Consulta: creatorFacets:"Juhel, Jean-baptiste"
Registros recuperados: 6
Data/hora: 06/06/2024 09:42:52

From the cradle to the grave: Green turtle hatchlings (Chelonia mydas) preyed upon by two-spots red snappers (Lutjanus bohar)
Provedor de dados: 5
Autores: Juhel, Jean-baptiste; Maire, Eva; Sucré, Elliott; Cheutin, Marie-charlotte; Marques, Virginie; Benkwitt, Cassandra; Gunn, Rachel L.; Richards, Eilísh; Albouy, Camille.
The observation of trophic interactions such as predation provide valuable information to model food webs and better understand ecosystem functioning. Such information is crucial for rare and endangered species in order to adapt management measures and ensure their conservation. However, trophic interactions are rarely observed in the marine realm, even for well-known or widespread species. During a scientific cruise in the Scattered Islands (Southwestern Indian Ocean), we observed endangered green turtle hatchlings (Chelonia mydas) in the gut content of two subadults two-spots red snappers (Lutjanus bohar). This trophic link involving emblematic species has not been previously described. The two-spots red snapper is a widespread coral reef fish in the...
Tipo: Text
Palavras-chave: Trophic interaction; Marine turtle; Red bass; Snapper; Lutjanids.
Ano: 2019
URL: https://archimer.ifremer.fr/doc/00589/70160/68162.pdf

Accumulation curves of environmental DNA sequences predict coastal fish diversity in the coral triangle
Provedor de dados: 5
Autores: Juhel, Jean-baptiste; Utama, Rizkie S.; Marques, Virginie; Vimono, Indra B.; Sugeha, Hagi Yulia; Kadarusman,; Pouyaud, Laurent; Dejean, Tony; Mouillot, David; Hocdé, Régis.
Environmental DNA (eDNA) has the potential to provide more comprehensive biodiversity assessments, particularly for vertebrates in species-rich regions. However, this method requires the completeness of a reference database (i.e. a list of DNA sequences attached to each species), which is not currently achieved for many taxa and ecosystems. As an alternative, a range of operational taxonomic units (OTUs) can be extracted from eDNA metabarcoding. However, the extent to which the diversity of OTUs provided by a limited eDNA sampling effort can predict regional species diversity is unknown. Here, by modelling OTU accumulation curves of eDNA seawater samples across the Coral Triangle, we obtained an asymptote reaching 1531 fish OTUs, while 1611 fish species...
Tipo: Text
Palavras-chave: EDNA metabarcoding; Sequence clustering; Operational Taxonomic Unit; Diversity assessment; Detectability.
Ano: 2020
URL: https://archimer.ifremer.fr/doc/00640/75232/79601.pdf

Environmental DNA illuminates the dark diversity of sharks
Provedor de dados: 5
Autores: Boussarie, Germain; Bakker, Judith; Wangensteen, Owen S.; Mariani, Stefano; Bonnin, Lucas; Juhel, Jean-baptiste; Kiszka, Jeremy J.; Kulbicki, Michel; Manel, Stephanie; Robbins, William D.; Vigliola, Laurent; Mouillot, David.
In the era of "Anthropocene defaunation," large species are often no longer detected in habitats where they formerly occurred. However, it is unclear whether this apparent missing, or "dark," diversity of megafauna results from local species extirpations or from failure to detect elusive remaining individuals. We find that despite two orders of magnitude less sampling effort, environmental DNA (eDNA) detects 44% more shark species than traditional underwater visual censuses and baited videos across the New Caledonian archipelago (south-western Pacific). Furthermore, eDNA analysis reveals the presence of previously unobserved shark species in human-impacted areas. Overall, our results highlight a greater prevalence of sharks than described by traditional...
Tipo: Text
Ano: 2018
URL: https://archimer.ifremer.fr/doc/00442/55321/56837.pdf

Isolation and no-entry marine reserves mitigate anthropogenic impacts on grey reef shark behavior
Provedor de dados: 5
Autores: Juhel, Jean-baptiste; Vigliola, Laurent; Wantiez, Laurent; Letessier, Tom B.; Meeuwig, Jessica J.; Mouillot, David.
Reef sharks are vulnerable predators experiencing severe population declines mainly due to overexploitation. However, beyond direct exploitation, human activities can produce indirect or sub-lethal effects such as behavioral alterations. Such alterations are well known for terrestrial fauna but poorly documented for marine species. Using an extensive sampling of 367 stereo baited underwater videos systems, we show modifications in grey reef shark (Carcharhinus amblyrhynchos) occurrence and feeding behavior along a marked gradient of isolation from humans across the New Caledonian archipelago (South-Western Pacific). The probability of occurrence decreased by 68.9% between wilderness areas (more than 25 hours travel time from the capital city) and impacted...
Tipo: Text
Ano: 2019
URL: https://archimer.ifremer.fr/doc/00483/59500/62369.pdf

Remote reefs and seamounts are the last refuges for marine predators across the Indo-Pacific
Provedor de dados: 5
Autores: Letessier, Tom B.; Mouillot, David; Bouchet, Phil J.; Vigliola, Laurent; Fernandes, Marjorie C.; Thompson, Chris; Boussarie, Germain; Turner, Jemma; Juhel, Jean-baptiste; Maire, Eva; Caley, M. Julian; Koldewey, Heather J.; Friedlander, Alan; Sala, Enric; Meeuwig, Jessica J.
Since the 1950s, industrial fisheries have expanded globally, as fishing vessels are required to travel further afield for fishing opportunities. Technological advancements and fishery subsidies have granted ever-increasing access to populations of sharks, tunas, billfishes, and other predators. Wilderness refuges, defined here as areas beyond the detectable range of human influence, are therefore increasingly rare. In order to achieve marine resources sustainability, large no-take marine protected areas (MPAs) with pelagic components are being implemented. However, such conservation efforts require knowledge of the critical habitats for predators, both across shallow reefs and the deeper ocean. Here, we fill this gap in knowledge across the Indo-Pacific...
Tipo: Text
Ano: 2019
URL: https://archimer.ifremer.fr/doc/00509/62107/66283.pdf

Environmental DNA metabarcoding reveals and unpacks a biodiversity conservation paradox in Mediterranean marine reserves
Provedor de dados: 5
Autores: 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