Marta Coll

Marine conservation must advance towards global biodiversity targets despite significant climatic and geopolitical uncertainties. We present an expert-informed scenario framework to support systematic conservation planning in marine environments in the face of such unpredictable conditions. Through a six-step process involving an expert workshop and a survey of 85 respondents, climate change and international politics, governance and legislation were identified as the most relevant and uncertain drivers of marine conservation futures amongst the fourteen drivers considered. Their contrasting states were combined into four qualitative scenarios, ranging from effective climate mitigation and international cooperation to inadequate climate action and geopolitical conflict. We propose ways to translate these scenario narratives into conservation planning options by linking them to spatial decision-support tools and analytical workflows, considering biodiversity distributions, ecological connections amongst areas, climate risks, socio-economic costs and other effective area-based conservation measures. Two proposed analytical approaches illustrate how these considerations could be combined under different scenarios about the future. The resulting conservation priorities would provide information for ecosystem-based marine spatial planning by identifying biodiversity objectives and spatial requirements for consideration alongside other marine uses. The proposed framework provides a basis for exploring the way in which conservation strategies may perform under contrasting futures and adapting planning choices as ecological and governance conditions change. Expert-informed scenarios explore alternative futures for marine conservation. Climate action and geopolitics frame four contrasting conservation scenarios. Proposed planning approaches link these scenarios to systematic conservation planning. Comparing priorities across scenarios could support adaptive decisions. Conservation priorities can provide information for wider marine spatial planning processes.

Cities are increasingly important actors in food governance, yet their role in blue food systems remains poorly understood, particularly because they generally lack authority over fisheries management. This study examines how municipal policies shaped Barcelona’s blue food system between 1940 and 2023 and asks how local governments influence seafood provisioning through powers exercised beyond production. We combine long-term official statistics, archival and legal analysis, and semi-structured interviews within a historical PESTEL framework. The findings reveal a transition from direct market intervention to infrastructural governance. During the mid-twentieth century, municipal price controls, centralized distribution rules, and investments in wholesale and public retail markets structured seafood flows and reinforced the position of local fishmongers. Subsequent economic liberalization, European integration, technological change, and the relocation of the central wholesale market reduced direct municipal control while facilitating Barcelona’s integration into global seafood networks. At the same time, ecological decline in local fisheries weakened the connection between urban consumption and surrounding marine ecosystems and contributed to the marginalization of the city’s fishing community. Nevertheless, Barcelona’s continuing network of municipal food markets has helped preserve a comparatively strong role for fishmongers and access to fresh seafood. The case demonstrates that cities shape blue food systems not primarily by managing fisheries or regulating prices, but through long-term decisions about markets, logistics, spatial planning, and retail infrastructure. Such decisions can preserve urban food access while simultaneously reinforcing dependence on distant ecosystems and redistributing benefits and vulnerabilities across seafood supply chains.

Understanding the trophic ecology of marine megafauna is essential for elucidating their ecological roles and supporting effective conservation strategies. The ocean sunfish ( Mola mola ) is the second-largest bony fish worldwide and has a broad distribution, including the Mediterranean Sea. Despite its size and widespread occurrence, many aspects of its biology remain poorly understood. Traditionally regarded as an obligate feeder on gelatinous zooplankton, recent evidence instead points to a more generalist feeding strategy. Here, we applied a multi-method approach integrating stomach content analysis, DNA metabarcoding, and stable isotope analysis to investigate the feeding ecology of ocean sunfish in the western Mediterranean Sea. Our results revealed that, indeed, ocean sunfish mainly consume gelatinous zooplankton, particularly siphonophores such as Chelophyes appendiculata . However, substantial arthropod, mollusc and chordate contributions were also detected by molecular or observational methods, suggesting a more generalist diet. Stable isotope analysis showed high δ ¹⁵ N values compared to other sympatric marine predators reported in the literature, while δ ¹³ C values showed that ocean sunfish feed extensively in oceanic/pelagic environments. Our results suggest that ocean sunfish in the western Mediterranean Sea occupy an intermediate trophic position but are isotopically segregated from other sympatric marine predators, reflecting a distinct trophic niche. Our integrated approach shows that ocean sunfish play an important role as intermediate predators, facilitating energy transfer from low pelagic trophic levels to higher-level predators, and potentially contributing to the regulation of gelatinous plankton populations.

