Associate Professor, Department of Fisheries, Wildlife, and Conservation Sciences, Oregon State University
HJ Andrews Experimental Forest, Oregon

Dr. Ivan Arismendi is an aquatic ecologist who currently holds an Associate Professor position at Oregon State University. He leads scientific research focused on global environmental change, invasion biology, and aquatic food webs. He is also interested in the people who use or study in natural resources, which has led to emergent research on diversity, equity, and inclusion in science. To date, Dr. Arismendi has published 103 peer-reviewed articles and book chapters and has received various awards, including the Savery Outstanding Young Faculty Award from the College of Agricultural Sciences at Oregon State University and the Emmeline Moore Prize from the American Fisheries Society (AFS), a career achievement award that recognizes efforts in the promotion of demographic diversity in AFS. He self-identifies as a Latinx scientist with a strong commitment to serve as an example to students that science is available to everyone.

Shrinking Sizes of Unexploited Fish and Salamanders Over the Past 60 Years

Decreases in body sizes of animals related to recent climate warming can affect population persistence and stability. However, direct observations of body size over time and its interrelationships with underlying drivers remain poorly understood owing to the lack of appropriate long-term ecological datasets. Here, we show consistent decreases in body sizes for two unexploited, coexisting aquatic predators Coastal Giant Salamander and Coastal Cutthroat Trout in headwater streams from separate eco-regions over multiple decades in response to continued climate change. Relatively pristine ecosystems may provide some buffering capacity against effects of climate change, as body size decreased less in basins dominated by old-growth forest. We highlight the intricate links between density-independent and density-dependent factors in controlling population-level processes in streams. Our findings demonstrate that multi-decadal population studies can provide foundational information for answering complex questions that emerge from ongoing environmental change.