Today: Gretchen Hansen, an assistant professor of fisheries ecology at the University of Minnesota. Hansen is a former research scientist in the Department of Natural Resources in both Minnesota and Wisconsin. Her research focuses on the effects of climate change and invasive species on fish, food webs and ecosystems.


I am planning a new course at the University of Minnesota focused on critical thinking and skepticism as tools to create better scientists and better citizens. To prepare for this course, I am delving into a number of fascinating books, including the “Skeptics’ Guide to the Universe” by Steven Novella, “Thinking, Fast and Slow” by Daniel Kahneman, and “The Demon Haunted World: Science as a Candle in the Dark” by Carl Sagan. These books and others like them provide a sobering reminder that everyone has blind spots and biases, no matter how objective we might think we are.

Still, we do have tools for gathering and assessing evidence, and science is among the most important of these tools. I love how these books bring together lessons from psychology, neurology, anthropology, evolutionary biology and statistics to help us all become better thinkers and decisionmakers.


I use Twitter professionally to learn about new science, methods and movements within the science world. When I started using Twitter I thought it would be a good way to learn about new scientific (peer-reviewed) publications in order to stay on top of the latest research on climate change, freshwater science and ecology. That has proved to be true, but I have also learned a lot of even more valuable things through science Twitter.

Most importantly for me, there are a number of leaders across multiple scientific disciplines and career stages working hard to create an inclusive and supportive scientific culture. I value these ideas tremendously as I embark on my role as a faculty mentor and adviser.


In preparation for the new course I am developing, I am watching all of the lectures for the course “Calling Bullshit”at the University of Washington (available on YouTube). Biologist Carl Bergstrom and data scientist Jevin West do an entertaining and thorough job of exploring the different ways that data and science can be used to persuade and manipulate people. Importantly, they also provide a number of tools and tricks for “calling bull.”


I am thinking a lot about adaptation and resilience, and what those somewhat vague terms mean for Minnesota’s lakes. In the context of climate change, I am collaborating with others to measure how much warming lakes across the Upper Midwest can absorb and still support coldwater fish habitat. We are also quantifying how protecting or restoring forested watersheds can influence a lake’s capacity to support coldwater fish (that is, how can we adapt watershed land use practices to maintain critical habitat). We hope that by incorporating knowledge of fish habitat, climate change and individual lake characteristics into our research that we will be able to prioritize management actions to the locations where they will be most effective.

I am volunteering to help get out the vote! I am enjoying time outside as the leaves change by biking and running along the beautiful Mississippi, and getting ready to play hockey and continue teaching my daughters how to skate this winter.

Bob Timmons