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Auteur Puerta, P.; Johnson, C.; Carreiro-Silva, M.; Henry, L.-A.; Kenchington, E.; Morato, T.; Kazanidis, G.; Luis Rueda, J.; Urra, J.; Ross, S.; Wei, C.-L.; Manuel Gonzalez-Irusta, J.; Arnaud-Haond, S.; Orejas, C.
Titre Influence of Water Masses on the Biodiversity and Biogeography of Deep-Sea Benthic Ecosystems in the North Atlantic Type Article scientifique
Année 2020 Publication Revue Abrégée Front. Mar. Sci.
Volume 7 Numéro Pages 239
Mots-Clés antarctic intermediate water; biodiversity; biogeography; climate-change impacts; coral lophelia-pertusa; deep-sea; food-supply mechanisms; global habitat suitability; meridional overturning circulation; ne atlantic; North Atlantic; ocean acidification; porcupine seabight; rockall trough margin; vulnerable marine ecosystems; water masses
Résumé Circulation patterns in the North Atlantic Ocean have changed and re-organized multiple times over millions of years, influencing the biodiversity, distribution, and connectivity patterns of deep-sea species and ecosystems. In this study, we review the effects of the water mass properties (temperature, salinity, food supply, carbonate chemistry, and oxygen) on deep-sea benthic megafauna (from species to community level) and discussed in future scenarios of climate change. We focus on the key oceanic controls on deep-sea megafauna biodiversity and biogeography patterns. We place particular attention on cold-water corals and sponges, as these are ecosystem-engineering organisms that constitute vulnerable marine ecosystems (VME) with high associated biodiversity. Besides documenting the current state of the knowledge on this topic, a future scenario for water mass properties in the deep North Atlantic basin was predicted. The pace and severity of climate change in the deep-sea will vary across regions. However, predicted water mass properties showed that all regions in the North Atlantic will be exposed to multiple stressors by 2100, experiencing at least one critical change in water temperature (+2 degrees C), organic carbon fluxes (reduced up to 50%), ocean acidification (pH reduced up to 0.3), aragonite saturation horizon (shoaling above 1000 m) and/or reduction in dissolved oxygen (> 5%). The northernmost regions of the North Atlantic will suffer the greatest impacts. Warmer and more acidic oceans will drastically reduce the suitable habitat for ecosystem-engineers, with severe consequences such as declines in population densities, even compromising their long-term survival, loss of biodiversity and reduced biogeographic distribution that might compromise connectivity at large scales. These effects can be aggravated by reductions in carbon fluxes, particularly in areas where food availability is already limited. Declines in benthic biomass and biodiversity will diminish ecosystem services such as habitat provision, nutrient cycling, etc. This study shows that the deep-sea VME affected by contemporary anthropogenic impacts and with the ongoing climate change impacts are unlikely to withstand additional pressures from more intrusive human activities. This study serves also as a warning to protect these ecosystems through regulations and by tempering the ongoing socio-political drivers for increasing exploitation of marine resources.
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Numéro d'Appel MARBEC @ isabelle.vidal-ayouba @ collection 2767
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Auteur Brandt, M.; Trouche, B.; Henry, N.; Liautard-Haag, C.; Maignien, L.; de Vargas, C.; Wincker, P.; Poulain, J.; Zeppilli, D.; Arnaud-Haond, S.
Titre An Assessment of Environmental Metabarcoding Protocols Aiming at Favoring Contemporary Biodiversity in Inventories of Deep-Sea Communities Type Article scientifique
Année 2020 Publication Revue Abrégée Front. Mar. Sci.
