Port areas, located at the land-sea interface, are crucial coastal socio-ecosystems exposed to local pollution and terrigenous inputs from watersheds. Silting and sedimentation in ports pose complex management challenges. It is essential to understand port environments, which requires regular monitoring of water and sediment quality. In-depth knowledge, especially under varying hydroclimatic conditions, helps better understand and manage the effects of dredging operations, including the potential reuse of sediments based on their quality.

Special attention has been given to data acquisition and comparing dredging operations at two Mediterranean observatories: the Ghar El Melah lagoon (GEM) in Tunisia, an UNESCO-IHP Ecohydrology Demonstration Site through the Observatory of MEdjerda LIttoral (OMELI) and the Gulf of Aigues-Mortes (GAM) (France), studied by the Human-Environment Observatory Mediterranean Coastline (OHM-LM). Research at these sites focuses on knowing, understanding, and better managing coastal ecosystems. Extensive fieldwork, including spatio-temporal monitoring during various cycles and dredging operations, has been conducted between 2019 and 2023 to determine chemical contamination and characterisation of water and sediments. The resulting database, analyzed with chemical tracers, helps identify major contamination sources, understand contaminant dynamics and distribution and sediment proprieties. A crucial aspect of this work involves the precise characterization of sediments. detailed characterizations of dredged sediments (composition, classification, distribution, ...) open up opportunities for valorization.

At the GEM lagoon site, sampling campaigns revealed heterogeneous trace metal contamination in the water column. High arsenic concentrations, exceeding environmental quality standards (EQS), were systematically observed. The northeast zone showed very high copper levels (7 times the EQS), and most water samples had high zinc concentrations. To assess contamination profiles and sediment quality for potential reuse in beach nourishment, sediment toxicity was evaluated using ERL (Effects Range Low) and ERM (Effects Range Median) calculations. Very high cadmium, copper, lead, and zinc levels were found in sediments near ports, likely due to active navigation and high hydrodynamic processes. These spatio-temporal data coupled with physical and mineralogical characterizations will allow for the selection of the most suitable sediments for dune cordon replenishment.

In the GAM case, monitoring of chemical contamination in several ports was done before, during and after dredging. Dredging increased chemical concentrations in the water, resuspending trace metals (As, Cu, Zn, Ni) and organotin compounds from sediments. Sediments in concrete formulation was explored. Concrete formulated with 15 or 30% sediments showed properties like the control. Finally, the potential release of contaminants was studied through dynamic leaching tests. While surface leaching followed by diffusion for certain metals was observed, the released quantities remained very low and all below environmental quality standards. These concretes were tested in maritime structures.

This approach aims to promote the rational reuse of dredged materials in maritime construction, fostering sustainable and equitable management practices. This includes circular economy principles and nature-based solution, such as beach nourishment, contributing to ecosystem restauration. These efforts are crucial for the sustainable management of port ecosystems, balancing economic development and environmental preservation. The results guide port managers’ decisions, considering meteorology, port usage changes, occupancy and traffic.

How to cite: Montigny, C., Amrouni, O., Souche, J.-C., Salgues, M., Pringault, O., and Mahé, G.: From Dredging to Restoration: Enhancing Coastal Ecosystems with Reused Sediments, One Ocean Science Congress 2025, Nice, France, 3–6 Jun 2025, OOS2025-118, https://doi.org/10.5194/oos2025-118, 2025.

Mangrove forests are some of the most effective carbon sinks on Earth, but they are globally threatened. Understanding the effects of active restoration efforts on mangrove blue carbon dynamics has therefore become a conservation priority. Here, we reconstructed mangrove carbon storage over the past 200 years in northern Vietnam, comparing old-growth forest, areas of artificial restoration and areas of natural spontaneous regeneration. The amount of carbon in the old-growth forest sediments has been higher than the restored or regenerated areas since the 1960s, highlighting the blue carbon benefit of established habitat. Stable isotope signatures indicate this stored carbon has been consistently dominated by marine plants and algae for at least the past 120 years. However, since the 1960s in the restored mangrove area, there has been a shift in the carbon source towards a dominance of mangrove-derived organic matter. This suggests that restoration activities may change the carbon cycling of mangrove forests, creating a ‘closed’ system of autochthonous carbon fixation and storage, and reduced interaction with marine-derived carbon. Mangrove restoration therefore holds potential for promoting blue carbon storage, but this may coincide with a loss in external linkages – which may have cascading impacts on wider ecosystem functioning. Careful consideration of blue carbon actions must therefore be taken to yield optimal conservation benefit.

How to cite: Burdett, H. L., Mao, J., Hien, H. T., Thi Thuy, D., Tu Ho, C., Kaiser, M. J., McGill, R. A., Poulton, A. J., Sweetman, A. K., Yang, H., and Thi Kim Cuc, N.: Mangrove restoration elevates local carbon storage but changes centennial-scale carbon burial dynamics , One Ocean Science Congress 2025, Nice, France, 3–6 Jun 2025, OOS2025-224, https://doi.org/10.5194/oos2025-224, 2025.

Bottom trawling and dredging gears have devastating impacts upon vulnerable marine seafloor habitats, but the antiquity of their use means that the true magnitude of change is often obscured. Within Europe, bottom trawling and dredging started centuries ago, with no scientific oversight of the initial impacts of these gears to seafloor structure and functioning. We describe how historical records published over a period of >350 years were used to evidence historical transformation of Europe’s seafloor ecosystems. We uncovered the loss of at least 17,000km2 of native oyster reef, largely driven by the 19^th century intensification of trawling and dredging. The collapse of this once dominant coastal and shallow seafloor ecosystem occurred more than 100 years ago and points to a previously unreported restructuring and ‘flattening’ of European seafloor ecosystems. We will present the findings from this study and our collation of similar evidence from around the world to rewrite the known history of seafloor ecosystem transformation. In so doing we aim to alert the conservation and restoration communities to the magnitude of seafloor restructuring that has occurred, highlight the implications of this transformation for biodiversity, ecosystem service provision, and carbon storage, and subsequently raise ambitions for global restoration and management.

How to cite: Thurstan, R., Roberts, C., McClaverty, C., and zu Ermgassen, P.: Historical records reveal the antiquity of seafloor ecosystem transformation: a global view , One Ocean Science Congress 2025, Nice, France, 3–6 Jun 2025, OOS2025-252, https://doi.org/10.5194/oos2025-252, 2025.

