RACHEL KAPLAN, PHD STUDENT IN ATMOSPHERIC SCIENCES
Over the last six months, I’ve existed in a kind of parallel universe to that of my normal life in Oregon. I spent May until October at Palmer Station, Antarctica as part of a team studying Antarctic krill (Euphausia superba) – a big change from the Oregon krill species I typically study, and one that taught me so much.
My work is part of a project titled “The Omnivore’s Dilemma: The effect of autumn diet on winter physiology and condition of juvenile Antarctic krill”. Through at-sea fieldwork and experiments in the lab, we spent the field season investigating how climate-driven changes in diet impact juvenile and adult krill health during the long polar night. Winter is a crucial time for krill survival and recruitment, and an understudied season in this remote corner of the world.
During the field season, we were part of two great research cruises along the Western Antarctic Peninsula (check out this great blog post by CEOAS undergraduate Abby Tomita!), and spent the rest of the time at Palmer Station, running long-term experiments to learn how diet influences krill winter growth and development.
There were so many wonderful parts to our time in Antarctica. While at sea, I was constantly aware that each new bay and fjord we sampled was one of the most beautiful places I would ever have the privilege to visit. I was also surprised and thrilled by the number of whales we saw – I recorded over one hundred sightings, including humpbacks, minke, and killer whales. As consumed as I was by looking for whales during the few hours of daylight, it was also rewarding to broaden my marine mammal focus and learn about another krill predator, the crabeater seal, from a great team researching their ecology and physiology.
In between our other work, I processed active acoustic (echosounder) data collected during a winter 2022 cruise that visited many of the same regions of the Western Antarctica Peninsula. Antarctic krill have been much more thoroughly studied than the main krill species that occur off the coast of Oregon, Euphausia pacifica and Thysanoessa spinifera, and it has been amazing to draw upon this large body of literature.
Working with a new flavor of echosounder data has presented me with puzzles that are teaching me to navigate different modes of data collection and their analytical implications, such as for the cruise track data above. I’ll never take data collected along a standardized grid for granted again!
I’ve also learned new techniques that I am excited to apply to my research in the Northern California Current (NCC) region. For example, there are two primary different ways of detecting krill swarms in echosounder data: by comparing the results of two different acoustic frequencies, and by training a computer algorithm to recognize swarms based on their dimensions and other characteristics. After trying a few different approaches with the Antarctic data this season, I developed a way to combine these techniques. In the resulting dataset, two different methods have confirmed that a given area represents krill, which gives me a lot of confidence in it. I’m looking forward to applying this technique to my NCC data, and using it to assess some of my next research questions.
Throughout it all, the highlight of the field season was being part of an amazing field team. I worked alongside CEOAS professor Kim Bernard and undergraduate Abby Tomita, who actually started her senior year at OSU remotely from Palmer. From nights full of net tows to busy days in the lab, we became a well-oiled machine, and laughed a lot along the way. Working with the two of them always made me confident that we’d be able to best any difficulties that come up.
After a long, busy, and productive field season, our final challenge was to wrap up our last lab work, pack up equipment and samples, and say goodbye to this beautiful place. Leaving Antarctica is always heartbreaking – you never really know if you’ll be back. But, it’s been amazing to come home to Oregon: I have loved hugging my friends, eating salad, and beginning to apply what I learned in Antarctica to the rest of my graduate school journey.
