Fecal Coliforms in Antarctica

Sally Freeley bounced in her seat as the C-130’s powerful turboprops screamed to life, pulling the cargo plane down the runway. After months of planning, she checked her mental lists, knowing it was too late to go back. She took comfort in knowing her scientific equipment was secure in the hold. Sally was heading to Antarctica for the 2002 field season. Re-supply was impossible, so she needed everything in perfect order for the next three months of field work.

The brief austral summer is October through January. Only then does the midnight sun warm the coast to -15ºC (5ºF), balmy enough for a dedicated group of scientists to study the coldest continent on Earth. Scientists like Sally have alerted us to the growing hole in the ozone layer, discovered cold-loving life forms, and demonstrated the importance of polar oceans in global carbon and oxygen cycles.

Sally would spend her next three months at McMurdo Station. This facility offers 1,100 seasonal scientists warm meals, a place to sleep, logistical support such as air and surface transportation, and laboratory space. Funded by the U.S. government, the National Science Foundation (NSF) oversees the management of McMurdo’s daily operations.¹

Several months before, Sally’s boss had stopped outside her office. “Sally, I just got a call from NSF. The polar programs office is concerned about how McMurdo Station is managing its waste. It turns out that Greenpeace has been poking around the facility. Those environmentalists raised a big stink over McMurdo’s sewage. They collected samples at the sewage outfall and claim that the U.S. is polluting the International waters of McMurdo Sound!”

Sally knew how to measure fecal coliforms, indicator bacteria that suggest the presence of pathogenic organisms from human waste. After researching the subject, she learned that raw sewage is collected from the housing and laboratory buildings and pumped to a masticator (literally, “chewer”) that purees the sewage before a pipe carries it to the waters of McMurdo Sound. She also learned that ocean currents rarely mix water in the bay, so if they survived the ice-cold salt water (-1.8ºC)², fecal contaminants could accumulate, posing health risks to Antarctic researchers and polluting pristine waters.

“What can we do to help?” Sally asked.

“We need to get down there pronto. I’d like to provide background data so we can make some informed decisions,” was the reply.

Questions

1. Why is Greenpeace concerned that McMurdo Station is releasing raw sewage into McMurdo Sound?
2. What type of sampling scheme would you design to see how much of McMurdo Sound is contaminated by fecal bacteria?
3. What are the potential outcomes of the sampling scheme you designed?
4. What experimental controls did you include? Why?

References

1. “McMurdo Station,” http://www.nsf.gov/od/opp/support/mcmurdo.htm. [A National Science Foundation publication that describes McMurdo Station operations.]
2. McFeters, G.A., Barry, J.P., and J.P. Howington. Distribution of enteric bacteria in Antarctic seawater surrounding a sewage outfall. 1993. Water Research 27:645-650. [The original citation from which this case grew.]

Image Credit: The National Science Foundation’s main office in McMurdo, known as the Chalet. NSF photo by Peter West.

Date Posted: 08/27/02 nas

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