• In support of the implementation of the Green Deal and the biodiversity strategy, and in order to better understand biodiversity decline, its main direct drivers and their interrelations, successful proposals will contribute to all of the following expected outcomes: Closure of the gap in the knowledge and exploration of marine and coastal biodiversity at the level of species, the intraspecific/genetic level, ecosystems, functionalities, trophic-interactions and interconnections across temporal and spatial scales;
• New theoretical frameworks for the organisation of marine biotic communities, with key species, from microbiome to megafauna, from benthic to pelagic, especially invertebrates and apex predators, and considering sex segregation determined by environmental parameters, in space and time and the ecosystem processes linking them (energy and biogeochemical cycles, including the role of migratory species behaviour ), from deep sea to coastal biotopes including intertidal areas
• Ocean health prediction (including climate change vulnerability), decision-making and policy implementation supported by the full integration of ecological components with physical and geochemical components (in four dimensions: surface, water columns, seafloor, time) into improved global and regional high-resolution models of ecosystems conditions and dynamics;
• Improved detection and monitoring of invasive alien species, assessment of their impact on biodiversity and conservation monitoring of endangered species;
• Natural capital accounting with an estimation of the value and co-benefits of services from healthy deep sea to coastal ecosystems, including non-financial benefits such as well-being and social and cultural values for policy and decision-making; development of a common EU methodology and criteria for the non-financial ecosystem benefits;
• Improved science-based maritime spatial planning and identification of Ecologically or Biologically Significant Marine Areas and design of Marine Protected Areas.

Studies estimate there may be 0.7 to 1.0 million eukaryotic marine species, of which about only 226,000 are described. The EEA State of Nature Report 2013-2018 found a general lack of marine species data that hampers the elaboration of conservation and restoration measures, the sustainable management of ecosystems and, therefore, the achievement of favourable conservation status. For instance, invertebrates supporting the lower level of the food chain or marine mammals are among those species with the highest proportion of unknown assessments (over 78 %). In the deep sea, over 90% of the species may be new to science. Additionally, very little is known about the effects of modern biogenic structures related to feeding types and morphological traits that may play a major role in biogeochemical cycles. Marine biodiversity hotspots in tropical and subtropical shallow areas host species and processes that are yet undescribed. The lack of biodiversity knowledge and appropriate monitoring are critical limiting factors in the definition and implementation of measures, where the range, population size and suitable habitat area are unknown in the majority of Member States and for the majority of vulnerable marine species and ecosystems. The main reasons are the limited access and high cost of explorations of the diversity of biotopes in the vast marine and coastal realm, in particular the deep sea, and the resources available to identify organisms across the full range of sizes (from microorganisms to megafauna).

Acidification, deoxygenation, global warming and climate change, including seasonal patterns, are affecting marine ecosystems faster than terrestrial ecosystems, with their cumulative and long term effects amplifying the unprecedented pressures of the rapidly evolving ocean economy, driven by human needs for food, energy, transportation and recreation, as underlined by the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES) Global Assessment Report on Biodiversity and Ecosystem Services (IPBES GA, 2019). The effects have been documented on mobile and habitat building species over the past two decades and reveal an accelerating trend (IPBES GA, IPCC 2019). Many marine species are highly mobile, often migratory and rely on a number of different habitats throughout their developmental stages. In addition, the marine realm hosts numerous species for which sex determination is dependent upon environmental conditions such as temperature, seasonal patterns, and other geochemical parameters. For these species, environmental changes may cause different responses and effects on species populations and related ecosystems functions that are not shown when studying the species indiscriminately of sex and population dynamics.

