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Full-Text Articles in Life Sciences

Phytoplankton Community Dynamics In The Northern California Current System, Kristin Forgrave May 2024

Phytoplankton Community Dynamics In The Northern California Current System, Kristin Forgrave

Student Research Symposium

The Northern California Current system is a productive coastal ecosystem that encompasses a variety of temporal and spatial features. The photosynthetic microbial community plays a crucial role in supporting the rich ecosystem and economically important fisheries. My research integrates data across distance and two years to investigate the community composition of two major phytoplankton groups in this system: picocyanobacteria and picoeukaryotes. The abundances and sizes of the phytoplankton were measured using flow cytometry. Picoeukaryotes were found to be present at similar concentrations in both summer and winter. Abundances of both cell types were comparable in the winter, but picocyanobacteria were …


Drivers And Dynamics Of Phytoplankton Communities And Harmful Algal Blooms In Mountain Lakes, Lara Stephanie Jansen Aug 2023

Drivers And Dynamics Of Phytoplankton Communities And Harmful Algal Blooms In Mountain Lakes, Lara Stephanie Jansen

Dissertations and Theses

Harmful cyanobacterial blooms (cyanoHABs) are a complex and widespread disturbance in freshwater water bodies, impacting water quality for wildlife and human populations. While cyanobacteria often bloom in warm lakes impacted by human development like agriculture, blooms are increasingly reported in cooler waters with limited development in the surrounding watershed. As much of cyanoHAB research has focused on lakes in highly developed watersheds, the understanding of factors leading to cyanobacteria dominance and blooms in the absence of major development remains limited. Mountain lakes can serve as ideal systems to study bloom-forming cyanobacteria in watersheds with minimal development. In addition, mountain lakes …


Invasive Predator, Bythotrephes, Has Varied Effects On Ecosystem Function In Freshwater Lakes, Angela L. Strecker, Shelley E. Arnott Jan 2008

Invasive Predator, Bythotrephes, Has Varied Effects On Ecosystem Function In Freshwater Lakes, Angela L. Strecker, Shelley E. Arnott

Environmental Science and Management Faculty Publications and Presentations

Bythotrephes longimanus is an invertebrate predator that has invaded the North American Great Lakes and a number of inland lakes, where it preys on crustacean zooplankton. We examined the effect of Bythotrephes on two measures of ecosystem function during a four month observational study of freshwater lakes on the boreal shield. Bythotrephes-invaded lakes had significantly lower epilimnetic zooplankton abundance and production compared to reference lakes. On average, Bythotrephes consumed 34% ofzooplankton production when it was present in lakes. There was some evidence of changes in the timing of zooplankton production, as well as shifts to cooler, less productive habitats, which …


The Use Of Track Autoradiography To Determine Species-Specific Phytoplankton Productivity, Ralph Martin Vaga Jan 1978

The Use Of Track Autoradiography To Determine Species-Specific Phytoplankton Productivity, Ralph Martin Vaga

Dissertations and Theses

Methods of measuring primary productivity are discussed in terms of what information they provide concerning energy flow in the phytoplankton community. A track autoradiographic technique is presented which measures species-specific phytoplankton productivity and its use is demonstrated under laboratory conditions. Controls and standardized processing conditions are established which permit the use of the track technique in quantitative evaluations of primary productivity.