Polar bears, caribou and walrus may be among the most well known members of the arctic ecosystem, but some of the most important organisms aren’t visible to the naked eye. Microbes are the fuel driving the arctic food web—providing nutrients and energy to all polar inhabitants. And just like the arctic’s flagship species, the microbial communities will likely feel the affects of climate change.
Marc Frischer, a professor and microbial ecologist at the Skidaway Institute of Oceanography in Savannah, Georgia, just returned from a two-week research trip to Barrow, Alaska, where he and his colleagues collected baseline data that will help scientists understand the potential impacts of rising temperatures and melting tundra on the very base of the food web.
“We’re interested in the microbial response to climate change processes, specifically the loss of sea ice and increased nutrient loading from melting permafrost,” Frischer explained. “We hypothesize that these two processes will really change the dynamics between the photosynthetic organisms and heterotrophic organisms.”
A wide variety of microbes collectively make up the base of the food web in the Arctic, all competing for the essential ingredients for life: nitrogen and carbon. Frischer’s attention is focused on the two groups–green autotrophic organisms that produce their own food from inorganic substances and the non-green heterotrophs that must feed off other life forms.
Together with colleagues Patricia Yager from the University of Georgia (who leads the National Science Foundation-funded collaboration) and Deborah Bronk of the Virginia Institute of Marine Science, Frischer hopes to understand how these two microbial groups partition carbon and nitrogen resources under a variety of conditions and how they may adapt to climate-driven changes.
“Our suspicion is that non-green organisms will end up with an advantage and that will be to the detriment of the green organisms, which really fuel the food web. So our suspicion is that this [climate change] is not going to be a good thing for productivity in the Arctic.” Frischer said.
With that suspicion in mind, Frischer set out on a 10-day trip to Point Barrow, Alaska to collect hundreds of gallons of microbe-rich water.
A Day in the Field, Weather Permitting
A typical day in the field began bright and early at 8:00 a.m. with assistance from Quuniq (Michael) Donovan, an Alaskan Native whaling captain and Barrow Arctic Science Consortium employee who captained the 27-foot aluminum boat that served as central command during sample collection trips. If they were lucky, favorable weather and sea conditions would keep them on schedule, but that wasn’t always the case.
“Every day the weather was such that it was either too foggy or too windy and we’d either have to cancel the trip for the day or postpone it until around noon,” Frischer said. “Sea conditions were fairly variable. We had some choppy seas and some fairly big swells and sometimes it was almost completely flat. All this in a week!”
Over the course of the trip, Frischer collected water at a standard location that he will visit at different times of the year. The site is roughly 50 feet deep and is very well mixed—meaning water characteristics at a lesser depth are nearly identical to those at the middle or bottom of the water column. Water was collected using a specially designed submersible pump or a spring-loaded five-liter Niskin bottle lowered to a desired depth, opened to collect the sample and then closed before being brought to the surface.
Back at the BASC lab facilities, Frischer and his colleagues purified and processed the samples in a streamlined, portable version of a molecular lab they brought with them. The water was passed through incredibly fine filters to collect all the microbes. Some microbes were incubated under tightly controlled conditions in experiments to simulate environmental changes that might occur as a result of climate change. “We added different types of carbon and nitrogen and then took rate measurements of the incubated samples to measure uptake,” Frischer explained.
Other samples were preserved either chemically or by freezing in liquid nitrogen to protect the microbial DNA and RNA during shipment back to Skidaway where more detailed analyses will be carried out.
During the two-week mission the team collected over 200 gallons of water, enough to fill nearly five standard bathtubs. But water sampling wasn’t the only thing on Frischer’s agenda. The trip offered insight into Barrow’s Native community and proved to be a good platform for teaching locals the important roles microbes play in their environment.
Taking Science to the Community
All data collection took place in whaling and fishing areas owned by a consortium of Native tribes. With the assistance of BASC personnel, Frischer worked closely with whale commission members and others to ensure his work had as little impact on the area as possible. Collection times and trips had to be carefully planned and vetted so as not to interfere with hunting, fishing and whaling activities, he explained.
And while Frischer was out collecting samples, he had the unique opportunity to experience some aspects of Native life thanks to his boat captain. On one occasion, Captain Quuniq and his cousin Nelson spotted a few large caribou bulls and were off in hot pursuit. But fortune was on the caribous’ side that day. “We were pleased though, since if they had been successful we would have had to share the ride back with two huge dead caribou,” Frischer said.
When not in the field or lab, Frischer and his co-investigators spent time developing an initiative to teach high school students to study the affects a local sewage treatment plant may be having on the area’s lagoons by collecting water samples themselves. In the coming months, the students will get a fluorometer and learn how to analyze the samples and process data on critical nutrient levels and phytoplankton biomass. On this trip, Frischer also hosted a screening of “A Sea of Change,” a film about the causes and potential consequences of ocean acidification, at the public library (www.aseachange.net). Future visits may include an entire day dedicated to outreach and education.
Frischer will be back to sample again in January. In 2011 he will return in the winter, spring and summer to study seasonal variability and add to the solid body of baseline data.
“The role of microbes on our planet is absolutely fundamental. They are essential. And it’s important to study the impact of climate change on these organisms.”
For a more in-depth look at Frischer’s daily activities, read his entries on Skidaway’s blog, http://oceanscience.wordpress.com/—Alicia Clarke