Water is essential for human life and nature and plays a critical role in most natural processes. Water covers about 70% of the Earth’s surface and over 97% of it is in oceans, and most of the remaining freshwater is in the form of ice.

Water is of huge global geopolitical importance and is central to all the key, current environmental issues: climate change, biodiversity, natural hazards, pollution, ecosystem services, and desertification.

Most water on Earth, including that present in lakes, rivers, deltas/estuaries, lagoons, etc., is part of the hydrological cycle and is inter-linked with the atmosphere, cryosphere, soils, sediments and the rest of the geosphere, as well as with the entire biosphere. Water must therefore be seen and studied in a holistic way.

Climate change, land use and abuse, economic activities such as energy production, industry, agriculture and tourism, urban development and demographic change mostly impact negatively on the status of water and as a result, the ecological and chemical status of EU waters, from mountain springs to coastal zones, is threatened. In addition, more parts of the EU are at risk of water scarcity. Water ecosystems – on whose services our societies depend – become more exposed to extreme events such as floods and droughts. It is essential to better address these challenges on the basis of improved scientific understanding of all relevant processes so as to preserve our resource base and increase its resilience for life, nature, society and to protect human health in the changing climate.

Freshwater

ICE, GROUNDWATER, LAKES, RIVERS, ESTUARIES

A holistic view on the water cycle requires integrated, interdisciplinary and trans-sectorial approaches that provide solutions to managing water-related societal risks. Environmental monitoring agencies across Europe continuously collect vast amount of data on freshwater. Linking this routine sampling with high-resolution data from freshwater supersites and remote sensing data would benefit society directly as well as by supporting research in the area. Some research facilities have collected data on snow, ice and freshwater and complementary environmental and ecological information for more than a century. These long time series have been instrumental in understanding the coupling between the water cycle, the changing climate and ecosystems. It is of vital importance to ensure that the long-time series are continued. Experimental facilities for studying complex water-related phenomena – e.g. physical modifications of estuaries, behaviour of substances and energy in mesocosms, etc. – allow physical models to underpin better systemic understanding, often in conjunction with mathematical models.

Current Status

Much of the current science is done relying on access to existing water bodies, i.e. without specific and dedicated large-scale Research Infrastructures. The ESFRI Project DANUBIUS-RI (International Centre for Advanced Studies on River-Sea Systems), supporting interdisciplinary research in river-sea systems, is the only physical pan-European Research Infrastructure devoted to support also research on transitional zones between coastal marine and freshwater areas, together with the ESFRI Landmark LifeWatch ERIC (e-Infrastructure for Biodiversity and Ecosystem Research) as the only e-RI, which extends its area of interest also to the whole freshwater environments. There are European networks of basins for hydrological monitoring and research, such as the European Network of Hydrological Observatories (ENOHA). The HYDRALAB+ network supports the use of environmental hydraulic facilities. The ESFRI Project AnaEE (Infrastructure for Analysis and  Experimentation on Ecosystems, H&F) also offers access to experimental facilities in freshwater environments.

Gaps, challenges and future needs

Europe needs a dense, highly instrumented super-sites network of freshwater monitoring, as well as simulation and experimental platforms. Lake, river and ground water monitoring and experimental super-sites should serve as calibration, validation and development services for remote sensing applications as well as for ecosystem and for ecosystem service modelling. For the  comprehensive analysis of the changes in the aquatic ecosystems an integrated basin approach is necessary to understand the impact of different drivers and to find measures for sustainable water resources management. The ESFRI Project DANUBIUS-RI, with its structure consisting of the four Nodes (Observation/Measurements – Analysis – Modelling – Impact), is aiming to bridge the before mentioned gaps, at a basin-wide, river-to-sea approach.

The Water JPI Strategic Research and Innovation AgendaWater JPI, 2016 http://www.waterjpi.eu/images/documents/SRIA%202.0.pdf and the WssTP Strategic Innovation and Research AgendaWssTP, 2017 http://wsstp.eu/wp-content/uploads/sites/102/2017/01/WssTP-SIRA_online.pdf provide frameworks for collaborative research and innovation efforts. The Water JPI intends to increasingly play a role in facilitating the use of relevant RIs, whereas for example WssTP advocates the use of “real life living labs” where innovative solutions can be tested hence facilitating the scaling up of solutions.

