RESUMEN
Until not so long ago, Antarctica was considered to be a polar region practically pristine. The Antarctic Peninsula has the highest concentration of scientific stations from different countries. Anthropogenic activity has caused alterations in the Antarctic ecosystems directly affecting terrestrial vegetation. This fact requires the finding of biomarkers in native plants to estimate the effects of human impact. Deschampsia antarctica Desv. (Poaceae) is the unique native grass described so far for Antarctica and was used for multiple investigations. In this study, plants were collected on Carlini scientific station, 25 de Mayo (King George) Island, Potter Peninsula, South Shetland Islands. Thus, the main objective planned consists of the evaluation of leaf stomata-related parameters as pollution biomarkers. The results of the stomatic index (SI), density (SD), and area (SA) were shown at sites with different levels of human impact (close and far away from the scientific station). It was found that the correlation between SD and SI, on the adaxial side of the leaves, resulted in a good biomarker for estimating the degree of anthropogenic impact in each studied area. Graphical abstract.
Asunto(s)
Ecosistema , Poaceae , Regiones Antárticas , Biomarcadores , Contaminación Ambiental/efectos adversos , Humanos , Hojas de la PlantaRESUMEN
Human activities are increased in Antarctica during decades, primarily due to the logistic and tourism operations, which consequent negative impact on penguin populations, altering their physiological responses. Therefore, we aimed to assess the blood biochemistry and oxidant/antioxidant balance of Adélie penguins (Pygoscelis adeliae) inhabiting two selected colonies: Potter Peninsula, considered as a low impacted colony, and Esperanza/Hope Bay as a high impacted colony. The levels of calcium, uric acid, and fructosamine, showed significant high values (p<0.05) for the Potter Peninsula´s penguins. Besides, this population showed high levels of plasma protein oxidation and erythrocyte lipid peroxidation (p<0.005) while the Esperanza/Hope Bay population presented high levels of erythrocyte protein oxidation and plasma lipid peroxidation (p<0.005). The oxidative damage values were similar in the Potter Peninsula population and slightly lower in the Esperanza/Hope Bay penguins if the results were compared to previous reports. The enzymes superoxide dismutase and glutathione peroxidase had significantly (p<0.005) high activity in the Esperanza/Hope Bay population, which also showed high reduced glutathione levels. The glutathione S-transferase activity was significantly high (p<0.005) in the Potter Peninsula population. The obtained results might take into account for making decisions about management and protection plans for the different penguin nesting areas in Antarctica.
Asunto(s)
Spheniscidae , Animales , Regiones Antárticas , Efectos Antropogénicos , Antioxidantes , Humanos , Spheniscidae/fisiologíaRESUMEN
Clearwater Mesa is a pristine area located SE of Croft Bay in James Ross Island, at the northeast of the Antarctic Peninsula. The closest anthropic construction is the summer Mendel station located 25 km to the NE. Clearwater is a remote basalt volcanic mesa, (64° 01' S, 57° 42' W) located at ~ 250 m a.s.l., with around 50 small shallow lakes, a well-developed lichens flora and scarce fauna. The mesa offers a good opportunity to use lichens, like Usnea antarctica, as a biomonitor species. The aim of this study was to determine the baseline levels of trace elements in Usnea antarctica and their relationships with geographical parameters and climatological aspects, to use them as reference levels in futures studies. Usnea antarctica was collected in 23 sites in two transects: perpendicular and parallel to the shore. We found high contents of the elements associated with long-distance transport like Sm, La, Sc, Fe, Co, Hg, and Ca. The elements linked to the marine biogenic cycle as Sr, Rb, Cs, K, Na, Sb, As, Se, and Br were less significant. The distance to the sea was the factor that related the element contents. Hg, Se, As, and Br content in Usnea antarctica increased from the inland towards the sea coast.
Asunto(s)
Monitoreo del Ambiente , Oligoelementos , Usnea , Regiones Antárticas , Oligoelementos/análisis , Usnea/químicaRESUMEN
Pollution threats Antarctica and scientists blame xenobiotics and anthropic activities. Yet little is known about their effect on Antarctic ichthyofauna. Accordingly, we investigated the endocrine system of male fish Notothenia rossii and N. coriiceps (Perciformes, Nototheniidae) collected during Austral summer. For N. rossii, hormone levels of estradiol, testosterone, and 11-ketotestosterone were higher in fish collected during March than those of January; whereas for N. coriiceps estradiol and androgens levels were higher and lower in March, respectively. Histological analysis of the testes showed an unrestricted lobular type with no pathological alterations. However, detection of vitellogenin-like in plasma and skin mucus were seen in 75% of N. coriiceps males and 7% of N. rossii males. This is the first report of mucus vitellogenin-like detection as a non-invasive biomarker of endocrine disruption in notothenioid males and settles a baseline for future studies of reproductive biology and endocrine disruption in Antarctic fishes.
