2. Marine biodiversity: it’s all about the baselines and trends
This theme is open to all sessions related to the broader, global picture of marine biodiversity and how our (species) knowledge affects the way we protect our ocean and how this influences conservation & restoration management, as well as policy decisions and how it can serve as a measure for future needs.
2.1 Marine Mammals in the Anthropocene: Navigating Challenges, Shaping Recommendations
Convenors:
Krishna Das (University of Liège)
Ursula Siebert (University of Veterinary Medicine Hannover, Foundation)
Summary:
Marine mammals serve as sentinel species, offering critical insights into ocean health and broader ecosystem changes. As the Anthropocene unfolds, they face mounting pressures from climate change, habitat degradation, pollution, and increasing human activities. Understanding their status, health, and trends is essential for effective conservation and management.
This session will align with the overarching themes of the World Conference on Marine Biodiversity 2026—focusing on baselines, trends, and monitoring efforts to assess the pulse of marine biodiversity. We will explore how long-term monitoring programs and interdisciplinary approaches contribute to our understanding of marine mammal populations, their health, and their role in ecosystem functioning.
Key topics will include:
The role of marine mammals in biodiversity monitoring and ecosystem assessments
Advances in passive acoustic monitoring, telemetry, and emerging technologies
The impact of contaminants, including legacy and emerging pollutants, on marine mammal health Climate-driven shifts in distribution and behavior Policy implications and conservation strategies based on monitoring data
By integrating perspectives from ecotoxicology, marine mammal biology, and conservation science, this session aims to foster discussions on best practices, identify knowledge gaps, and propose actionable recommendations.
2.2 Marine Biodiversity at Risk: The Climate-Fisheries Nexus and the Future of Ocean Resources
Convenors:
Kit Yue Kwan (Jimei University)
Khor Waiho (Universiti Malaysia Terengganu)
Summary:
Marine biodiversity is undergoing rapid shifts due to climate change and human activities, fundamentally altering the structure and function of ocean ecosystems. As species distributions shift, fish stocks decline, and marine habitats degrade. Ultimately, both the marine biodiversity and food security are affected. Thus, understanding biodiversity baselines and tracking long-term trends is essential for guiding conservation, fisheries management, and climate adaptation strategies.
This session will explore how climate change and fisheries interact to reshape marine biodiversity across spatial and temporal scales. Discussions will focus on establishing historical baselines for key species and habitats, identifying emerging biodiversity trends, and assessing the consequences of these changes on ecosystem services and food security. How are warming oceans influencing fishery productivity? What role do genetic diversity and habitat shifts play in ecosystem resilience? How can scientific data on marine biodiversity trends inform sustainable fisheries management and international conservation policies? By integrating species-level, population-level and ecosystem-scale data, this session aims to provide a global perspective on the Climate-Fisheries Nexus, in addition to serving as baseline for the future development of appropriate conservation and resource management strategies. We welcome case studies on biodiversity monitoring, predictive modeling, and ecosystem-based fisheries approaches that has or will inform and support decision-makers in setting realistic conservation targets and policy frameworks.
As we strive to balance marine biodiversity conservation with fisheries for food security amid a changing ocean climate, understanding the current biodiversity baselines and trends is crucial to safeguarding marine resources for future generations. This session invites marine scientists, conservationists, and policymakers to discuss innovative ways to track biodiversity change, protect vulnerable marine species, and build climate-resilient fisheries for a sustainable ocean future.
2.3 Towards a holistic understanding of ecosystem impacts of renewable energy installations across space and time
Convenors:
Jan Vanaverbeke (Institute of Natural Sciences, Belgium)
Jolien Buyse (Flanders Research Institute for Agriculture, Fisheries and Food)
Summary:
Renewable energy installations such as offshore wind farms, tidal energy systems and floating solar panels are being introduced into the marine environment at an unprecedented rate to meet global energy and climate goals. Their large-scale deployment can potentially drive ecosystem-wide changes at a scale well beyond the occupied area. Current monitoring programs typically focus on site-specific structural impacts, are limited in both space and time, and primarily focus on specific aspects of the marine environment. This approach has led to valuable insights into structural changes, mainly in terms of organism density and diversity at the wind farm scale. However, the assessment of functional changes by integrating the effects of multiple offshore renewable energy installations on a sea basin-wide scale, requires a holistic approach. This necessitates innovative observation and monitoring techniques, integration of scientific disciplines and the development of adequate tools to simultaneously investigate both the positive and negative consequences of offshore renewable energy installations on the marine ecosystem.
