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| Registros recuperados: 11 | |
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| Loiseau, Nicolas; Gaertner, Jean-claude. |
| We present the first representative and quantified overview of the indices used worldwide for assessing the biodiversity of coral reef fishes. On this basis, we discuss the suitability and drawbacks of the indices most widely used in the assessment of coral fish biodiversity. An extensive and systematic survey of the literature focused on coral reef fish biodiversity was conducted from 1990 up to the present. We found that the multicomponent aspect of biodiversity, which is considered as a key feature of biodiversity for numerous terrestrial and marine ecosystems, has been poorly taken into account in coral reef fish studies. Species richness is still strongly dominant while other diversity components, such as functional diversity, are underestimated even... |
| Tipo: Text |
Palavras-chave: Coral reef fishes; Diversity indices; Monitoring; Multicomponent; Review. |
| Ano: 2015 |
URL: https://archimer.ifremer.fr/doc/00286/39686/80168.pdf |
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| Legras, G.; Loiseau, Nicolas; Gaertner, Jean-claude. |
| Functional richness, currently defined as the amount of niche space occupied by the species within a community, is one of the three major components of functional diversity. Different indices have been developed in order to quantify this component. However, the range of indices available for assessing functional richness, often mathematically complex and based on different rationales, can cause confusion for field ecologists and lead to misinterpretation of the results obtained. In this context, we have provided the first study exclusively focused on the comparison of the definitions, advantages and drawbacks of a large set of functional richness indices. The first part of this work is focused on four indices (FDP&G, FRic, TOP and N-hypervolumes... |
| Tipo: Text |
Palavras-chave: Functional richness indices; Index properties; Limitations; Guidelines. |
| Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00435/54666/59606.pdf |
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| Legras, Gaëlle; Loiseau, Nicolas; Gaertner, Jean-claude; Poggiale, Jean-christophe; Lenco, Dino; Mazouni, Nabila; Mérigot, Bastien. |
| Describing how communities change over space and time is crucial to better understand and predict the functioning of ecosystems. We propose a new methodological framework, based on network theory and modularity concept, to determine which type of mechanisms (i.e. deterministic versus stochastic processes) has the strongest influence on structuring communities. This framework is based on the computation and comparison of two networks: the co-occurrence (based on species abundances) and the functional networks (based on the species traits values). In this way we can assess whether the species belonging to a given functional group also belong to the same co-occurrence group. We adapted the Dg index of Gauzens et al. (2015) to analyze congruence between both... |
| Tipo: Text |
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| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00599/71142/69458.pdf |
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| Loiseau, Nicolas; Mouquet, Nicolas; Casajus, Nicolas; Grenie, Matthias; Gueguen, Maya; Maitner, Brian; Mouillot, David; Ostling, Annette; Renaud, Julien; Tucker, Caroline; Velez, Laure; Thuiller, Wilfried; Violle, Cyrille. |
| 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. We use global species distributions and functional traits for birds and mammals to identify the ecologically rare species, understand their characteristics, and identify hotspots. We find that ecologically rare species are disproportionately represented in IUCN threatened categories, insufficiently covered by protected areas, and for some of them sensitive to current and future threats. While they are more abundant overall in countries with a low human development index, some countries with high human development... |
| Tipo: Text |
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| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00657/76892/78052.pdf |
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| Lagabrielle, Erwann; Allibert, Agathe; Kiszka, Jeremy J.; Loiseau, Nicolas; Kilfoil, James P.; Lemahieu, Anne. |
| Understanding the environmental drivers of interactions between predators and humans is critical for public safety and management purposes. In the marine environment, this issue is exemplified by shark-human interactions. The annual shark bite incidence rate (SBIR) in La Réunion (Indian Ocean) is among the highest in the world (up to 1 event per 24,000 hours of surfing) and has experienced a 23-fold increase over the 2005–2016 period. Since 1988, 86% of shark bite events on ocean-users involved surfers off the leeward coast, where 96% of surfing activities took place. We modeled the SBIR as a function of environmental variables, including benthic substrate, sea temperature and period of day. The SBIR peaked in winter, during the afternoon and dramatically... |
| Tipo: Text |
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| Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00429/54011/55227.pdf |
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| Boulanger, Emilie; Loiseau, Nicolas; Valentini, Alice; Arnal, Véronique; Boissery, Pierre; Dejean, Tony; Deter, Julie; Guellati, Nacim; Holon, Florian; Juhel, Jean-baptiste; Lenfant, Philippe; Manel, Stéphanie; Mouillot, David. |
| Although we are currently experiencing worldwide biodiversity loss, local species richness does not always decline under anthropogenic pressure. This conservation paradox may also apply in protected areas but has not yet received conclusive evidence in marine ecosystems. Here, we survey fish assemblages in six Mediterranean no-take reserves and their adjacent fishing grounds using environmental DNA (eDNA) while controlling for environmental conditions. We detect less fish species in marine reserves than in nearby fished areas. The paradoxical gradient in species richness is accompanied by a marked change in fish species composition under different managements. This dissimilarity is mainly driven by species that are often overlooked by classical visual... |
