STUDENTS JOIN FACULTY, ALUMS TO STUDY MICROSCOPIC ODYSSEY AT NORTHERN LAKE

By Sullivan Shubert ’23

Lawrence University biology professor

Bart De Stasio ’82, senior Reese Lavajo, and junior Eleanor Meng collaborated over the summer with Lawrence alumni to research the incredible migration patterns of the microscopic zooplankton species Daphnia at UW–Madison’s Trout Lake Station in northern Wisconsin.

De Stasio, the Singleton Professor of Biology, began this research more than 20 years ago as a postdoc. He revived the project two years ago with Lawrence alumna Gretchen Gerrish ’98, who became director of Trout Lake Station in Vilas County in 2019. Meng and Lavajo are adding to data from last summer’s project. Another collaborator is alumnus Bennett McAfee ’21, who assisted De Stasio with his previous research and shares their lab at Trout Lake for his own zooplankton project with Gerrish.

Daphnia eat mostly algae, but all their food is at the surface of lakes where they’re vulnerable to predators like minnows and sunfish that need light to see their food. Daphnia hide in the dark depths during the day or when there is lots of moonlight, but every night they ascend the human equivalent of miles in search of food—a process called diel vertical migration.

“What they use is the amount of light as a cue to come up, but evolutionarily, what they’ve done is they’ve evolved to use light as a cue to avoid predators,” De Stasio said. No predators mean no migrations.

“There’s a lot of research on the migration patterns that Daphnia do … but there aren’t a lot of studies done on what sizes of Daphnia are at what depth,” Meng said.

Size affects their visibility to predators, and that became a focus of their research project.

Along with studying Daphnia sizes, the project has a side objective, which is where Gerrish comes in. A specialist in underwater videography (it got her featured in David Attenborough’s 2016 documentary, Life That Glows), she and the team are testing new recording technologies that could revolutionize zooplankton research.

“She’s awesome,” Lavajo said. “She’s very fun to work with, she’s got a great personality and is always willing to help you in whatever you need, and she does a lot on station being both the field station director and working on projects with us.”

These connections with alumni and other scientists are one of Meng and Lavajo’s favorite parts of working at the station. Speaking with graduate students around the station or at seminars allows them to learn what their own experiences as graduates might be like.

“There’s a really good community on station, which is really nice,” Meng said. “A lot of people will hang out in cabins, or we have something called Pizza Sundays where one of the grad students will make everyone homemade pizza.”

Trout Lake Station is state and University of Wisconsin-funded. It’s located at the 3,800-acre Trout Lake in far northern Wisconsin, about 180 miles north and west of Appleton. Meng and De Stasio said with Gerrish in charge, they’re hoping the station’s ties with Lawrence grow even stronger in the future.

“I know Reese and I now have connections up here that’ll last for a long time, both with the permanent staff like Gretchen and with the other interns who are up here … they might even have professors with other connections for you,” Meng said. ▪