52nd Liège Colloquium on Ocean Dynamics – Towards understanding and assessing human impacts on coastal marine environments

Liège, Belgium – 25th to 29th May 2020

The University of Liège


Terms of reference

The coastal ocean (i.e. regions that are directly influenced by their watershed, including estuaries) is under increasing pressures that affect its functioning and health, and compromise the provision of services to the society. Since the middle of the last century, the massive increase in the use of fertilizers has resulted in worldwide eutrophication of the coastal zone resulting in the proliferation hypoxic regions. Overfishing, dredging activities and pollution with notably the increasing amounts of marine litter are further affecting coastal systems with impacts on the physics, biogeochemistry and biodiversity. More recently, the implementation of the Blue Growth strategy led to an increase of marine and maritime activities. In particular, offshore wind farms and dredging have modified the sedimentary environment with consequences for biodiversity and biogeochemistry that are still poorly known at large scales. All these activities are developing in a context of global change with warming, acidification, deoxygenation and global sea level rise adding complexity to the challenge of unraveling the intricate interplay between multiple stressors that may act synergistically or antagonistically. Only after having achieved a proper understanding of human impacts on the coastal ocean, we will be able to set-up a scientifically underpinned ecosystem-based management scheme for the marine ecosystem. Such management should hence be firmly embedded in the science-management-policy interface, taking account of selecting useful and communicable indicators for ecosystem health, targeting ecosystem services and making use of novel analytical tools acknowledging the complexity of Drivers-Pressures-Stressors-Impacts-Responses (DPSIR) interactions.

The complexity of the coastal ocean combined with the conjunction of multiple stressors pose significant challenges to scientists that have to develop the adequate innovative and robust science-based tools in support of a sound management. The colloquium would like to gather an interdisciplinary community of scientists in order to obtain an overview of the progress in our capabilities to understand, monitor and forecast the impact of human activities on coastal marine environments to guarantee a productive and healthy system as requested by the EU Marine Strategy Framework Directive and the UN Sustainable Development Goal 14. A special event gathering scientists, stakeholders and industries is foreseen for reviewing current knowledge and gaps on offshore wind farms impacts on biodiversity and biogeochemistry. The special event will set the scene for a follow-up discussion during a networking reception directly following the presentations.

Regular sessions will be held on the following themes:

  • Assessing the impact of sedimentary changes on the coastal ocean physics, biodiversity and biogeochemistry. KEYNOTE Speaker: Martin Solan, University of Southampton, UK
    In coastal ecosystems, seafloor disturbance resulting from aggregate extraction, dredge disposal and beam trawling leads to changes in the composition of the sediment (fining or coarsening). These changes can have important implications for physical habitat characteristics, biogeochemical cycling, biodiversity and food web structure. This session focuses on contributions that increase our understanding of sediment-induced changes in the ecological, physical and chemical characteristics of the marine ecosystem, and the feedback of biological activity (bioturbation, capture and burial of fine fractions) on the sediment composition. Especially, new tools to measure the composition changes in situ or in laboratory conditions are welcomed.
  • Assessing the impact of marine structures on the coastal ocean physics, biodiversity and biogeochemistry
    Marine structures for coastal defence and marine (renewable) energy generation (e.g., wind farms, oil and gas platforms, harbour extensions, floating platforms, wave-energy devices, tidal turbines, seaweed farms) introduce obstacles for flow and light, and hard substrates that can support marine flora and fauna species that would otherwise be rare in soft-sediment environments. For instance, the offshore wind industry has seen considerable investment and a significant expansion of the sector is expected by 2030-2040, and other large-scale activities may well follow. Each of these types of structures can be expected to have different effects on the ocean physics and habitats, with consequences for marine biodiversity and biogeochemistry, but these effects are not well understood. Moreover, if deployed side by side, combined effects of different types of structures on the marine environment may well be different. This session welcomes experimental, observational, theoretical and modelling studies that aim at monitoring, quantifying, understanding and predicting the effects of structures on the marine environment and their interactions with other processes such as eutrophication and climate change.
  • Assessing the impact of land-based pressures on the coastal environment, river-estuary-coastal ocean coupling. KEYNOTE Speaker: Marjorie A.M. Friedrichs, Virginia Institute of Marine Science, USA
    This session welcomes contributions, dealing with experimental, observational (including satellites) and modelling approaches, targeted at investigating the transfer of organic and inorganic (e.g nutrients, plastics, minerals) materials across the river-ocean continuum and its impacts on the coastal ocean (e.g. hypoxia, HABs, turbidity enhancement). Focus will be on the understanding and assessment of the impact of human activities (e.g. eutrophication, dredging) on this transfer and on the coastal zone health. New technologies (e.g. sensors), hyperspectral satellites and numerical models are expected to considerably advance our capacity to deliver high quality information to stakeholders and to improve our forecasting capacity of the coastal zone status under continental pressures.
  • Multiple stressors, multi-use, cumulative effect assessment, including climate change.KEYNOTE Speaker: Philip Boyd (University of Tasmania, Australia)
    Preserving the health of the marine environment requires a sound allocation in space and time of the multiple activities affecting the coastal zone. This needs to be grounded in a thorough understanding of the cumulative impacts of multiple activities at the ecosystem scale across borders and sectors. This section welcomes contributions with experimental or modelling approaches that deal with the combination of effects of ocean acidification, warming, hypoxia, changes in salinity, microplastics, etc. on different aspects of the marine ecosystem (biodiversity, biogeochemistry, food web dynamics). We particularly encourage contributions that target community- or ecosystem-wide responses (in space and time).
  • Ecosystem services. KEYNOTE Speaker: Tara Hooper, Plymouth Marine Laboratory, UK
    This session aims at addressing the currently poor link between biologically-mediated coastal processes and their direct and indirect societal relevance, notably by incorporating the fields of functional biodiversity and ecosystem functioning into the ecosystem goods and services concept. The notion of ecosystem functioning introduces the theoretical background and examines the mechanistic role of biodiversity and humans in shaping ecosystem services. Human activities in coastal seas impact both biotic and abiotic factors that drive the link between biodiversity and ecosystem functioning, affecting the provision of coastal and marine ecosystem services. In this session, we embrace contributions bridging the gaps between biodiversity and ecosystem functioning, and between ecosystem functioning and ecosystem services, in order to facilitate the assessment and valuation of the societal implications of environmental changes and human impacts in global coastal environments. We also welcome contributions on the science-policy interface that make an effort in translating the above-mentioned research domain to ocean and coastal policies.
  • Indicators definition for ocean health assessment in connection with SDG14 and GES assessment.
    Conservation and sustainable use of the oceans, seas and marine resources for sustainable development is the target of the sustainable development goal 14 of the United Nations. This requires tools that permit defining marine health across different marine habitats and measuring changes induced by several anthropogenic pressures. Triggered by e.g. EU environmental legislation such as the Marine Strategy Framework Directive, much scientific progress has been realised in the last decades. This session welcomes contributions on integrative assessment frameworks, new types of indicators (functional, genetic-based, …), indicator-pressure responses, baseline definition, practical ways to set thresholds-limits and appropriate spatial and temporal monitoring programs, contributing to a better assessment of the ecosystem health .
  • Science base for marine spatial planning. KEYNOTE Speaker: Vanessa Stelzenmüller , Thünen Institute, GE.
    Maritime spatial planning (MSP) is a process to analyse and organise human activities in the marine space to achieve specific ecological, economic and social objectives. MSP works across borders and sectors to ensure human activities at sea take place in an efficient, safe and sustainable way. Nowadays, MSP is considered one of the key enabling mechanisms to underpin sustainable blue growth. Integrating the Ecosystem-Based Management (EBM) with the concept of MSP has been suggested as a way forward to reconcile human activities at sea with the concern for the marine environment. EBM takes into account the entire range of interactions within an ecosystem, including humans. As such, it moves away from considering single issues, species or ecosystem services in isolation. To date, a fully-fledged uptake of the EBM principles throughout the full MSP process is often lacking.. Multi-sectoral EBM that integrates sectorally-driven EBM such as EBM for fisheries or EBM for energy production, hence offer great potential for MSP. This session welcomes presentations on the integration of EBM into MSP, such as EBM-embracing MSP initiatives and science-based considerations of how to facilitate EBM-based MSP.