Marine

from coast to deep oceans and ice caps

Shelf seas and the world-embracing ocean form a group of dynamic complex systems with a strong interplay of physical, chemical and biological phenomena at multiple spatial and temporal scales. Due to inaccessibility, even their static features – e.g. ocean bathymetry – are poorly known. Seas and oceans provide food, energy, and many other resources on which mankind depends. The oceans have a fundamental influence on our climate. Society is increasingly concerned about global change and its regional impacts. Sea level is rising at an accelerating rate, the Arctic sea ice cover isshrinking as high latitude areas are warming rapidly, and storminess is forecast to increase. Since 1955, over 90% of the excess heat trapped by greenhouse gases has been stored in the oceansIPCC (2013) WG1 AR5 http://www.ipcc.ch/report/ar5/wg1/. The oceans are affected by the increased amount of CO2 in the atmosphere leading to ocean acidification which poses threats for many species. Changes in the thermal structure of water masses are likely to influence currents and stratification. The effects of climate change add to other stresses, such as pollution, in particular [micro]-plastics, and overfishing that are already threatening the biodiversity and health of the seas and oceans.

Last but not least, sources of geo-hazards such as slide prone slopes, active tectonic structures and volcanoes to mention some, lay in marine environment at various depth and distance from the coasts. Wherever they are adjacent to populated regions, to economically developed areas or sites of strategic relevance, they represent threats for the socio-economic fabrics and wellness. Marine observatories provide an essential integration to land-based RIs for a broader vision in the comprehension of the natural phenomena.

Ocean observation is currently a key component of the EU Strategy for Marine and Maritime Research and has become a high priority on the worldwide environmental political agenda.

Current Status

Marine RIs consist of up to 800 – increasingly networked – distributed facilities in Europe, serving various domains such as ocean – seafloor, subseafloor and water layers above – and coastal sea monitoring, marine biology research, blue biotechnology  innovation, research in aquaculture and ocean engineering. Their observation and data management components form the foundation for a European Ocean Observing System (EOOS), providing the platforms and services to deliver environmental data, information and ultimately knowledge. Marine RIs, including e-RIs, are as diverse as: research vesselsUNESCO (2017), Global Ocean Science Report—The current status of ocean science around the world, L. Valdés et al. (eds), UNESCO Publishing, Paris https://en.unesco.org/gosr and their underwater vehicles for sea access and deep sea exploration/sampling; voluntary vessels for surface and sub-surface monitoring;fixed and mobile, autonomous, including drifting, in situ observing systems for seawater column and seabed observation and monitoring; satellites for remote sensing for sea-surface monitoring; marine data centres; land-based facilities for ocean engineering, such as deep wave basins, water circulation canals, sensors tests and calibration laboratories; and experimental facilities for biology and ecosystem studies and for marine genomics, biodiversity, blue biotechnology, aquaculture, mesocosms; virtual research experimental facilities for biodiversity and ecosystem studies integrating data resources from the physical infrastructures and observation systems. Marine research stations, of which there is  a high density around Europe, often provide a combination of services to marine researchers.

Key RIs for water-related research are fostered in ESFRI, as reported in Figure 2, while there are also other EU projects and initiatives supporting networks that are directly relevant for research.

Figure 2. Simplified diagram of the observation capabilities of ESFRI Landmarks and Projects respect to the hydrosphere components (Y axis) and to the environmental processes therein (X axis).

