381 research outputs found
Uptake and accumulation of metals in Spartina alterniflora salt marshes from a South American estuary
Salt marshes are capable of reducing metal pollution in coastal waters, but this capacity is highly dependent on the metal, the physico-chemical characteristics of the sediment, the plant species, the production of biomass, the time of the year, etc. The aim of this study was to assess the uptake and accumulation of Pb, Ni, Cu and Zn in Spartina alterniflora from three salt marshes within the BahĂa Blanca estuary (BBE), a human-impacted Argentinean system. Metal concentrations in sediments and plants showed the same order at all sites: Zn > Cu > Pb ≥ Ni. The site with lower organic matter and fine sediment content had lower metal concentrations in the sediments, but not a lower metal content in the plant tissues, meaning that the sediment characteristics influenced the metal concentrations in the sediment and their uptake by plants. Despite differences in sediment characteristics between sites, metals were always higher in the belowground tissues than in aboveground ones and, in general, higher in dead than in live tissues. Some metals were accumulated in plant tissues, but not others, and this is dependent on the metal and the sediment characteristics. Allocation patterns of metals in tissues of S. alterniflora were mainly dependent on metal concentrations, determining higher belowground pools, but the aboveground pools were important in some cases due to higher biomass. Partitioning of metals in above or belowground pools determines their fate within the estuarine system, since tissues can decompose in situ (belowground) or be exported (aboveground). Seasonal dynamics were important for some variables but were less noticeable than the differences between sites and tissues. Our results indicate that S. alterniflora from the BBE is efficient in accumulating some metals, despite usually low metal concentrations in sediments and plants. This accumulation capacity has implications for the whole system through the fate of the tissues.Fil: Negrin, Vanesa Lorena. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - BahĂa Blanca. Instituto Argentino de OceanografĂa. Universidad Nacional del Sur. Instituto Argentino de OceanografĂa; Argentina. Universidad Nacional del Sur. Departamento de BiologĂa, BioquĂmica y Farmacia; ArgentinaFil: BottĂ©, Sandra Elizabeth. Universidad Nacional del Sur. Departamento de BiologĂa, BioquĂmica y Farmacia; Argentina. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - BahĂa Blanca. Instituto Argentino de OceanografĂa. Universidad Nacional del Sur. Instituto Argentino de OceanografĂa; ArgentinaFil: la Colla, Noelia Soledad. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - BahĂa Blanca. Instituto Argentino de OceanografĂa. Universidad Nacional del Sur. Instituto Argentino de OceanografĂa; ArgentinaFil: Marcovecchio, Jorge Eduardo. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - BahĂa Blanca. Instituto Argentino de OceanografĂa. Universidad Nacional del Sur. Instituto Argentino de OceanografĂa; Argentina. Universidad TecnolĂłgica Nacional. Facultad Regional BahĂa Blanca; Argentina. Universidad FASTA "Santo Tomas de Aquino"; Argentin
Elaboration d'une déformation expérimentale en valgus du radius chez l'agneau
Le cartilage de croissance (CC) est constitué d'un ensemble de structures dynamiques à l'origine de la croissance longitudinale osseuse. Son activité est régulée par de nombreux facteurs, dont les facteurs mécaniques. L'auteur réalise premièrement un bilan des connaissances sur l'anatomie et la physiologie du CC, ainsi que sur les déformations angulaires, puis répertorie les résultats des études de compression symétrique et asymétrique du CC. Dans une seconde partie, une étude biomécanique in vitro a permis d'adapter le dispositif de compression du CC distal du radius (CCDR) décrit par ASIMUS, afin d'exercer des forces de compression asymétriques. Au cours de cette étape, le couple de force latérale/ distale à appliquer a été déterminé afin d'obtenir un freinage asymétrique et non un blocage de la croissance. Enfin, l'auteur a induit in vivo une déformation angulaire expérimentale en valgus par activité asymétrique du CC. Il a étudié l'influence de la durée de compression sur cette déformation. 