Museo Acatushun de Aves y Mamiferos Marinos Australes

Ushuaia, Argentina

Museo Acatushun de Aves y Mamiferos Marinos Australes

Ushuaia, Argentina

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Zenteno L.,University of Barcelona | Crespo E.,CONICET | Crespo E.,National University of Patagonia | Goodall N.,Museo Acatushun de Aves y Mamiferos Marinos Australes | And 8 more authors.
Journal of Zoology | Year: 2013

Stable isotopes of oxygen have been widely used to reconstruct paleotemperatures and to investigate the thermal environment of fishes and mollusks, but they have only occasionally been used as geographical markers in marine systems. As bone apatite grows at a constant temperature in marine mammals and food is the major source of water for these animals, particularly for pinnipeds, variations in the ratio of stable isotopes of oxygen (δ18O) of bone apatite will likely reflect changes in the δ18O values of diet, and thus of the surrounding water mass, despite the potential confounding role of factors as the proximate composition of diet, sex and body size. Here, we used the δ18O values in bone apatite to investigate whether adult males of South American sea lion (Otaria byronia), from three regions in southwestern Atlantic Ocean (Brazil, Patagonia and Tierra del Fuego in Argentina), used the same water masses to forage and whether differences exist in the water masses used by sea lions differing according to sex and developmental stage. Statistically significant differences were observed among the δ18O bone values of adult males from the three regions, with those from Patagonia more enriched in 18O, as expected from the δ18Oseawater values. These results revealed restricted dispersal movements of adult males between the three areas. On the other hand, adult males and females from Patagonia did not differ in average δ18Obone values, thus indicating the use of foraging grounds within the same water mass. Finally, the variability in the δ18Obone values of young of both sexes was much wider than the adults of the same sex from the same region, which suggests the existence of a juvenile dispersal phase in both sexes, although much shorter in females than in males. These results confirm the usefulness of stable isotopes of oxygen as habitats tracers in marine mammals. © 2013 The Zoological Society of London.

Caceres-Saez I.,Museo Argentino de Ciencias Naturales Bernardino Rivadavia | Goodall R.N.P.,Museo Acatushun de Aves y Mamiferos Marinos Australes | Goodall R.N.P.,CONICET | Dellabianca N.A.,Museo Acatushun de Aves y Mamiferos Marinos Australes | And 4 more authors.
Chemosphere | Year: 2015

The skin of bycaught Commerson's dolphins was tested for mercury (Hg) and selenium (Se) biomonitoring in Subantarctic environments. The correlation of levels detected in the skin with those found in internal tissues - lung, liver, kidney and muscle - was assessed to evaluate how skin represents internal Hg and Se distribution for monitoring purposes. Mercury in skin had a concentration range of 0.68-3.11μgg-1 dry weight (DW), while Se had a higher concentration range of 74.3-124.5μgg-1 DW. There was no significant correlation between selenium levels in any of the analyzed tissues. Thus, the skin selenium concentration did not reflect the tissular Se levels and did not provide information for biomonitoring. The lack of correlation is explained by the biological role of Se, provided that each tissue regulates Se levels according to physiological needs. However, the skin Hg level had significant positive correlation with the levels in internal tissues (ANOVA p<0.05), particularly with that of muscle (R2=0.79; ANOVA p=0.0008). Thus, this correlation permits the estimation of Hg content in muscle based on the multiplication of skin biopsy levels by a factor of 1.85. Mercury bioindication using skin biopsies is a non-lethal approach that allows screening of a large number of specimens with little disturbance and makes possible an adequate sampling strategy that produces statistically valid results in populations and study areas. The correlation between Hg levels in the skin and internal tissues supports the use of the epidermis of Commerson's dolphins for Hg biomonitoring in the waters of the Subantarctic, which is a poorly studied region regarding Hg levels, sources and processes. © 2015 Elsevier Ltd.