Asunto(s)
Sistema Endocrino/metabolismo , Perciformes/fisiología , Reproducción/efectos de los fármacos , Contaminantes del Agua/toxicidad , Animales , Regiones Antárticas , Ecotoxicología , Sistema Endocrino/efectos de los fármacos , Monitoreo del Ambiente , Estradiol/metabolismo , Femenino , Masculino , Perciformes/crecimiento & desarrollo , Testosterona/análogos & derivados , Testosterona/metabolismoRESUMEN
We report the contents of elements in feathers of Chinstrap penguin (Pygoscelis antarcticus), which had not been informed up to now, such as silver and bromine and others listed as hazardous by the United States Environmental Protection Agency as arsenic, cobalt, chromium, and mercury. Analyses of the element concentrations in feathers, adult and chicken, from Barton Peninsulas at 25 de Mayo (King George) Island, South Shetlands, were made by Instrumental Neutron Activation Analysis. Samarium, lanthanum a, thorium, and uranium concentrations in Chinstrap penguin feathers were below 0.1 mg/kg. This suggests that the elements in feather do not come from atmospheric particles surface deposition. Arsenic (0.120 ± 0.050 mg/kg) and cobalt (0.030 ± 0.020 mg/kg) concentrations were lower than the reports for other colony of Chinstrap penguins, and essential elements as iron (26 ± 12 mg/kg), zinc (78.0 ± 5.3 mg/kg), and chromium (0.51 ± 0.27 mg/kg) were in the same range while Se (2.90 ± 0.65 mg/kg) content were the lowest reported. Mercury (0.43 ± 0.21 mg/kg), chromium (0.210 ± 0.060 mg/kg), and silver (0.083 ± 0.003 mg/kg) in chicks tended to be lower than in adults. Iron, cobalt, and arsenic concentrations in feathers found in this study were the lowest compared to measurements were in several penguin species in Antarctica. These results confirm to feathers like effective indicators for the trace elements incorporated in the penguins and it provide a data set which can adds to the baseline for bioindication studies using feathers.
Asunto(s)
Plumas/química , Oligoelementos , Animales , Regiones Antárticas , Islas , SpheniscidaeRESUMEN
We investigated the effect of long-term starvation and posterior feeding on energetic reserves, oxidative stress, digestive enzymes, and histology of C. quadricarinatus midgut gland. The crayfish (6.27 g) were randomly assigned to one of three feeding protocols: continuous feeding throughout 80 day, continuous starvation until 80 day, and continuous starvation throughout 50 day and then feeding for the following 30 days. Juveniles from each protocol were weighed, and sacrificed at day 15, 30, 50 or 80. The lipids, glycogen, reduced glutathione (GSH), soluble protein, lipid peroxidation (TBARS), protein oxidation (PO), catalase (CAT), lipase and proteinase activities, and histology were measured on midgut gland. Starved crayfish had a lower hepatosomatic index, number of molts, specific growth rate, lipids, glycogen, and GSH levels than fed animals at all assay times. The starvation did not affect the soluble protein, TBARS, PO levels and CAT. In starved juveniles the lipase activity decreased as starvation time increased, whereas proteinase activity decreased only at day 80. The histological analysis of the starved animals showed several signs of structural alterations. After 30 days of feeding, the starved-feeding animals exhibited a striking recovery of hepatosomatic index, number of molts, lipids and glycogen, GSH, lipase activity and midgut gland structure.
Asunto(s)
Astacoidea/fisiología , Inanición , Alimentación Animal , Animales , Astacoidea/enzimología , Astacoidea/crecimiento & desarrollo , Astacoidea/metabolismo , Catalasa/metabolismo , Glutatión/metabolismo , Glucógeno/análisis , Mucosa Intestinal/enzimología , Mucosa Intestinal/metabolismo , Mucosa Intestinal/patología , Lipasa/metabolismo , Peroxidación de Lípido , Lípidos/análisis , Estrés Oxidativo , Péptido Hidrolasas/metabolismo , Proteínas/químicaRESUMEN
Several pollutants, which include metals, are present in the Antarctic atmosphere, snow, marine and terrestrial organisms. This work reports the elements incorporated by Usnea sp thalli in Potter Peninsula, 25 de Mayo (King George) Island, South Shetlands, Antarctica. Geological origin was analyzed as possible sources of elements. For this purpose, correlations were done using a geochemical tracer, principal component analysis and enrichment factors were computed. Lithophile elements from particulate matter were present in most of the sampling sites. Bromine, Se and Hg showed the highest enrichment factors suggesting other sources than the particulate matter. Mercury values found in Usnea sp were in the same range as those reported for Deception Island (South Shetlands) and remote areas from the Patagonia Andes.
