Nutrient Loading Impacts on Estuarine Phytoplankton Size and Community Composition: Community-Based Indicators of Eutrophication

2018 ◽  
Vol 42 (2) ◽  
pp. 504-512 ◽  
Author(s):  
Elise Van Meerssche ◽  
James L. Pinckney
Keyword(s):  
Community Composition ◽  
Nutrient Loading ◽  
Community Based ◽  
Phytoplankton Size ◽  
Estuarine Phytoplankton

scholarly journals Nitrogen Biogeochemistry in Lakes – Chemical and Biological Drivers and Developing Techniques to Explicitly Measure Concurrent Processes

2021 ◽  
Author(s):  
Yat-Fung (Jeremy) Lau
Keyword(s):  
Nitrogen Cycling ◽  
Community Composition ◽  
Nutrient Loading ◽  
Chamber System ◽  
Benthic Chamber ◽  
Concurrent Processes ◽  
Flow Through

A benthic chamber system was developed to measure all major nitrogen cycling processes in lakes. The system coupled advantages of flow-through systems common in core incubations with those of Nutrient loading ratios (Si:N and P:N) and community composition of herbivores (

scholarly journals Microbial Community Composition and Denitrifying Enzyme Activities in Salt Marsh Sediments

2008 ◽  
Vol 74 (24) ◽  
pp. 7585-7595 ◽  
Author(s):  
Yiping Cao ◽  
Peter G. Green ◽  
Patricia A. Holden
Keyword(s):  
Microbial Community ◽  
Salt Marsh ◽  
Carbon Content ◽  
Community Composition ◽  
Enzyme Activities ◽  
Nutrient Loading ◽  
Microbial Community Composition ◽  
Marsh Sediments ◽  
Salt Marsh Sediments ◽  
And Function

ABSTRACT Denitrifying microbial communities and denitrification in salt marsh sediments may be affected by many factors, including environmental conditions, nutrient availability, and levels of pollutants. The objective of this study was to examine how microbial community composition and denitrification enzyme activities (DEA) at a California salt marsh with high nutrient loading vary with such factors. Sediments were sampled from three elevations, each with different inundation and vegetation patterns, across 12 stations representing various salinity and nutrient conditions. Analyses included determination of cell abundance, total and denitrifier community compositions (by terminal restriction fragment length polymorphism), DEA, nutrients, and eluted metals. Total bacterial (16S rRNA) and denitrifier (nirS) community compositions and DEA were analyzed for their relationships to environmental variables and metal concentrations via multivariate direct gradient and regression analyses, respectively. Community composition and DEA were highly variable within the dynamic salt marsh system, but each was strongly affected by elevation (i.e., degree of inundation) and carbon content as well as by selected metals. Carbon content was highly related to elevation, and the relationships between DEA and carbon content were found to be elevation specific when evaluated across the entire marsh. There were also lateral gradients in the marsh, as evidenced by an even stronger association between community composition and elevation for a marsh subsystem. Lastly, though correlated with similar environmental factors and selected metals, denitrifier community composition and function appeared uncoupled in the marsh.

scholarly journals Phytoplankton community structuring and succession in a competition-neutral resource landscape

2021 ◽  
Vol 1 (1) ◽  
Author(s):  
Michael J. Behrenfeld ◽  
Emmanuel S. Boss ◽  
Kimberly H. Halsey
Keyword(s):  
Community Composition ◽  
Phytoplankton Community ◽  
Resource Competition ◽  
Stable Solution ◽  
Size Distributions ◽  
Predator Prey ◽  
Phytoplankton Community Composition ◽  
Governing Factor ◽  
Phytoplankton Size ◽  
Aquatic Food

AbstractPhytoplankton community composition and succession affect aquatic food webs and biogeochemistry. Resource competition is commonly viewed as an important governing factor for community structuring and this perception is imbedded in modern ecosystem models. Quantitative consideration of the physical spacing between phytoplankton cells, however, suggests that direct competition for growth-limiting resources is uncommon. Here we describe how phytoplankton size distributions and temporal successions are compatible with a competition-neutral resource landscape. Consideration of phytoplankton-herbivore interactions with proportional feeding size ranges yields small-cell dominated size distributions consistent with observations for stable aquatic environments, whereas predator–prey temporal lags and blooming physiologies shift this distribution to larger mean cell sizes in temporally dynamic environments. We propose a conceptual mandala for understanding phytoplankton community composition where species successional series are initiated by environmental disturbance, guided by the magnitude of these disturbances and nutrient stoichiometry, and terminated with the return toward a ‘stable solution’. Our conceptual mandala provides a framework for interpreting and modeling the environmental structuring of natural phytoplankton populations.

scholarly journals Nitrogen Biogeochemistry in Lakes – Chemical and Biological Drivers and Developing Techniques to Explicitly Measure Concurrent Processes

2021 ◽  
Author(s):  
Yat-Fung (Jeremy) Lau
Keyword(s):  
Nitrogen Cycling ◽  
Community Composition ◽  
Nutrient Loading ◽  
Chamber System ◽  
Benthic Chamber ◽  
Concurrent Processes ◽  
Flow Through