Volume 7 Numéro Pages 234
Mots-Clés benthic ecology; biomonitoring; deep-sea biodiversity; diversity; environmental metabarcoding; extracellular dna; extracellular DNA; extraction; foraminifera; impacts; method testing; preservation; RNA versus DNA; sediments; taxa
Résumé The abyssal seafloor covers more than 50% of planet Earth and is a large reservoir of still mostly undescribed biodiversity. It is increasingly targeted by resource-extraction industries and yet is drastically understudied. In such remote and hard-to-access ecosystems, environmental DNA (eDNA) metabarcoding is a useful and efficient tool for studying biodiversity and implementing environmental impact assessments. Yet, eDNA analysis outcomes may be biased toward describing past rather than present communities as sediments contain both contemporary and ancient DNA. Using commercially available kits, we investigated the impacts of five molecular processing methods on eDNA metabarcoding biodiversity inventories targeting prokaryotes (16S), unicellular eukaryotes (18S-V4), and metazoans (18S-V1, COI). As the size distribution of ancient DNA is skewed toward small fragments, we evaluated the effect of removing short DNA fragments via size selection and ethanol reconcentration using eDNA extracted from 10 g of sediment at five deep-sea sites. We also compare communities revealed by eDNA and environmental RNA (eRNA) co-extracted from similar to 2 g of sediment at the same sites. Results show that removing short DNA fragments does not affect alpha and beta diversity estimates in any of the biological compartments investigated. Results also confirm doubts regarding the possibility to better describe live communities using eRNA. With ribosomal loci, eRNA, while resolving similar spatial patterns than co-extracted eDNA, resulted in significantly higher richness estimates, supporting hypotheses of increased persistence of ribosomal RNA (rRNA) in the environment and unmeasured bias due to overabundance of rRNA and RNA release. With the mitochondrial locus, eRNA detected lower metazoan richness and resolved fewer spatial patterns than co-extracted eDNA, reflecting high messenger RNA lability. Results also highlight the importance of using large amounts of sediment (>= 10 g) for accurately surveying eukaryotic diversity. We conclude that eDNA should be favored over eRNA for logistically realistic, repeatable, and reliable surveys and confirm that large sediment samples (>= 10 g) deliver more complete and accurate assessments of benthic eukaryotic biodiversity and that increasing the number of biological rather than technical replicates is important to infer robust ecological patterns.
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Notes WOS:000531310000001 Approuvé pas de
Numéro d'Appel MARBEC @ isabelle.vidal-ayouba @ collection 2791
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Auteur Dobrovolski, R.; Loyola, R.D.; Guilhaumon, F.; Gouveia, S.F.; Diniz, J.A.F.
Titre Global agricultural expansion and carnivore conservation biogeography Type Article scientifique
Année 2013 Publication Revue Abrégée Biol. Conserv.
Volume 165 Numéro Pages 162-170
Mots-Clés Agriculture; Global biodiversity conservation priorities; Image; Mammal; Spatial prioritization; Zonation; biodiversity; biodiversity conservation; conservation; conserving; extinction risk; hotspots; human-population density; integrating economic costs; land-use; mammal conservation; prioritization schemes; protected areas
Résumé Global conservation prioritization must address conflicting land uses. We tested for spatial congruence between agricultural expansion in the 21st century and priority areas for carnivore conservation worldwide. We evaluated how including agricultural expansion data in conservation planning reduces such congruence and estimated the consequences of such an approach for the performance of resulting priority area networks. We investigated the correlation between projections of agricultural expansion and the solutions of global spatial prioritizations for carnivore conservation through the implementation of different goals: (1) purely maximizing species representation and (2) representing species while avoiding sites under high pressure for agriculture expansion. We also evaluated the performance of conservation solutions based on species' representation and their spatial congruence with established global prioritization schemes. Priority areas for carnivore conservation were spatially correlated with future agricultural distribution and were more similar to global conservation schemes with high vulnerability. Incorporating future agricultural expansion in the site selection process substantially reduced spatial correlation with agriculture, resulting in a spatial solution more similar to global conservation schemes with low vulnerability. Accounting for agricultural expansion resulted in a lower representation of species, as the average proportion of the range represented reduced from 58% to 32%. We propose that priorities for carnivore conservation could be integrated into a strategy that concentrates different conservation actions towards areas where they are likely to be more effective regarding agricultural expansion. (C) 2013 Elsevier Ltd. All rights reserved.
