Consulta: subjectFacets:"Megafauna"
Registros recuperados: 15
Data/hora: 09/06/2024 06:01:20

Megafauna from sublittoral to abyssal depths along the Mid-Atlantic Ridge south of Iceland
Provedor de dados: 5
Autores: Copley, Jtp; Tyler, Pa; Sheader, M; Murton, Bj; German, Cr.
101 species were identified from 102 biological samples obtained between 225 and 2600 m depth on the Reykjanes Ridge, extending the biogeographic records for several species. Multivariate analysis of between-sample species similarity reveals a two-zone bathymetric faunal distribution with the transition at 800-1000 m. A hydrographic survey of the ridge axis suggests that this faunal zonation is influenced by the water mass structure. Despite the limitations of a sampling programme not designed a priori for biological sampling, the recovery and preservation of the samples and the insight that they provide serves to reinforce that every effort should be made to capitalise on the opportunities for obtaining samples afforded by non-biological sampling...
Tipo: Text
Palavras-chave: Mid-ocean ridge; Megafauna; Reykjanes Ridge; Bathymetric zonation; Water mass structure.
Ano: 1996
URL: http://archimer.ifremer.fr/doc/00096/20725/18362.pdf

Tools and constraints in monitoring interactions between marine litter and megafauna: Insights from case studies around the world
Provedor de dados: 5
Autores: Claro, F; Fossi, Mc; Ioakeimidis, C; Baini, M; Lusher, Al; Mc Fee, W; Mcintosh, Rr; Pelmatti, T; Sorce, M; Galgani, Francois; Hardesky, Bd.
Adverse impacts of marine litter is documented on &gt;1400 species, including marine megafauna (fish, birds, sea turtles and mammals). The primary impacts include ingestion and entanglement, and there is increasing concern about chemical contamination via ingestion. Numerous survey approaches and monitoring programs have been developed and implemented around the world. They may aim to provide data about parameters such as species distribution and interactions with anthropogenic activities. During the Sixth International Marine Debris Conference, a session was dedicated to the tools and constraints in monitoring interactions between litter and megafauna. In the present paper, we summarize 7 case studies which discuss entanglement and ingestion including...
Tipo: Text
Palavras-chave: Litter impact; Megafauna; Tools; Entanglement; Ingestion; Policies.
Ano: 2019
URL: https://archimer.ifremer.fr/doc/00482/59390/65963.pdf

Large-scale distribution of a deep-sea megafauna community along Mediterranean trawlable grounds
Provedor de dados: 5
Autores: Fernandez-arcaya, Ulla; Bitetto, Isabella; Esteban, Antonio; Farriols, M. Teresa; García-ruiz, Cristina; Gil De Sola, Luis; Guijarro, Beatriz; Jadaud, Angelique; Kavadas, Stefanos; Lembo, Giuseppe; Milisenda, Giacomo; Maina, Irida; Petovic, Slavica; Sion, Letizia; Vaz, Sandrine; Massutí, Enric.
The large-scale distribution pattern of megafauna communities along the Mediterranean middle slope was explored. The study was conducted between 500 and 800 m depth where deep-water fishery occurs. Although community studies carried out deeper than 500 m are partly available for some geographic areas, few large-scale comparative studies have been carried out. Within the framework of the MEDITS survey programme, we compared the megafauna community structure in ten geographical sub-areas (GSAs) along the Mediterranean coasts. Additionally, the spatial distribution of fishing was analysed using vessel monitoring by satellite information. Overall, the community showed a significant difference between sub-areas, with a decreasing eastward pattern in abundance...
Tipo: Text
Palavras-chave: Distribution pattern; Fishing impact; Continental slope; Deep sea; Megafauna; Red shrimp; Community.
Ano: 2019
URL: https://archimer.ifremer.fr/doc/00489/60051/63328.pdf

