Bridging Science and Solutions for Marine Biodiversity and Ecosystem Sustainability
Chairs: Annette Breckwoldt & Hauke Kegler
Understanding and conserving marine biodiversity is a cornerstone of sustainable ocean management, requiring interdisciplinary research and collaborative solutions. This session brings together diverse studies that highlight key ecological processes, advance conservation genetics, and strengthen scientific capacity for ecosystem monitoring. From the mechanisms underpinning coral reef recovery and the role of genetic tools in shark and ray conservation to innovative training initiatives and integrated frameworks linking land and sea, these presentations showcase pathways for safeguarding marine ecosystems while supporting sustainable development. Together, they underscore the vital connections between research, societal impact, and policy in addressing global environmental challenges.
14:00
Density-Dependent Recruitment Drives Coral Reef Recovery
by Subhendu Chakraborty | Sonia Bejarano | Bob Kooi | Agostino Merico
Systems Ecology Group, ZMT | Reef Systems Research Group, ZMT | Vrije Universiteit Amsterdam, Amsterdam, The Netherlands | Systems Ecology Group, ZMT
Coral reefs are among the most biodiverse and productive ecosystems on Earth, yet they are experiencing rapid degradation due to multiple disturbances. Post-disturbance recovery is often patchy and depends on local community structure and ecological processes. Among these processes, larval recruitment is pivotal for reestablishing coral populations, largely determined by density-dependent relationships between adult coral cover and new recruits. However, the specific nature of this density dependence—whether linear, convex, or concave—remains uncertain in predicting coral recolonization success.
To address this gap, we developed a coral–algae competition model to explore how varying forms of density-dependent recruitment impact coral population trajectories after disturbance. Our findings show that coral species exhibiting concave density dependence are more likely to recover, even under substantial environmental stress. In contrast, corals with convex density dependence can only rebound if disturbances are relatively weak or local recruitment rates are high. These distinctions emphasize the importance of precisely characterizing the density-dependent recruitment function when assessing reef resilience.
From a management perspective, selecting coral taxa with concave density dependence and strong recruitment rates may significantly enhance the success of reef restoration efforts. By targeting species best suited for rapid and sustained recovery, practitioners can help restore coral-dominated communities that are more resilient to future disturbances. Ultimately, a refined understanding of density-dependent recruitment dynamics will inform conservation strategies aimed at safeguarding the ecological and economic services provided by coral reefs worldwide.
14:15
From barcoding to genomes: genetic approaches to shark and ray conservation
by Martin Helmkampf | Oscar Puebla | Amy Yee-Hui Then
ZMT | ZMT | Institute of Biological Sciences, Universiti Malaya, Kuala Lumpur
Sharks and rays are among the most endangered groups of vertebrates. Their slow reproduction rates and high economic value make them particularly vulnerable to overfishing and coastal habitat loss, with one-third of species now threatened with extinction. To enable effective protection measures, it is crucial to improve our understanding of their diversity, a goal increasingly supported by genetic tools. In this talk, I will present several of our projects that investigate shark and ray populations and provide genetic resources for conservation purposes. The first study focuses on the species and genetic diversity of wedgefishes, a group of large, critically endangered rays, in Malaysian waters. Over seven years, 85 specimens of the genus Rhynchobatus were collected from 15 locations and identified using both morphology and DNA barcoding. The latter approach corrected many misidentifications based on morphological features alone and confirmed a new species record in Malaysia, underscoring the value of molecular tools in biodiversity assessment. In the most common species, R. australiae, population genetic analyses revealed unexpected population structure within the Strait of Malacca, despite its small size and shallow depth. With wedgefishes currently unprotected in Malaysia, these findings could inform short-term fisheries management and long-term conservation planning. While single-gene approaches like DNA barcoding are powerful, they have limitations that can be addressed by sequencing complete genomes. Using several ongoing and future projects as examples, I will demonstrate how reference genomes can help estimate population sizes, develop genetic markers for population genetic analyses, and facilitate eDNA-based biodiversity monitoring, providing valuable insights for marine conservation efforts.
14:30
The West African Hands-on MinION workshop: Capacity strengthening in Biodiversity Monitoring
by Achim Meyer | Béatrice Adepo-Gourene | Oscar Puebla | Jean-Dominique Durand
ZMT | Université Nangui Abrogoua (UNA), Abidjan, Côte d’Ivoire | Institut de Recherche pour le Développement (IRD), Montpellier, France
From September 9th to 14th, 2024, the West African Marine Fish DNA Barcoding Network (WAMBA.net) summer school took place at the Université NANGUI Abrogoua (UNA) in Abidjan, Côte d’Ivoire co-sponsored by the Partnership for Observation of the Global Ocean, POGO. The training empowered 20 scientists and multiplicators from Fisheries Science (Universities) and governmental institutions from France, Morocco and seven West African countries: Mauritania, Senegal, Côte d’Ivoire, Ghana, Benin, Nigeria and Cameroon with skills and knowledge to implement third generation sequencing at their home institutions. Within a one-week lab training and networking event at UNA, participants gained expertise in DNA extraction, index PCR and library construction plus simple bioinformatics, covering the end-to-end process of nanopore sequencing (Oxford Nanopore Technologies, ONT) for reference barcodes, which are a precondition for eDNA monitoring activities. This in-person course was accompanied by the e-Learning platform (https://academy.leibniz-zmt.de) hosted by the ZMT academy. In addition to the presented summer school activities, we highlight a novel approach for reference libraries in fish monitoring and give an outlook on future implementation strategies for capacity strengthening in biodiversity monitoring.
Foto: Hongo Anderson
14:45
How the Source-to-Sea (S2S) approach links Sustainable Development Goals 6 and 14 towards a more sustainable world
by Tim Jennerjahn | ZMT
Life on Earth today is a challenge. The accelerated pace of development since the second half of the 20th century has led to great achievements for humanity, but has also created pressures that are reflected in commonly used terms such as ‘climate crisis’, ‘biodiversity crisis’ and ‘water crisis’. The will to act is documented in the United Nations’ 2030 Agenda for Sustainable Development, with its 17 Sustainable Development Goals (SDGs). A large proportion of the world’s population lives in the coastal zone and is economically dependent on its resources. The coast separates but also connects land and sea. In this context, water is of paramount importance in connecting land and ocean, as a resource in its own right, as a habitat for aquatic life, as a major carbon sink, and as a transport and transformation medium. As a result, there are separate SDGs for water on land, SDG 6 ‘Clean water and sanitation’, and for the ocean, SDG 14 ‘Life below water’. The Source-to-Sea approach recognizes that everything we do on land can affect the downstream coastal and open ocean through the flow of water and associated human activities. It acknowledges that water management requires a holistic approach, combining the targets of SDGs 6 and 14 to achieve greater benefits for system Earth and humanity. The concept was developed and is promoted by the Action Platform for Source-to-Sea Management, a multi-stakeholder initiative to share and generate knowledge and support collaborative action for improved management of land, water, coastal and marine linkages. The vision is to enable sustainable development across the land-freshwater-marine continuum. The strategic aims of the S2S approach are (i) to strengthen partnership across actors and initiatives, (ii) to increase understanding of S2S linkages, (iii) to build commitment for S2S action and (iv) to take action on the ground.