Open Access. Powered by Scholars. Published by Universities.®
Physical Sciences and Mathematics Commons™
Open Access. Powered by Scholars. Published by Universities.®
Articles 1 - 3 of 3
Full-Text Articles in Physical Sciences and Mathematics
Succession Of The Late Summer Phytoplankton Blooms In The York River Estuary, Va, Heather Kathleen Corson
Succession Of The Late Summer Phytoplankton Blooms In The York River Estuary, Va, Heather Kathleen Corson
Dissertations, Theses, and Masters Projects
The influence of bottom-up and top-down controls on the formation and persistence of phytoplankton blooms has been well studied. However, the relative importance of these bottom-up and top-down controls vary spatially and temporally. In the tidal tributaries and mainstem of Chesapeake Bay, the summer dinoflagellate population follows a succession of bloom-producing species. The dinoflagellate species Margalefidinium polykrikoides and Alexandrium monilatum are currently considered the end of this succession. These species form near-annual blooms in the lower half of Chesapeake Bay and are considered harmful algal bloom (HAB) species due to their negative ecological impacts. However, analysis of long-term monitoring data …
Biotic And Abiotic Factors Associated With Temporal And Spatial Variability Of Constitutive Mixotroph Abundance And Proportion, Marcella Dobbertin Da Costa
Biotic And Abiotic Factors Associated With Temporal And Spatial Variability Of Constitutive Mixotroph Abundance And Proportion, Marcella Dobbertin Da Costa
Dissertations, Theses, and Masters Projects
Mixotrophic protists, which combine the use of photosynthesis and prey ingestion to obtain nutrients for growth, comprise a substantial portion of the plankton community. However, there is a major gap in our understanding of how mixotroph prevalence varies spatially and temporally and under what conditions they dominate. I utilized a recently developed molecular technique to experimentally identify active mixotrophs (taxa identified to be grazing when samples were collected) and combined this with microscopy data to estimate active mixotroph abundance and proportion at two locations in a temperate estuary over a year. Active mixotroph abundance was compared to potential mixotroph (taxa …
Impacts And Uncertainties Of Climate Change On The Chesapeake Bay, Kyle E. Hinson
Impacts And Uncertainties Of Climate Change On The Chesapeake Bay, Kyle E. Hinson
Dissertations, Theses, and Masters Projects
Climate change impacts in the Chesapeake Bay will limit the efficacy of nutrient reduction efforts and decrease dissolved oxygen, but uncertainties associated with the magnitude of these effects remain. An understanding of underlying mechanisms that have driven recent warming trends will narrow uncertainties for future pathways of temperature change. Additionally, future simulations of climate impacts in the estuary are dependent on multiple different sources of uncertainty, many of which have not yet been fully evaluated. This dissertation used a three- dimensional coupled hydrodynamic-biogeochemical model to investigate recent warming trends as well as underlying uncertainties likely to influence regional projections of …