lab phone: 250-472-5427
Current Research Project
Ocean Acidification Impacts on Arctic Phytoplankton and Their Physiology
Rising atmospheric carbon dioxide levels are increasing the acidity of global oceans, especially at high latitudes. Of particular importance within high-latitude marine ecosystems are diatoms, a group of silica-walled phytoplankton that play a significant role in taking up carbon dioxide, producing oxygen, supporting food webs, and regulating nutrient cycles. These cycles are highly connected and are important in determining the nutritional value of phytoplankton at the base of the food web and the ability of the ocean to absorb, export, and sequester carbon from the atmosphere. Little is known about the effects of ocean acidification (OA) on individual diatom species or mixed diatom assemblages, and in the Pacific Arctic, diatoms are among the most abundant and ecologically important phytoplankton. With OA increasing more quickly in the Arctic than in other marine ecosystems, it is critical to evaluate the response of diatom physiology to such changes. My proposed research will investigate the response of Arctic diatom physiology to OA using three objectives. First, the broad geographic distribution of diatoms and their growth physiology will be determined by measuring the standing stock composition and uptake rates of nutrients. Second, the physiological responses of natural phytoplankton communities from the Arctic Ocean will be measured under controlled pH manipulation conditions that will simulate end-of-the-century OA scenarios. Lastly, individual species of diatoms will be isolated from marine Arctic waters and subjected to controlled OA experiments as in the second objective. Overall this research will provide an important first look at the impact of OA on an important group of phytoplankton in one of the most sensitive marine ecosystems. The results will be crucial for informing our understanding about how Arctic food webs and nutrient cycles change as carbon dioxide emissions continue.
Other Research and Teaching Interests
- Physiological responses of phytoplankton to anthropogenic changes
- Dissolved nutrient and particle stoichiometry within Subarctic and Arctic phytoplankton assemblages
- Role of diatoms in the biogeochemical silicon cycle
- Carbon and nitrogen cycling through phytoplankton assemblages
- Use of case studies and “flipped” classrooms in science education
- Incorporation of meaningful formative assessment practices into daily learning routines
- Inquiry and project-based learning to create student-led learning experiences
- Increasing student advocacy and engagement with climate science
2017 – present, Ph.D Candidate. Biology, University of Victoria
2014 – B.Ed., UBC West Kootenay Teacher Education Program
2010 – B.Sc. Honours with Distinction, UVic Biology
Publications, Peer Reviewed
Kafrissen, S.M., K.E. Giesbrecht, B.J. McNabb, J.E. Long, C. Martin, S.N. Wyatt, M.G. Lagunas and D.E. Varela. 2021. An 8-year record of phytoplankton productivity and nutrient distributions from surface waters of Saanich Inlet. Nature – Scientific Data, Submitted: SDATA-21-01132.
Wyatt, S.N., B.J. McNabb and D.E. Varela. (2021). Ocean acidification effects on the morphology and nutrient stoichiometry of a cosmopolitan marine diatom under optimal light and temperature. Journal of Phycology, Submitted: JPY-21-173-ART.
Wan Z, Azam M, Wyatt S, Ramsay K, Korner J, Elvira K, Padmawar R, Varela D, Hore D. (2021). Algae adhesion onto silicone is sensitive to environment-induced surface restructuring. Langmuir 31: 9597-9604, DOI:10.1021/acs.langmuir.1c01493
Wan Z, MacVicar B, Wyatt S, Varela D, Padmawar R, and Hore D. (2021). An automated image analysis platform for the study of weakly-adhered cells. Biofouling, DOI:10.1080/08927014.2021.1917555
Crawford D, Cefarelli A, Wrohan I, Wyatt S, Varela D. (2018). Spatial patterns in abundance, taxonomic composition and carbon biomass of nano- and microphytoplankton in Subarctic and Arctic seas. Progress in Oceanography. 162: 132-159.