With so much still unknown, ecosystem processes cannot be fully understood. This weakens models of marine ecosystems and their responses to pressures and diminishes our capacity to predict and take the best measures. Since biodiversity is declining at an unprecedented rate in Earth’s history, there is an urgent need to take conservation measures and develop holistic ecosystem-based management approaches, so that these ecosystems become resilient to environmental changes and are able to provide services for humankind and the planet’s life support system. For this, it is critical to improve the knowledge and understand and model marine biodiversity as soon as possible. Proposals should address all of the following aspects:

• Increase understanding of the dynamics of marine biodiversity and ecosystems processes and functioning (including primary production, food webs and biogeochemical cycles) in Europe, in its outermost regions and overseas countries and territories, whose participation is encouraged, and in areas beyond national jurisdictions. Ensure that new modelling and scenario approaches integrate new and existing biodiversity data and knowledge from other EU, international and national projects and from long-term ecosystem and socio-ecological research infrastructure on species, biotopes and ecosystem processes.Genomics and taxonomic technologies for the inventory and fast identification of marine species from microbes, plankton and invertebrates to migratory species (including diadromous species), apex predators such as sharks and mammals, corals and other habitat building species, generating reference datasets from identified voucher specimens and novel methods to improve biodiversity monitoring and inventory.
• Increase understanding of how input from freshwater and estuarine systems influence coastal marine communities and their ecosystem functionality.
• Use acoustic and non-invasive monitoring as an integral component of any marine ecosystem exploration and assessment.
• Develop methods and indicators for regular and timely integrated assessments of the state / health of marine biodiversity and its key ecosystem services, in the EU and associated countries’ marine waters (Good Environmental Status) and in areas beyond national jurisdiction.
• Contribute to the Global Taxonomy Initiative of the Convention on Biological Diversity (CBD) and to free and open access to the Global Biodiversity Information Facility’s biodiversity data.
• Identify opportunities for cooperation with relevant projects, such as EUROPABON^[1], which was awarded funding under the call ‘SC5-33-2020: Monitoring ecosystems through research, innovation and technology’, or the projects resulting from topics under the Heading ‘Understanding biodiversity decline’" in Destination ‘Biodiversity and ecosystem services’ as well as topics from Destination ‘Fair, healthy and environmentally-friendly food systems from primary production to consumption’ (aquaculture, fisheries), Destination ‘Circular economy and bioeconomy sectors’ (biotechnologies, microbiome), Destination ‘Land, ocean and water for climate action’ (Carbon cycle and natural processes) and Destination ‘Innovative governance, environmental observations and digital solutions in support of the Green Deal’ (environmental observation). Cooperation is also expected with the Biodiversity Partnership^[2] (HORIZON-CL6-2021-BIODIV-02-01) and other relevant Horizon Europe missions and partnerships. Proposals should outline a plan on how they intend to collaborate with other projects selected and with the initiatives mentioned, by e.g. participating in joint activities, workshops, common communication and dissemination activities, etc. Applicants should allocate the necessary budget to cover the plan. The plan’s relevant activities will be set out and carried out in close co-operation with the relevant Commission departments, ensuring coherence with related policy initiatives.
• Where relevant, create links, contributing to and using the information and data of the European Earth observation programme Copernicus, the Group on Earth Observations (GEO) and the Global Earth Observation System of Systems (GEOSS), the European Space Agency’s Earth Observation Programme and in particular the flagship actions on biodiversity and ocean health of the EC-ESA Joint Earth system science initiative, is expected.
• Improve professional skills and competences on marine taxonomy and system thinking.
• Engage in cooperation with the EC Knowledge Centre for Biodiversity^[3] and other relevant existing platforms and information sharing mechanisms^[4].
• Contribute through education and training (school & ocean literacy, art and citizen science platforms) to a greater overall societal and public understanding of the link between biodiversity and the functioning of ecosystems.

To achieve the expected outcomes, international cooperation is strongly encouraged.

[1] https://europabon.org/

[2] https://www.biodiversa.org/1759

[3] The EC Knowledge Centre for Biodiversity (KCBD) is an action of the EU biodiversity strategy for 2030. It aims to enhance the knowledge base, facilitate its sharing and foster cross-sectorial policy dialogue for EU policy making in biodiversity and related fields. https://knowledge4policy.ec.europa.eu/biodiversity_en.

[4] BISE, BiodivERsA, Oppla, NetworkNature and their joint work streams.