• River-sea interaction, freshwater, water- ice: the ESFRI Project DANUBIUS-RI, the ESFRI Landmark LifeWatch ERIC – as e-RI, HYDRALAB+, AQUACOSM (mesocosms).
• Open ocean mobile platforms: the ESFRI Landmark EURO-ARGO ERIC (European contribution to the international Argo Programme), EuMarineRobots.
• Open ocean fixed point observatories: the ESFRI Landmark EMSO ERIC (European Multidisciplinary Seafloor and water-column Observatory).
• Research vessels and underwater vehicles: ARICE, EUROFLEETS.
• Coastal/shelf seas observatories: JERICO-NEXT.
• Data storage and standards, access: EMODnet and linked Copernicus Marine Service (CMEMS) for operational oceanographic services; EuroGOOS, SeaDataNet/SeaDataCloud.
• Marine biology, omics and bio-informatics: the ESFRI Landmark ELIXIR (A distributed infrastructure for life-science information, H&F), the ESFRI Landmark EMBRC ERIC (European Marine Biological Resource Centre, H&F), the ESFRI Landmark LifeWatch ERIC – as e-RI – and the ESFRI Project AnaEE (H&F).
• Carbon cycle: the ESFRI Landmark ICOS ERIC and the ESFRI Landmark LifeWatch ERIC, as e-RI.

Gaps, challenges and future needs

Taking into account recent efforts to define research priorities and infrastructure needs, such as European Marine Board position paper, JPI Oceans SRIA agenda, SEAS-ERA reports, a gap analysis has been performed by the marine community to identify gaps and weaknesses of the present understanding of how the ocean function sand our observing system. Marine  regions in open seas are under-sampled, thus additional observatory nodes, together with an acceleration of technological developments, are required – e.g. deeper measurements from Argo floats, Biogeochemical Argo floats and from SMART CablesITU/WMO/UNESCO IOC Joint Task Force https://www.itu.int/en/ITU-T/climatechange/task-forcesc/Pages/default.aspx. The UNESCO Intergovernmental Oceanographic Commission (IOC) is preparing the UN Decade of Ocean Science for Sustainable Development (2021-2030) to improve the scientific knowledge base, in view of humanity’s increasing reliance  on ecosystem goods and services from the ocean. The current global knowledge base is very weak – e.g. IOC estimates that 99% of habitable marine areas lack basic biodiversity knowledge for their management 19IOC, 2018. The United Nations Decade of Ocean Science for Sustainable Development (2021-2030) http://unesdoc.unesco.org/images/0026/002619/261962e.pdf. However, efforts are on-going to employ newly developed sensors and samplers that can be mounted on observing autonomous platforms – buoys, glider, profiler etc. – or vessels and ships seizing opportunities for more automated sampling and analysis for biochemical and biological parameters. The use of opportunistic sampling needs to be further expanded, e.g. sensors could be further deployed on commercial ships operated by the private and public sector (analogue to ESFRI Landmark ICOS ERIC).

Beyond the development of existing or planned individual Research Infrastructures and networks, a more holistic approach is needed for the observing components which are serving many different communities, including but not limited to the scientific community. The observation component is the first crucial part of the system which needs standardisation and interoperability effort to ultimately allow us to better know and understand the functioning of marine ecosystems. Other components will require more sophisticated models. From the perspective of a user of scientific information for utilisation in policy, a large gap is the frequent absence of science-based assessment criteria to evaluate the impact of human activities on environmental statusIdentified gaps on MSFD assessment elements. PERSEUS Project. ISBN 978-960-9798-01-3. Laroche S. et al., 2013. http://www.rmri.ro/WebPages/Perseus/download/Deliverabil%205.2.%20Identificarea%20lipsurilor%20informationale%20in%20privinta%20elementelor%20de%20evaluare%20conform%20Directivei%20Cadru%20Strategia%20pentru%20Mediu%20Marin.pdf and ecosystem services, indicating a strong need to understand better the multiple cause-effect chains in the marine environmental realm as a contribution to sustainable use of marine and maritime resources.

Economic constraints impose a flexible and multi-use approach, innovation towards cost-effective observing strategies, and prioritisation among possibly conflicting needs. Efforts towards an integrated and sustained EOOS are ongoing with discussions among the community on a specific strategy, implementation plan and sustainable budget. EOOS should build on the wealth of existing RIs capabilities and multi-platform assets already operational across European waters. EOOS would integrate marine observations from the coast to the open ocean and from surface to deep sea; promote multi-stakeholder partnerships for funding observing systems and sharing of data and align with global efforts within a robust framework. The EOOS should also be smart, resilient and adaptable, driven by scientific excellence, stakeholder needs and technological innovation, to fill the need for cross-disciplinary research and multi-stakeholder engagement.