Chronic declines in coral cover across the Florida Reef Tract and the Caribbean have spurred widespread propagation efforts for threatened coral species that once blanketed western Atlantic reefs. Studies on these corals reveal remarkable differences in growth rates and stress responses among genetically distinct individuals (genets) within the same species, indicating the potential for customizing restoration stock to meet specific goals. However, most of these studies have been limited to a small number of genets and constrained spatial and temporal scales, precluding comprehensive comparisons of genet performance. To address this, we developed the Acropora cervicornis Data Coordination Hub (AcDC), a web-based database and interface that compiles and standardizes extensive genet-specific performance data. AcDC facilitates users to generate custom reports that show where a particular genet ranks within nursery stock and create tailored lists of genets best suited for specific restoration objectives. Our approach includes transparent data standardization, full metadata integration, and raw data availability, promoting both consistency and data stewardship. Currently, AcDC includes data on 220 genotypes from three species across 30 performance metrics, contributed by over 30 collaborators. Among these, 89 (38%) genotypes are shared in more than one study, and 25 (10%) are shared in four or more studies. Our standardized assessment has highlighted genets with consistently high growth rates and bleaching resistance, while also revealing phenotypic tradeoffs. As propagation and outplanting efforts expand, the coordination and assessment of stock performance must scale in tandem. AcDC supports the restoration community by aligning disparate datasets and helping practitioners make informed restoration choices.

How to cite: Kiel, P. M., Karp, R., Jankulak, M., and Enochs, I. C.: Acropora cervicornis Data Coordination Hub (AcDC), an open-access tool for aligning datasets and evaluating genet-specific performance, One Ocean Science Congress 2025, Nice, France, 3–6 Jun 2025, OOS2025-371, https://doi.org/10.5194/oos2025-371, 2025.

The value of a multi-sectoral approach to coral restoration in the Pacific of Costa Rica

Theme 3: Protection and restoration of marine and coastal ecosystems to ensure sustainable and equitable management

Juan José Alvarado;   https://orcid.org/0000-0002-2620-9115
Centro de Investigación en Ciencias del Mar y Limnología (CIMAR), Escuela de Biología, Centro de Investigación en Biodiversidad y Ecología Tropical (CIBET), Universidad de Costa Rica, San Pedro, 11501-2060 San José, Costa Rica; juan.alvarado@ucr.ac.cr

Culebra Bay is a small inlet in the North Pacific of Costa Rica, known for its high biological diversity. Due to these attributes, it has been a place where tourism and fishing activities have been strongly developed, which has probably had an impact on the health of the marine-coastal ecosystems in the area. Since the early 2000s, a decrease in live coral cover (LCC) and the integrity of coral reefs has been observed, going from 60% of LCC in the 90s to 5% in the 2010s. Due to this strong loss, a public-private alliance was established between the hotel sector, government, academia, international cooperation, and civil society to restore the coral reefs in the area. The Culebra Reefs Gardens project was then born in 2019, based on a scientific learning component, followed by continuous monitoring and volunteer participation. In the first phase of the project, personnel were trained and then monitoring of the most suitable type of structure to work in the bay was launched, as well as the species to be used. Coral growth and survival rates were measured, as well as operating costs of each structure. In a second stage, the experimental planting of fragments of the Pocillopora coral was carried out where a high growth rate and survival greater than 90% was observed. The third stage was scaling up, based on the first two, and worked with a greater number of nurseries fixed to the substrate (“spider” type) in various places in the bay, and with a greater planting of corals. In this stage, monthly monitoring of live coral coverage, coral growth, diversity of fish associated with the structures, as well as physical-chemical parameters of the water such as nutrients and temperature are carried out. Throughout the almost 5 years of the project, the results are positive, except for the ENSO 2023 event that causes high coral bleaching. Our nurseries showed a notable recovery after 3 months of temperatures dropping to less stress values. The joint work of this public-private alliance has demonstrated that synergistic cooperation in science-based conservation activities can generate good results for the ecosystem health of the reefs of the North Pacific of Costa Rica.

How to cite: Alvarado, J. J.: The value of a multi-sectoral approach to coral restoration in the Pacific of Costa Rica, One Ocean Science Congress 2025, Nice, France, 3–6 Jun 2025, OOS2025-394, https://doi.org/10.5194/oos2025-394, 2025.

Human activities such as afforestation, reforestation and off-shore oil exploitation have tremendous impact on the coastal ecosystems including the soil biota. The link between soil bacterial and fungal community structure diversity, other soil attributes, and environmental crises such as climate change, land degradation, biodiversity loss, and pollution in mixed-species plantations involving nitrogen-fixing species.

The prevalence of Actinobacteria playing a key role in decomposing organic material, may have been increased soil C storage reported in the acacia and eucalyptus plantations. Regarding fungal community structure and diversity, the relative abundance of Ascomycota which have the ability to preserve the community stability following environmental disturbances due to the expanded number of resources, was dominant. High sulfur concentrations, or H₂S emissions, derived in all likelihood from oil exploitation, have the potential to enhance Actinobacteria growth and biomass, while they decrease, in contrast, the prevalence and ability of the Ascomycota. The sulfur was found to being positively correlated to Actinobacteria, but negatively interrelated to Ascomycota.

Acacia and eucalyptus plantations boost soil resilience against the climate and land-use changes through C storage and co-benefits. However, oil exploitation activities involving H₂S emissions may diminish the ability of such mixed-species plantations to withstand the environmental stress and they also tend to harm soil health and coastal environment in the long term. Oil exploitation has an enormous economic importance for the Republic of the Congo. Special attention may be paid to the risk of harming the coastal ecosystems when off-shore oil exploitation is occurring.

How to cite: Koutika, L.-S.: To what extent is soil biota linked to soil attributes, climate change, land degradation, biodiversity loss, and pollution in Congolese coastal plains?, One Ocean Science Congress 2025, Nice, France, 3–6 Jun 2025, OOS2025-494, https://doi.org/10.5194/oos2025-494, 2025.

With an average discharge of 100 m³s^-1, the Tana River is Kenya’s most important river, entering the Indian Ocean via the 160,000 ha Tana Delta Ramsar site, also an Important Bird Area and a biodiversity hotspot for threatened plant and animal species. Its floodplains and mangroves are key nursery areas for a coastal fisheries, both semi-industrial targeting shrimp and artisanal for a wide range of species. 

