Destroying the Antarctic environment
Scientists have held up Antarctica as an example of one of the few pristine environments left on Earth. This has likely been the case in the recent past, but as accessibility barriers to travel to Antarctica are removed, the potential exists for habitat degradation on both a macro- and microscopic level. A recent review article in Trends in Microbiology examines the relative risks of ecosystem damage, due to the introduction of exogenous microorganisms.
The authors define impact rather broadly; for large species, the numbers and distribution of individuals, as assessed by unit biomass, can give a relatively good idea of trends over time. For microorganisms, the distinctions are a bit more difficult to determine, in many cases because the microorganisms are exceedingly difficult to impossible to currently culture in the laboratory. Some of the environments that scientists are concerned about altering with non-indigenous microbes are ones such as Lake Vostok, a sub-glacial lake of liquid water found approximately 4 km below the ice surface, and is believed to contain water that was last exposed to the outside environment between 15 to 25 million years ago. The lake make contain a microbial ecosystem that would therefore be unique on Earth, and maintaining the integrity of that environment would be of paramount importance. Currently, scientists are exploring mechanisms to obtain a water sample from Lake Vostok that would prevent the introduction of surface microorganisms.
The authors of the Trends in Microbiology article argue that the impacts of introducing novel microorganisms raise 3 main concerns. First, the possibility of introducing a novel pathogen (bacterial, fungal, or viral) would have profound effects on the plants and animals indigenous to Antarctica, and that the risks of introducing pathogens are “real and significant.” One reason for the danger is because the endogenous Antarctic biome is not very diverse to begin with, allowing an introduced species to have a large advantage and effect.
Second, the authors suggest that introduced microorganisms would significantly impact the microbial ecosystems themselves, but the potential ramifications of this disruption is not known. The movement of the scientists from site to site likely contributes to this problems as well, as they bring microbes from one location to another within Antarctic research stations, leading to a homogenization of microbial diversity.
Third, microbial ecological effects may be an unavoidable consequence of climate change. As global temperatures trend upwards, the ability of strict psycrophiles to thrive may be impacted, as more psycrotolerant organisms begin to replace them. The authors argue that these trends may actually increase microbial diversity as biochemical cycling and energy flow increase.
The final recommendation for the paper is to establish a “no-go, no-fly zone” where any access is prohibited, except only under the strictest of conditions. This area would provide protection to prevent the unavoidable introduction of non-indigenous microbes by human movement. Such a move would require the ratification of an international treaty, because Antarctica has no formal national government. Several countries do maintain territorial claims, however these are not universally recognized.
Posted on November 2, 2011, in Baby it's cold outside!, Microbes in the News and tagged Antarctica, Gary Larson, Lake Vostok. Bookmark the permalink. Comments Off on Destroying the Antarctic environment.