35 agneaux ont été divisé en 3 groupes en fonction des durées de compression (3,6 et 9 semaines). Une compression asymétrique continue a été appliquée sur le CCDR à l'aide du dispositif décrit antérieurement. Les longueurs des radius, les distances entre les broches, ainsi que les angles entre les surfaces articulaires du radius ont été mesurés, et comparés aux radius controlatéraux. Une étude histologique a été réalisée. A la fin des périodes de compression, une faible différence de longueur entre les deux radius a été observée. La croissance n'a pas été bloquée. Sur les radius appareillés, les angles ont augmenté contrairement aux menbres témoins qui sont restés stables. Une déformation angulaire s'est développée non proportionnelle à la durée de compression. Aucune lésion histologique n'a été observée. Le modèle décrit par l'auteur devrait permettre à l'avenir d'étudier les mécanismes de mise en place de déformations angulaires et leur évolution spontanée
Nesting of the American Oystercatcher (haematopus palliatus) in the BahĂa Blanca estuary, Argentina
Se estudiaron diversos aspectos de la nidificaciĂłn del Ostrero ComĂşn (Haematopus palliatus) en dos áreas (islote y continente) en el estuario de BahĂa Blanca, durante dos temporadas reproductivas consecutivas. Hubo sincronĂa en la puesta de los huevos en ambas áreas y en los dos años de estudio, ocurriendo en un perĂodo de 20–30 dĂas. El tamaño promedio de la nidada fue similar en las dos áreas, con una moda de dos huevos, mientras que nidadas de tres huevos fueron halladas Ăşnicamente en el islote. Los huevos fueron más grandes (más largos y de mayor volumen) en el continente. La perturbaciĂłn por la presencia humana, con un mayor impacto en el continente, serĂa el principal condicionante de la mayor densidad de parejas y de nidos hallada en el islote. El mayor grado de cobertura vegetal y la cercanĂa a la lĂnea de marea de tormenta en los nidos del islote podrĂan estar vinculados a la protecciĂłn de los huevos frente a potenciales ataques por parte de predadoresSeveral aspects of the reproduction of the American Oystercatcher (Haematopus palliatus) were studied in two areas (continent and islet) in the BahĂa Blanca estuary during two consecutive breeding seasons. Laying dates were synchronous in each area and in both years, occurring in a period of 20–30 days. Mean clutch size was similar in both areas, with a mode of two eggs, while nests with three eggs were only found in the islet. Eggs were bigger (larger and more voluminous) in the continent than in the islet. Human disturbance, with a greater impact on the continent, could explain the higher density of pairs and nests found on the islet. Higher plant cover and proximity to the storm line in the islet nests could be associated to the protection of eggs from the potential attacks by predators.Fil: Simonetti, Pia. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico BahĂa Blanca. Instituto Argentino de OceanografĂa (i); ArgentinaFil: Fiori, Sandra Marcela. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico BahĂa Blanca. Instituto Argentino de OceanografĂa (i); Argentina. Universidad Nacional del Sur. Departamento de BiologĂa, BioquĂmica y Farmacia; ArgentinaFil: BottĂ©, Sandra Elizabeth. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico BahĂa Blanca. Instituto Argentino de OceanografĂa (i); Argentina. Universidad Nacional del Sur. Departamento de BiologĂa, BioquĂmica y Farmacia; ArgentinaFil: Marcovecchio, Jorge Eduardo. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico BahĂa Blanca. Instituto Argentino de OceanografĂa (i); Argentina. Universidad TecnolĂłgica Nacional. Facultad Regional BahĂa Blanca; Argentina. Universidad FASTA "Santo Tomas de Aquino"; Argentin
NidificaciĂłn del ostrero comĂşn (haematopus palliatus) en el estuario de BahĂa Blanca, Buenos Aires, Argentina.