Since the 1960s, five upstream hydropower dams have reduced peak discharge of the Tana by 30% and a larger dam, capable of storing up to 2 years of the river’s flow, has been planned. The reduced discharge of the Tana has resulted in less flooding of the Delta, exacerbating resource conflicts between sedentary farmers and mobile livestock keepers. Moreover, the fertile floodplains were targeted for large-scale irrigated agriculture (including by interbasin transfer) and its terraces for biofuel production, adding threats to local livelihoods.  

In order to favour tidal rice cultivation in the lower reaches of the delta, just upstream of the mangrove systems, local communities have blocked the Kalota Brook, a major section of the river mouth, dominant prior to the 20^th century. Though these interventions have maintained fresh water in the main riverbed, they have interfered with land-building processes downstream of Kalota and resulted in increased saltwater intrusion and erosion as well as a decline of biodiversity, biological productivity and nursery functions in the central part of the delta. In spite of repeated and expensive engineering attempts, the blockage of Kalota Brook has been unsuccessful, circumvented by new and increasingly deep tidal channels while in turn the central river mouth has been widening, allowing more and more seawater to enter compounded by Sea Level Rise.

Through a participatory science approach developed in DIDEM project, key local observers have been involved in the analysis of the hydrodynamics of the Delta and its impact on its biodiversity values and ecosystem service delivery to vulnerable groups. 

Methods applied include biodiversity surveys, hydrodynamic modelling of impacts of the changes on local agro-ecological systems, geomorphological and palaeo-ecological analysis (through coring), groundwater studies, focus group discussions, in depth interviews and commented field visits, stakeholder feedback and discussion workshops;  the outcomes of which have been communicated at policy and decision-maker level, both locally and nationally.

In addition to the participatory research and monitoring activities, a communication strategy was developed for information sharing and awareness building. Communication products include a documentary, a science festival during World Wetlands Day celebrations, a traveling exhibition, debates at several levels, a stakeholder peace dialogue, as well as numerous popular publications targeting schoolchildren and civil society. 

Our findings suggest that, in contrast to traditional compartmented land use planning, deltas require an adaptive and flexible multi-user approach adapted to climatic and river discharge conditions. In collaboration with the stakeholders, we propose a nature-based solution for Kalota Brook. This would allow a dynamic environmental flow, calibrated in relation to the critical equinox tides, to the central river mouth sufficient to maintain and enhance the land-building mangrove systems.

How to cite: Nyingi, W., Gitau, P. N., Hamerlynck,, O., Duvail, S., Kalota, J., Kome, M., and Otoi, K.: Advances in restoring and enhancing ecosystem services in vulnerable lower Tana Delta and coastal communities: amplifying local voices through transdisciplinary science, One Ocean Science Congress 2025, Nice, France, 3–6 Jun 2025, OOS2025-792, https://doi.org/10.5194/oos2025-792, 2025.

The El Niño phenomenon of 2015-2016 caused significant dieback of mangroves across the Pacific basin. Most noticeably, mangrove dieback from the arid regions in northwestern Australia has been reported, while a few reports have emerged from the eastern Pacific. This study reports on mangrove dieback associated with 2015-16 El Niño in the Bay of Panama in Central America, particularly highlighting how strong anthropogenic influences exacerbated mangrove tree mortality, increasing mangrove vulnerability to extreme climatic conditions and drought.

By mid-2016, the effects of the El Niño drought were evident, registering up to 70% mangrove dieback in mangroves near the city. This was not solely due to the drought conditions associated with El Niño, which typically extends the dry season four to five months rather than the usual 3 months. Instead, it appears that a combination of factors contributed to the observed high mangrove tree mortality, including aggressive urban development and land use changes, along with coastal erosion resulting from recurrent rainy years, increasing sedimentation that created new coastal areas. These new coastal areas resulted in the rapid colonization and structural overshoot of the Avicennia germinans (black mangrove) species, creating an “Ecological mirage.”

The El Niño drought of 2015-2016 intensified salinity-and-drought-mediated mangrove dieback in the Bay of Panama near the city due to freshwater shortages caused by reduced rainfall, declining water table levels, and increased evaporative demands from heightened temperatures. This study emphasizes how human-induced changes in the middle and upper watershed, mainly due to land use alterations, can lead to drought-related mortality during extreme years. This increases the vulnerability of mangrove ecosystems to climate change and extreme events. The research highlights the vital connection between land and coastal processes and underscores the necessity for integrated management of coastal ecosystems.

How to cite: López Alfano, O. R., Paton, S., De Sedas, A., Feller, I., and Cruz, L.: Exacerbated Vulnerability in Coastal Ecosystems: The Impact of El Niño and Urban Development on Mangrove Dieback in the Bay of Panama, One Ocean Science Congress 2025, Nice, France, 3–6 Jun 2025, OOS2025-915, https://doi.org/10.5194/oos2025-915, 2025.

Corallium rubrum is an octocoral endemic of the Mediterranean Sea, which suffers from population decline due to overfishing and warming-driven mass mortality events. For several years, scientists and managers have been interested in fostering the persistence of this resource, promoting various conservation and restoration actions. Understanding how the mating system influences the reproductive success of a species and, consequently, its persistence over time is crucial to planning efficient and successful restoration initiatives. In recent years, relatedness and kinship analysis suggested that breeding units in the red coral are highly restricted in space, even at a scale of half a meter. In this study, we aim to elucidate the processes underlying the genetic structure of C. rubrum, understanding the influence of fertilization distance and population density on reproductive success. By looking at a population in a semi-controlled environment (i.e., artificial caves) where the genetic print, sex, and morphology are known for all the individuals, we aimed to 1) estimate C. rubrum maximum fertilization distance, 2) evaluate the effect of sperm dilution on the fertilization of female colonies, and 3) verify if sperm limitation affects female larval production. After collecting all the larvae released during two breeding seasons (summer 2022 and 2023), we performed parentage analysis to assign each larva to its respective parents. Results show that polyandry is likely the norm in C. rubrum and that the species' potential fertilization distance can reach at least 13 meters. Notably, we detected a significant negative relationship between the number of larvae produced by females and the distance of the siring male, demonstrating that sperm dilution can play a crucial role in limiting fertilization success and that sperm limitation in sparse populations significantly impacts the coral fecundity. These findings have important implications for restoration, as they suggest that inter-colonial distance in transplantation projects has a significant role in ensuring the reproductive success of restored populations. Hence, we propose replicating the structural patterns characteristic of C. rubrum populations by restoring small, dense patches of reproductive colonies capable of sustaining breeding interactions and ensuring recruitment over generations.