Asunto(s)
Líquenes/química , Usnea/química , Regiones Antárticas , Monitoreo del Ambiente , Mercurio/análisis , Metales/análisis , Material Particulado/análisis , Usnea/metabolismoRESUMEN
Endosulfan (ES), a persistent organochlorine pesticide, is widely used despite its toxicity to non-target animals. Upon reaching water bodies, ES can cause negative effects on aquatic animals, including disruption of hormonal systems. However, the action of ES on fish reproductive axis has been hardly studied thus far. The aim of the present work was to assess the endocrine disruptive potential of endosulfan on the pituitary gonadotropins levels and on the testes function due to ES in the South American freshwater fish Cichlasoma dimerus, using in vitro and in vivo approaches. In vitro experiments showed that ES inhibited the LH-stimulated steroidogenesis in gonads; no change was observed in gonadotropins release from pituitaries in culture. Laboratory waterborne ES (0.1, 0.3 and 1 µg/L) exposure for two months caused decrease in ßFSH pituitary content and γGT activity in the testes (Sertoli cell function marker). Testicular histology revealed pathologies such as scarce intermediate stages of spermatogenesis, release of immature germ cells into the lobular lumen, presence of foam cells and interstitial fibrosis. As FSH and FSH-mediated steroidogenesis regulate spermatogenesis and Sertoli cell function, the effect of ES on FSH could be responsible for the morphological alterations observed in testes. In vitro, ES disrupted steroidogenesis in gonads, therefore similar effects in vivo cannot be ruled out. Based on this evidence, ES exhibits an endocrine disruptive action on the reproductive axis of C. dimerus, causing disruption at the pituitary and/or at the gonad level. These effects could acquire ecological significance under prolonged exposure to the pesticide in nature.
Asunto(s)
Cíclidos , Endosulfano/toxicidad , Ovario/efectos de los fármacos , Testículo/efectos de los fármacos , Contaminantes Químicos del Agua/toxicidad , Animales , Células Cultivadas , Endosulfano/análisis , Femenino , Gonadotropinas Hipofisarias/metabolismo , Masculino , Hipófisis/química , Hipófisis/efectos de los fármacos , Contaminantes Químicos del Agua/análisisRESUMEN
Biomphalaria glabrata is a widespread freshwater gastropod mollusc. The easy aquaculture of these organisms allow its use as an accessible tool for contamination bioassays. B. glabrata showed marked metabolic responses when exposed to cadmium, lead and arsenic. Those responses could also affect the reproduction of the snails. Taking into account this hypothesis, B. glabrata were exposed for 96 h (acute laboratory bioassays) to different concentrations of cadmium (0.1, 0.05 and 0 mg/L), lead (0.5, 0.1, 0.05 and 0 mg/L) and arsenic (0.5, 0.1, 0.05 and 0 mg/L). Snails were removed from the aquaria while eggs were left in the same contaminant concentrations. The effect of the assayed toxicants on snail reproduction was registered as the alterations of the total number of laid eggs (TNLE), hatching time and embryonic survival. At 0.10 mg/L cadmium significantly decreased the TNLE (p<0.05) and no embryos survived. The lowest assayed level (0.05 mg/L) of cadmium, delayed the hatching time twice when it was compared with the control group (p<0.01). Lead decreased the TNLE at 0.5 mg/L level (p<0.01). The other assayed doses (0.05 and 0.10 mg/L) also decreased embryonic survival significantly (p<0.05 and p<0.01 respectively) and extended twice the time to hatching (p<0.01). The 0.50 mg/L level killed all embryos. Arsenic at all studied concentrations decreased the TNLE (p<0.05) while the hatching time was increased by 50%. Embryo survival only decreased at the highest level (0.5 mg/L) of arsenic assayed. In summary, the acute exposure (96 h) to cadmium lead and arsenic, altered the reproduction of B. glabrata, modifying the TNLE, hatching time and embryonic survival.
