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2003-2004 USAP
Field Season
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Biology & Medicine
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Dr. Polly Penhale
Program Manager
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B-010-M
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NSF/OPP
01-26319
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Station:
McMurdo Station
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RPSC POC:
Curt LaBombard
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Research Site(s):
Cape Armitage, Cinder Cones, Cape Chocolate, Cape Evans, New Harbor, Turtle Rock, McMurdo area sea ice, McMurdo Station
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Dates in Antarctica:
Early October to early December
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Community dynamics in a polar ecosystem: Benthic recovery from organic enrichment in the Antarctic
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While diving at the Dailey Islands, Andrew Thurber prepares to enter a tide crack. Photo Stacy Kim.
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Deploying Team Members:
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Kathleen Conlan
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Jonna Engel
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Jennifer L. Fisher
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Stacy L. Kim
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Craig V. Lewis
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Daniel P. Malone
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James M. Oakden
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Research Objectives:
The Antarctic is considered one of the most pristine habitats on the planet. Humans occupy only a tiny portion of the continent. Though the human footprint in Antarctica is small and generally highly localized, there are areas where anthropogenic contamination is severe. For example, past practices at McMurdo Station have resulted in a few highly contaminated marine areas, such as the one near the sewage outfall. High levels of organic enrichment have radically altered the local benthic community. The altered community and surrounding undisturbed communities have been well described over a 10-year period.
In January 2003, a sewage treatment plant was completed at McMurdo Station, and the organic input to the seafloor has dropped markedly. On the basis of existing information on community recovery dynamics in polar ecosystems from ice-mediated disturbances (icebergs and anchor ice) and in temperate ecosystems from organic-loading, we predict that recovery will begin immediately. However, growth and reproduction are often slow in antarctic species. Thus, complete recovery may extend over a much longer period than in temperate areas. In addition, slow microbial processes at low polar temperatures have allowed a large pile of organic material to build up at the outfall site, and some changes may be the result of burial rather than organic enrichment. Finally, the size of the disturbance is unusual; small organic inputs such as seal feces and dead fish are common, but large sewage outfalls are not. Thus, the outfall and new treatment plant provide a unique opportunity for a large-scale experiment on recovery.
In October and November 2002, we collected data to describe the habitat and community while the outfall was still in operation. This will be added to the data we collected from 1988 to 1998 to provide a baseline. We initiated experiments with organic content, burial, and disturbance size as variables. During the next two seasons, we will track the recovery of the benthic community, compare the rates with those predicted from a meta-analysis of recovery from organic disturbance in a variety of habitats, and contrast the role of organic loading with burial and patch size. Our integrated approach will further the understanding of anthropogenic impacts in polar environments.
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