Lithological controls on lake water biogeochemistry in Maritime Antarctica.

Although the Antarctic lakes are of great importance for the climate and the carbon cycle, the lithological influences on the input of elements that are necessary for phytoplankton in lakes have so far been insufficiently investigated. To address this issue, we analyzed phytoplankton cell concentrations and chemical compositions of water samples from lakes, ponds and a stream on Fildes and Ardley Islands of King George Island in the South Shetland Archipelago. Furthermore, lake sediments, as well as soil and rock samples collected from the littoral zone were analyzed for their mineralogical/petrographic composition and pollutant contents of polycyclic aromatic hydrocarbons (PAHs).

Carrageenan from : A Novel Molecular Probe to Detect SARS-CoV-2.

The COVID-19 pandemic has caused an unprecedented health and economic crisis, highlighting the importance of developing new molecular tools to monitor and detect SARS-CoV-2. Hence, this study proposed to employ the carrageenan extracted from algae as a probe for SARS-CoV-2 virus binding capacity and potential use in molecular methods. specimens were collected in the Chilean subantarctic ecoregion, and the carrageenan was extracted -using a modified version of Webber's method-, characterized, and quantified.

A combined microbial and biogeochemical dataset from high-latitude ecosystems with respect to methane cycle.

High latitudes are experiencing intense ecosystem changes with climate warming. The underlying methane (CH) cycling dynamics remain unresolved, despite its crucial climatic feedback. Atmospheric CH emissions are heterogeneous, resulting from local geochemical drivers, global climatic factors, and microbial production/consumption balance.

Methane and carbon dioxide cycles in lakes of the King George Island, maritime Antarctica.

Freshwater ecosystems are important contributors to the global greenhouse gas budget and a comprehensive assessment of their role in the context of global warming is essential. Despite many reports on freshwater ecosystems, relatively little attention has been given so far to those located in the southern hemisphere and our current knowledge is particularly poor regarding the methane cycle in non-perennially glaciated lakes of the maritime Antarctica. We conducted a high-resolution study of the methane and carbon dioxide cycle in a lake of the Fildes Peninsula, King George Island (Lat.

Temperature differently affected methanogenic pathways and microbial communities in sub-Antarctic freshwater ecosystems.

Freshwater ecosystems are responsible for an important part of the methane (CH) emissions which are likely to change with global warming. This study aims to evaluate temperature-induced (from 5 to 20 °C) changes on microbial community structure and methanogenic pathways in five sub-Antarctic lake sediments from Magallanes strait to Cape Horn, Chile. We combined in situ CH flux measurements, CH production rates (MPRs), gene abundance quantification and microbial community structure analysis (metabarcoding of the 16S rRNA gene).

Initial report on methane and carbon dioxide emission dynamics from sub-Antarctic freshwater ecosystems: A seasonal study of a lake and a reservoir.

The sub-Antarctic Magellanic ecoregion is a part of the world where ecosystems have been understudied and where the CH cycling and emissions in lakes has not ever been reported. To fill that knowledge gap, a lake and a reservoir located at 53°S were selected and studied during three campaigns equally distributed over one year. Among the parameters measured were CH and CO emissions, as well their dissolved concentrations in the water column, which were determined with high spatial resolution.

Baseline concentrations of trace metals in macroalgae from the Strait of Magellan, Chile.

Samples of four different species of seaweed were collected monthly between October 2000 and March 2001 from the coast of the Strait of Magellan, Chile to establish baseline levels of trace metals (silver, total mercury, nickel, lead, antimony, vanadium and zinc) and to compare the accumulation capacity among species. The algae included in the study were Adenocystis utricularis (n=15); Enteromorpha sp. (n=11), Mazzaella laminarioides (n=12) and Porphyra columbina (n=6).