Se estudiaron diversos aspectos de la nidificaciĂłn del Ostrero ComĂşn (Haematopus palliatus) en dos áreas (islote y continente) en el estuario de BahĂa Blanca, durante dos temporadas reproductivas consecutivas. Hubo sincronĂa en la puesta de los huevos en ambas áreas y en los dos años de estudio, ocurriendo en un perĂodo de 20?30 dĂas. El tamaño promedio de la nidada fue similar en las dos áreas, con una moda de dos huevos, mientras que nidadas de tres huevos fueron halladas Ăşnicamente en el islote. Los huevos fueron más grandes (más largos y de mayor volumen) en el continente. La perturbaciĂłn por la presencia humana, con un mayor impacto en el continente, serĂa el principal condicionante de la mayor densidad de parejas y de nidos hallada en el islote. El mayor grado de cobertura vegetal y la cercanĂa a la lĂnea de marea de tormenta en los nidos del islote podrĂan estar vinculados a la protecciĂłn de los huevos frente a potenciales ataques por parte de predadores.Nesting of the american oystercatcher (haematopus palliatus) in the BahĂa Blanca estuary, Argentina. Several aspects of the reproduction of the american oystercatcher (haematopus palliatus) were studied in two areas (continent and islet) in the bahĂa blanca estuary during two consecutive breeding seasons. Laying dates were synchronous in each area and in both years, occurring in a period of 20–30 days. Mean clutch size was similar in both areas, with a mode of two eggs, while nests with three eggs were only found in the islet. Eggs were bigger (larger and more voluminous) in the continent than in the islet. Human disturbance, with a greater impact on the continent, could explain the higher density of pairs and nests found on the islet. Higher plant cover and proximity to the storm line in the islet nests could be associated to the protection of eggs from the potential attacks by predators.Fil: Simonetti, Pia. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico BahĂa Blanca. Instituto Argentino de OceanografĂa (i); Argentina;Fil: Fiori, Sandra Marcela. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico BahĂa Blanca. Instituto Argentino de OceanografĂa (i); Argentina; Universidad Nacional del Sur. Departamento de BiologĂa, BioquĂmica y Farmacia; Argentina;Fil: BottĂ©, Sandra Elizabeth. Universidad Nacional del Sur. Departamento de BiologĂa, BioquĂmica y Farmacia; Argentina; Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico BahĂa Blanca. Instituto Argentino de OceanografĂa (i); Argentina;Fil: Marcovecchio, Jorge Eduardo. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico - CONICET - Bahia Blanca. Instituto Argentino de Oceanografia (i); Argentina; Universidad Tecnologica Nacional; Argentina; Universidad FASTA "Santo Tomas de Aquino"; Argentina
Lead in the marine environment: concentrations and effects on invertebrates
Lead (Pb) is a non-essential metal naturally present in the environment and often complexed with other elements (e.g., copper, selenium, zinc). This metal has been used since ancient Egypt and its extraction has grown in the last centuries. It has been used until recently as a fuel additive and is currently used in the production of vehicle batteries, paint, and plumbing. Marine ecosystems are sinks of terrestrial contaminations; consequently, lead is detected in oceans and seas. Furthermore, lead is not biodegradable. It remains in soil, atmosphere, and water inducing multiple negative impacts on marine invertebrates (key species in trophic chain) disturbing ecological ecosystems. This review established our knowledge on lead accumulation and its effects on marine invertebrates (Annelida, Cnidaria, Crustacea, Echinodermata, and Mollusca). Lead may affect different stages of development from fertilization to larval development and can also lead to disturbance in reproduction and mortality. Furthermore, we discussed changes in the seawater chemistry due to Ocean Acidification, which can affect the solubility, speciation, and distribution of the lead, increasing potentially its toxicity to marine invertebrates
Changes in the metabolic potential of the sponge microbiome under ocean acidification.
