Untouched Antarctica: mapping a finite and diminishing environmental resource

Globally, areas categorically known to be free of human visitation are rare, but still exist in Antarctica. Such areas may be among the most pristine locations remaining on Earth and, therefore, be valuable as baselines for future comparisons with localities impacted by human activities, and as sites preserved for scientific research using increasingly sophisticated future technologies. Nevertheless, unvisited areas are becoming increasingly rare as the human footprint expands in Antarctica. Therefore, an understanding of historical and contemporary levels of visitation at locations across Antarctica is essential to a) estimate likely cumulative environmental impact, b) identify regions that may have been impacted by non-native species introductions, and c) inform the future designation of protected areas under the Antarctic Treaty System. Currently, records of Antarctic tourist visits exist, but little detailed information is readily available on the spatial and temporal distribution of national governmental programme activities in Antarctica. Here we describe methods to fulfil this need. Using information within field reports and archive and science databases pertaining to the activities of the United Kingdom as an illustration, we describe the history and trends in its operational footprint in the Antarctic Peninsula since c. 1944. Based on this illustration, we suggest that these methodologies could be applied productively more generally

Methane and Carbon Monoxide Production, Oxidation, and Turnover Times in the Caribbean Sea as Influenced by the Orinoco River

The surface distribution of CH4, photoproduction capacity of seawater for CO, and CH4 and CO microbial oxidation rates and turnover times were determined for the surface waters of the southeastern Caribbean Sea and Gulf of Paria as affected by the Orinoco River. Measurements were made during the spring (low fiver flow) and the fall (high fiver flow) in order to determine the influence of Orinoco River discharge on these parameters. Methane concentrations were generally lower in the fall than in the spring. Low CH4 oxidation rates and similar surface distributions were observed during both seasons. Methane oxidation in the fiver plume was significantly higher in the fall. Potential CO photoproduction and CO oxidation rates were generally higher during the fall. Possible effects of the Orinoco River on potential CO photoproduction capacity were observed as far as Puerto Rico. Turnover times for CH4 were in the order of years, whereas CO turnover times were in the order of hours. The Orinoco River has a significant impact on the consumption of CO and CH4 and the photoproduction of CO in the southeastern Caribbean Sea, presumably resulting from inputs of five fine carbon and nutrients