This session will explore monitoring, modelling, and analytical approaches that enhance our ability to evaluate the ecosytem-wide effects of multiple renewable energy developments across relevant spatial and temporal scales.
2.4 Assessing the Impact of Plastic Pollution on Marine Biodiversity
Convenor:
Erin Murphy (Ocean Conservancy)
Britta Baechler (Ocean Plastics Research) (to be confirmed)
Summary:
Renewable energy installations such as offshore wind farms, tidal energy systems and floating solar panels are being introduced into the marine environment at an unprecedented rate to meet global energy and climate goals. Their large-scale deployment can potentially drive ecosystem-wide changes at a scale well beyond the occupied area. Current monitoring programs typically focus on site-specific structural impacts, are limited in both space and time, and primarily focus on specific aspects of the marine environment. This approach has led to valuable insights into structural changes, mainly in terms of organism density and diversity at the wind farm scale. However, the assessment of functional changes by integrating the effects of multiple offshore renewable energy installations on a sea basin-wide scale, requires a holistic approach. This necessitates innovative observation and monitoring techniques, integration of scientific disciplines and the development of adequate tools to simultaneously investigate both the positive and negative consequences of offshore renewable energy installations on the marine ecosystem.
This session will explore monitoring, modelling, and analytical approaches that enhance our ability to evaluate the ecosytem-wide effects of multiple renewable energy developments across relevant spatial and temporal scales.
2.5 Solving the Ocean Biodiversity Data Crisis... one byte at a time
Convenors:
Randi Rotjan (Tufts University / Blue Nature Alliance)
Jason Landrum (Lenfest Ocean Program at The Pew Charitable Trusts)
Summary:
In the midst of the global biodiversity crisis, we also have a global biodiversity data crisis. Comprehensive and up-to-date marine biodiversity data - both baselines and repeated measures - are the foundation that enables identification of marine biodiversity hotspots, recognition of threatened species and habitats, and design of targeted conservation strategies. Although we currently have amassed more data than ever before, with greater accessibility, fundamental gaps still remain. Data paucity increases with ocean depth, there are few places with comprehensive biodiversity data, and even fewer with time series data. In addition, there are data quality issues, such as significant gaps in spatial, temporal, and topical data coverage, compounded by other data challenges such as data interoperability, quality, and accessibility. To successfully assess the influence of human interventions and global change on biodiversity outcomes, it is urgently necessary to address these challenges. For example, the adoption of the Kunming-Montreal Global Biodiversity Framework, which has four goals and 23 targets, directly depends on high quality biodiversity data that currently has room for improvement both in data density and form. Importantly, the biodiversity data crisis is a major problem, but a solvable one. In this session, we will convene a timely and essential conversation about biodiversity data - how it is generated, quality-controlled, used, and re-visited. From museums to eDNA to back-end computing, our session presenters will provide concrete examples of how research results and data benefit from strong biodiversity data, and likewise, suffer from data quality or quantity issues. We will discuss how databases, data sources, and stakeholders can work together towards better biodiversity data solutions.
2.6 Integrating biodiversity as a measure of seagrass status in monitoring, conservation, and restoration - challenges and opportunities
Convenors:
Kristina Kvile (Norwegian Institute for Water Research - NIVA)
Louise Forsblom (Finnish Environment Institute - SYKE)
Summary:
Seagrass meadows are known as hotspots for coastal biodiversity, providing habitat for multiple trophic levels from fish to invertebrates to microbiota. As concern for the future of seagrass meadows grows, an ever-increasing number of conservation and restoration projects are being put into place around the world, leading to a need for established baselines for biodiversity and other ecosystem services. Initially, monitoring of seagrass status and restoration success focused solely on measures linked to the seagrass itself – cover, biomass, shoot density. More recently, focus has shifted to the communities of fish and invertebrates supported by restored seagrass, and several studies have compared faunal communities in restored vs established seagrass as a measure of restoration success.
