Extremophiles: The Environments

THE ARCTIC: Photographs were taken during the “Malina” project in the Beaufort Sea during August 2009. The project examined how increases in light in the Arctic Ocean are affecting both the biology and chemistry in the water. As the Arctic warms, seasonal ice cover recedes to unprecedented levels. Now, instead of sunlight being reflected off the ice and back into the atmosphere, it is being absorbed into the water increasing warming and accelerating the process. This includes all wavelengths of light from infra-red (heat) to the high-energy ultraviolet that can change water chemistry, alter cellular structure including damage to DNA, and affect growth and ecological processes.

ATACAMA DESERT: This region is the driest place on earth in terms of precipitation (less than 1 mm per year) and is often considered to be an analog for Mars. The cold Pacific Ocean currents and the Andes Mountains prevent moisture from reaching this long, thin region of northern Chile. Several salt plains (evaporite salars) can be found which have groundwater fed ponds that may be up to eight times saltier than seawater, yet microbial communities as well as some plants and animals thrive there. The clear skies, low latitude and high altitude (8,000 – 14,000 feet) make these high UV environments. These strong selective pressures lead to the formation of unique communities.

ANTARCTICA: The highest, driest, and windiest continent was visited eleven times since 1981. The first project focused on studying the microbial mats that grow in the bottom of the ice covered lakes in the Dry Valleys. Subsequent trips were to study ozone depletion and increases in ultraviolet radiation during oceanographic research cruises to the Gerlache Straits and Ross Sea. Temperature and ice cover changes cause similar effects as those seen in the Arctic, especially important during the spring phytoplankton bloom that drives much of the biological production during the rest of the year. Sea ice and icebergs play an even more important role in the ecology of the Southern Ocean.

THREATS: The Arctic is a sentry for global warming and climate change. Increasing temperatures reduces ice cover that changes light penetration that alters water and cellular chemistry. Much of how the Arctic ecosystem responds to the changes remains unknown. Loss of sea ice has also opened up new competing global commercial interests for natural resources and shipping. The Antarctic is subject to climate change issues as well, but they vary by location. Changes in temperature and ice cover are more prevalent on the Antarctic Peninsula side of the continent. The Antarctic ozone hole creates a seasonal increase in UV radiation each year that, unfortunately, happens during the spring bloom. Diminishing ice on land now results in increased temperatures and light exposure to lands not seen in the past. Increased melting means increased freshwater. Places that have remained dry are now seeing episodic flowing water, perhaps allowing microbial growth where none was found before. The Atacama Desert ponds are threatened by a completely different problem. Water rights in Chile are private, and the extensive mining operations in Chile are abusing the limited water supplies for commercial and industrial purposes. Water for drinking, farming and ecological impacts of water loss are given minimal consideration. There is significant concern that the salt ponds of the Atacama Desert may dry up.