Anthropogenic CO2 emissions are causing ocean acidification, which can affect the physiology of marine organisms. Here we assess the possible effects of ocean acidification on the metabolic potential of sponge symbionts, inferred by metagenomic analyses of the microbiomes of two sponge species sampled at a shallow volcanic CO2 seep and a nearby control reef. When comparing microbial functions between the seep and control sites, the microbiome of the sponge Stylissa flabelliformis (which is more abundant at the control site) exhibits at the seep reduced potential for uptake of exogenous carbohydrates and amino acids, and for degradation of host-derived creatine, creatinine and taurine. The microbiome of Coelocarteria singaporensis (which is more abundant at the seep) exhibits reduced potential for carbohydrate import at the seep, but greater capacity for archaeal carbon fixation via the 3-hydroxypropionate/4-hydroxybutyrate pathway, as well as archaeal and bacterial urea production and ammonia assimilation from arginine and creatine catabolism. Together these metabolic features might contribute to enhanced tolerance of the sponge symbionts, and possibly their host, to ocean acidification
Heavy metals in kidney tissues of Franciscana dolphin, Pontoporia blainvillei (Cetacea: Pontoporiidae), and their relationship with biological parameters
En este estudio se determinĂł los niveles de metales pesados (Cd, Pb, Zn, Cu, Cr y Ni) en el tejido renal del delfĂn franciscana, Pontoporia blainvillei, y se estableciĂł la influencia de los parámetros ecolĂłgicos y biolĂłgicos sobre la bioacumulaciĂłn de estos elementos. Se analizaron muestras de 38 ejemplares colectados entre 2004 y 2010 en el sur de Buenos Aires, Argentina. La edad de los animales y el estado de madurez sexual se determinaron por mĂ©todos histolĂłgicos, y los niveles de metales pesados por EspectrofotometrĂa de AbsorciĂłn AtĂłmica. No se determinaron diferencias significativas para las concentraciones de Zn, Cu y Cd entre ambos sexos. Los niveles de Cd presentaron diferencias segĂşn el estado de madurez sexual y se relacionaron positivamente con la longitud, peso corporal y edad. Los niveles de Cd,Cu y Zn resultaron menores a los informados en estudios previos realizados en el norte de Buenos Aires y Uruguay.Heavy metal (Cd, Pb, Zn, Cu, Cr,Ni) concentrations were determined in the kidney tissue of the Franciscana dolphin, Pontoporia blainvillei, and the influence of ecological and biological parameters on the bioaccumulation of these elements was established. Samples from 38 specimens, collected between 2004 and 2010 off southern Buenos Aires, Argentina, were analyzed. Histological methods were used to determine both the age and sexual maturity of the animals. Heavy metal concentrations were measured by atomic absorption spectrophotometry. No significant differences were found by sex for Zn, Cu, and Cd. However, Cd levels differed between maturity stages and were positively related to length, body weight, and age. The Cd, Cu, and Zn levels reported here in were lower than those included in previous studies done off northern Buenos Aires and UruguayFil: Panebianco, MarĂa Victoria. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Oficina de CoordinaciĂłn Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"; ArgentinaFil: Negri, Maria Fernanda. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Oficina de CoordinaciĂłn Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"; ArgentinaFil: BottĂ©, Sandra Elizabeth. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - BahĂa Blanca. Instituto Argentino de OceanografĂa. Universidad Nacional del Sur. Instituto Argentino de OceanografĂa; ArgentinaFil: Marcovecchio, Jorge Eduardo. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - BahĂa Blanca. Instituto Argentino de OceanografĂa. Universidad Nacional del Sur. Instituto Argentino de OceanografĂa; ArgentinaFil: Cappozzo, Humberto Luis. Universidad MaimĂłnides; Argentina. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas; Argentin
Biogeographic variation in the microbiome of the ecologically important sponge, Carteriospongia foliascens
Sponges are well known for hosting dense and diverse microbial communities, but how these associations vary with biogeography and environment is less clear. Here we compared the microbiome of an ecologically important sponge species, Carteriospongia foliascens, over a large geographic area and identified environmental factors likely responsible for driving microbial community differences between inshore and offshore locations using co-occurrence networks (NWs). The microbiome of C. foliascens exhibited exceptionally high microbial richness, with more than 9,000 OTUs identified at 97% sequence similarity. A large biogeographic signal was evident at the OTU level despite similar phyla level diversity being observed across all geographic locations. The C. foliascens bacterial community was primarily comprised of Gammaproteobacteria (34.2% ± 3.4%) and Cyanobacteria (32.2% ± 3.5%), with lower abundances of Alphaproteobacteria, Bacteroidetes, unidentified Proteobacteria, Actinobacteria, Acidobacteria and Deltaproteobacteria. Co-occurrence NWs revealed a consistent increase in the proportion of Cyanobacteria over Bacteroidetes between turbid inshore and oligotrophic offshore locations, suggesting that the specialist microbiome of C. foliascens is driven by environmental factors
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