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The biogeochemical behavior of selenium (Se) has been extensively studied in Se-enriched or Se contaminated soils at low and middle latitudes. However, the Se distribution patterns have not been studied in tundra ecosystems of remote Antarctica. Here, the soils/sediments were collected from penguin and seal colonies, their adjacent tundra and lakes, tundra marsh, human-activity areas, normal tundra and the periglacial in maritime Antarctica, and total Se and seven operationally defined Se fractions were analyzed. Overall the regional distribution of Se levels showed high spatial heterogeneity (coefficient of variation, CV = 114%) in tundra soils, with the highest levels in penguin (mean 6.12 ± 2.66 μg g-1) and seal (mean 2.29 ± 1.43 μg g-1) colony soils, and the lowest in normal tundra soils and periglacial sediments (

10 páginas, 3 figuras, 3 tablas, Guano is an important source of marine-derived nutrients to seabird nesting areas. Seabirds usually present high levels of metals and other contaminants because the bioaccumulation processes and biotic depositions can increase the concentration of pollutants in the receiving environments. The objectives of this study were to investigate: the toxicity of seabird guano and the joint toxicity of guano, Cu and Pb by using the sea urchin embryo-larval bioassay. In a first experiment, aqueous extracts of guano were prepared at two loading rates (0.462 and 1.952 g L−1) and toxicity to sea-urchin embryos was tested. Toxicity was low and not dependent of the load of guano used (EC50 0.42 ± 0.03 g L−1). Trace metal concentrations were also low either in guano or in aqueous extracts of guano and the toxicity of extracts were apparently related to dissolved organic matter. In a second experiment, the toxicity of Cu–Pb mixtures in artificial seawater and in extracts of guano (at two loadings: 0.015 and 0.073 g L−1), was tested. According to individual fittings, Cu added to extracts of guano showed less toxicity than when dissolved in artificial seawater. The response surfaces obtained for mixtures of Cu and Pb in artificial seawater, and in 0.015 g L−1 and 0.073 g L−1 of guano, were better described by Independent Action model adapted to describe antagonism, than by the other proposed models. This implied accepting that EC50 for Cu and Pb increased with the load of guano and with a greater interaction for Cu than for Pb, This work was partly supported by the Spanish Ministry of Agriculture, Food and Environment Grant PN384/2011. Diego Rial was funded by a postdoctoral contract from the Xunta de Galicia, Spain (ED481B 2014/098-0 Plan I2C). The work of A.J. was supported by a Ramón y Cajal grant from the Spanish Ministry of Economy and Competitiveness. The CSIC, under the program JAE (Junta para la Ampliación de Estudios) co-funded by the Fondo Social Europeo (FSE), is greatly acknowledge for the post-doctoral fellowships to J. Santos-Echeandía

In recent times, the apparent population decline of the southern bent-wing bat (Miniopterus schreibersii bassanii) at Bat Cave, Naracoorte has been ascribed to pesticide use in the region, following the finding of organochlorine and orgaonophosphate insecticide residues in bat guano. Adult southern bent-wing bats were collected from Bat Cave and Starlight Cave in 2003. Organochlorine contaminants were detected in all carcass samples: p,p'-DDE was by far the most dominant contaminant with concentrations ranging from 11,000 to 59,000ngg(-1), followed by p,p'-DDT (110-1600ngg(-1)), p,p'-DDD (35-620ngg(-1)), summation operatorPCBs (33-490ngg(-1)), summation operatorchlordane and related compounds (7.9-270ngg(-1)), HCB (1.6-120ngg(-1)), HP epox. (3.1-230ngg(-1)), TCPMOH (3.8-38ngg(-1)), summation operatorHCHs (1.4-9.6ngg(-1)), and TCPMe (0.1-4.2ngg(-1)) (all values on lipid-weight basis). No significant difference in DDE, DDD, DDT, summation operatorDDT, summation operatorPCB, trans-chlordane, heptachlor epoxide, trans-nonachlor, alpha-HCH, beta-HCH, gamma-HCH, TCPMOH or TCPMe concentrations were observed either between sexes within sites, or between sites (p0.05). However, there were significant differences in HCB and oxychlordane concentrations between sexes and between sites (p0.05), between site differences in cis-nonachlor concentrations in male bats (p0.05), and cis-chlordane concentrations between sexes at Starlight Cave, and between males of each site (p0.05). There were also significant differences in the liver concentrations of some metals between sexes within sites (Ag, Cd, Co, Cu, Pb, Se, Zn), and between sites (Ag, Cd, Co, Cu, Hg, Pb, Se, V, Zn). Clustering or grouping of sites was observed when the OC data was expressed on a lipid-weight basis. These inter-site differences in OC concentrations reflect local exposure over a period of time, and do not unambiguously support any suggestion that we are witnessing incipient speciation. However, for conservation purposes, it may be prudent to assume that there are two sub-populations of M. s. bassani feeding in different locations in this region of southern Australia, rather than the single homogeneous population suggested by genetic studies.

