Temporal Distribution of Arsenic and Metals in Soil From King George Island, Antarctica

The polar regions are vulnerable to impacts caused by local and global pollution. The Antarctic continent has been considered an environment that has remained little affected by human activities. Direct exposure to contaminants may occur in areas continuously occupied by research stations for several decades. Admiralty Bay on the southeast coast of King George Island, has potential for being affected by human activities due research stations operating in the area, including the Brazilian Commandant Ferraz Antarctic Station (CFAS). The levels of metals and arsenic were determined in soils collected near CFAS (points 5, 6, 7, and 9), Base G and at two points distant from the CFAS: Refuge II and Hennequin. Samples were collected after the fire in CFAS occurred in February 2012, up to December 2018 to assess the environmental impacts in the area. Al and As were related with Base G. Refuge II and Hennequin can be considered as control points for this region. As a consequence of the accident, the increased levels for Cd, Cu, Pb, and Zn, especially at point 9 (inside the CFAS) and in the soil surrounding the CFAS in 2013. The results from 2016 to 2018 demonstrated a reduction in levels of all studied metals near CFAS, which may be related to the leaching of metals into Admiralty Bay; it is thus, being important the continue monitoring soil, sediments, and Antarctic biota.

Genetic variation in the small bivalve Nuculana inaequisculpta along a retreating glacier fjord, King George Island, Antarctica

Climate change is strongly influencing regions of Antarctica but the consequences on microevolutionary processes have been little studied. Patterns of population genetic diversity were analysed in the Antarctic bivalve Nuculana inaequisculpta (Protobranchia: Nuculanidae) from a fjord with 70 years of documented climate-forced glacier retreat. Thirty-nine individuals from five sites at different distances from the glacier terminus were collected, and the COI gene was sequenced from each individual. No statistically significant genetic differentiation was found between sites nor a significant correlation between the proximity of glaciers and genetic diversity, suggesting a high dispersal capability and therefore, a planktonic larval stage for this species. Nevertheless, we encourage increasing the sample size and number of loci in future studies to confirm our findings.

Chemical compounds and antioxidant activity of Antarctic lichens

We assessed the content of some major and trace elements and lichen compounds as well as antioxidant activity in eight lichen species representing four families collected in areas > 1 km distant from Bellingshausen (King George Island) and > 1 km distant from Molodezhnaya (Thala Hills, Enderby Land) research stations. Content levels of Cu, Pb, Cd, Zn and As in Physcia caesia, Physconia muscigena, Umbilicaria aprina, Umbilicaria decussata and Usnea aurantiaco-atra thalli were similar to or lower than previously reported for these species in the Maritime and Continental Antarctic, as well as from reference sites. The first data on the contents of 15 elements in Ramalina terebrata and Thamnolecania brialmontii thalli from the Maritime Antarctic are reported. Our analyses confirmed the presence of the main photosynthetic pigments in the species examined (chlorophyll a and b, phaeophytin a and b, neoxanthin, violaxanthin, lutein and β-carotene). We identified protolichesterinic acid in T. brialmontii thalli for the first time. Antioxidant activity varied from 190 μg/g dry weight (U. decussata) to 14,740 μg/g dry weight (T. brialmontii). The data obtained complement previous research while also providing new baseline data that will have utility in monitoring and identifying future change.

Appendicularia (Tunicata) in an Antarctic Glacial Fjord–Chaotic Fjordic Structure Community or Good Indicators of Oceanic Water Masses?

Appendicularians are important but remain poorly studied groups of zooplankton in polar regions. The present research is based on samples collected in Admiralty Bay (King George Island) during a year-long period. Six larvacean species were noted, among which Fritillaria borealis and Oikopleura gaussica were found to be the most numerous, while the other species were relatively rare. Fritillaria borealis was a dominant part of the late summer (warm water) community, while O. gaussica had the highest presence in the winter (cold water) community. The abundance of appendicularians recorded in the bay was less numerous than that described by other authors. The most important factors influencing annual changes in the larvaceans in the bay was season, but only in the case of the two species. These facts were probably linked to the very dynamic changes in the abiotic conditions in the fjord, and the influx of specific masses of water.

Genome Sequence of Pseudomonas sp. Strain LAP_36, A Rhizosphere Bacterium Isolated from King George Island, Antarctica

Pseudomonas sp. strain LAP_36 was isolated from rhizosphere soil from Deschampsia antarctica on King George Island, South Shetland Islands, Antarctica. Here, we report on its draft genome sequence, which consists of 8,794,771 bp with 60.0% GC content and 8,011 protein-coding genes.