Student Vignettes

Alexander Timpe

About my research

My research deals with the physiological response of organisms to changes their environment, as measured by the change in an organism’s metabolic activity in response to stimuli. Physiological responses are important, as they represent a metabolic “cost” to an organism. When environmental conditions change or are pushed outside an organism’s natural or acclimated tolerance levels, that organism must actively compensate to maintain homeostasis; a process which requires energy. As a consequence of having to “spend” extra energy, that organism may be less competitive, resilient, or prolific in the changed environment. The stimuli that I will study include temperature, oxygen availability, pH, and CO2 concentration; important abiotic factors affected by climate change and eutrophication. 

In the past, I worked with the copepod zooplankton Eurytemora carolleeae, which is a member of a prolific and diverse genus that inhabits coastal waters all around the world. They are a common invasive species, as they are able to withstand a wide range of salinities and therefore successfully transition between the ocean and freshwater lakes and streams. The population I studied in Little Sturgeon Bay, Wisconsin, was likely introduced via ballast water discharge from oceanic cargo ships. By measuring the respiration rate (a way to determine the amount of energy spent by the organism) and the activity of its metabolic enzymes at different temperatures, we determined that the copepod is living close to its maximum temperature tolerance. These findings have implications for the animal’s continuing success in a warming future. I am a first-year member of Pr. Seibel’s physiology lab here at USF, and will be continuing similar work with horseshoe crabs. We will be investigating the crab’s response to several of the environmental stimuli enumerated above to test novel ideas about oxygen availability, use, and efficiency at high temperatures. 


I was drawn to the College of Marine Science because of its vibrant scientific community and the opportunities to work with some of the most cutting edge researchers in oceanography. I also appreciate the interdisciplinary attitude of the departments, which encourages collaborations between different fields and bolsters the quality of every research project and enhances its impact in the world. The passion for ocean science is nearly palpable, and reminds me every day why I love the sea. As a member of Prof. Seibel’s lab, I will be able to investigate how animals will adapt (or not) to the rapid changes brought about by human activities and help protect aquatic resources and allow for sustainable use into the future. This next summer, I will have the opportunity to work in the field around Catalina Island in southern California as part of a project to create ecological models for ecologically and commercially important species along the Pacific coastline. As ocean temperatures increase and oxygen availability decreases as a result of climate change and global warming, these models will be useful for anticipating the animals’ available habitat. 

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