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Full-Text Articles in Physical Sciences and Mathematics

Diatom Blooms In Harpswell Sound: Seasonality, Succession, And Origin, Charlie Francis O'Brien Jan 2023

Diatom Blooms In Harpswell Sound: Seasonality, Succession, And Origin, Charlie Francis O'Brien

Honors Projects

Harpswell Sound (HS) is an inlet in northeastern Casco Bay that exerts control on Gulf of Maine ecosystem health, yet its complex phytoplankton community dynamics have not been characterized with sufficiently detailed analyses. In this research, high-resolution automated microscopy and current velocity observations were used to test the seasonality, ecological succession, bloom origin location, and potential toxicity of populations in HS between 2020 and 2022. Winter months could exhibit slow accumulation of diatom biovolume. Cold, salty surface water has net outflow in winter as nutrients from depth are replenished during net upwelling conditions, and populations could be exported from the …


Living Upstream: Kennebec River Influence On Nutrient Regimes And Phytoplankton Communities In Harpswell Sound, Siena Brook Ballance Jan 2020

Living Upstream: Kennebec River Influence On Nutrient Regimes And Phytoplankton Communities In Harpswell Sound, Siena Brook Ballance

Honors Projects

Phytoplankton underpin marine trophic systems and biogeochemical cycles. Estuarine and coastal phytoplankton account for 40-50% of global ocean primary productivity and carbon flux making it critical to identify sources of variability. This project focuses on the Kennebec River and Harpswell Sound, a downstream, but hydrologically connected coastal estuary, as a case study of temperate river influence on estuarine nutrient regimes and phytoplankton communities. Phytoplankton pigments and nutrients were analyzed from water samples collected monthly at 8 main-stem rivers stations (2011-2013) and weekly in Harpswell Sound (2008-2017) during ice-free months. Spatial bedrock and land use impacts on river nutrients were investigated …