How to cite: Giordano, B., Cannas, R., Cau, A., Guizien, K., Costantini, F., and Bramanti, L.: Decoding reproductive strategies to guide restoration and conservation: the case study of Mediterranean red coral (Corallium rubrum), One Ocean Science Congress 2025, Nice, France, 3–6 Jun 2025, OOS2025-1037, https://doi.org/10.5194/oos2025-1037, 2025.

Climate change has compromised large areas of coral reefs around the world due to raising temperatures and the arrival of heat waves. These conditions create an uncontrolled production of the so-called reactive oxygen species (ROS) that attack the tissues of corals, as well as the loss of the symbiont microalgae, which are the main source of energy to the coral, leading to mass bleaching events and coral death. Some species of microalgae produce ROS scavengers de novo, such as antioxidants, that can destroy these harmful compounds. Additionally, many antioxidants are commercially available in their purified form; however, the way of delivery as feed is crucial given their fast degradation rates due to their unstable chemical properties. Here we discuss our results of challenging the coral species Stylophora pistillata to thermal stress scenarios while providing them with antioxidant protection using two approaches, protection through the food web and environmentally in the surrounding water. S. pistillata was fed with Artemia salina, which was first fed with microalgae and antioxidant-enriched pellets, using vitamin C and E, fucoxanthin, astaxanthin and curcumin. The environmental antioxidant protection of the same five compounds was tested by preparing composites containing the antioxidants. These findings will contribute to strengthening the resilience of fragile coral species as well as protecting and restoring reef biodiversity. 

How to cite: Dorantes-Aranda, J. J., Camp, E., Matthews, J., Keaney, D., Moorhead, J., Kimberley, D., Doble, P., and Ferrier-Pages, C.: Antioxidant boost to corals to endure thermal stress as a climate change scenario, One Ocean Science Congress 2025, Nice, France, 3–6 Jun 2025, OOS2025-1063, https://doi.org/10.5194/oos2025-1063, 2025.

Restoring marine ecosystems is urgent to stop marine biodiversity loss caused by mounting anthropogenic and climate change pressures, and the subsequent impact on human well-being. Corals are priority targets of restoration efforts because they are ecosystem engineers that support high biodiversity and provide many ecosystem services. Diverse methods exist to favour coral recovery (e.g., direct adults’ transplantation, coral gardening, artificial reefs), and their strengths and limitations are well documented. The main concerns related to these approaches are that they are rarely adapted to the biology of the organism being restored and are not based on the ecological processes fundamental to the reproduction and survival of the species. Nature-based approaches that take advantage of ecological processes (i.e. - relying on sexually derived propagules and improved larval settlement to support coral reproductive, recruitment, and growth successes), are more promising for corals’ long-term recovery and for improving their resilience to climate change.

Mortality events of the Mediterranean white gorgonian (Eunicella singularis), mainly caused by climate change, have been observed at shallow depths over the last two decades, and exacerbated environmental pressures are expected to further impact this species in the future. The settlement of E. singularis larvae is promoted by selected crustose coralline algae (CCAs), but the exact mechanism involved in this facilitative process is unknown. A better understanding of the dynamics driving the early life stages of this species is needed to inform its conservation and restoration.

We present the knowledge gained through an experimental study that aimed at understanding 1) whether the microbiome and/or metabolites of specific CCAs may be drivers of higher settlement rate of E. singularis larvae, and 2) how the related mechanisms can be affected by ocean acidification and warming. First, we collected two phylogenetically identified CCA morphotypes, predominant and closely associated with E. singularis forests in Banyuls-sur-Mer (France, Western Mediterranean Sea). Prior to larvae arrival, CCA holobionts were exposed for eight weeks to projected 2100 temperature and pH conditions for the area (+2.5ºC and pH 7.78), and to a heatwave (26ºC for three weeks). Then we used these CCAs as substrates in experimental aquaria in the presence of E. singularis larvae. The bacterial community composition of these holobionts and the production of metabolites were analyzed before and after the treatments, and at the end of the settlement experiment to disentangle their effects on E. singularis larvae. We also assessed the potential transfer of bacteria from CCAs to gorgonian settlers.

Our results suggest that the production of chemical cues by CCAs in synergy with their associated bacterial communities promote a higher settlement success of E. singularis larvae. The unique sharing of bacterial sequences between CCAs and settlers hints at a potential influence of CCAs on the bacteria community composition of E. singularis microbiome, at least in its early life stages.

The study provides ecological knowledge on E. singularis settlement capacity under different climate change scenarios, and inform nature-based restoration strategies.

How to cite: Manea, E., Galand, P. E., Comeau, S., Ferrier-Pages, C., Giordano, B., Pezzolesi, L., Raina, J.-B., Tignat-Perrier, R., and Bramanti, L.: Positive micro- and macro-organism interactions: the way forward for nature-based restoration of Mediterranean octocorals. , One Ocean Science Congress 2025, Nice, France, 3–6 Jun 2025, OOS2025-1107, https://doi.org/10.5194/oos2025-1107, 2025.

Seagrass meadows and macroalgal forests are known to create rich ecosystems, that provide numerous ecosystem services, for example food provisioning, carbon storage, and erosion control. The Mediterranean coast in France has undergone significant artificialization due to urbanization, tourism, and industrial activities. Coastal development has led to the construction of ports, marinas, coastal defenses, and urban infrastructure, which have impacted natural habitats, leading to biodiversity loss and changes in coastal dynamics. Efforts are being made to balance development with conservation through coastal management plans and regulations aimed at protecting and restoring natural habitats.

In this project new habitat was created at the Cape of Agde, on the Mediterranean French coast by deploying structures that resemble seagrass meadows and kelp forests, with the aim to prevent local erosion and enhance local fish abundance and diversity. This demonstration was settled in the frame of an experimental project aiming at eco-designing underwater cables and supporting sediment stability in their vicinity for risk mitigation concerns. The structures were deployed on sand at shallow depths and monitored for sediment movements, water currents, and biodiversity monthly over a 7-month duration (March-October 2024).

Results indicate a strong increase in fish abundance during the day, as well as an increase in cephalopods during the night. The structures both served as a hiding habitat and feeding ground, with slightly better results for the macroalgae imitation. Both structures showed colonization of different organisms, with Fucus settling on the seagrass meadow imitating structure and mussels growing on the macroalgae imitating structure.

Overall, the project can be considered as a successful eco-design project, since the presence of the structures have had positive effects on the biodiversity and fish abundance and have proven to provide a wide range of habitat functions. That kind of approach may be settled as an addition for marine or offshore project in order to tackle biodiversity impacts and support or restore local nursery and habitat ecological functions.