Crespo E.A.,CONICET | Crespo E.A.,Brown University | Schiavini A.C.M.,CONICET | Garcia N.A.,CONICET | And 5 more authors.
Marine Mammal Science | Year: 2015

The South American fur seal (SAFS), Arctocephalus australis, was severely depleted during the 18th century. This work updates information on distribution, abundance, seasonal movements, and genetic structure along the southwestern South Atlantic. Its distribution in Argentine waters includes nineteen rookeries on the Patagonian coast, Isla de los Estados, and islets of the Beagle Channel. Censuses were carried out in rookeries from Isla Escondida to Isla de los Estados from 1996 to 2014. The largest concentrations are found in Chubut, (4,500-15,500 seals) and Isla de los Estados (4,500). Pups were recorded on Isla Escondida, Rasa, and Isla de los Estados. An increasing number of SAFS were recorded in northern Patagonia, including seals marked in Uruguay. Skin samples were taken from southern Brazil to Tierra del Fuego in order to evaluate population structure and demographic trends. Genetic results indicated no population subdivisions (Φst = -0.0292, Fst = -0.00716, P > 0.05). Bayesian skyline plots constructed for the entire data set indicated evidence of rapid population expansion discernible in Nef between the last 20,000 and 17,000 yr. Genetics results and observation data from marked fur seals support the hypothesis of ancient gene flow and a single Atlantic population. Therefore, SAFS should be managed under international and integrated conservation policies. © 2015 Society for Marine Mammalogy.

Caceres-Saez I.,Museo Argentino de Ciencias Naturales Bernardino Rivadavia | Ribeiro Guevara S.,Bariloche Atomic Center | Dellabianca N.A.,Museo Acatushun de Aves y Mamiferos Marinos Australes | Dellabianca N.A.,CONICET | And 4 more authors.
Environmental Monitoring and Assessment | Year: 2013

A survey of the elemental contents of K, Mg, Mn, Na, Cl, Br, Cs, Co, Rb, Fe, Zn, Al, Ti, V, As, Ag, Au and Cd in liver, kidney and muscle was performed in specimens of Commerson's dolphins (Cephalorhynchus c. commersonii) from subantarctic waters. The concentrations were determined by Instrumental Neutron Activation Analysis and the specimens derives from animals incidentally caught in artisanal fishing nets. Liver had the highest concentrations of Fe, 897(79) μg g-1 DW (dry weight) (average; standard deviation in parenthesis), kidney had the highest Cd, 35 (24) μg g-1 DW; Cl, 9,200 (1,700) μg g-1 DW; Na, 6,800 (1,100) μg g-1 DW and Br, 73(12) μg g-1 DW; and muscle the highest Mg 954 (71) μg g-1 DW. Potassium and Cs concentrations in muscle and kidney ranged in 12,510-13,020 and 0.230-0.252 μg g-1 DW, respectively; Zn and Mn concentrations were similar in liver and kidney (117-122.1 and 3.66-16.5 μg g-1 DW, respectively). Silver was high in liver 5.4(5.0) μg g-1 DW and kidney 1.2(2.7) μg g-1 DW. Gold, Rb, Co and As had no differences among tissues. Likewise, as in other odontocete species, the concentrations of essential elements showed little variation between the specimens analyzed, since they are regulated biochemically; however, heavy metals showed high variability. This study constitutes the first large description of the elemental composition in Commerson's dolphins from subantarctic waters of the South Atlantic Ocean. © 2012 Springer Science+Business Media Dordrecht.

Caceres-Saez I.,Museo Argentino de Ciencias Naturales Bernardino Rivadavia | Panebianco M.V.,Museo Argentino de Ciencias Naturales Bernardino Rivadavia | Panebianco M.V.,Maimónides University | Perez-Catan S.,Bariloche Atomic Center | And 8 more authors.
Chemistry and Ecology | Year: 2016