Variation in structure and biomass of the benthic communities at three contrasting sites in the tropical Northeast Atlantic
Provedor de dados: 5
Autores: Galeron, Joelle; Sibuet, Myriam; Mahaut, Ml; Dinet, A.
Three major size classes of the benthic metazoan communities (megafauna, macrofauna and meiofauna) were investigated simultaneously at 3 sites in the tropical Northeast Atlantic. The sites varied in their level of surface primary productivity (eutrophic, mesotrophic and oligotrophic). Results for 3 cruises in 3 seasons (Eumeli 2, winter 1991; Eumeli 3, autumn 1991; Eumeli 4, spring 1992) are given for each size class in terms of taxonomic composition, density and biomass. The benthic communities did not exhibit evidence of seasonal variation, but there were substantial differences in the quantitative structure of the metazoan communities between the 3 sites. Total metazoan density and biomass, as well as density and biomass of each size class, decreased...
Tipo: Text
Palavras-chave: Deep sea; Tropical Atlantic; Meiofauna; Macrofauna; Megafauna; Taxonomic composition; Density; Biomass; Environmental conditions.
Ano: 2000
URL: http://archimer.ifremer.fr/doc/00000/10519/7602.pdf

Cold-seep assemblages on a giant pockmark off West Africa: spatial patterns and environmental control
Provedor de dados: 5
Autores: Olu, Karine; Caprais, Jean-claude; Fifis, Alexis; Fabri, Marie-claire; Galeron, Joelle; Budzinsky, H; Le Menach, K; Khripounoff, Alexis; Ondreas, Helene; Sibuet, Myriam.
A giant pockmark colonised by dense cold-seep assemblages near 3160 m depth along the Congo-Angola margin has been surveyed by the ROV Victor 6000. The quantitative distribution of chemosynthetic communities was mapped along the dive tracks from a video study using GIS and image mosaicking. Several types of faunal assemblages, either dominated by bivalves of the families Mytilidae (Bathmodiolus sp.) Vesicom idae (Calyptogena sp., 'Vesicomya' aff. chuni), or by Siboglinidae polychaetes (Escarpia southwardae) were mapped over the 800-m diameter pockmark area and sampled for fauna, water and sediment. The isotopic analyses (delta C-13) of tissues from symbiont-bearing species were within the range typical of nutrition via symbiosis using methane for mussels...
Tipo: Text
Palavras-chave: Symbiont bearing species; Spatial distribution; Methane; Megafauna; Cold seeps.
Ano: 2007
URL: http://archimer.ifremer.fr/doc/2007/publication-2681.pdf

Structure et connectivité de la mégafaune marine à l’échelle d’une région océanique. Enjeux pour la gestion durable des tortues vertes dans l’océan Indien occidental
Provedor de dados: 5
Autores: Bourjea, Jerome.
This thesis is a comprehensive work aiming to improve scientific knowledge on the green turtle (Chelonia mydas) in order to provide key scientific evidences needed for the implementation of coherent and effective management measures to protect at the Western Indian Ocean scale this threatened species. In a first step, this work aimed to established baseline data on the abundance of green turtles nesting females and long term trends of some key nesting populations of the region by applying different modelling methods. In a second step, this work determined the regional genetic structure of this species and the relationships that exists between the different populations. Finally, the conservation of marine turtles being closely dependant to external...
Tipo: Text
Palavras-chave: Tortues marines; Tortue verte; Chelonia mydas; Mégafaune; Évaluation de population; Tendance sur long terme; Structure génétique; Génétique des populations; Capture accidentelle; Biologie de la conservation; Unité de gestion; Océan Indien; Marines turtles; Green turtle; Chelonia mydas; Megafauna; Population assessment; Long term trend; Genetic structure; Population genetic; By-catch; Incidental catch; Biological conservation; Management units; Indian ocean.
Ano: 2014
URL: http://archimer.ifremer.fr/doc/00244/35505/34009.pdf

Impacts of an Eruption on Cold-Seep Microbial and Faunal Dynamics at a Mud Volcano
Provedor de dados: 5
Autores: Girard, Fanny; Sarrazin, Jozee; Olu, Karine.
Cold seeps are widespread in the deep sea and, like other chemosynthesis-based ecosystems, often host high faunal biomass. Temporal changes at seeps have been inferred by comparing communities at different successional stages; nonetheless, temporal studies in seep ecosystems are rare. Using data collected as part of a benthic observatory, we characterized intra-annual microbial and faunal dynamics in a microbial mat habitat on the Håkon Mosby mud volcano (1256 m depth; Barents Sea), and evaluated the effects of a mud eruption on the biota. Video sequences recorded twice daily for 4.5 months with an autonomous imaging module were analyzed to quantify changes in microbial mat cover and megafaunal density and behavior. In addition, time series data for...
Tipo: Text
Palavras-chave: Håkon Mosby Mud Volcano; LOOME; Arctic; Beggiatoa; Deep-sea observatories; Time series; Megafauna.
Ano: 2020
URL: https://archimer.ifremer.fr/doc/00624/73631/73069.pdf