Aim: To quantify temporal (Middle Holocene, historical and future) and spatial changes in habitat suitability for marine species in two South American Large Marine Ecosystems, and to evaluate the ecological consistency of long‐term Species Distribution Model projections using archaeological records as independent evidence of past species occurrences. Location: Humboldt Current and Patagonian Shelf Large Marine Ecosystems (LMEs). Time Period: Middle Holocene (~8200–4200 years BP), present day (1850–2014), and a projected future warming scenario (2015–2099; SSP5‐8.5). Major Taxa Studied: Marine fish, penguins and pinnipeds. Methods: SDMs were developed for nine marine species using present‐day occurrence records and contemporary environmental predictors. Models were projected to Middle Holocene climatic conditions and to a future high‐emissions scenario. Archaeological records of fish, penguins and pinnipeds from the Middle Holocene were compiled and used as proxies for past species occurrences to evaluate model projections through time. Results: Bathymetry emerged as a key predictor of habitat suitability for most species. Projections revealed pronounced temporal and spatial shifts in suitable habitat. Most fish species showed higher suitability at higher latitudes during the Middle Holocene, followed by contractions in the historical period and future projection. Penguin species exhibited heterogeneous responses, with several showing strong declines in future suitable habitat. Pinniped species displayed mixed patterns of contraction and expansion depending on region and time period. Comparison with archaeological records indicated that seven of the nine SDMs correctly identified suitable habitats consistent with Middle Holocene occurrences. Main Conclusions: Zooarchaeological data provide an independent line of evidence to assess the temporal robustness of marine SDMs. Incorporating past climatic periods improves confidence in long‐term biogeographical projections and enhances understanding of species' distributional dynamics under climate change.

Aim: To identify and map Priority Penguin Habitat Areas (PPHAs), defined as marine regions that are environmentally suitable for penguins under present and future climates, in order to inform climate‐smart conservation planning across Southern Hemisphere. Location: Marine realms of the Southern Hemisphere. Methods: We modelled occurrence data for 12 of the 21 currently recognised penguin species using a Bayesian joint species distribution framework to estimate present and future suitable habitats under two contrasting climate scenarios (SSP1‐2.6, low forcing; SSP5‐8.5, high forcing). We quantified species‐level expansions and contractions in suitable habitat, then integrated these projections into a systematic conservation planning optimisation framework to delineate present and future PPHAs and to assess their spatial overlap with existing (implemented and proposed) Marine Protected Areas (MPAs). Results: Most species (King, Southern Rockhopper, Macaroni, Snares, Chinstrap, Gentoo, Yellow‐eyed and Magellanic penguins) are projected to gain environmentally suitable habitat, whereas Emperor, Fiordland, Little and Adélie penguins show marked contractions and, in some scenarios, complete loss of optimal conditions. Consistent with a homogenization of habitat suitability for the expanding species, PPHAs increase in extent and cluster in established sub‐Antarctic and temperate hotspots. Despite this expansion, current MPA coverage of PPHAs is low and is projected to decline further under both climate scenarios. Main Conclusions: Climate‐driven shifts in penguin habitats will alter the spatial configuration and protection needs of PPHAs across the Southern Hemisphere. Our approach provides a transferable blueprint to align conservation priorities with expected climate trajectories, enabling proactive MPA design and coordinated transboundary actions to safeguard PPHAs before they are irreversibly lost.

Marine protected areas (MPAs) are a proven conservation tool, but their effects on adjacent fisheries remain unclear, contributing to ongoing debate over whether achieving global biodiversity targets will ultimately benefit or disadvantage fisheries. Using the French Gulf of Lion MPA network as an example, we applied a spatio-temporal mechanistic model with 56 functional groups to assess the ecological and fisheries outcomes of meeting the European Commission target of 10% strict protection. We show that locating networks of strict protection in the most productive areas, even when overlapping with fishing grounds, can generate positive fisheries outcomes with increased catch and revenues in comparison with a business-as-usual scenario, with no additional protection. In some scenarios, revenues recovered after 6 years, while catches took more than a decade to recover, and both were preceded by small short-term declines. In contrast, random placement of strict protection, as well as strategies avoiding fishing grounds and minimizing short-term conflict, may impose costs on the fishing sector without co-delivering positive outcomes. Our results highlight how strategically designed networks of fully protected areas can contribute to both conservation and sustainable use targets, informing broader global conservation planning efforts.