We explored the potential of using energy-dispersive X-ray analysis (EDX), a non-destructive technique, to assess elemental contents in dolphin bones. Specimens were deposited in museum collections, and prepared by different methodologies. Fifty eight Commerson’s dolphins (Cephalorhynchus c. commersonii) chevron bones and 24 Franciscana dolphins (Pontoporia blainvillei) were analysed. The EDX allowed us to detect the following elements: Ca, P, Na, Mg, Fe, K, Zn, S, Cl and Al; and quantify their proportion (weight percent of element). Principal components analysis differentiates two groups according to the cleaning procedures applied, supporting that cleaning methods could influence the chemical integrity of bone. No significant age-dependent increase was found for elements analysed in species, and no significant differences were found between sex and physical maturity stages. Alternative assessment was made through atomic absorption spectrophotometry, providing quantitative information on the principal elements in bones (Ca, P, Mg, Na, Fe and Zn) and allowing comparisons with other studies. A standard protocol for bone cleaning and conditioning is needed to exclude any effect on the mineral integrity of calcified tissue. This would enable future comparative studies on the bone mineral matrix over time housed in natural history museums or other scientific collections. © 2016 Informa UK Limited, trading as Taylor & Francis Group

Caceres-Saez I.,Museo Argentino de Ciencias Naturales Bernardino Rivadavia | Ribeiro Guevara S.,Bariloche Atomic Center | Goodall R.N.P.,Museo Acatushun de Aves y Mamiferos Marinos Australes | Goodall R.N.P.,CONICET | And 4 more authors.
Polar Biology | Year: 2016

The skin of cetaceans is the most accessible tissue, and its sampling has been proposed as a noninvasive method to evaluate trace element concentrations in free-ranging populations. In the present work, concentrations of essential (Cl, Na, K, Mg, Fe, Zn, Mn and Co), nonessential (As and Ag), and of unknown essentiality (Br, Rb and Cs) elements were determined in the skin from nine by-caught Commerson’s dolphins (Cephalorhynchus commersonii) from Tierra del Fuego, Argentina. Skin correlations with internal tissues—lung, liver, kidney and muscle—were assessed to evaluate how the skin represents internal element concentration for monitoring purposes. Elemental contents were analyzed by instrumental neutron activation analysis (INAA). Regarding tissue distribution, skin had the highest concentration of Zn being two orders of magnitude higher than internal tissues, while other elements such as Co and Rb had similar concentrations among tissues. High mean concentrations of Cl, Na, Mg, Br and Mn were observed in the lung and liver. Our results support the use of skin to evaluate Fe, Br and Rb concentrations in internal tissues for biomonitoring purposes; however, other elements did not show significant skin-to-tissue correlations. Overall, toxic element levels were far below concentrations found to cause harm in marine vertebrates. This study provided baseline data on elemental concentrations in tissues of Commerson’s dolphins in subantarctic waters from the South Atlantic Ocean. © 2016 Springer-Verlag Berlin Heidelberg

Caceres-Saez I.,Museo Argentino de Ciencias Naturales Bernardino Rivadavia | Dellabianca N.A.,Museo Acatushun de Aves y Mamiferos Marinos Australes | Dellabianca N.A.,CONICET | Goodall R.N.P.,Museo Acatushun de Aves y Mamiferos Marinos Australes | And 4 more authors.
Biological Trace Element Research | Year: 2013

Total mercury (THg) and selenium (Se) concentrations were determined in hepatic, renal, and muscle tissues of seven specimens of Commerson's dolphins incidentally captured in artisanal fisheries of Tierra del Fuego, Argentina, by instrumental neutron activation analysis. Liver yielded the mean highest concentration of THg 9.40 (9.92) μg g-1 dry weight (DW) (standard deviation of the average in parenthesis); kidney and muscle showed similar values, ranging from 2.34 to 3.63 μg g-1 DW. Selenium concentrations were similar in hepatic and renal tissues, with values from 13.62 to 14.56 μg g-1 DW; the lowest concentration was observed in muscle, 4.13 (2.05) μg g-1 DW. Among the specimens analyzed, the maximum concentrations of THg and Se were observed in the single adult female studied. An increasing age trend is observed for THg concentrations in tissues analyzed. The molar ratio of Se/Hg in the hepatic, renal, and muscle tissues were 8.7 (9.6), 13.2 (9.5), and 9.0 (11.4), respectively, suggesting Se protection against Hg toxicity. Silver concentrations in the three tissues were included, and the Se/(Hg + 0.5×Ag) molar ratio showed values closer to 1. Both Hg and Se concentrations in liver and kidney were comparable to those found in other small odontocetes from Argentine and Brazilian waters. This study constitutes the first joint description reported of Hg and Se concentrations in liver, kidney, and muscle of the Commerson's dolphin species. © 2012 Springer Science+Business Media New York.