This special event will provide an overview of the state of science of environmental impacts of offshore wind farms, which are still being planned and built in European coastal seas. Special attention will be paid to the science-management-policy nexus, with a focus on how best to achieve an environment-friendly implementation of offshore renewables. Besides lessons-learned from the Belgian offshore wind farm environmental monitoring programme (WinMon.BE),we also welcome other presentations on ecosystem-based management of offshore renewables in Europe and elsewhere. This special event is targeted at scientists, industry, managers and policy makers. The special event will set the scene for a follow-up discussion during a networking reception directly following the presentations.


  • Ulrike Braeckman (UGent, BE)
  • Arthur Capet (ULiège, BE)
  • Steven Degraer (RBINS, BE)
  • Marilaure Grégoire (ULIège, BE)
  • Tom Moens (UGent, BE)
  • Karline Soetaert (NIOZ, BE)
  • Jan Vanaverbeke (RBINS, BE)
  • Gert Van Hoey (ILVO, BE)

Scientific Committee

  • Tundi Agardy (Marine Conservation, US)
  • Salvatore Arico (IOC-Unesco)
  • Silvana Birchenough (CEFAS, UK)
  • Angel Borja (AZTI, SP)
  • Denise Breitburg (Smithsonian, US)
  • Joop Coolen (Wageningen Marine Research, NE)
  • Valérie Cummins (University College Cork, Future Earth Coast, IE)
  • Farid Dahdouh-Guebas (ULB, BE)
  • Minhan Dai (Xiamen University, CN)
  • Ghada El Serafy (Deltares, NE)
  • Emmanuel Hanert (UCL, BE)
  • Stéphane Isoard (EEA)
  • Philippe Laleye, (UAC, Benin)
  • Diego Macias (JRC, IT)
  • Patrick Meire (UA,BE)
  • Angélique Mélet (MOI, FR)
  • George Petiakis (EuroGOOS)
  • Pierre Petitgas (IFREMER, FR)
  • Nadia Pinardi (UB, IT)
  • Augustin Sanchez Arcilla (Polytechnic University of Barcelona, SP)
  • Irene Schloss (University of Ushuaïa, AR)
  • Emily Snail (NOAA, US)
  • Emil Stanev (HZG, GE)
  • Adrian Stanica (GeoEcoMar, RO)
  • Vanessa Stelzenmüller (Thünen Institut, DE)
  • Michiel Vandegehuchte (VLIZ, BE)
  • Johan van der Molen (NIOZ, NE)