2002-2003 Science Planning Summary

Biology & Medicine

Dr. Polly Penhale
Program Manager

BO-010-O

NSF/OPP 01-26319
Station: McMurdo Station
RPSC POC: Rob Robbins
Research Site(s): Cinder Cones, sea ice, Cape Armitage, Cape Evans, Cape Chocolate, Turtle Rock, New Harbor

Community dynamics in a polar ecosystem: Benthic recovery from organic enrichment in the Antarctic
Dr. Stacy L. Kim
San Jose State University
Moss Landing Marine Laboratories
skim@mlml.calstate.edu

Deploying Team Members: Aaron Carlisle . Kathleen Conlan . Stacy L Kim . Dan Malone . John S Oliver . Andrew R Thurber
Research Objectives: In 2002–2003, McMurdo Station, the U.S. base that houses over 1,100 people during the summer season, is installing a sewage treatment plant that will be online in 2003. The existing outfall is a large source of organic enrichment (135,150 liters per day of untreated sewage). The new plant will output a small fraction of this amount. The organically enriched outfall area and surrounding unperturbed areas have been well described. Detailed community descriptions of the epi- and infaunal community at the outfall location before effluent release are available and were collected over a long period (1988 to 1998), which minimizes the interannual variability.

This group will examine community responses in a polar soft-bottom subtidal system to test the generality of an already elucidated paradigm. Community recovery rates from iceberg scours and anchor ice have been described. These researchers hypothesize that recovery rates following cessation of organic input will be on the same scale as benthic community recovery from seasonal ice-mediated disturbances and as recovery rates in temperate systems. This research builds on a 10-year time series that follows benthic community degradation resulting from a sewage outfall. Sampling will span the implementation of sewage treatment. To test the generality of recovery patterns, the data will be incorporated in a meta-analysis of community recovery from organic disturbance in a variety of habitats. Experimental manipulations will compare the roles of burial and patch size. In addition, efforts will be directed at microbial biochemical response and diversity, in tandem with the recovery of the infaunal community.

The knowledge gained from this research can be applied to any high-organic loading in polar habitats. Significant anthropogenic inputs in high latitudes include pulp mills and increases in human occupation and visitation (gray water dumping from boats). Natural sources, including woody debris in river outputs and carcass-falls from the productive surface waters above, also present significant carbon input. In the McMurdo area, marine mammals and large fish are abundant and add fecal material to the system. Supply vessels dock in Winter Quarter’s Bay, and the number of tourist cruises is increasing. By using an integrated approach to evaluate the recovery of the microbial, infaunal, and epifaunal assemblages after a massive, 10-year carbon-loading perturbation, this study will further the understanding of anthropogenic impacts in polar environments.


Field Season Overview:
Project team members will initiate a large scale experiment to study the effect of the installation of the new secondary sewage treatment plant. Smaller scale experiments on biodiversity, physical disturbance and patch dynamics will be conducted across McMurdo Sound, near Cape Armitage, and north of McMurdo Station.

Researchers will be diving to perform experiments and collect benthic samples. Support contractor personnel will drill holes and transport huts to the dive locations. Researchers will travel by tracked vehicle to diving locations at Cinder Cones and Cape Evans, by snowmobile to Cape Armitage and Winter Quarters Bay, and by helicopter to reach sites around New Harbor. The aquarium, darkroom and freezers in the Crary Lab will be used for sample processing.