Jasmine Mancuso defends her thesis focusing on harmful algal blooms in Muskegon Lake
On July 2, 2020, graduate student Jasmine Mancuso successfully defended her Master’s thesis, titled “Bloom or bust: Search for phytoplankton community drivers using long-term time-series observations and field measurements in a model Great Lakes estuary”. Her thesis committee consisted of Drs. Bopi Biddanda (chair), Sarah Hamsher, Megan Woller-Skar, and Eric Snyder.
Jasmine’s thesis focused on the Harmful Algal Bloom (HAB) impairment in Muskegon Lake, a Great Lakes Area of Concern. Her study had two components: 1) a historical understanding of the trends of HABs on Muskegon Lake from 2003-2019 and 2) a focus on the year 2019, a year of unusually cold and rainy conditions. Environmental data clearly show the improvement in water quality over the study period, marked by a decrease in nutrient concentrations, as a result of intensive restoration activity. In response, the HAB impairment has improved substantially. However, it was found that Microcystis, a competitive, toxin-producing genus, was dominant in the cyanobacteria community in most years and has begun to make a reappearance in recent years, likely due to rising water temperatures. The year 2019, however, was relatively cool and experienced record-breaking rainfall amounts. The impacts on the phytoplankton community were unexpected – diatoms were dominant throughout the entire study period (April through October), and HABs were negligible. The driving forces behind this anomalous community are relatively low water temperatures, high turbidity, diluted nutrients, and frequent mixing – all of which benefit diatoms and disadvantage HABs. These results demonstrate that substantial regional climatic events can override the general trends of climate change and have notable effects on the phytoplankton community, with likely effects on the rest of the food web.
After submitting her final thesis documents, Jasmine plans to continue to work in the Biddanda Lab through the end of the year and then will pursue a job in the aquatic science field.
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