to assess the impact of the physical and biogeochemical glider observations. The deliverable also describes the pre-processing activities of the BGC-glider data to provide qualified observations for the data assimilation and the cross validation of chlorophyll glider data with other sensors (ocean colour and BGC-Argo floats). Results of the simulations show that BGC-glider data assimilation, as already shown for BGC-Argo floats, provides complementary information with respect to Ocean Colour data (which is the only or the most commonly assimilated data in biogeochemical operational systems). Beside their relatively limited horizontal spatial impact, the assimilation of BGC profiles can constrain model simulations for relevant biogeochemical processes in specific periods (summer and transition periods) and layers (surface and subsurface). Results also highlight the importance of the assimilation modelling systems that can efficiently resolve the inconsistencies between chlorophyll observations of different sensors.

Description: The EuroSea project is improving the coordination of the European ocean observing and forecasting system to strengthen its capability of tacking the societal challenges related to ocean health, climate change, mitigation of ocean-related natural hazards, and the sustainable exploitation of marine ecosystem services in the Blue Economy. The scientific excellence of the project is based on its better integration, assimilation, coordination and governance of methods, practices, and instruments to collect fit-for-purpose ocean data and the development of innovative tools and solutions to manage some natural coastal risks and support more efficiently fisheries and aquaculture. The societal impact of the research and innovation activities carried out by the EuroSea consortium is enabled through the responsible research and innovation (RRI) policy concept implemented throughout the project progress development and, in particular, in the demonstrators work packages and in those activities focused on communication, dissemination, exploitation and legacy. This report summarizes how the six articulations of the RRI approach were applied so far in the EuroSea project. It also offers some recommendations to boost the societal benefits provided by inclusivity, equality, ethics, transparency and collaborative co-design and co-creation in the research and innovation process applied to ocean observing. Now, and even more in the future, it is necessary to multiply the opportunities to share knowledge and expertise among all transdisciplinary actors to be engaged in improving the European and global ocean observing and forecasting. Moreover, the emerging critical problems affecting the ocean require an increased public involvement through open access to ocean information, effective communication and dissemination of research findings, more diffuse ocean literacy and collective mobilisation. Only these factors seem to be able to establish the global common responsibility necessary to enhance the ocean sustainability, as advocated by the UN Decade for Ocean Science for Sustainable Development supporting the achievement of the SDG 14 in the UN Agenda 2030.

Description: Eutrophication in marine waters is traditionally assessed by checking if nutrients, algal biomass and oxygen are below/above a given threshold. However, increased biomass, nutrient concentrations and oxygen demand do not lead to undesirable environmental effects if the flow of carbon/energy from primary producers toward high trophic levels is consistently preserved. Consequently, traditional indicators might provide a misleading assessment of the eutrophication risk. To avoid this, we propose to evaluate eutrophication by using a new index based on plankton trophic fluxes instead of biogeochemical concentrations. A preliminary, model-based, assessment suggests that this approach might give a substantially different picture of the eutrophication status of our seas, with potential consequences on marine ecosystem management. Given the difficulties to measure trophic fluxes in the field, the use of numerical simulations is recommended although the uncertainty associated with biogeochemical models inevitably affects the reliability of the index. However, given the effort currently in place to develop refined numerical tools describing the marine environment (Ocean Digital Twins), a reliable, model-based, eutrophication index could be operational in the near future.

Description: The Global Ocean Data Analysis Project (GLODAP) is a synthesis effort that provides high-quality, quality-controlled ocean biogeochemical bottle data with annual-updates, playing a crucial role in advancing our understanding of the Earth's oceans and their complex biogeochemical processes. This deliverable covers the GLODAP annual updates under the EuroSea funding, as well as the automatization of the quality control process of the data. Under the EuroSea funding, GLODAP has received three updates (GLODAPv2.2020, GLODAPv2.2021 and GLODAPv2.2022) with a total number of 245 cruises added, and in addition, a new version release (GLODAPv3) is planned. These updates were possible as a result of the large degree of automatization of the quality control process that ensures the accuracy of the data. The core of the quality control process is the crossover analysis that is currently performed via the 2nd QC Matlab toolbox from Lauvset and Tanhua (2015). However, following Eurosea’s vision of a user-focused, truly interdisciplinary, and responsive European ocean observing and forecasting system, this deliverable aims to migrate from the Matlab toolbox to an online web application based on the open-source software Django and Python. This will allow the user to simply upload the data file to be quality controlled and the web application performs the secondary quality control through the deep water crossover analysis just as in Matlab, and offers similar graphics for visualization. Because the crossover analysis is partially automated on this online tool, the users do not need to possess any programming knowledge in order to quality control their data. In addition, this online tool can be part of a fully automated GLODAP quality control process, without need for manual intervention.

Description: The dynamics of marine systems at decadal scales are notoriously hard to predict—hence references to this timescale as the “grey zone” for ocean prediction. Nevertheless, decadal-scale prediction is a rapidly developing field with an increasing number of applications to help guide ocean stewardship and sustainable use of marine environments. Such predictions can provide industry and managers with information more suited to support planning and management over strategic timeframes, as compared to seasonal forecasts or long-term (century-scale) predictions. The most significant advances in capability for decadal-scale prediction over recent years have been for ocean physics and biogeochemistry, with some notable advances in ecological prediction skill. In this paper, we argue that the process of “lighting the grey zone” by providing improved predictions at decadal scales should also focus on including human dimensions in prediction systems to better meet the needs and priorities of end users. Our paper reviews information needs for decision-making at decadal scales and assesses current capabilities for meeting these needs. We identify key gaps in current capabilities, including the particular challenge of integrating human elements into decadal prediction systems. We then suggest approaches for overcoming these challenges and gaps, highlighting the important role of co-production of tools and scenarios, to build trust and ensure uptake with end users of decadal prediction systems. We also highlight opportunities for combining narratives and quantitative predictions to better incorporate the human dimension in future efforts to light the grey zone of decadal-scale prediction.

Description: Current global warming results in rising sea-water temperatures, and the loss of sea ice in arctic and subarctic oceans impacts the community composition of primary producers with cascading effects on the food web and potentially on carbon export rates. This study analyzes metagenomic shotgun and diatom rbcL amplicon-sequencing data from sedimentary ancient DNA (sedaDNA) of the subarctic western Bering Sea that records phyto- and zooplankton community changes over the last glacial–interglacial cycle, including the last interglacial period (Eemian). Our data show that interglacial and glacial plankton communities differ, with distinct Eemian and Holocene plankton communities. The generally warm Holocene period is dominated by pico-sized cyanobacteria and bacteria-feeding heterotrophic protists, while the Eemian period is dominated by eukaryotic pico-sized chlorophytes and Triparmaceae. In contrast, the glacial period is characterized by micro-sized phototrophic protists, including sea-ice associated diatoms in the family Bacillariaceae and co-occurring diatom-feeding crustaceous zooplankton. Our deep-time record of plankton community changes reveals a long-term decrease in phytoplankton cell size coeval with increasing temperatures, and resembling community changes in the currently warming Bering Sea. The phytoplankton community in the warmer-than-present Eemian period is distinct from modern communities and limits the use of the Eemian as an analog for future climate scenarios. However, under enhanced future warming, the expected shift towards the dominance of small-sized phytoplankton and heterotrophic protists might result in an increased productivity, whereas the community’s potential of carbon export will be decreased, thereby weakening the subarctic Bering Sea’s function as an effective carbon sink.

Description: The purpose of this deliverable is to describe and highlight specificities of the observing networks involved in Eurosea and to display a list of main data management points done at European level in comparison to what exists at international level.