USING MULTIPLE METRICS TO ANALYZE BLOOM DYNAMICS DURING THE SUMMER OF 2023 IN THE GULF OF MAINE

Phytoplankton diversity is a critical indicator of ecosystem health and function, playing a crucial role in the health of higher trophic levels and biogeochemical cycling. The Gulf of Maine typically experiences a prominent spring bloom dominated by diatoms. However, in 2023, an extensive and intense bloom of the dinoflagellate Tripos muelleri was observed, with concentrations exceeding 50,000 cells L^-1, an order of magnitude higher than previously recorded. The bloom’s intensity contributed to biogeochemical shifts in water quality parameters, including low pCO₂ and high pH. Here, we use multiple methods including 18S rRNA amplicon sequencing, image analysis, and pigment analysis to reconstruct the bloom’s community structure. In addition, community composition was integrated with concurrent oceanographic data, to identify the potential triggers of the bloom’s persistence and demise. Our findings aim to enhance the understanding of phytoplankton dynamics in the context of changing marine environments.

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Primary Presenter: Madison Hurley, University of New Hampshire (madison.hurley@unh.edu)

Authors:

Madison Hurley, University of New Hampshire, Department of Biological Sciences  (madison.hurley@unh.edu)

Shawn Shellito, University of New Hampshire, Ocean Process Analysis Laboratory  (shawn.shellito@unh.edu)

Christopher Hunt, University of New Hampshire, Ocean Process Analysis Laboratory  (christopher.hunt@unh.edu)

Kai Ziervogel, University of New Hampshire, Ocean Process Analysis Laboratory  (kai.ziervogel@unh.edu)

Douglas Vandemark, University of New Hampshire, Ocean Process Analysis Laboratory  (doug.vandemark@unh.edu)

Elizabeth Harvey, University of New Hampshire, Department of Biological Sciences  (elizabeth.harvey@unh.edu)