Dominique Pelletier

Understanding the status and trends of Essential Ocean Variables (EOV) and Essential Biodiversity Variables (EBV) is crucial for informing policy-makers and the public about sustainable management of marine biodiversity. Marine image data hold significant potential in this context, offering a permanent, information-rich and non-extractive record of marine environments at the time of capture. Quantitative image-based measurements such as species abundance and distribution have proven to be highly effective for engaging diverse stakeholders. The exchange and reuse by experienced fisheries scientists and marine ecologists of nine image-based datasets (including images, metadata and annotations) collected through various protocols revealed a substantial disconnect between initial expectations and actual practical usability, particularly in terms of understanding and reusing data. Two key issues were highlighted. First, the link between the datasets and their potential applications in deriving EOV/EBV was often inadequately described or absent. Second, despite both initial and ongoing efforts to document the data, new users continued to face challenges in understanding underlying properties and contextual features of datasets. We suggest these findings are likely to characterize many, if not most, historical image-based datasets. While standards promoting the FAIR principles (Findable, Accessible, Interoperable, and Reusable) for image-based data are emerging, our focus here is on the specific features of documentation that enable or facilitate reuse of data for the purpose of deriving EOV/EBV. From this perspective, we provide a set of recommendations for documenting both images and their associated annotations, aimed at supporting broader applications of in situ image data in marine conservation and ecology.

Small-scale fisheries operating in coastal areas represent 90% of worldwide fisheries and 84% of the European Union (EU) fleet. They are globally vital for coastal populations as they sustain a major source of animal protein, provide numerous job opportunities, livelihoods, support economic activities and are culturally central. In EU Outermost Regions (ORs), these fisheries are subject to the Common Fisheries Policy (CFP) and related regulations, although they benefit from derogatory or specific regimes for instance regarding fleet renewal. Obligations include in particular reporting on fleet fishing capacity to inform future fisheries policies.Small-scale fisheries are typically data-limited. In this context, assessing the ecological and socio-economic sustainability of local fisheries through the status and evolution of fish stocks and fleets is a challenge that relies on utilizing existing knowledge and collecting additional key data.In order to address this challenge, a holistic approach based on fisheries socio-ecosystems (FSES) wasinitiated. In 2022, a pluridisciplinary working group (WG) was formed that included fisheries scientists, marine ecologists, social scientists and fisheries economists, in order to compile fisheries-related knowledge and data in the five French EU ORs (Guadeloupe, Martinique and French Guiana in the Atlantic Ocean and Reunion and Mayotte in the Indian Ocean). This comprehensive endeavour of the group provided the first overview of fleets, stock status and overall social and economic context in each OR as well as the environmental and ecosystem interactions with fisheries.The WG organized institutional exchanges through an overall workshop and several meetings with stakeholders (national and local fisheries managers, fishers’ representatives and other stakeholders) of each territory. The fisheries’ current status were presented, together with existing research projects and knowledge gaps; and discussions were engaged about the challenges faced by stakeholders and their needs, and identifying the needs that can be studied or documented by science.In 2024, a first report presents validated assessment results for 38 coastal stocks, and describes in detail the economic and social situation of the different fleets of the French ORs, as well as the interactions with other uses of fishery resources (large-scale commercial fishing, recreational and subsistence fishing, illegal fishing), the seafood sectors, and the governance and regulation of fisheries. The impacts of fishing on ecosystems, other factors of erosion of populations and biodiversity and the implications for fishing are also discussed.We present the main findings of this report, and discuss knowledge gaps and potential solutions to make up for these. Although the WG work is iterative, the approach used proved fully relevant and effective, due to both the FSES integrated approach, the sharing of experiences and expertise from several OR, and the interactions with the stakeholders. The WG outcomes will contribute documenting sustainability indicators in the perspective of UN SDGs and improving the governability of FSES in a tight context regarding marine biodiversity conservation, maritime spatial planning and climate change.

Most platforms for collecting images to characterise marine benthic habitats involve a downward or forward‐facing field of view that is relatively constrained (~70°), covering a relatively small area of benthos (downward ~1 m², forward ~25 m²). Here we propose the use of a four‐camera platform having a wide combined field of view (~280°), covering a much greater area (up to 100 m²). We also present a stereo‐camera configuration that has the added benefit of being able to accurately measure sample area and dimensions of benthic biota. The design proposed is robust and self‐righting, facilitating rapid deployment and retrieval from a range of vessels, depths and environments. We present an exemplar workflow to generate a habitat map (~100 km²) within a no‐take National Park Zone within the South‐west Corner Marine Park, Australia and demonstrate the benefit of increasing the field of view to estimate habitat heterogeneity. The relatively broad sample unit of this wide‐field drop camera is well suited to estimating coverage (e.g. of a seagrass bed) and habitat mapping. It is time‐efficient in the field, enabling spatially balanced sampling designs to acquire ground‐truthing data for medium‐ to large‐scale habitat mapping projects. This platform is a practical tool to monitor change in marine environments and assess the environmental impact (e.g. sea bed alteration) of activities such as offshore energy or fishing gears.