In order to properly assess the status of biodiversity in seagrass meadows, proper baselines of faunal communities must be established. Seagrass fauna is highly spatially, seasonally, and temporally variable. However, the diversity and distribution of seagrass meadows around the world has resulted in a wide range of sampling methods targeting different groups and size classes of organisms, as well as varying levels of taxonomic resolution. This lack of standardised protocols can bias results and make it difficult to compare and assess the effects of conservation and restoration measures in seagrass meadows.
In this session, we discuss the challenges associated with establishing baselines for monitoring seagrass-associated biodiversity for conservation and restoration purposes, and the potential for harmonising methods as the interest in seagrass meadows and their associated communities grow. We propose a session with 1-2 introductory speakers + 4-5 contributed speakers (10 minutes each) working on a diversity of seagrass species around the world, followed by a joint question session and discussion with all speakers (30 minutes).
This is an initiative of the NORSE project, based at the Norwegian Institute of Marine Research.
2.7 Challenges and opportunities of monitoring biodiversity through environmental DNA (eDNA): Understanding and predicting the behaviour and fate of eDNA in marine environments
Convenors:
Martine Van den Heuvel-Greve (Wageningen Marine Research)
Carmen-Lucia David (Wageningen University - Marine Animal Ecology)
Summary:
This session focuses on the applicability of eDNA for monitoring marine life. This molecular method promises advantages over traditional biodiversity surveys by being easy to sample and noninvasive.
However, two major knowledge gaps remain for a full implementation of the use of eDNA data in marine environmental research and monitoring: the interpretability of measured eDNA concentrations and the identification of the source location of sampled eDNA. To interpret eDNA concentrations in environmental samples, a better understanding and qualification of DNA shedding and decay processes are needed from laboratory and field studies, for a width of species across various environments. To identify the source location of sampled eDNA, coupled transport and ocean models can help to reconstruct dispersal pathways of sampled eDNA.
The session will discuss the process of production, persistence and transport of eDNA and their impact on the reliability of eDNA incorporation in large routine monitoring programs. It welcomes studies from experiments, field sampling and numerical models dealing with one or a combination of the described processes.
2.8 Keeping your cool - Polar benthic biodiversity and ecosystem functioning in a changing ocean
Convenors:
Loïc MICHEL (University of Liège)
Nadescha Zwerschke (Greenland Institute of Natural Resources)
Ulrike Braeckman (Ghent University & Institute for Natural Sciences)
Bodil Bluhm (Arctic University of Norway)
Emil De Borger (Ghent University)
Philippe Archambault (Université Laval)
Summary:
Arctic and Antarctic ecosystems host a significant portion of global marine biodiversity, yet they are often underrepresented in global studies due to limited data availability. This is especially true for benthic compartments in both polar regions, which harbour the highest species richness and levels of endemism, encompass many of the most vulnerable marine ecosystems, and concentrate most invasive taxa — yet remain the least understood. Polar biodiversity is responsible for multiple crucial provisioning or regulating ecosystem services. However, human-induced climate change strongly impacts those communities. Both the Arctic and some large parts of the Antarctic continent are among the most rapidly warming regions of the marine realm, leading to significant losses of sea and land ice in recent years. Furthermore, the poleward expansion of lower latitude generalist species has been shown to substantially affect the structure and resilience of polar marine communities. Despite growing concern, much remains unknown about how these changes will impact ecosystem functioning and the ability of polar systems to withstand future disturbances.
In this context, the aim of this session is to bring together polar researchers exploring the interactions between environmental change, the structure of biological communities, the functions they exert, and the ecological relationships that underpin them. We will welcome contributions focusing on either Arctic, Antarctic, or both environments. Our goal is to gather insights about how climate change is currently influencing polar marine ecosystems, highlight potential tipping points in ecosystem functioning which might disrupt essential ecosystem functions beyond recovery, and predict how these changes could shape polar communities and ecosystem functioning in the future ocean.
