Dr. Lienne Sethna, Assistant Scientist

Ph.D., Indiana University (Environmental Science), 2022
B.S., The Ohio State University (Earth Science), 2016

Phone: (651) 243-0276
Email: lsethna@smm.org
Website: liennesethna.com

Research Interests 

My research focuses on nutrient cycling, transport, and stoichiometry in freshwater ecosystems, with a particular focus on nutrient biogeochemistry and its role in facilitating harmful algal blooms. The ultimate goal of my work is to better understand how society and people alter the function and integrity of our critical freshwater ecosystems. My work involves contemporary monitoring, paleolimnological reconstructions, and synthesis of large datasets to understand how climate change is affecting our water resources.

Eutrophication and toxic cyanobacterial blooms

A large part of my work is to understand how climate and land use change are increasing nutrient concentrations in lakes and streams and how this contributes to eutrophication and the formation of toxic cyanobacterial blooms. I have worked in human-dominated landscapes (agricultural and urban watersheds) as well as relatively pristine lakes (Superior National Forest) to characterize how direct human impacts as well as regional climate change has shifted the ecology and ecosystem function of lakes and streams.

Characterizing paleo-ecology of wild rice

Wild rice is culturally significant for many tribes in the Upper Midwest, however, its abundance has declined over the last several decades due to multiple stressors such as invasive species, water level fluctuations, and increased sulfate concentrations. Understanding the factors that contribute to wild rice decline or resilience will help inform how to sustainably care for wild rice in the future.

Characterizing the role of climate change on river function

As part of a multidisciplinary team, I am working to understand how riverine exports of nutrients, principally silicon, vary over space and time. Using a global dataset spanning more than 20 years and representing over 500 rivers on all seven continents, we seek to quantify how climate and land use change have altered biogeochemical processes and river exports.