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ISSN (up) 0006-3207 ISBN Médium
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Numéro d'Appel MARBEC @ isabelle.vidal-ayouba @ collection 622
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Auteur Grenie, M.; Mouillot, D.; Villeger, S.; Denelle, P.; Tucker, C.M.; Munoz, F.; Violle, C.
Titre Functional rarity of coral reef fishes at the global scale: Hotspots and challenges for conservation Type Article scientifique
Année 2018 Publication Revue Abrégée Biol. Conserv.
Volume 226 Numéro Pages 288-299
Mots-Clés biodiversity; Biodiversity facet; Coral triangle; diversity; ecology; ecosystem processes; Evolutionary distinctiveness; Functional distinctiveness; Funrar; marine-protected areas; ocean acidification; redundancy; species richness; trait; vulnerability
Résumé Characterizing functional diversity has become central in ecological research and for biodiversity assessment. Understanding the role of species with rare traits, i.e. functionally rare species, in community assembly, ecosystem dynamics and functioning has recently gained momentum. However, functional rarity is still ignored in conservation strategies. Here, we quantified global functional and evolutionary rarity for 2073 species of coral reef fishes and compared the rarity values to IUCN Red List status. Most species were functionally common but geographically rare. However, we found very weak correlation between functional rarity and evolutionary rarity. Functional rarity was highest for species classified as not evaluated or threatened by the IUCN Red List. The location of functional rarity hotspots (Tropical Eastern Pacific) did not match hotspots of species richness and evolutionary distinctiveness (Indo-Australian Archipelago), nor the currently protected areas. We argue that functional rarity should be acknowledged for both species and site prioritization in conservation strategies.
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ISSN (up) 0006-3207 ISBN Médium
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Numéro d'Appel MARBEC @ alain.herve @ collection 2434
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Auteur Ben Lamine, Y.; Pringault, O.; Aissi, M.; Ensibi, C.; Mahmoudi, E.; Daly Yahia Kefi, O.; Daly Yahia, M.N.
Titre Environmental controlling factors of copepod communities in the Gulf of Tunis (south western Mediterranean Sea) Type Article scientifique
Année 2015 Publication Revue Abrégée Cahiers de Biologie Marine
Volume 56 Numéro 3 Pages 213-229
Mots-Clés Competition; Copepod diversity; multivariate analysis; Salinity; Temperature; Top-down control
Résumé The copepod community structure and the distribution of the main groups of zooplankton were studied along an inshore-offshore gradient in the Gulf of Tunis during the rainy and dry seasons of 2007-2008. Hydrological parameters were also measured to assess the potential role of abiotic and biotic factors in the distribution of copepod species. The copepod community in the Gulf of Tunis comprises 86 species dominated by Paracalanus parvus, Clausocalanus lividus, Centropages kroyeri and Acartia clausi. Time had a greater influence than space (horizontal and vertical gradients) in shaping the copepod community structure with a significant influence of the seasons; winter (cold and rainy) resulted in hydrological conditions that were strongly different from those observed in summer (warm and dry). These hydrological differences were concomitant with changes in the community structure, with a high copepod diversity observed in winter while the summer period was characterized by a low specific richness and the dominance of a few species, Centropages kroyeri and Paracalanus parvus along the inshore-offshore gradient and Paracalanus aculeatus along the vertical. Canonical correspondence analysis showed that temperature, salinity and to a lesser extent chlorophyll a were the most important environmental factors structuring the copepod community. Interestingly, temperature and salinity showed a negative significant correlation with copepod specific richness. Competition with grazers (cladoceran) as well as top down control by predators (chaetognaths and siphonophors) were also identified as key factors for the copepod community structure.
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ISSN (up) 0007-9723 ISBN Médium
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Notes WOS:000358550200003 Approuvé pas de
Numéro d'Appel MARBEC @ isabelle.vidal-ayouba @ collection 1324
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