Influence of seep emission on the non-symbiont-bearing fauna and vagrant species at an active giant pockmark in the Gulf of Guinea (Congo-Angola margin)
Provedor de dados: 5
Autores: Olu, Karine; Caprais, Jean-claude; Galeron, Joelle; Causse, R.; Von Cosel, R.; Budzinski, H.; Le Menach, K.; Le Roux, C.; Levache, D.; Khripounoff, Alexis; Sibuet, Myriam.
Detailed surveying with an ROV found that a dense and diverse cold-seep community colonises a giant pockmark located at 3200 m depth, 8 km north from the deep Congo channel. Several types of assemblages, either dominated by Mytilidae and Vesicomyidae bivalves or Siboglinidae polychaetes, are distributed on the 800-m diameter active area. The site is characterised by a most active central zone in a depression with abundant carbonate concretions and high methane fluxes where high-density clusters of mussels and siboglinids dominate. In contrast, the peripheral zones display large fields of dead and live vesicomyids on soft sediment, with a lower mean density and lower methane concentration in seawater. The associated megafauna includes Alvinocarididae...
Tipo: Text
Palavras-chave: Congo Angola margin; Atlantic Equatorial African margin; Vagrant species; Isotopic signature; Megafauna; Cold seep.
Ano: 2009
URL: http://archimer.ifremer.fr/doc/2009/publication-7478.pdf

Detection of the elusive Dwarf sperm whale (     Kogia sima     ) using environmental DNA at Malpelo island (Eastern Pacific, Colombia)
Provedor de dados: 5
Autores: 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

Mollusk bycatch in trawl fisheries targeting the Atlantic seabob shrimp Xiphopenaeus kroyeri on the coast of Sergipe, northeastern Brazil
Provedor de dados: 84
Autores: Mendonça,Luana Marina de Castro; Guimarães,Carmen Regina Parisotto; Lima,Silvio Felipe Barbosa.
Abstract The malacofauna bycatch of sea-bob shrimp Xiphopenaeus kroyeri (Heller, 1862) trawl fisheries on the coast of Sergipe was studied for 5 years. The malacofauna bycatch considered was obtained in nine oceanographic sampling campaigns carried out between May 1999 and June 2003 in 18 stations distributed in six transects along depths of 10, 20 and 30 m. A total of 2,669 individuals of mollusk belonging to 54 species were captured on the 18 sea-bob shrimp trawl stations carried out along the coast of Sergipe. The considerable richness of mollusks was composed by 19 families and 31 species of gastropods, 12 families and 19 species of bivalves and 2 families and 4 species of cephalopods. The highest abundance were observed at stations 13 (373...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Megafauna; Mollusks; Gastropoda; Bivalvia; Cephalopoda.
Ano: 2019
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0031-10492019000100233

Swerving as the escape strategy of Macrauchenia patachonica Owen (Mammalia; Litopterna)
Provedor de dados: 41
Autores: Fariña,Richard A.; Blanco,R. Ernesto; Christiansen,Per.
The Lujanian megamammals (late Pleistocene of South America) show many palaeoautecological peculiarities. The present paper studies one of them, the locomotor habits of Macrauchenia patachonica Owen, through those morphological features related with its possible antipredation strategy. To avoid predation (especially by the sabre-tooth Smilodon Lund), this large litoptern seems to have been particularly adapted to swerving behaviour. This is suggested by the fact that its limb bones have indicators of higher transverse than anteroposterior strength (significantly so in the case of the femur), a feature which is also observed in modern swervers, and not so clearly in other fast running herbivores that do not use swerving so much.
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Palaeoecology; Megafauna; Pleistocene; South America; Biomechanics; Locomotion.
Ano: 2005
URL: http://www.scielo.org.ar/scielo.php?script=sci_arttext&pid=S0002-70142005000400007

