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Dive into the research topics where Silvia Jerez is active.

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Featured researches published by Silvia Jerez.


Environmental Pollution | 2011

Concentration of trace elements in feathers of three Antarctic penguins: Geographical and interspecific differences

Silvia Jerez; Miguel Motas; María José Palacios; Francisco Valera; José Javier Cuervo; Andrés Barbosa

Antarctica is often considered as one of the last pristine regions, but it could be affected by pollution at global and local scale. Concentrations of Al, Cr, Mn, Fe, Ni, Cu, Zn, As, Se, Cd and Pb were determinated by ICP-MS in feathers (n = 207 individuals) of gentoo, chinstrap and Adélie penguin collected in 8 locations throughout the Antarctic Peninsula (2006-2007). The highest levels of several elements were found in samples from King George Island (8.08, 20.29 and 1.76 μg g(-1) dw for Cr, Cu and Pb, respectively) and Deception Island (203.13, 3.26 and 164.26 μg g(-1) dw for Al, Mn and Fe, respectively), where probably human activities and large-scale transport of pollutants contribute to increase metal levels. Concentrations of Cr, Mn, Cu, Se or Pb, which are similar to others found in different regions of the world, show that some areas in Antarctica are not utterly pristine.


Chemosphere | 2010

Accumulation and tissue distribution of heavy metals and essential elements in loggerhead turtles (Caretta caretta) from Spanish Mediterranean coastline of Murcia

Silvia Jerez; Miguel Motas; Régulo Ángel Cánovas; J. Talavera; Ramón Miguel Almela; Alejandro Ángel Bayón del Río

Sea turtles are of increasing interest as potential bioindicators of the heavy metal pollution in marine ecosystems. In the present work, concentrations of heavy metals and essential elements (As, Cd, Hg, Pb, Se, Zn) in different organs and tissues (liver, kidney, muscle, bone, blood, central nervous system and skin) of loggerhead sea turtles (Caretta caretta) were determined from stranded animals found along the Spanish Mediterranean coastlines of Murcia. Relatively high average levels of As (skin: 52.13 microg g(-1) dry weight; muscle: 40.95 microg g(-1) dry weight), and especially high individual levels of Zn in muscle tissue (1002.4 microg g(-1) dry weight) were detected. Furthermore, a significant degree of organotrophism of Cd was observed in kidney tissue. The concentrations detected, the distribution among the tissues and the differences observed between juvenile and adult specimens are generally compatible with chronic exposure to the elements studied, whilst levels produced by acute exposure were ruled out.


Antarctic Science | 2013

Pollution and physiological variability in gentoo penguins at two rookeries with different levels of human visitation.

Andrés Barbosa; Eva De Mas; Jesús Benzal; Julia I. Diaz; Miguel Motas; Silvia Jerez; Luis R. Pertierra; Javier Benayas; Ana Justel; Pilar Lauzurica; Francisco Javier Garcia-Peña; Tania Serrano

Abstract Human activity and specifically tourism has been increasing in Antarctica over the last few years. Few studies have examined the indirect effects of human visits on Antarctic penguin rookeries. This work aims to study the differences between a highly visited (Hannah Point) and a rarely visited (Devils Point, Byers Peninsula) gentoo penguin rookery on Livingston Island. Our results suggest that potential indirect effects of human impact are observed in gentoo penguins at Hannah Point, a colony heavily visited by tourists. Penguins at Hannah Point showed a higher presence of heavy metals such as Pb and Ni and a higher number of erythrocytic nuclear abnormalities than penguins at Devils Point. Immunological parameters showed different results depending on whether we consider the cellular response - the number of lymphocytes being higher in penguins from Hannah Point - or the humoral response - the level of immunoglobulins being higher in penguins from Devils Point. Measurements of corticosterone levels in feathers and heterophil/lymphocyte (H/L) ratio in blood showed lower levels in the heavily visited rookery than in the rarely visited rookery. Finally, we did not detect Campylobacter jejuni, a bacteria potentially transmitted by humans in either of the populations and we did not find any difference in the prevalence of Campylobacter lari between the populations.


Parasitology Research | 2013

Gastrointestinal helminths of Gentoo penguins (Pygoscelis papua) from Stranger Point, 25 de Mayo/King George Island, Antarctica

Julia I. Diaz; Bruno Fusaro; Lucrecia Longarzo; Néstor Coria; Virginia Vidal; Silvia Jerez; J. Ortiz; Andrés Barbosa

The aim of this work is to contribute to the knowledge of gastrointestinal parasites of the Gentoo penguin (Pygoscelis papua) from 25 de Mayo/King George Island (South Shetlands, Antarctica). Gastrointestinal tracts of 37 fresh dead individuals (21 chicks, 10 juveniles, and 6 adults) were collected from December 2006 to February 2012 and examined for macroparasites. Four adult parasite species were found: one Cestoda species (Parorchites zederi), two Nematoda species (Stegophorus macronectes and Tetrameres wetzeli), and one Acanthocephalan (Corynosoma shackletoni). Two species of immature acanthocephalans, Corynosoma hamanni and Corynosoma bullosum, were found in a single host. This is the first record of Tetrameres wetzeli in Gentoo penguins. The low parasite richness observed could be related to the stenophagic and pelagic diet of this host species which feeds almost exclusively on krill.