Keywords: Ecological Restoration, Marine Environment, Ecological Functionalities, Seagrass, Eco-design, Impact Mitigation, Nursery, Habitat

How to cite: Schübert, C., Lapinski, M., Charlemaine, J., Martinot, M., and Dalle, J.: Seagrass and Macroalgae Imitations improve Marine Habitat Functions on the French Mediterranean coast, One Ocean Science Congress 2025, Nice, France, 3–6 Jun 2025, OOS2025-1258, https://doi.org/10.5194/oos2025-1258, 2025.

Stemming and reversing the (marine) biodiversity loss is one of the main global ambitions for the current decade and up to 2050. The European Union (EU) policy framework has responded with the European Green Deal, Biodiversity Strategy for 2030, and more recently Nature Restoration Regulation. These policies mirror the global ambitions and, sometimes, extend them even further. However, the question is how can these ambitious policy goals be achieved, particularly within the marine realm?

The EU policy framework tends to emphasise the importance of innovation, both to achieve the environmental goals and to ensure continued economic growth and increased EU global competitiveness. We have used the combination of semi-structured interviews, online surveys, focus groups, as well as policy and literature reviews to assess whether EU innovation policies provide adequate support for innovation to play a significant role in achieving the restoration targets for 2030 and 2050, with particular focus on the Atlantic-Arctic, Danube, and Mediterranean regions.

While the EU innovation policy has progressed significantly over the last 15 years, bridging many of the previously identified gaps and has been more and more linked to the EU environmental acquis as well, it is currently not adapted to the challenges that the restoration initiatives across Europe are facing. Most of the policy goals and tools are focussed on technological innovations, often specific to technologies for climate mitigation, but being vague when it comes to biodiversity, most often only mentioning “green transition”.  The financing mechanisms, governance structures, and ultimately policies are still in their infancy in relation to ecosystem restoration innovations. This contrasts with the fact that most restoration experts seem well aware of the relevance of different innovations (economic, financial, social, and policy), but there is little policy foundation to build upon.

The EU Mission Ocean initiative, in turn, is being effective in bringing innovation into the debate between policy makers, researchers, practitioners, and local administrators working on ecosystem restoration, also strengthening and widening existing networks in the four EU basins. At the same time, innovation in ecosystem restoration is still a new subject for many of them, and innovation ecosystems are not yet fully functional to streamline the entrepreneurial approaches. Evidence indicates that public sector support services for developing entrepreneurial initiatives in restoration activities remain limited, and there is little to no interest from the private sector in investing in such initiatives. For example, few existing services and mechanisms supporting innovation (e.g., incubators) can apply to ecosystem restoration practices.

Consequently, perhaps the role of innovation in restoration needs to be rethought, by either refocussing it more on the barriers that restorations actors are facing or moving towards wider implementation of tried and tested approaches with existing policy backing (e.g., strict protection and passive restoration). Where should we go to find restoration’s Holy Grail?

How to cite: Gorjanc, S., De Paoli, G., Jarry, C., Zaiter, Y., Rivière, C., Wang, J., Strosser, P., Lillebø, A. I., Pinho, M., Verling, E., O'Suilleabhain, D., Hausner, V. H., and Leines Dahle, M. L. D.: In search of the Holy Grail: Is innovation policy the one-size-fits-all solution to support marine, coastal, and freshwater ecosystem restoration in Europe?, One Ocean Science Congress 2025, Nice, France, 3–6 Jun 2025, OOS2025-1274, https://doi.org/10.5194/oos2025-1274, 2025.

One of the goals of the Coral Restoration Consortium (CRC) is to scale up coral restoration to ecologically meaningful scales by fostering collaboration and knowledge transfer among members and stakeholders. To accomplish this, several working groups were formed to address specific priorities within the various disciplines of coral reef restoration. One of these working groups, the larval (LP) propagation group, aims to improve methods to sexually propagate many millions of coral larvae for larger-scale coral restoration and research. The biggest challenge being addressed by the larval propagation group is to increase post-settlement survival of reef-settled and outplanted coral settlers to increase the effectiveness of this approach. Additional objectives include 1) Developing a coordinated breeding program to highlight best practices to successfully collect gametes, rear and settle coral larvae, and outplant sexual recruits; 2) Broadening the number of species targeted for restoration; 3) Expanding the number of locations that conduct larval propagation work globally; and 4) Developing new technologies to enable mass rearing and settlement of coral larvae as well as efficient outplanting to increase the cost-effectiveness of this approach. To help achieve these goals, a Caribbean Coral Spawning Database was created by members of the LP group, incorporating standardized spawning observations for as many coral species and locations as possible. The information compiled is used to generate accurate coral spawning prediction calendars, and to expand our knowledge about species-specific reproductive traits, which can then be used to develop coral breeding reference sheets. These breeding reference sheets include all information available on individual species’ reproductive biology and early life history as well as tailored best practices for larval propagation. Building on the members’ varied areas of expertise, the larval propagation group recently published a review article in Restoration Ecology highlighting best practices, knowledge gaps and priority actions for the application of coral breeding and restoration. The larval propagation membership is now expanding into Indo-Pacific and other reef regions, with the aim to create a global network of researchers, practitioners and stakeholders to increase the scales of mass larval production, settlement and recruitment of resilient corals on damaged reefs. Overall, the LP group aims to guide the coral restoration community toward actions that yield significant advances in larval rearing and coral breeding, foster collaborations, and ultimately achieve larger-scale and sustainable ecological restoration of corals and reefs.

How to cite: Banaszak, A., Chamblerland, V., Miller, M., and Harrison, P.: Actions to scale up and implement larval propagation in reef restoration, One Ocean Science Congress 2025, Nice, France, 3–6 Jun 2025, OOS2025-1285, https://doi.org/10.5194/oos2025-1285, 2025.

Seagrass meadows, especially those formed by Zostera species, are critical for coastal ecosystems, providing habitat, enhancing water quality, and stabilizing sediments. However, these meadows have  dramatically declined in the Arcachon Basin since 1989, primaly due to rising temperature. Then a positive feedback loop leads to a global decline as identified by Ifremer studies, which hinder their natural recovery. In response, our project aims to restore these valuable ecosystems by creating hydrodynamic conditions favorable to Zostera seagrass regrowth.