Asunto(s)
Arsénico/toxicidad , Biomphalaria/efectos de los fármacos , Cadmio/toxicidad , Plomo/toxicidad , Contaminantes Químicos del Agua/metabolismo , Animales , Biomphalaria/crecimiento & desarrollo , Relación Dosis-Respuesta a Droga , Embrión no Mamífero/efectos de los fármacos , Femenino , Dinámicas no Lineales , Oviposición/efectos de los fármacos , Contaminantes Químicos del Agua/toxicidadRESUMEN
In a previous study we analysed the effect of diesel seawater contamination in the digestive gland of the Antarctic limpet Nacella concinna. We observed that antioxidant enzyme activities decreased after one-week starvation prior to the experiment, and this was considered in the analysis of the obtained results. To know whether the digestive gland oxidant-antioxidant status may be altered by starvation and experimental conditions, we evaluated the food deprivation effect in limpets from the nearshore shallow waters of Potter Cove, Antarctica. Organisms were acclimated to laboratory conditions and were divided in fed and starved groups, and maintained in these conditions during one month. Every week 20 limpets were sampled from each group. Digestive glands were dissected and kept frozen until they were processed. Superoxide dismutase (SOD), catalase (CAT) and glutathione S-transferase (GST) activities, as well as lipid peroxidation (LPO) measured as thiobarbituric reactive substances (TBARS), protein oxidation (PO) and reduced glutathione (GSH) were measured. For both groups of limpets, SOD increased its activity in the first week of the exposure period, with a maximum in the second week. CAT activity increased significantly in the second week, only for the starved group. Similarly, GST activity also increased for starved group in the second week; but maintained this tendency for both groups until the fourth week. In fed and starved limpets, TBARS values increased significantly, during the first week and then returned to normal values. The PO levels in the starved group increased only during the first week. The GSH content, for the fed group, increased significantly after the third week. The obtained results indicate that biochemical or physiological studies conducted with N. concinna should consider the effects of food deprivation and time spent under experimental conditions.
Asunto(s)
Antioxidantes/metabolismo , Sistema Digestivo/metabolismo , Privación de Alimentos , Moluscos/fisiología , Estrés Oxidativo/fisiología , Inanición , Animales , Catalasa/metabolismo , Glutatión/metabolismo , Glutatión Transferasa/metabolismo , Peroxidación de Lípido , Oxidación-Reducción , Proteínas/metabolismo , Superóxido Dismutasa/metabolismoRESUMEN
In Tierra del Fuego (Southern South America), the stone or false king crab, Paralomis granulosa represents one of the most important crab fisheries. After capture, animals are kept in baskets and exposed to dryness for several hours, when the water flow through the gills is interrupted. As a consequence a concomitant increase of reactive oxygen species begins, triggering oxidative stress. The aim of this study was to determine oxidative stress and antioxidant enzyme activities due to air exposure in different tissues of P. granulosa. Fifty crabs (carapace length >82 mm) were captured in Beagle Channel (54 degrees 50'S, 68 degrees 20'W) during winter 2004. Five groups of 10 crabs each were exposed to dryness at 6 degrees C for 0, 3, 6, 12 or 24 h, respectively. Activity of superoxide dismutase (SOD), catalase (CAT), glutathione S transferase (GST) protein and lipid oxidation were measured in gills, muscle, hepatopancreas and haemolymph samples. Almost all analyzed tissues showed antioxidant enzymes activity, which varied with time of air exposure. The maximum enzyme activity was measured after 6 h of air exposure. Protein oxidation levels varied significantly in gills. Lipid peroxidation levels increased significantly in muscle and hepatopancreas. The critical time of air exposure probably occurs at 6 h. Thereafter animals were unable to induce the synthesis of antioxidant enzymes or proteins. This should be taken into account to minimize the stress generated by the commercial capture process.
Asunto(s)
Aire , Anomuros/metabolismo , Antioxidantes/metabolismo , Desecación , Exposición a Riesgos Ambientales/efectos adversos , Estrés Oxidativo/fisiología , Animales , Catalasa/metabolismo , Branquias/enzimología , Glutatión Transferasa/metabolismo , Hemolinfa/enzimología , Hepatopáncreas/enzimología , Masculino , Músculo Esquelético/enzimología , Superóxido Dismutasa/metabolismoRESUMEN
Biomphalaria glabrata, a freshwater gastropod mollusc, was tested as biondicator organism to assess cadmium, lead and arsenic exposure using acute laboratory bioassays. Modifications of glycogen levels were measured in different anatomical regions of B. glabrata in order to test the usefulness of this parameter as a general biomarker of chemical stress. The snails were exposed 96 h to different concentrations of the following contaminants: 0.1 and 0.05 mg Cd/L; 0.5, 0.1 and 0.05 mg Pb/L; 0.5, 0.1 and 0.05 mg As/L. Significant decreases in the polysaccharide content were observed in gonadal region for all treated animals. Arsenic and lead at 0.1 and 0.5 mg/L level of exposure were also able to decrease the levels of glycogen in the pulmonary and digestive gland region. Glycogen content in the cephalopedal region of treated animals presented a significant decrease (p<0.05) when compared with control organisms only for arsenic at the highest level of exposure. To establish possible correlations between glycogen and contaminants accumulated by snails, analyses of the elements bioaccumulated in the different anatomical regions of B. glabrata were also performed. Cadmium and lead followed a similar pattern of bioaccumulation with highest values in the digestive gland region. Arsenic bioaccumulation, however, was highest in the gonadal region.