Environmental Science and Pollution Research | 2013

Distribution of metals and trace elements in adult and juvenile penguins from the Antarctic Peninsula area

Silvia Jerez; Miguel Motas; Jesús Benzal; Julia I. Diaz; Virginia Vidal; Verónica L. D’Amico; Andrés Barbosa

The presence of metals in the Antarctic environment is principally a natural phenomenon caused by geochemical characteristics of the region, although some anthropogenic activities can increase these natural levels. Antarctic penguins present several of the characteristics of useful sentinels of pollution in Antarctica such as they are long-lived species situated at the top of food web. The concentrations of Al, Cr, Mn, Fe, Ni, Cu, Zn, As, Se, Cd, and Pb were determined by inductively coupled plasma–mass spectrometry in samples of liver, kidney, muscle, bone, feather, and stomach contents of gentoo, chinstrap, and Adélie penguin (12 adults, five juveniles) from carcasses of naturally dead individuals collected opportunistically in the Antarctic Peninsula area. The obtained results showed that accumulation and magnification of several elements can be occurring, so that Cd and Se reached levels potentially toxic in some specimens. The presence of human activities seems to be increasing the presence of toxic metals such as Mn, Cr, Ni, or Pb in penguins.


Marine Pollution Bulletin | 2013

Monitoring trace elements in Antarctic penguin chicks from South Shetland Islands, Antarctica

Silvia Jerez; Miguel Motas; Jesús Benzal; Julia I. Diaz; Andrés Barbosa

UNLABELLED The concentration of human activities in the near-shore ecosystems from the northern Antarctic Peninsula area can cause an increasing bioavailability of pollutants for the vulnerable Antarctic biota. Penguin chicks can reflect this potential impact in the rookeries during the breeding season. They also can reflect biomagnification phenomena since they are on the top of the Antarctic food chain. The concentrations of Al, Cr, Mn, Fe, Ni, Cu, Zn, As, Se, Cd and Pb were measured by ICP-MS in samples of liver, kidney, muscle, bone, feather and stomach content of gentoo, chinstrap and Adélie penguin chicks (n=15 individuals) collected opportunistically in the Islands of King George and Deception (South Shetland Islands, Antarctica). The detected levels of some trace elements were not as low as it could be expected in the isolated Antarctic region. Penguin chicks can be useful indicators of trace elements abundance in the study areas. CAPSULE Carcasses of Antarctic penguin chicks were used to evaluate the bioavailability of trace elements in the Islands of King George and Deception.


Journal of Wildlife Diseases | 2016

MODE OF ATTACHMENT AND PATHOLOGY CAUSED BY PARORCHITES ZEDERI IN THREE SPECIES OF PENGUINS: PYGOSCELIS PAPUA, PYGOSCELIS ADELIAE, AND PYGOSCELIS ANTARCTICA IN ANTARCTICA

María A. Martín; J. Ortiz; Juan Seva; Virginia Vidal; Francisco Valera; Jesús Benzal; José Javier Cuervo; Carlos de la Cruz; Josabel Belliure; Ana Martínez; Julia I. Diaz; Miguel Motas; Silvia Jerez; Verónica L. D'Amico; Andrés Barbosa

Abstract We identified and compared gross and microscopic lesions associated with the cestode, Parorchites zederi, in the digestive tracts of three species of penguins (Spheniscidae): the Chinstrap (Pygoscelis antarctica), Gentoo (Pygoscelis papua), and Adélie penguins (Pygoscelis adeliae). The gastrointestinal tracts of 79 recently dead individuals (71 chicks and eight adults) were collected in locations throughout the Antarctic Peninsula during summer field trips in 2006–09. Parorchites zederi was found in the small intestine of 37 animals (47%), and 23 (62%) of these had parasite-associated lesions. The cestodes were either free in the intestinal lumen, clustered within mucosal ulcers, or deeply embedded in the intestinal wall. Histopathologic changes were most severe in adult Gentoo Penguins and included transmural fibrogranulomatous enteritis, hemorrhage, and edema. This report of pathology associated with P. zederi in the digestive tracts of penguins can serve as reference to monitor health in Antarctic birds associated with environmental changes.


Toxicology Letters | 2008

Trace and toxic elements in three species of Antarctic penguins: A preliminary research

Silvia Jerez; Miguel Motas; María Del Mar Tortosa; J. Ortiz; Francisco Valera; María José Palacios; Jesús Benzal; Carlos de la Cruz; Javier Cuervo; Ana Martinez; Andrés Barbosa


Toxicology Letters | 2016

Metals found on Antarctic penguins, effect on homeostasis of hepatic cells determined by gene expression

A. Meseguer; J. Amores; Silvia Jerez; Andrés Barbosa; Miguel Motas


Toxicology Letters | 2016

Metals concentrations found in liver and kidney of Antarctic penguins, a potential toxic effect

A. Meseguer; Miguel Motas; Silvia Jerez; A. Bernabé; Andrés Barbosa

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Andrés Barbosa

Spanish National Research Council

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Jesús Benzal

Spanish National Research Council

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Julia I. Diaz

National University of La Plata

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Francisco Valera

Spanish National Research Council

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J. Ortiz

University of Murcia

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Ana Martinez

Spanish National Research Council

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