Distributional patterns of herbivore megamammals during the Late Pleistocene of South America
Provedor de dados: 42
Autores: GALLO,VALERIA; AVILLA,LEONARDO S.; PEREIRA,RODRIGO C.L.; ABSOLON,BRUNO A.
The geographic distribution of 27 species of the South American megafauna of herbivore mammals during the Late Pleistocene was analyzed in order to identify their distributional patterns. The distribution of the species was studied using the panbiogeographical method of track analysis. Six generalized tracks (GTs) and two biogeographic nodes were obtained. The GTs did not completely superpose with the areas of open savanna present in Pleistocene, nor with the biotic tracks of some arthropods typical of arid climate, indicating that these animals avoided arid environment. Overall, the GTs coincided with some biogeographic provinces defined on the basis of living taxa, indicating that certain current distributional patterns already existed in Pleistocene....
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Distributional patterns; Historical Biogeography; Panbiogeography; Megafauna; Late Pleistocene; South America.
Ano: 2013
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0001-37652013000200533

Splendid oddness: revisiting the curious trophic relationships of South American Pleistocene mammals and their abundance
Provedor de dados: 42
Autores: FARIÑA,RICHARD A.; CZERWONOGORA,ADA; GIACOMO,MARIANA DI.
The South American Pleistocene mammal fauna includes great-sized animals that have intrigued scientists for over two centuries. Here we intend to update the knowledge on its palaeoecology and provide new evidence regarding two approaches: energetics and population density and relative abundance of fossils per taxa. To determine whether an imbalance exists, population density models were applied to several South American fossil faunas and the results compared to those that best describe the palaeoecology of African faunas. The results on the abundance study for Uruguay and the province of Buenos Aires during the Lujanian stage/age reveal that bulk-feeding ground sloths (Lestodon and Glossotherium) were more represented in the first territory, while the more...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Abundance; Megafauna; Palaeoecology; Population density; Secondary productivity; Quaternary.
Ano: 2014
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0001-37652014000100311

A COMMUNITY ANALYSIS OF THE SOFT BOTTOM MEGAFAUNA (CRUSTACEA, MOLLUSCA) FROM THE SOUTHWESTERN REGION OF SANTA MARTA, COLOMBIAN CARIBBEAN
Provedor de dados: 50
Autores: Arango,Claudia P.; Solano,Oscar D.
Soft bottom megabenthic communities have been poorly studied in the Caribbean Sea. In this study we describe the structure and species composition of a Crustacea-Mollusca megafaunal community based on beam trawl samples taken between 13 and 60 m depth at the southwestern region of Santa Marta, Colombian Caribbean. Classification and ordination analyses using abundance data of crustaceans and molluscs produced two main groups (A and C), which seem to be controlled by depth and sediment characteristics. Group A consisted of species collected at the deeper stations and high content of silts (between 30 and 60 m depth) and exhibited the highest density and biomass mean values. The decapod Chasmocarcinus cilindricus was found as the characteristic species for...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Megafauna; Soft bottoms; Communities; Caribbean; Colombia.
Ano: 1999
URL: http://www.scielo.org.co/scielo.php?script=sci_arttext&pid=S0122-97611999000100008

DISTRIBUCIÓN DE LA MEGAFAUNA BENTÓNICA DEL CARIBE COLOMBIANO ASOCIADA A VARIABLES AMBIENTALES DEL FONDO MARINO*
Provedor de dados: 50
Autores: Vides Casado,Martha Patricia.
El presente análisis relaciona la distribución espacial de especies de la megafauna bentónica con gradientes de variables ambientales estimadas cerca al fondo oceánico, haciendo uso de datos obtenidos a lo largo de la provincia del mar Caribe colombiano. Los datos utilizados corresponden a muestras de megafauna bentónica obtenidas en 96 sitios de colecta entre los años 1999 y 2008 en un ámbito de profundidad entre 15 y 900 m. La distribución latitudinal de los taxa mayores se analizó a través de perfiles del fondo de 100 km de longitud desde la línea de costa. Se utilizaron curvas de acumulación de especies con intervalos de confianza de 95% para hacer las comparaciones. La distribución de la megafauna bentónica se relacionó con los parámetros ambientales...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Megafauna; Bentos; Ensamblajes; Profundidad; Caribe colombiano.
Ano: 2011
URL: http://www.scielo.org.co/scielo.php?script=sci_arttext&pid=S0122-97612011000200002