Publications by authors named "Laure Velez"

Marine protected areas (MPAs) are expanding worldwide, but industrial fishing within their boundaries remains poorly understood. By combining vessel Global Positioning System data with satellite imagery, we detected industrial fishing in 47% of coastal MPAs worldwide between 2022 and 2024, with two-thirds of vessel detections (67%) untracked by public monitoring. These untracked vessels were most prevalent (80%) in MPAs with the most restrictive management category, which aims to prohibit all extractive activities.

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The global network of protected areas has rapidly expanded in the past decade and is expected to cover at least 30% of land and sea by 2030 to halt biodiversity erosion. Yet, the distribution of protected areas is highly heterogeneous on Earth and the social-environmental preconditions enabling or hindering protected area establishment remain poorly understood. Here, using fourteen socioeconomic and environmental factors, we characterize the multidimensional niche of terrestrial and marine protected areas, which we use to accurately establish, at the global scale, whether a particular location has preconditions favourable for paestablishment.

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Article Synopsis
  • The study highlights that there is a lack of data on marine fish species' extinction risks, which hampers effective conservation planning, particularly for teleost fishes.
  • By using machine learning algorithms, researchers predicted an increased IUCN extinction risk for marine fishes from 2.5% to 12.7%, identifying specific traits like small geographic range and low growth rate as indicators of threat.
  • The research proposes integrating these predictions into conservation strategies, emphasizing the importance of prioritizing marine protected areas, especially in less diverse regions that are still crucial for vulnerable species.
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Marine protected areas (MPAs) are the most widely applied tool for marine biodiversity conservation, yet many gaps remain in our understanding of their species-specific effects, partly because the socio-environmental context and spatial autocorrelation may blur and bias perceived conservation outcomes. Based on a large data set of nearly 3000 marine fish surveys spanning all tropical regions of the world, we build spatially explicit models for 658 fish species to estimate species-specific responses to protection while controlling for the environmental, habitat and socio-economic contexts experienced across their geographic ranges. We show that the species responses are highly variable, with ~40% of fishes not benefitting from protection.

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Animal body-size variation influences multiple processes in marine ecosystems, but habitat heterogeneity has prevented a comprehensive assessment of size across pelagic (midwater) and benthic (seabed) systems along anthropic gradients. In this work, we derive fish size indicators from 17,411 stereo baited-video deployments to test for differences between pelagic and benthic responses to remoteness from human pressures and effectiveness of marine protected areas (MPAs). From records of 823,849 individual fish, we report divergent responses between systems, with pelagic size structure more profoundly eroded near human markets than benthic size structure, signifying greater vulnerability of pelagic systems to human pressure.

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Elasmobranchs (sharks, rays and skates) are among the most threatened marine vertebrates, yet their global functional diversity remains largely unknown. Here, we use a trait dataset of >1000 species to assess elasmobranch functional diversity and compare it against other previously studied biodiversity facets (taxonomic and phylogenetic), to identify species- and spatial- conservation priorities. We show that threatened species encompass the full extent of functional space and disproportionately include functionally distinct species.

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Quantifying fish species diversity in rich tropical marine environments remains challenging. Environmental DNA (eDNA) metabarcoding is a promising tool to face this challenge through the filtering, amplification, and sequencing of DNA traces from water samples. However, because eDNA concentration is low in marine environments, the reliability of eDNA to detect species diversity can be limited.

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Generating genomic data for 19 tropical reef fish species of the Western Indian Ocean, we investigate how species ecology influences genetic diversity patterns from local to regional scales. We distinguish between the , and components of genetic diversity, which we subsequently link to six ecological traits. We find that the and components of genetic diversity are strongly correlated so that species with a high total regional genetic diversity display systematically high local diversity.

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Assessing the impact of global changes and protection effectiveness is a key step in monitoring marine fishes. Most traditional census methods are demanding or destructive. Nondisturbing and nonlethal approaches based on video and environmental DNA are alternatives to underwater visual census or fishing.

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Protected areas are the flagship management tools to secure biodiversity from anthropogenic impacts. However, the extent to which adjacent areas with distinct protection levels host different species numbers and compositions remains uncertain. Here, using reef fishes, European alpine plants, and North American birds, we show that the composition of species in adjacent Strictly Protected, Restricted, and Non-Protected areas is highly dissimilar, whereas the number of species is similar, after controlling for environmental conditions, sample size, and rarity.

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Monitoring large marine mammals is challenging due to their low abundances in general, an ability to move over large distances and wide geographical range sizes.The distribution of the pygmy () and dwarf () sperm whales is informed by relatively rare sightings, which does not permit accurate estimates of their distribution ranges. Hence, their conservation status has long remained Data Deficient (DD) in the Red list of the International Union for Conservation of Nature (IUCN), which prevent appropriate conservation measures.

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Article Synopsis
  • Large marine fish carcasses contribute to carbon sequestration in the deep ocean, unlike terrestrial organisms that release carbon into the atmosphere after death.
  • Fisheries have significantly extracted this "blue carbon," releasing at least 0.73 billion metric tons of CO2 into the atmosphere since 1950.
  • Limiting blue carbon extraction in economically unprofitable fishing areas could decrease CO2 emissions and enhance natural carbon sequestration by allowing fish stocks to rebuild.
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Identifying species that are both geographically restricted and functionally distinct, i.e. supporting rare traits and functions, is of prime importance given their risk of extinction and their potential contribution to ecosystem functioning.

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Many islands are biodiversity hotspots but also extinction epicenters. In addition to strong cultural connections to nature, islanders derive a significant part of their economy and broader wellbeing from this biodiversity. Islands are thus considered as the socio-ecosystems most vulnerable to species and habitat loss.

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Genetic diversity is estimated to be declining faster than species diversity under escalating threats, but its spatial distribution remains poorly documented at the global scale. Theory predicts that similar processes should foster congruent spatial patterns of genetic and species diversity, but empirical studies are scarce. Using a mined database of 50,588 georeferenced mitochondrial DNA barcode sequences (COI) for 3,815 marine and 1,611 freshwater fish species respectively, we examined the correlation between genetic diversity and species diversity and their global distributions in relation to climate and geography.

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The depletion of natural resources has become a major issue in many parts of the world, with the most accessible resources being most at risk. In the terrestrial realm, resource depletion has classically been related to accessibility through road networks. In contrast, in the marine realm, the impact on living resources is often framed into the Malthusian theory of human density around ecosystems.

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Climate change is inducing deep modifications in species geographic ranges worldwide. However, the consequences of such changes on community structure are still poorly understood, particularly the impacts on food-web properties. Here, we propose a new framework, coupling species distribution and trophic models, to predict climate change impacts on food-web structure across the Mediterranean Sea.

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The Mediterranean Sea (0.82% of the global oceanic surface) holds 4%-18% of all known marine species (~17,000), with a high proportion of endemism [1, 2]. This exceptional biodiversity is under severe threats [1] but benefits from a system of 100 marine protected areas (MPAs).

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