Padeiro A.,University of Lisbon |
Amaro E.,University of Lisbon |
Dos Santos M.M.C.,University of Lisbon |
Araujo M.F.,University of Lisbon |
And 6 more authors.
Environmental Science: Processes and Impacts
The Ardley Cove area (located on the Maxwell Bay shoreline, Fildes Peninsula, King George Island, Antarctica) is characterized not only by its high biodiversity, but also by a high density of scientific stations, making it potentially one of the most impacted areas of Antarctica. In order to assess the source, contamination levels, distribution and availability of several trace elements (Cr, Ni, Cu, Zn, As, Pb, Cd and Hg) in and around Maxwell Bay, soil and seawater samples were collected. Soil samples were also collected in the study reference site near the Bellingshausen Dome area, as it lies far from centers of human activity and associated infrastructure. Enrichment factors (EFs) and sequential extractions were also used to assess the degree of contamination and availability of the trace elements under investigation. The results obtained in this study pointed to the existence of several contamination hotspots, mainly related to high levels of Zn, Pb, Cd, Cr and Ni. Comparison of the contaminant distribution patterns with data from earlier studies allowed the identification of anthropogenic sources. Use of the EF approach and sequential extractions confirmed these findings. In particular, higher extraction proportions were obtained for Zn and Pb (68 and 71%, respectively), which were also the same elements where the highest EFs were determined. The results obtained in this study clearly point to human impact on the natural environment in this region of Antarctica and we recommend the implementation of appropriate contamination control and remediation methods. © 2016 The Royal Society of Chemistry. Source
Amaro E.,University of Lisbon |
Padeiro A.,University of Lisbon |
Mao de Ferro A.,University of Lisbon |
Mota A.M.,University of Lisbon |
And 5 more authors.
Marine Pollution Bulletin
King George Island, situated in the South Shetland Islands archipelago, is one of the most visited sites in Antarctica. This has contributed to a high density of scientific stations and shelters in the region, especially in Fildes Peninsula. In order to evaluate the natural and anthropogenic sources of trace elements (As, Cd, Cu, Zn, Pb and Hg) soil and moss samples were collected from different sites in January 2013. In general, the results revealed homogeneous concentrations (μgg-1) for each element in the majority of collected samples (As: 3.8±1.4; Cd: 0.4±0.9; Cu: 34±4; Zn: 115±13; Pb: 20±5; Hg; 0.011±0.009). However, some samples in specific areas of Fildes Bay showed the existence of local anthropogenic activities that have contributed to the enrichment of contaminants in soils and moss samples that correlated to one another (e.g. Pb: 1101μgg-1).Human presence is linked to examples of contamination and environmental perturbation, making essential the implementation of this type of study in order to understand and protect unique places in Antarctica. © 2015 Elsevier Ltd. Source
Branco P.C.,University of Sao Paulo |
Pressinotti L.N.,University of Sao Paulo |
Borges J.C.S.,Metropolitan United Faculties |
Iunes R.S.,University of Sao Paulo |
And 7 more authors.
Global warming is a reality and its effects have been widely studied. However, the consequences for marine invertebrates remain poorly understood. Thus, the present study proposed to evaluate the effect of elevated temperature on the innate immune system of Antarctic sea urchin Sterechinus neumayeri. Sea urchins were collected nearby Brazilian Antarctic Station "Comandante Ferraz" and exposed to 0 (control), 2 and 4°C for periods of 48 h, 2, 7 and 14 days. After the experimental periods, coelomic fluid was collected in order to perform the following analyses: coelomocytes differential counting, phagocytic response, adhesion and spreading coelomocytes assay, intranuclear iron crystalloid and ultra structural analysis of coelomocytes. The red sphere cell was considered a biomarker for heat stress, as they increased in acute stress. Besides that, a significant increase in phagocytic indexes was observed at 2°C coinciding with a significant increase of intranuclear iron crystalloid at the same temperature and same time period. Furthermore, significant alterations in cell adhesion and spreading were observed in elevated temperatures. The ultra structural analysis of coelomocytes showed no significant difference across treatments. This was the first time that innate immune response alterations were observed in response to elevated temperature in a Polar echinoid. © 2011 Springer-Verlag. Source
Boyd I.L.,University of St. Andrews |
Frisk G.,Florida Atlantic University |
Urban E.,University of Delaware |
Tyack P.,Woods Hole Oceanographic Institution |
And 22 more authors.
The effect of noise on marine life is one of the big unknowns of current marine science. Considerable evidence exists that the human contribution to ocean noise has increased during the past few decades: human noise has become the dominant component of marine noise in some regions, and noise is directly correlated with the increasing industrialization of the ocean. Sound is an important factor in the lives of many marine organisms, and theory and increasing observations suggest that human noise could be approaching levels at which negative effects on marine life may be occurring. Certain species already show symptoms of the effects of sound. Although some of these effects are acute and rare, chronic sublethal effects may be more prevalent, but are difficult to measure. We need to identify the thresholds of such effects for different species and be in a position to predict how increasing anthropogenic sound will add to the effects. To achieve such predictive capabilities, the Scientific Committee on Oceanic Research (SCOR) and the Partnership for Observation of the Global Oceans (POGO) are developing an International Quiet Ocean Experiment (IQOE), with the objective of coordinating the international research community to both quantify the ocean sound scape and examine the functional relationship between sound and the viability of key marine organisms. SCOR and POGO will convene an open science meeting to gather community input on the important research, observations, and modeling activities that should be included in IQOE. © 2011 by The Oceanography Society. All rights reserved. Source