Phosphine (PH(3)) is a natural gaseous carrier of phosphorus in its geochemical cycles, and it might be of importance to the phosphorus balance of natural ecosystem. For the first time phosphine levels were investigated in the Earth's coldest, driest, and most southerly Antarctic biosphere. Matrix-bound phosphine (MBP) was found in sea animal guanos, ornithogenic sediments and soils. Phosphine concentrations varied with different sea animal guanos. Average phosphine concentrations in empire penguin, gentoo penguin, sea lion, skua and gull guanos were 2.54+/-1.28 ng kg(-1), 6.21+/-2.15 ng kg(-1), 9.12+/-4.66 ng kg(-1), 11.90+/-1.29 ng kg(-1) and 14.55+/-6.74 ng kg(-1), respectively. The contents of phosphorus in these various matrixes have an important effect on MBP concentrations. The levels of phosphine appeared an increasing tendency with the content of TP, IP and OP in sea animal guanos, ornithogenic sediments or soils. The correlation between PH(3) and Fe, Mn, Al in these matrixes was also analyzed and discussed. Phosphine showed an obviously positive correlation with Fe in sea animal guanos. However, excessively high Fe, Al and Mn may inhibit the formation of PH(3) in the ornithogenic soils or sediments in the Antarctic biosphere.

The southern bent-wing bat (Miniopterus schreibersii bassanii) is an insectivorous, obligate cave dwelling species found in south-eastern South Australia and western Victoria, Australia. In recent times, the finger of blame for an apparent population decline at Bat Cave, Naracoorte (one of only two known maternity roosts for this species, the other being Starlight Cave, Warrnambool) has been pointed at pesticide use in the region, following the finding of organochlorine and organophosphate insecticide residues in bat guano. This study sampled juvenile southern bent-wing bats from Bat Cave and Starlight Cave, and determined DDT, DDD and DDE concentrations in liver, pectoral muscle, brain and back-depot fat tissues. DDT was detected in only three tissue samples (highest concentration, 126 microg kg(-1) (wet weight) in back-depot fat), DDD was detected only in brain tissue (highest concentration, 115 microg kg(-1) (wet weight)), but DDE was detected in most tissues (highest concentration, 24,200 microg kg(-1) (wet weight) in back-depot fat). A minimum DDE body burden was estimated for each bat, and then for each sex at each site, from the data from all tissues sampled. The DDE body burdens estimated were highest in male bats from Starlight Cave (114 microg kg(-1)), then females from Starlight Cave (54.5 microg kg(-1)), and males from Bat Cave (53.2 microg kg(-1)). Female bats at Bat Cave contained the lowest estimated body burden (24.2 microg kg(-1)). Comparisons of DDE concentrations between the sexes showed that contamination was not statistically different within each maternity site. The different chemical concentrations observed in the Bat Cave and Starlight Cave bats is suggestive of different feeding locations, and perhaps an emerging population split, further threatening a species already at risk as a result of landscape scale changes to land use across their range.

Total concentrations of major and trace elements were determined in samples of the epilithic lichen Umbilicaria decussatu from 24 ice-free areas in coastal Victoria Land (Antarctica). Overall average concentrations of trace elements except Cd were the lowest ever reported for lichens of the genus Umbilicaria. Specifically, the mean level of Pb in lichens from granitic rocks (0.46 * 0.18 pg g-’ dry wt) was more than four times lower than the lowest record in .4rctic lichens. No impact of local human activities was detected, but the elemental composition of U. decussata was affected by entrapment of soil or rock dust particles and probably by uptake of soluble elements from substrate. Relationships between elements and their distribution patterns in the study area indicated that the marine environment is the main source of major ions and perhaps of Cd in lichens. Accumulation of P was detected in samples from coastal sites frequented by seabirds. Although the present results can be taken as baseline levels of major and trace elements in Antarctic U. decussata from substrates with very different geochemical features. further research is necessary to evaluate the relative element contribution from each substrate with respect to those from snow. marine aerosol, salt encrustations and guano. c)I 998 Elsewer Swnce Ltd. All rights reserved