We developed a flexible, biomimetic structure designed to mimic the physical properties of seagrass leaves. This solution reduces current velocities and bottom shear stress, similar to natural seagrass meadows. Initial design and calibration were performed on a small scale, testing various configurations of "leaves" on the field with in-situ monitoring, to determine the optimal size, density and position in the water column for effective hydrodynamic control. Numerical modeling further refined the design, predicting system performance across various environmental conditions.

Pilot installations at larger scales in the Arcachon Basin have shown promising results. Early field data indicate a significant reduction in current speed and bottom shear stress around the structures. Additionally, the altered hydrodynamic environment has already begun showing signs of improved sediment stability and enhanced suitability for Zostera transplantation. These findings suggest that our biomimetic approach could serve as a scalable and effective tool for the ecological restoration of seagrass meadows, offering a new pathway to enhance coastal resilience and biodiversity.

How to cite: Cognat, M., Schubert, C., Lapinski, M., Fauvel, T., Ganthy, F., and Dalle, J.: Innovative Approaches to Zostera Seagrass Meadow Restoration in the Arcachon Basin: Biomimetic Solutions for Hydrodynamic Control, One Ocean Science Congress 2025, Nice, France, 3–6 Jun 2025, OOS2025-1321, https://doi.org/10.5194/oos2025-1321, 2025.

CLIMAREST project represents a pioneering approach to marine restoration integrating scientific knowledge with stakeholder engagement to enhance marine biodiversity. In Madeira Island, the project emphasizes the crucial role of macroalgae in coastal ecosystems, which serve as habitat-forming species that support diverse marine life and contribute to ecosystem services such as nutrient cycling, and carbon sequestration or food provision. The restoration actions undertaken in this case study highlight the importance of identifying and involving key local stakeholders in the restoration process. Stakeholder engagement is a critical component of successful restoration projects, as it helps to align conservation goals with local community interests and knowledge. During the project, local stakeholders were ranked based on their potential impact and engagement levels, which were assessed through questionnaire surveys. In Madeira, dive operators were identified as key stakeholders that benefit from restoration actions that can effectively contribute to restoration efforts. The involvement of dive centres is particularly significant, as they are often at the forefront of marine tourism and have direct access to the underwater environment. Their participation in restoration efforts at selected dive sites is expected to enhance the effectiveness of the restoration actions by providing valuable data and facilitating monitoring. A key innovation of this project is the use of the Dive Reporter a custom mobile application and web interface that enables dive centres to report occurrences of key indicator taxa. By providing digital kiosks and tablets with Dive Reporter app, it is possible to assess biota occurrences and shifts over time. Periodic contact with these stakeholders is necessary to maintain their commitment and willingness to assist and contribute to algae transplantation, grazing control and other restoration efforts. This collaborative approach is expected to yield more sustainable outcomes, as it fosters a shared commitment to marine conservation among local communities. The involvement and engagement with other stakeholders and the local population relied on various methods, including online surveys, workshops, one-on-one meetings, and outreach sessions which were designed, not only to inform on the project efforts, but also to gauge general perception of the need and benefits of local restoration actions. These initiatives not only empower local stakeholders but also fosters a sense of ownership and responsibility towards marine conservation efforts. CLIMAREST project on Madeira Island serves as a model for combining scientific research with stakeholder engagement in macroalgae restoration. The lessons learned from this case study could inform future restoration initiatives in similar coastal environments, emphasizing the importance of collaboration and adaptive management in achieving ecological restoration goals

How to cite: Parretti, P., Dinis, A., Schäfer, S., Silva, R., Buzinkai, M., Bernal, A., Gouveira, M., Piazzese, L., Bernasconi, C., Freitas, R., Orfão, I., Vieira, D., Almeida, A., Radeta, M., Canning-Clode, J., and Gama Monteiro, J.: Connecting Communities: Digital Pathways to  a Collaborative Successful Restoration, One Ocean Science Congress 2025, Nice, France, 3–6 Jun 2025, OOS2025-1403, https://doi.org/10.5194/oos2025-1403, 2025.

The Tetiarao Atoll Restoration Program is an innovative conservation research program that is focusing on the land/ocean interface to protect coral reefs by restoring the terrestrial habitat of an atoll. Seabirds are the key to this system because they transport nutrients from the ocean to the island and deposit them as guano. These nutrients, while essential to the terrestrial and marine ecosystems of the island have been in short supply in modern times since the seabird populations have dwindled due to invasive species. We are removing all invasive species from the island including rats, ants, and coconut trees (planted as a plantation). Since removal of rats and ants we have already seen over 100% increase in nesting for one seabird species and another species arrive and nest for the first time in recorded history. A detailed monitoring plan is recording the recovery of the island biota from the island to the barrier reef. The aim with this program is to provide a model for other atolls to use to promote healthy islands and reefs as the climate changes.

How to cite: Murphy, F.: Tetiaroa Atoll Restoration Program, One Ocean Science Congress 2025, Nice, France, 3–6 Jun 2025, OOS2025-1438, https://doi.org/10.5194/oos2025-1438, 2025.

Restoration ecology is an emerging branch of environmental science. Current measures to protect the marine environment primarily aimed at reducing environmental stressors, for example through the establishment of MPAs, but this passive protection is not sufficient. The precious Mediterranean coral Corallium rubrum is listed in the IUCN red list: in several countries, the deep stocks are heavily harvested, and climate change poses an additional threat to the shallow populations. Therefore, basic transplantation techniques are inappropriate for this extremely slow growing species. The only successful way to obtain more colonies is through reproduction and the generation of newly born colonies. Our goal is to establish a protocol based on science that focuses on sexual reproduction as the main vector of restoration. To this aim, we set up colonies of C. rubrum in 6 artificial caves at 40 m depth in 2021 and focused on finding the ideal sex ratio and colony density to obtain an optimal reproduction.

In each cave, 9 plates could be inserted, and colonies of Corallium rubrum, already identified as male or female, were placed on each of these plates. On each tile 4 substrates were glued (smooth and rough terracotta, and red and white marble) to find out whether the larvae have a settlement preference. The sliding tiles can be removed and brought back to the laboratory, to monitor the recruitment success or the growth of the colonies. These caves constitute an underwater laboratory in semi-controlled conditions and allow the development of standardized rearing protocols that are optimized for the restoration C. rubrum populations.

Our results show that two of the 6 caves were particularly favorable to larval settlement as we counted 139 and 102 larvae attached to the substrates. Concerning the sex ratio, the presence of one or at most 3 males for 6 to 8 females was the most favorable combination. In these caves, we counted 250 recruits in total, with 84 recruits on the terracotta without distinction between smooth and rough, and 166 recruits on marble (64 on red and 79 on white marble).

