Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 20 for “"phytoplankton productivity"”.
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Phytoplankton productivity of tropical Lake Chapala, Mexico.
Phytoplankton productivity and other environmental variables were measured for one year (June 1983 - June 1984) at five stations on Lake Chapala, Mexico. Contrary to expectations, productivity in this shallow, tropical lake 14 was low. Phytoplankton productivity, estimated from C data, was 76.4 g C …
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Nitrogen uptake and phytoplankton productivity in the changing Barents Sea
… study is to quantify nitrogen<br/>uptake and phytoplankton productivity in the marginal ice zone of the Barents<br/>Sea during winter, spring, and summer 2018, in the context of the seasonal transition<br/>in sea ice coverage and upper ocean dynamics. These results will contribute to …
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Spatial and Temporal Patterns of Areal and Volumetric Phytoplankton Productivity of Lake Texoma
Phytoplankton productivity of Lake Texoma was measured for one year from August 1999 to August 2000 for four stations, using the oxygen change method and laboratory incubation. Mean values of the photosynthetic parameters, PBmax and alphaB ranged from 4.86 to 46.39 mg O2.mg Chl-1.hr-1 for PBmax and …
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Phytoplankton productivity and Milankovitch Cycles in the Cenomanian-Turonian Bridge Creek member of the Greenhorn Formation in southeastern Colorado
… caused by a combination of fluctuating primary productivity and humid/arid climate cycles. Species richness and evenness indices for palynomorph assemblages from 24 Bridge Creek beds were statistically analyzed using Analysis of Variance. The results indicate that assemblages for the limestone …
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From the ice to the open ocean : threats to phytoplankton productivity in the Antarctic marine ecosystem from a changing climate
… open ocean, sea ice and meltwater environments. Phytoplankton are key species in the structure and function of the Antarctic ecosystem, instrumental in the regions biogeochemistry, fundamental to the food web and strong contributors to global primary production and carbon sequestration. …
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Uncovering Mechanisms of Phytoplankton Response to Climate Change
Phytoplankton are responsible for approximately half the primary production on earth, fueling marine food webs and driving the cycling of carbon and inorganic nutrients in the oceans. Climate change is predicted to alter the marine environment by elevating carbon dioxide, increasing temperature, …
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Seasonal variability of phytoplankton photophysiology in the Southern Ocean: an analysis of uncertainties and the impact of assumptions
… fully understood. One approach for estimating phytoplankton productivity is through active single-turnover chlorophyll-a fluorescence (ST-ChlF) techniques, such as Fast Repetition Rate fluorometry (FRRf), which infer photosynthetic capacity by measuring the transport of electrons during …
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Urea and nickel utilization in marine cyanobacteria as evaluated by incubation, proteomic, and uptake techniques
… and trace metal biogeochemical effects on phytoplankton productivity were compared through whole water bottle incubations and proteomic evaluation of in situ harvested particulate matter from two distinct oceanographic regions: the Equatorial Pacific Upwelling and the South Pacific Gyre. …
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Urea and nickel utilization in marine cyanobacteria as evaluated by incubation, proteomic, and uptake techniques
… and trace metal biogeochemical effects on phytoplankton productivity were compared through whole water bottle incubations and proteomic evaluation of in situ harvested particulate matter from two distinct oceanographic regions: the Equatorial Pacific Upwelling and the South Pacific Gyre. …
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FLOW CYTOMETRIC INVESTIGATION OF THE SIZE SPECTRUM OF NORTH SEA PHYTOPLANKTON COMMUNITIES
… biogeochemical processes are closely linked to phytoplankton community assemblages. Cell abundance and biomass are a measure of the successful conversion of inorganic to organic carbon. Carbon estimates are therefore often used to analyse metabolism and energy transfers within marine …
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Marine phytoplankton in a high CO2 world
Marine phytoplankton is responsible for ~50% of global primary productivity, it supports the oceanic food web and affects biogeochemical cycles. I participated in a large mesocosm experiment that observed altered community structure and carbon drawdown in response to increased CO2. There was a 27% …
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Measurements and modelling of eutrophication processes in Lake Rotoiti, New Zealand
… examined the spatial and temporal variability of phytoplankton biomass and made a detailed consideration of the performance of three-dimensional lake ecosystem models. To gain insight in the spatial variability in phytoplankton productivity, surface phytoplankton productivity measurements were …
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Modeling the Biogeochemical Cycle of Selenium in the San Francisco Bay
… to simulate salinity, total suspended material, phytoplankton concentrations, dissolved selenium and its speciation (selenite, selenate, and organic selenide), and particulate selenium and its speciation (selenite + selenate, elemental selenium, and organic selenide). Actual data from 1999 were …
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Effect of future CO2 and temperature regimes on phytoplankton community composition, biomass and photosynthetic rates in the western English Channel
… processes. Production of organic matter through phytoplankton photosynthesis drives CO2 sequestration, which feeds back to atmospheric CO2 and global climate. The ongoing increase in atmospheric CO2 and temperature is strongly associated with changes in ocean chemistry and increasing seawater …
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Investigation of the distribution, structure, composition, development and primary productivity of blue-green algal mat communities in an Antarctic lake
… meltstreams. The contribution of mat primary productivity to the total lake metabolism was estimated. Thin lemon-yellow mats of high algal diversity dominated by diatoms and filamentous blue-green algae comprised the stream mat community. These mats inoculated shallow areas in the lake …
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Submesoscale Biophysical Interactions on the Gulf Stream: Eddies, Fronts, and New Observational Methods
… for submesoscale dynamics that may influence phytoplankton productivity and diversity with ramifications across marine ecosystems. In this dissertation I: 1) review the use of drones and ocean color remote sensing for observing biology at the submesoscale and below, and articulate a vision for …
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The Biogeochemistry of iron, zinc and cobalt in the Atlantic Ocean: the Atlantic Meridional Transect and UK GEOTRACES sections
… occurs in marine environments, primarily by phytoplankton. The trace metal micronutrients iron, zinc and cobalt are known to exert a significant biological control on phytoplankton productivity by serving as essential active centres in enzymatic processes such as inorganic carbon, nitrogen …
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Factors controlling bacterial abundance, biomass and growth at the Bermuda Atlantic time-series site
… fall. There were striking seasonal patterns in phytoplankton productivity with a strong maximum immediately following the deep winter mixing and the intrusion of inorganic nutrients. Bacterial growth rates showed a similar pattern but had a secondary peak in late summer/fall of the same …
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Ecosystem impacts of variable recruitment in Antarctic krill investigated with long-term monitoring and archived ADCP backscatter data
… variability drives five-year cycling in marine phytoplankton productivity, leading to phase-offset five-year cycling in the size of the krill population. We demonstrate that the rate of change of the Adélie breeding population also shows five-year cycling. We link this population response to …
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Zooplankton phytoplankton interactions in the San Joaquin River, Ca
<p>The dynamics of zooplankton and phytoplankton growth and interactions play a significant role in water quality (e.g., pH and dissolved oxygen [DO]) and the available food supply for higher order organisms in the San Joaquin River Delta. Algae have been shown to significantly impact DO …