Human activities exert increasing pressure on the northwestern Mediterranean Sea, a region of high ecological and socio-economic importance. In this context, it is crucial to assess which activities contribute most to ecological risk in order to inform management options within an Ecosystem-Based Management (EBM) framework. This study applies the Spatial Cumulative Assessment of Impact Risk for Management (SCAIRM) method to assess cumulative impact risks arising from multiple activities and pressures to identify priority activities and ecosystem components for maritime management and spatial planning. SCAIRM explicitly links activities, pressures, and ecosystem components while accounting for their spatial distribution. This study provides the first comprehensive quantitative assessment of cumulative ecological risk in the northwestern Mediterranean. The results indicate that fishing is the dominant contributor to cumulative impact risk in the region (51%), with bottom trawling representing the most significant activity, followed by tourism-related maritime traffic and coastal development (18%). At the same time, we quantified their contribution over the main ecosystem components. Demersal communities, circalittoral habitats, and seagrass beds exhibited the highest levels of risk. Findings complete partial existing literature, providing a holistic systematic approach to marine risk assessment supporting the achievement of marine Good Environmental Status in the study region.

The Western Mediterranean Sea is a region of high biodiversity and cultural heritage that is subject to significant cumulative pressures, such as fishing, shipping, invasive species, coastal development, and climate change. Effective marine management requires comprehensive assessments of cumulative pressures and their effect on environmental status. This study presents the first integrated assessment of the environmental status of the Western Mediterranean Sea using the Nested Environmental status Assessment Tool (NEAT) within the context of the European Union's Marine Strategy Framework Directive (MSFD). Combining an extensive amount of data, modelled and measured, from various sources including open databases and scientific literature, this assessment utilized a comprehensive set of 755 indicator values, covering four MSFD descriptors and 14 ecosystem components. Two distinct assessment methods were employed: a standard NEAT application, and an assessment adapting NEAT to the MSFD's hierarchical criteria structure. The results consistently showed that the Western Mediterranean does not achieve Good Environmental Status (GES) on a basin-wide scale, with non-GES across all sub-regions. The degraded conditions of several ecosystem components, specifically those associated with seafloor integrity and biodiversity, were the primary drivers of this status. While the current assessment is not completely aligned with the MSFD framework, it represents a critical step towards a standardized methodology for evaluating marine environmental status and implementing Ecosystem-Based Management (EBM) in the Western Mediterranean Sea.

Despite the potential to mediate species ecological responses to environmental perturbations, functional traits are rarely incorporated into Species Distribution Models. Furthermore, complex ecological data often exhibit spatial autocorrelation, which, if ignored, can reduce model power and compromise robustness. Here, we present a hierarchical Bayesian framework that incorporates functional traits and spatial autocorrelation into spatial SDMs using Integrated Nested Laplace Approximation (INLA) and Stochastic Partial Differential Equations (SPDE). We applied this framework to four case studies to examine how trait-based, spatially explicit approaches affect single-species and multispecies models. In both scenarios, we tested the hypothesis that incorporating functional traits (here body size) and accounting for spatial autocorrelation improves model performance using simulations, and we reinforced these findings with empirical analyses of a single species, the European hake (Merluccius merluccius), and a multispecies approach using the Iberian demersal fish assemblages. In all cases, incorporating body size as a functional trait improved model fit and predictive accuracy. Moreover, explicit spatial models outperformed non-explicit spatial models, underscoring the importance of accounting for spatial autocorrelation. Results revealed a consistent relationship between body size and thermal sensitivity, with larger-bodied species showing stronger responses in their distributions to temperature gradients. These findings highlight the value of integrating traits into spatial SDMs to capture intraspecific and interspecific variation of distributions, strengthen ecological inference, and enhance predictive performance. Our trait-based SDM framework provides a scalable, interpretable, and ecologically grounded tool to support population and biodiversity forecasting and conservation planning under global change.