Jordan Von Eggers - "Investigating how anthropogenic stressors have shaped the biodiversity of mountain lakes"
"The generous funding from the Biodiversity Institute has been critical for supporting the final stages of laboratory analyses for this research. Through their support we are able to measure atmospheric nutrient pollution using nitrogen isotopes from our California and Washington sites. Sediment cores from California serve as a region with relatively high nitrogen deposition compared to Wyoming, while Washington sites likely have lower nitrogen deposition. By sampling over this nitrogen gradient, we will be able to understand broader patterns of biodiversity and the regional drivers that shape them. We are extremely grateful to the Biodiversity Institute and the many funders that contribute to our research."
Jordan Von Eggers, Ph.D. Candidate in Department of Geology and Geophysics
2024 Recipient of the Biodiversity Institute Graduate Student Excellence Grant
Advisors: Bryan Shuman and Amy Krist
We often think of mountain lakes as pristine and undisturbed, primarily due to their remote nature. Despite being secluded in mountains, human impacts affect these lake ecosystems in multiple ways. High elevation lakes are naturally fishless, cold, and possess few nutrients yet today these lakes are being transformed by introductions of non-native species, atmospheric nutrient pollution, and warming temperatures. Starting in the early 1900's, trout were introduced into 60% of all of mountain lakes in the Western U.S. for angling purposes. Introduced trout consume macroinvertebrates and large-bodied zooplankton, which can induce a trophic cascade that may propagate down to the primary producers (phytoplankton). These non-native trout can also impact the surrounding terrestrial ecosystem by reducing prey available for alpine nesting birds, spiders, and amphibians, and by directly predating on amphibian tadpoles. Also starting around the 1900, increases in agriculture and industrialization lead to increased atmospheric deposition of nitrogen. Increasing nutrient loads into oligotrophic lakes increases primary productivity and changes phytoplankton communities. Simultaneously, climate change can affect aquatic organisms by modifying metabolic rates of primary producers at lower trophic levels, altering growing and reproductive seasons for producers and consumers, and placing physiological stress on species with narrow thermal tolerances.
Lake sediments can be used to track the effects of multiple human-induced stressors because they preserve a rich history of past biological communities and conditions from the time they were deposited. My research focuses on using DNA stored in the sediment to assess how phytoplankton and zooplankton have responded to anthropogenic stressors in mountain lakes in Wyoming, Washington, and California over the past few hundred years. This research will aid efforts to anticipate ecosystem transformations and potential state shifts by testing how these three stressors may interact to shape the biodiversity we see today in mountain lakes.
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