A benthic chamber system was developed to measure all major nitrogen cycling processes in lakes. The system coupled advantages of flow-through systems common in core incubations with those of Nutrient loading ratios (Si:N and P:N) and community composition of herbivores (

Effect of Nutrient Loading on Bacterioplankton Community Composition in Lake Mesocosms

2006 ◽  
Vol 51 (2) ◽  
pp. 137-146 ◽  
Author(s):  
Kaisa Haukka ◽  
Eija Kolmonen ◽  
Rafiqul Hyder ◽  
Jaana Hietala ◽  
Kirsi Vakkilainen ◽  
...  
Keyword(s):  
Community Composition ◽  
Nutrient Loading ◽  
Bacterioplankton Community

scholarly journals Oligotrophication of Lake Balaton over a 20-year period and its implications for the relationship between phytoplankton and zooplankton biomass

Hydrobiologia ◽  
2020 ◽  
Vol 847 (19) ◽  
pp. 3999-4013
Author(s):  
Gábor Bernát ◽  
Nóra Boross ◽  
Boglárka Somogyi ◽  
Lajos Vörös ◽  
László G.-Tóth ◽  
...  
Keyword(s):  
Phytoplankton Biomass ◽  
Nutrient Loading ◽  
Zooplankton Biomass ◽  
Anthropogenic Sources ◽  
Phosphorus Loading ◽  
Fish Stock ◽  
Lake Balaton ◽  
Small Phytoplankton ◽  
Phytoplankton Size ◽  
The 1960S

Abstract Lake Balaton, the largest lake in Central Europe, underwent severe eutrophication from the 1960s to the 1990s, due to phosphorus loadings from external anthropogenic sources. The subsequent and complex eutrophication control and lake restoration program resulted in a significant decrease in the external phosphorus loading to the lake. Consequently, Lake Balaton has been returning to its former meso-eutrophic character. In this paper, we explore the long-term dynamics of chlorophyll a (Chl a) concentration, a proxy for phytoplankton biomass, and zooplankton biomass in Lake Balaton during its re-oligotrophication period from 2001 to 2017, and attempt to draw some conclusions on the subsequent changes in the fish stock. We found a proportional decrease in zooplankton and phytoplankton biomasses at moderate phytoplankton levels. However, below a certain phytoplankton concentration (< 10 μg l−1 Chl a), the decrease in phytoplankton biomass was not coupled with a further decline in zooplankton biomass because the fraction of small phytoplankton, edible for zooplankton, showed a much smaller decrease in biomass compared with large non-edible phytoplankton. Thus, improvements in water quality (i.e., reduced nutrient loading), partly via concomitant changes in the phytoplankton size distribution, did not cause a large difference in the fish stock in this shallow lake.

scholarly journals Underway Hyperspectral Bio-Optical Assessments of Phytoplankton Size Classes in the River-Influenced Northern Gulf of Mexico

2021 ◽  
Vol 13 (17) ◽  
pp. 3346
Author(s):  
Neeharika Verma ◽  
Steven Lohrenz ◽  
Sumit Chakraborty ◽  
Cédric G. Fichot
Keyword(s):  
Gulf Of Mexico ◽  
Community Composition ◽  
Phytoplankton Community ◽  
River Plume ◽  
Small Scale ◽  
Ocean Mixing ◽  
Northern Gulf Of Mexico ◽  
Size Classes ◽  
Phytoplankton Community Composition ◽  
Phytoplankton Size

High inflows of freshwater from the Mississippi and Atchafalaya rivers into the northern Gulf of Mexico during spring contribute to strong physical and biogeochemical gradients which, in turn, influence phytoplankton community composition across the river plume–ocean mixing zone. Spectral features representative of bio-optical signatures of phytoplankton size classes (PSCs) were retrieved from underway, shipboard hyperspectral measurements of above-water remote sensing reflectance using the quasi-analytical algorithm (QAA_v6) and validated against in situ pigment data and spectrophotometric analyses of phytoplankton absorption. The results shed new light on sub-km scale variability in PSCs associated with dynamic and spatially heterogeneous environmental processes in river-influenced oceanic waters. Our findings highlight the existence of localized regions of dominant picophytoplankton communities associated with river plume fronts in both the Mississippi and Atchafalaya rivers in an area of the coastal margin that is otherwise characteristically dominated by larger microphytoplankton. This study demonstrates the applicability of underway hyperspectral observations for providing insights about small-scale physical-biological dynamics in optically complex coastal waters. Fine-scale observations of phytoplankton communities in surface waters as shown here and future satellite retrievals of hyperspectral data will provide a novel means of exploring relationships between physical processes of river plume–ocean mixing and frontal dynamics on phytoplankton community composition.

Bioterrorism-Related Beliefs, Attitudes and Behaviors of Community-Based Clinicians

2002 ◽  
Vol 17 (S2) ◽  
pp. S48
Author(s):  
Robyn R. M. Gershon ◽  
Kristine A. Qureshi ◽  
Stephen S. Morse ◽  
Marissa A. Berrera ◽  
Catherine B. Dela Cruz
Keyword(s):  
Community Based ◽  
Attitudes And Behaviors ◽  
And Behaviors
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