| Tipo: Text |
Palavras-chave: Environmental DNA metabarcoding; Marine reserves; Alpha and beta diversity. |
| Ano: 2021 |
URL: https://archimer.ifremer.fr/doc/00692/80374/83491.pdf |
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| Legras, Gaëlle; Loiseau, Nicolas; Gaertner, Jean-claude; Poggiale, J-c.; Gaertner-mazouni, N.. |
| The impact of the variation of the number of functional traits on functional diversity assessment is still poorly known. Although the covariation between these two parameters may be desirable in some situations (e.g. if adding functional traits provides relevant new functional information), it may also result from mathematical artefacts and lead to misinterpretation of the results obtained. Here, we have tested the behaviour of a set of nine indices widely used for assessing the three main components of functional diversity (i.e. functional richness, evenness and divergence), according to the variation in the number of functional traits. We found that the number of functional traits may strongly impact the values of most of the indices considered, whatever... |
| Tipo: Text |
Palavras-chave: Functional traits; Dissimilarity metric; Functional diversity; Index sensitivity; Trend analysis. |
| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00503/61438/65561.pdf |
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| Olivier, Damien; Loiseau, Nicolas; Petatan-ramirez, David; Trujillo Milian, Oscar; Suarez-castillo, Alvin N.; Torre, Jorge; Munguia-vega, Adrian; Reyes-bonilla, Hector. |
| The Gulf of California (GC) is a semi-closed sea in the Tropical Eastern Pacific and is recognised as a highly diverse marine ecosystem. Despite this status, this region is still poorly studied in comparison to other marine hotspots. To start filling this gap, we attempt to provide a global overview of reef-fish diversity around the numerous islands of the region. We evaluated species richness, the abundance and biomass, and the functional diversity of the fish assemblages for the major islands of the GC. We first highlight that the southwestern part of the central GC is the hotspot of reef-fishes diversity within the GC, in terms of species richness, functional diversity, and fish abundance. We then found out an important functional divergence between... |
| Tipo: Text |
Palavras-chave: Biodiversity; Biologically important area; Functional traits; Marine protected area; Sea of Cortez; Tropical Eastern Pacific. |
| Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00476/58786/62421.pdf |
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| Murgier, Juliette; Mclean, Matthew; Maire, Anthony; Mouillot, David; Loiseau, Nicolas; Munoz, François; Violle, Cyrille; Auber, Arnaud. |
| Functionally distinct species (i.e. species with unique trait combinations in the community) can support important ecological roles and contribute disproportionately to ecosystem functioning. Yet, how functionally distinct species have responded to recent climate change and human exploitation has been widely overlooked. Here, using ecological traits and long-term fish data in the North Sea, we identified functionally distinct and functionally common species, and evaluated their spatial andtemporaldynamics in relation to environmental variables and fishing pressure. Functionally distinct specieswere characterized by late sexualmaturity, few, large offspring, and high parental care,many being sharks and skates that play critical roles in structuring food... |
| Tipo: Text |
Palavras-chave: Functional diversity; Ecological trait; Fisheries; Global change; Ecosystem functioning; Conservation. |
| Ano: 2021 |
URL: https://archimer.ifremer.fr/doc/00668/78019/80270.pdf |
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| Tessier, Emmanuel; Pothin, Karine; Chabanet, Pascale; Fleury, Pierre-gildas; Bissery, Claire; David, Gilbert; Thomassin, Aurélie; Lemoigne, Valerie; Loiseau, Nicolas. |
| The objectives of marine protected areas (MPA), such as Reunion’s Marine Reserve founded in 2007, are (i) protect habitats (ecosystems) and resources (biodiversity) from increasing pressure due to a major urban, economic and recreational development; ii) manage uses and conflicts between traditional fisheries, spear-fishing, diving and recreational activities inside the coastal zone. These goals necessitate monitoring tools such as indicators and diagnostics. The PAMPA programme involves seven MPA including the Natural Marine Reserve of La Reunion (RNMR). It aims for each site to identify and validate indicators according to management objectives and group them in a MPA performance dashboard. This panel will help to visualize temporal trends and define... |
| Tipo: Text |
Palavras-chave: Aires Marines Protégées; RNMR de La Réunion; Ressources; Usages; Gouvernance; Indicateurs de performance; Tableau de bord; Marine Protected Area; Reunion Natural Marine Reserve; Resources; Uses; Gouvernance; Performance indicators; Dashboard. |
| Ano: 2011 |
URL: http://archimer.ifremer.fr/doc/00050/16161/13644.pdf |
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| Juhel, Jean‐baptiste; Marques, Virginie; Polanco Fernández, Andrea; Borrero‐pérez, Giomar H.; Mutis Martinezguerra, Maria; Valentini, Alice; Dejean, Tony; Manel, Stéphanie; Loiseau, Nicolas; Velez, Laure; Hocdé, Régis; Letessier, Tom B.; Richards, Eilísh; Hadjadj, Florine; Bessudo, Sandra; Ladino, Felipe; Albouy, Camille; Mouillot, David; Pellissier, Loïc. |
| 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 (Kogia breviceps) and dwarf (Kogia sima) 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. Environmental DNA (eDNA) metabarcoding uses DNA traces left by organisms in their environments to detect the presence of targeted taxon, and is here proved to be useful to increase our knowledge on the... |
| Tipo: Text |
Palavras-chave: EDNA; Megafauna; Mobile species; Pelagic. |
| Ano: 2021 |
URL: https://archimer.ifremer.fr/doc/00683/79484/82076.pdf |
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| Registros recuperados: 11 | |
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