Fish spawning aggregations (FSAs) are critical events in the life cycle of many commercially and ecologically important species, yet FSAs are often exploited and highly vulnerable to fishing due to their predictability in time and space. Although FSAs are increasingly recognized as a conservation and management priority, monitoring these ephemeral dynamic events remains challenging. Here, we assessed the ability of remote underwater video (RUV) to monitor reef FSAs, using blacksaddled coral grouper (Plectropomus laevis) as a case study. We deployed RUV systems monthly on a year-round basis in a reef channel of the New Caledonian barrier reef where P. laevis was assumed to form spawning aggregations. Specifically, we investigated whether RUV could both track spatiotemporal changes in fish abundance and detect spawning signs to validate the purpose of potential gatherings. Our analysis revealed strong seasonal changes in P. laevis abundance, characterized by a 5-fold increase between October and February, and marked variations among sampled habitats. The probability of occurrence of males in courtship colouration showed spatiotemporal patterns fairly similar to those in abundance. Finally, we recorded clear courtship behaviours between November and April, providing evidence that P. laevis aggregate monthly to spawn during a protracted reproductive season. This study advances our understanding of the spawning aggregation dynamics of this understudied grouper, and highlights the potential of RUV to monitor and ultimately inform management of reef FSAs.

Numerous conceptual frameworks exist for best practices in research data and analysis (e.g., Open Science and FAIR principles). In practice, there is a need for further progress to improve transparency, reproducibility, and confidence in ecology. Here, we propose a practical and operational framework for researchers and experts in ecology to achieve best practices for building analytical procedures from individual research projects to production-level analytical pipelines. We introduce the concept of atomization to identify analytical steps that support generalization by allowing us to go beyond single analyses. The term atomization is employed to convey the idea of single analytical steps as “atoms” composing an analytical procedure. When generalized, “atoms” can be used in more than a single case analysis. These guidelines were established during the development of the Galaxy-Ecology initiative, a web platform dedicated to data analysis in ecology. Galaxy-Ecology allows us to demonstrate a way to reach higher levels of reproducibility in ecological sciences by increasing the accessibility and reusability of analytical workflows once atomized and generalized.

The Chesterfield-Bellona atolls and reefs are a vast reef complex located in the Coral Sea Marine Park, estab-lished in 2014 in the New Caledonian Economic Exclusive Zone. In 2013, the New Caledonia government supported the first assessment of fish and benthic habitats conducted in all habitats and over the entire area. The assessment provided a primary knowledge base for establishing the importance of these atolls in terms of biodiversity and fished resources. This comprehensive survey relied on the STAVIRO unbaited underwater video technique and collected 185 successful camera drops distributed over all shallow habitats in the atolls. The analysis of video foot-ages revealed 18 fish species and one snake species that had not been previously reported in this area. Sharks were frequently observed (43% of stations) and to a lesser extent sea snakes (9% of stations). The overall list of observed species included the globally threatened sicklefin lemon shark and commercially important species. The findings of the survey supported the establishment of strongly protected areas at these atolls in 2018. These outcomes highlight the interest of unbaited underwater video for effective surveying of large areas, and for observing infrequent and shy species. Additionally, video provides actionable and shareable scientific evidence that can support further re-search, management and educational purposes.

New Caledonia is internationally renowned for its exceptional marine biodiversity, which has resulted in 80% of the lagoons and reef areas being placed on the UNESCO World Heritage list. This chapter presents the main features of this outstanding marine biodiversity and its ecological significance, highlighting the threats posed by anthropogenic pressures and global drivers, and associated conservation challenges. Oceanic and coastal dynamics determine distinct marine ecosystems. The oceanic ecosystem of the Coral Sea will be described first, and this chapter will focus on the lagoon and reef areas, which are in close relation to human populations.

Editorial: Marine Biodiversity Observation Network (MBON)

Background: Monitoring the ecological status of coastal ecosystems is essential to track the consequences of anthropogenic pressures and assess conservation actions. Monitoring requires periodic measurements collected in situ, replicated over large areas and able to capture their spatial distribution over time. This means developing tools and protocols that are cost-effective and provide consistent and high-quality data, which is a major challenge. A new tool and protocol with these capabilities for non-extractively assessing the status of fishes and benthic habitats is presented here: the KOSMOS 3.0 underwater video system. Methods: The KOSMOS 3.0 was conceived based on the pre-existing and successful STAVIRO lander, and developed within a digital fabrication laboratory where collective intelligence was contributed mostly voluntarily within a managed project. Our suite of mechanical, electrical, and software engineering skills were combined with ecological knowledge and field work experience. Results: Pool and aquarium tests of the KOSMOS 3.0 satisfied all the required technical specifications and operational testing. The prototype demonstrated high optical performance and high consistency with image data from the STAVIRO. The project’s outcomes are shared under a Creative Commons Attribution CC-BY-SA license. The low cost of a KOSMOS unit (~1400 €) makes multiple units affordable to modest research or monitoring budgets.