How to cite: Reynaud, S., Bramanti, L., Giordano, B., Tambutte, S., Ferrier-Pages, C., Beraud, E., Loentgen, G., Ganot, P., Tignat-Perrier, R., and Allemand, D.: Recruits of Corallium rubrum in artificial caves, One Ocean Science Congress 2025, Nice, France, 3–6 Jun 2025, OOS2025-1461, https://doi.org/10.5194/oos2025-1461, 2025.

Deoxygenation of the marine environment has been linked to: 1) global climate change, through decreasing gas solubility, increased stratification reducing deep ventilation and changes of the spatiotemporal and biogeochemical properties of ocean currents and 2) excessive nutrient input to the marine environment causing eutrophication. Both are linked to human activities¹. The low oxic conditions are threatening biodiversity and the the marine ecosystem through reduction of habitat and altering biogeochemical processes in water and sediment². This deterioration is significantly impacting regional economies, affecting thousands of jobs and billions of dollars^3,4.  Apart from limitations of greenhouse gas emissions and nutrient pollution, current conservation measures do not effectively address the impacts of reduced oxygen in the marine environment featureing large implementation time lags in projected outcomes^5,6.

Global offshore wind energy production potential is huge⁷ and often linked to the planned production of green hydrogen (e.g., 0.5 GW electrolyzer: ~210 t H₂ d^-1; ~1700 t O₂ d^-1). The oxygen could be used to mitigate anoxia, restore benthic habitat, reduce phosphorus loading, and suppress algal blooms in the coastal setting. Constant artificial oxygen injection (AO) could help combat hypoxia caused by circulation shifts, decreased deep mixing in autumn and winter and climate change⁸.

In freshwater, except for coastal ocean aquaculture, small-scale AO is used, but larger-scale efforts are rare. Techniques were largely developed and implemented in US reservoirs^{9 (}largest is 350t O₂/d). AO for the marine environment has received little attention, likely due to the missing science basis in the marine environment, the investment costs (e.g. oxygen¹⁰) and/or lack of infrastructure and awareness.

We want to present a first step toward the long-term objective of AO implementation in a larger scale setting. This first step is a small-scale AO pilot installation in a rather constrained marine environment. This effort was prepared by the BOxHy project (BSAP funded 10/2023 to 10/2024), generating a methodology and data analysis concerning a pilot study site for AO in the Baltic Sea with the perspective of upscaling the science/technology to basin wide scales. AO, as a novel innovative mitigation technique could be adapted to other anoxia-prone coastal environments after successful research and demonstration, closing major knowledge gaps and exploring the risks for unintended consequences. Exploring AO as a mitigation measure directly aligns with the principles of "prevention of harm” and the “precautionary approach” outlined in the “Declaration of Ethical Principles in Relation to Climate Change”¹¹.

1 Breitburg 2018.

2 Gregoire 2023.

3 Pitcher 2021. 

4 Dewar 2009. 

5 STAC 2023. 

6 Guidelines for Sea-Based Measures to Manage Internal Nutrient Reserves in the Baltic Sea Region. (2021) 

7 IEA2019 Offshore wind outlook 2019: world energy outlook special report

8 Wallace 2023. 

9 Mobley 2019.  

10 Stigebrandt 2022.

11 Declaration of Ethical Principles in Relation to Climate Change. 2017 UNESCO Paris

How to cite: Handmann, P., Walve, J., Austin, D., and Wallace, D.: A Pilot Site Study to Remediate Low oxygen Conditions in Coastal Seas, One Ocean Science Congress 2025, Nice, France, 3–6 Jun 2025, OOS2025-1574, https://doi.org/10.5194/oos2025-1574, 2025.

This virtual poster presentation is to present the The Bahama Banks Blue Carbon project, a first-of-its-kind seagrass conservation project, innovating with methodology and technology to map and protect the world's largest seagrass meadow.

Blue Carbon International (BCI) is an independent extension of the internationally renowned ocean conservation not-for-profit Beneath The Waves. BCI empowers Governments, indigenous landowners and the private sector to map, value, finance and protect ocean ecosystems at scale.

The Bahama Banks Blue Carbon project is a seagrass conservation project undertaken by the government of The Bahamas in partnership with BCI. The Bahamas is home to the world's largest seagrass ecosystem (estimated to be 9.3 million hectares), but our mapping reveals that as much as 30% of the ecosystem was lost between 2010 and 2020. 

This project is the first-of-its-kind, deploying methodologies and technologies at a scale not seen before in seagrass conservation.

Firstly, representing one of the largest ocean discoveries of the decade, BCI’s founding partner Beneath The Waves discovered the seagrass meadow while studying tiger shark movements, with sharks tagged with satellite tags and custom-built cameras.

Secondly, innovating with scalable methodology and technology, an initial subsample of 500,000 hectares has already been mapped to 5cm accuracy using satellite imagery and aerial Lidar, following Verra-developed and approved methodology (VM0007/VM0033).

Regarding conservation project activities, environmental impact assessments have been completed, recommending a primary focus on seagrass health and extent. Proposed project activities aim to improve water clarity and reduce nutrient loading to coastal waters, which induces favorable conditions for seagrass. Because of strong evidence of land-based pollution degrading coastal waters, the majority of proposed project activities to improve water quality will likely focus near the shore. Some of the project activities include: tertiary treatment to remove nutrients in wastewater; remediating former aqua/agriculture and/or landfills in coastal lowlands; tightening regulations for sediment from dredging/construction activities; and restoring mangroves for coastal and erosion control.

How to cite: Richardson, H.: Bahama Banks Seagrass Conservation: Mapping and Protecting the World’s Largest Seagrass Meadow, One Ocean Science Congress 2025, Nice, France, 3–6 Jun 2025, OOS2025-33, https://doi.org/10.5194/oos2025-33, 2025.

The coastal marine environment is a social-ecological system that is inherently fluid and highly dynamic – the relationships between marine ecosystems and social systems are multifunctional, multiscale, complex and fluctuating. In Aotearoa New Zealand (NZ), like many other countries around the world, the coastal marine environment is increasingly under threat from competing human uses and climate change which are affecting marine ecosystem resilience and contributing to marine biodiversity decline.  Impacts are further exacerbated by a preservation-focused western regulatory framework, underpinned by colonialist limitations and static approaches (such as traditional area-based management tools), which fail to recognize the marine environment as a social-ecological system and are not well suited to govern an acting and shifting environment. 

