Carlyn Scott, College of Marine Science
Margaret (Maggi) Mars Brisbin is an assistant professor at the 同性恋色情 College of Marine Science where she leads the .
Following a training program for polar chief scientists, Brisbin developed the National Science Foundation funded project Linking Ice Melt with the Biogeochemistry and Organisms of the Weddell Sea (LIMBOW) with colleagues (University of Illinois) and (University of New England). The project took the researchers to the Weddell Sea in Antarctica aboard the on its first expedition to the Southern Ocean.
Following the expedition 鈥 Brisbin鈥檚 second journey to Antarctica 鈥 she reflects on her time aboard the ship and the research that led her there.
Q: How did this project come together?
A: The project is called LIMBOW, which stands for Linking Ice Melt to Biogeochemistry and Organisms in the Weddell Sea. It brings together three early-career women scientists thinking about different parts of the ecosystem.
Ellen Buckley is an ice scientist, Trisha Thibodeau is a zooplankton ecologist, and I鈥檓 the microbiologist. We are thinking about the ecosystem from the bottom up starting with changing ice conditions, changing microbial activity, phytoplankton primary production, and then changes in zooplankton productivity.
It鈥檚 unique for us to work together and conduct all the sampling 鈥 ice stations, nets in the water, coring, and all the physics and chemistry 鈥 at the same time.
Q: What is the purpose of your study?
A: We鈥檙e thinking about how meltwater is changing the physical and chemical properties of seawater and what鈥檚 happening to the water column and the organisms that live there as sea ice melts.
It happens every year 鈥 ice grows and retreats 鈥 so we鈥檙e looking at how changes in salinity, temperature, nutrient conditions, and light affect the organisms that live there. And then we can extrapolate that out. If the ice is no longer growing and retreating in that region, how is that going to change the ecosystem?
Q: What kinds of processes are you most interested in?
A: Ice is a major controlling factor of water column structure, stability, nutrient availability, and light. When the ice is there, you don鈥檛 have as much light going through. If that cycle is truncated or the timing changes, it will change the phenology, or life cycle, of phytoplankton and zooplankton, with effects cascading all the way through the food web.
We鈥檙e also thinking about nutrients within the ice 鈥 things like nitrogen from atmospheric deposition or even penguins that poop on the ice 鈥 and then as the ice melts, all those nutrients are released into the water. We are asking, 鈥淲hat organisms respond to that? What grows best under those conditions?鈥
Q: What tools did you use during the expedition?
A: At each station, we鈥檇 start near the ice edge, in the marginal ice zone. The ice team would go out onto a floe; dig a snow pit to measure snow temperature, density, and crystal structure; and take ice cores to characterize the temperature and salinity of the ice and measure the nutrients it contains. Buckley would also fly a drone to look at the ice landscape and features like melt ponds.
At the same time, we鈥檇 do our oceanographic observations such as CTD casts, collecting temperature and salinity of the water through different layers, net tows for plankton, and sediment sampling.
We also used a holographic camera that takes 3D images of particles as it鈥檚 lowered through the water. That lets us calculate how many organisms are in the water column and see how changes in the system might affect particle formation and sinking.
Q: How does this project fit into your lab鈥檚 work?
A: The overarching theme of MICO lab is microbial interactions in a changing ocean, so it fits squarely. We鈥檙e thinking about bacteria and phytoplankton 鈥 where they co-occur, how they might exchange metabolites, and how those interactions change with more or less sea ice.
The Southern Ocean is an important carbon sink, so changes in production and export will have an overall impact on carbon in the atmosphere.
It鈥檚 also a more pristine system than a lot of the other places we study, so there are processes and interactions there that can give us insight into how systems used to be or how they could be in the future.
We are writing a follow-up proposal to look at ice and biogeochemistry in the Arctic, which would give us a comparison between the two systems.
Q: How was life aboard an icebreaker?
A: One of my favorite things was the Antarctic RRR; the ride-row-run challenge. We had sheets in the galley where we recorded how many kilometers we each did on the bike, treadmill, or rowing machine. The goal was 100 kilometers, but most people got to like 300. It got very competitive and was really fun and great for morale when we were iced in.
Brisbin was part of the Linking Ice Melt to Biogeochemistry and Organisms in the Weddell Sea project, which brought together three early-career women scientists to study changing ice conditions in Antarctica. YouTube photo credit: Tricia Thibodeau