Crawford D, Wyatt S, Wrohan I, Cefarelli A, Giesbrecht K, Kelly B, Varela D. (2015). Low particulate carbon to nitrogen ratios in surface waters of the Beaufort Sea and Canada Basin in the Arctic Ocean. Global Biogeochemical Cycles. 29(12): 2021–2033.
Wyatt S, Crawford D, Wrohan I, Varela D. (2013). Distribution and composition of suspended biogenic particles in surface waters across Subarctic and Arctic Seas. Journal of Geophysical Research: Oceans. 118(12): 6867–6880.
Varela D, Crawford D, Wrohan I, Wyatt S, Carmack E. (2013). Pelagic primary productivity and upper ocean nutrient dynamics across Subarctic and Arctic Seas. Journal of Geophysical Research: Oceans. 118(12): 7132–7152.
Gilbert, B K. (2019). One of Us: A Biologist’s Walk Among Bears. Kaylene Johnson-Sullivan (Ed), Shea Wyatt (Photographer). Friesen Press.
Wyatt S. (2010). A Pan-Arctic Perspective on the Contribution of Siliceous Phytoplankton to Autotrophic Biomass in Canada’s Oceans. University of Victoria. B.Sc. Honours Thesis.
Presentations and Posters
Wyatt S, McNabb B, and Varela D. (2020). Resilience of a Cosmopolitan Diatom to Induced Ocean Acidification Based on C, N, Si and Chlorophyll-a Stoichiometric Ratios, Nutrient Uptake Rates, and Morphology. Ocean Science Meeting 2020, San Diego, CA. February 2020. (poster)
Varela D, and Wyatt S. (2019). Marine pelagic primary productivity and nutrient dynamics in the Canadian and Alaskan Arctic: Over a decade of studies under the umbrella of the Canada’s Three Oceans, Distributed Biological Observatory, and GEOTRACES programmes. Synoptic Arctic Survey Planning Workshop, Woods Hole Oceanographic Institution, MA. May 15, 2019.
Wyatt S, Varela D, and Grundle D. (2019). Ocean acidification effects on siliceous phytoplankton from the Subarctic Northeast Pacific and Subtropical North Atlantic Oceans. ASLO 2019, San Juan, Puerto Rico. February 26, 2019.
Wyatt S. (2018). Effects of ocean acidification and allelopathic toxins on biogenic silica precipitation in diatom assemblages in the northeast Pacific Ocean. Line P Meeting, Sidney, BC. March 20, 2018.
Wyatt S, Wrohan I, and Varela D. (2010). Contribution of siliceous plankton to autotrophic biomass and primary productivity in arctic and subarctic surface waters. Ocean Sciences Meeting ASLO/AGU, Portland, United States. February 22 – 26, 2010.
Institutional Presentations and Posters
Wyatt S, Varela D, and Grundle D. (2019). Ocean acidification effects on the elemental ratios and nutrient uptake rates of siliceous phytoplankton from the Subarctic Northeast Pacific and Subtropical North Atlantic Oceans. University of Victoria Biology Symposium, Victoria, November 14, 2019.
Wyatt S, Varela D, and Grundle D. (2018). Particulate chlorophyll biomass at the Bermuda-Atlantic Time-series Study. BIOS Research Symposium, Bermuda. November 23, 2018.
Wyatt S, and Varela D. (2018). Ocean acidification impacts on primary producers from productive and oligotrophic oceans. University of Victoria Biology Symposium, Victoria, November 13, 2018.
Wyatt S, Varela D, and Grundle D. (2018). Methods to assess ocean acidification impacts on primary producers from productive and oligotrophic oceans. BIOS Research Symposium, Bermuda. November 2, 2018. (poster)
Wyatt S, and Varela D. (2020). Teaching and Learning during the Climate Crisis – Promoting Positive Thinking and Meaningful Action. Workshop Facilitator. Ocean Science Meeting 2020, San Diego, CA. February 2020
Varela D, and Wyatt, S. (2019). Teaching and Mentoring in the Aquatic Sciences Under the Threat of Climate Change. Workshop Facilitator. ASLO 2019, San Juan, Puerto Rico, February 26, 2019