As NZ (and other coastal nations) grapple with these issues and seek to meet international biodiversity obligations, marine experts across a range of disciplines are increasingly advocating for a shift away from traditional static preservation/protection approaches to more adaptive legal frameworks that support flexible and dynamic marine ‘restoration’ at appropriate scales. However, there is uncertainty and lack of consensus in international scholarly and policy debates about how marine laws and policies can be sufficiently flexible to cope with the dynamic nature of marine ecosystems and the multi-scale and complex challenges presented by the climate-biodiversity-extinction crisis. 

How to cite: Mortiaux, R.: Dynamic Coasts, Evolving Laws: innovative approaches to flexible marine ecosystem restoration, One Ocean Science Congress 2025, Nice, France, 3–6 Jun 2025, OOS2025-398, https://doi.org/10.5194/oos2025-398, 2025.

Marine Ecosystems are under multifaceted stress worldwide. Key ecological functions are being degraded, damaged and destroyed. Ecological restoration approaches are a global priority to assist the recovery of ecosystem functions and services and are an essential complement to conservation. The UN Decade on Ecosystem Restoration highlights the potential for ecosystem restoration to provide transformative change and to simultaneously meet multiple goals and targets for social, economic and ecological benefit. Against the background of reef habitat restoration, this presentation will discuss perspectives and potential of the EU Nature Restoration Law (NRL) and the application of Society for Ecological Restoration (SER) standards in marine systems: The identification of reference ecosystems, and the use of reference models to describe restoration targets and success metrics, the cumulative value of projects across all scales and the concept of applying and integrating passive and active restoration measures along a restorative continuum, from reducing threats to the full recovery of natural ecosystems.

How to cite: Pogoda, B.:  Nature Restoration Law (NRL) & UN Decade of Ecosystem Restoration: Perspectives and potential of reef habitat restoration , One Ocean Science Congress 2025, Nice, France, 3–6 Jun 2025, OOS2025-761, https://doi.org/10.5194/oos2025-761, 2025.

Despite the extreme environmental conditions of the Arabian Gulf, three species of seagrass are observed in its coastal waters, Halodule uninervis, Halophila stipulacea and H. ovalis. These species are forming large seagrass beds representing up to 6% of the worldwide meadows. The Gulf’s seagrass meadows are supporting the World second largest population of dugongs, Dugong dugon. They are also playing a vital role in this vegetation-scarce region as blue carbon ecosystems, alongside the mangrove forests. Based on all these reasons, scientific interest is growing rapidly to understand the mechanisms behind their resilience to heat as well as to develop large scale effective restoration methodologies.

An aquaculture system has been designed to support the development of optimum indoor cultivation methodologies of the local seagrass species. The Recirculatory Aquaculture System is based on aquaponic principles with water from large fish tanks feeding into the seagrass raceways. Temperature and salinity are controlled in the fish tanks while lighting, water depth and currents are adjustable in the raceways. The current trials are aiming to define the optimum cultivation conditions focusing on the light intensitya and spectrum, the sediments characteristics and the nutrient inputs.

Samples from mixed meadows of H. uninervis and H. ovalis have been successfully maintained in this aquaculture system since their collection in winter time.The ability to control the water quality, the photoperiod as well as the light spectrum and intensity distributed over the seagrass raceways is critical to define the species growth optimums.

As little knowledge is existing about these seagrass species’ sexual reproduction in the Gulf, subsequent trials will be developped to pinpoint environmental conditions that could trigger their flowering in this indoor cultivation setting. The aim of the overall project is to enable the production of seeds that would support large-scale restoration programs in the Gulf region. 

How to cite: Marquis, E., Nguyen, H., Koothuparambil, A., Velakkandy, S., Robles, G., Lewes, C., Kandiyil, R., Alves, A., and Waqalevu, V.: Development of an indoor seagrass nursery in the United Arab Emirates: mastering the cultivation methods of the seagrass species living in the hottest sea on Earth. , One Ocean Science Congress 2025, Nice, France, 3–6 Jun 2025, OOS2025-1346, https://doi.org/10.5194/oos2025-1346, 2025.

Coral reefs around the world are threatened by multiple stressors, including changing temperatures, overfishing, pollution, and disease. The survival and resilience of corals will depend on their ability to adjust to these environmental challenges through adaptive evolutionary processes. Since the 1970s, the reef-building corals of the Florida Reef Tract (the world’s third largest barrier reef) have declined due to a complex mix of local and global pressures: a pattern reflected throughout the Caribbean. Elkhorn coral, the region’s dominant reef-builders, once had a Florida population in excess of 500,000 colonies. Even before the 2023 bleaching event, only 200 elkhorn genets remained.

Despite the historical loss of reef-building corals, active restoration efforts have shown that corals can survive and reach sexual maturity in Florida and the Caribbean. However, the health of Caribbean reefs and their long-term resiliency will depend on restored populations to sexually reproduce and adaptively evolve to changing environmental conditions. Unfortunately, no wild-born juvenile corals have been observed along the Florida reef tract in the past 15 years and there is evidence that normal development of very young corals is being disrupted throughout the Caribbean, preventing the completion of the coral life cycle. A return to growth via sexual reproduction on Florida and Caribbean reefs will be essential for increasing genetic diversity and the regeneration of the tract at the necessary pace, scale, and resiliency to meet our goals.

The “Closing the Coral Circle” workshop united international experts in coral biology and ecology, advanced forensics, engineered biology, and robotics to tackle this critical conservation challenge. Together, we discussed various aspects of coral biology, as well as biological, chemical, and physical factors in the corals’ environment that could be hindering the completion of the coral life cycle. Major themes identified fell into two categories: (1) problems for recruitment that are well-understood, and (2) knowledge gaps in our understanding of coral recruitment dynamics and how these might contribute to the problems. In this presentation, we will discuss the outcomes of the workshop including our “service blueprint” for coral recruitment, which is a visual map of the challenges, knowledge gaps, and potential solutions, (available on Zenodo) to aid the community in project planning.  

How to cite: Baums, I. B., Baumsgartner, B., Gerdes, M., Miraglia, P., Moore, J., Williamson, L., and Winters, R. S.: “Closing the Coral Circle”: Approaches to overcome the recruitment bottleneck preventing coral recovery in the Caribbean, One Ocean Science Congress 2025, Nice, France, 3–6 Jun 2025, OOS2025-1412, https://doi.org/10.5194/oos2025-1412, 2025.