Caceres-Saez I.,Museo Argentino de Ciencias Naturales Bernardino Rivadavia | Caceres-Saez I.,CONICET | Polizzi P.,CONICET | Polizzi P.,University of the Sea | And 12 more authors.
Marine Pollution Bulletin | Year: 2016

The Commerson's dolphin is the most common endemic odontocete of subantarctic waters of Tierra del Fuego, Argentina incidentally caught in fishing nets. The species is classified as "Data Deficient" by the IUCN. Metallothioneins (MTs) are considered as suitable biomarkers for health and environmental monitoring. The aims of the study were to assess MT concentrations in the liver and kidney of bycaught specimens. Moreover, correlations with Zn, Se, Cd, Ag and Hg, and the molar ratios of MT:metals were estimated to evaluate if there is an indication of their respective protective role against metal toxicity in tissues. Hepatic and renal MT concentrations were similar, ranging from 11.6 to 29.1nmol·g-1 WW, and Kidney/Liver ratios ranging from 0.73 to 1.93 corresponded to normal ranges. Results suggest that MTs are related to physiological ranges for the species. This information constitutes the first MT report on Commerson's dolphins and possibly considered as baseline for species' conservation. © 2016.

Goodall R.N.P.,Museo Acatushun de Aves y Mamiferos Marinos Australes | Goodall R.N.P.,CONICET | Marchesi M.C.,Museo Acatushun de Aves y Mamiferos Marinos Australes | Pimper L.E.,Museo Acatushun de Aves y Mamiferos Marinos Australes | And 7 more authors.
Polar Biology | Year: 2011

Bottlenose dolphins (Tursiops spp.) are cosmopolitan animals widely distributed in waters of both hemispheres. The taxonomy of Tursiops has long been controversial, with over 20 specific names being published, and subspecies and inshore/offshore forms being proposed. In the southwestern South Atlantic, subspecies T. truncatus truncatus and T. truncatus gephyreus were proposed for specimens along the coasts of Brazil, Uruguay, and Argentina. Sightings of bottlenose dolphins are common along the coast of Argentina as far south as the Province of Chubut (ca. 46°S). Here, we summarize and discuss the southernmost records of bottlenose dolphins. We cannot make inferences about the species or subspecies to which these animals belong given the small number of specimens. Future studies of external measurements, pigmentation, DNA, and isotopes from both sides of the continent should help clarify the situation off southern South America. Furthermore, research is needed to explore a possible link between an effect of general global warming and the Tursiops specimens found this far south. The sighting and specimens described here, at 53°S-nearly 55°S, are the southernmost records for the genus and extend the range of the species in the southern South Atlantic. © 2011 Springer-Verlag.

Orgeira J.L.,Instituto Antártico Argentino | Scioscia G.,CONICET | Torres M.A.,Museo Acatushun de Aves y Mamiferos Marinos Australes | Dellabianca N.A.,CONICET
Polar Research | Year: 2013

During ship-based seabird surveys in the south Atlantic and Antarctica in the austral summers of 1994/95, 2009, 2010, 2011 and 2012, we documented at-sea distributions of Buller's albatross (Thalassarche bulleri), Atlantic petrel (Pterodroma incerta), soft-plumaged petrel (Pterodroma mollis), Kerguelen petrel (Lugensa brevirostris) and great-winged petrel (Pterodroma macroptera). In some cases, sightings were considered as extralimital, but for other species updating their distributions in the literature seems warranted. Atlantic petrel, for example, has been regularly observed in the Drake Passage and north of the Antarctic Peninsula for about 30 years, but the distribution of this species has not been updated in the literature. The observations reported here will contribute to update the at-sea distributions of these species and to changes in their distributions. © 2013 J.L. Orgeira et al.

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