scholarly journals Phytoplankton Community Response to Changes in Light: Can Glacial Rock Flour Be Used to Control Cyanobacterial Blooms?

2020 ◽  
Vol 8 ◽  
Author(s):  
Jacob A. Gaskill ◽  
Ted D. Harris ◽  
Rebecca L. North
Keyword(s):  
Phytoplankton Community ◽  
Community Response ◽  
Cyanobacterial Blooms

Experimental culling of minnows suppresses cyanobacterial bloom under low-nutrient conditions

2019 ◽  
Vol 76 (11) ◽  
pp. 2102-2109 ◽  
Author(s):  
Blake R. Stuparyk ◽  
Mark Graham ◽  
Jenna Cook ◽  
Mitchell A. Johnsen ◽  
Karen K. Christensen-Dalsgaard ◽  
...  
Keyword(s):  
Fisheries Management ◽  
Trophic Cascade ◽  
Phytoplankton Biomass ◽  
Management Practices ◽  
Phytoplankton Community ◽  
Cyanobacterial Bloom ◽  
Nutrient Status ◽  
Cyanobacterial Blooms ◽  
Phytoplankton Blooms ◽  
Cascade Effect

Cyanobacterial blooms in lakes of low nutrient status are recent ecological surprises. Culling of planktivorous fish may help suppress phytoplankton blooms via a trophic cascade effect. To test this hypothesis, we conducted a 90-day experiment adjacent to a shallow oligomesotrophic lake increasingly beset by midsummer cyanobacterial blooms in the presence of high abundances of minnows and sparse herbivorous zooplankton. The single-factor (± three spottail shiners, Notropis hudsonius) experimental design was replicated 10 times for a total of twenty 1200 L capacity mesocosms. Contrary to the trophic cascade hypothesis, minnow removal decreased the abundance of bosminids capable of grazing cyanobacteria. Nevertheless, removal of the minnows significantly both suppressed phytoplankton biomass and offset the development of cyanobacteria, such as Gloeotrichia echinulata. Lower concentrations of phosphorus and nitrogen in the fishless relative to stocked mesocosms best explained these differences in the phytoplankton community. Our findings highlight how fisheries management practices that enhance minnow populations in lakes of low productivity may inadvertently contribute to cyanobacterial blooms through increased nutrient cycling.

Influence of extended water column mixing during the first 2 years of hypolimnetic oxygenation on the phytoplankton community of Amisk Lake, Alberta

1997 ◽  
Vol 54 (9) ◽  
pp. 2133-2145 ◽  
Author(s):  
D J Webb ◽  
R D Robarts ◽  
E E Prepas
Keyword(s):  
Water Column ◽  
Trophic Status ◽  
Phytoplankton Community ◽  
Euphotic Zone ◽  
Open Water ◽  
Eutrophic Lake ◽  
Cyanobacterial Blooms ◽  
Chl A ◽  
Hypolimnetic Oxygenation ◽  
Physical Variables

The phytoplankton community, physical variables, and nutrient and chlorophyll a (Chl a) concentrations were monitored during the first two of six open-water seasons of hypolimnetic oxygenation in double-basined Amisk Lake, Alberta. Deep mixing of the water column in the treated basin (Zmax = 34 m) in spring was enhanced by hypolimnetic oxygenation. Oxygenation began in June 1988, when stratification was likely already established, but subsequent year-round treatment favoured an extended spring diatom bloom (Asterionella formosa and Cyclotella spp.), followed by a delay in the development of, and reduction in the severity of, cyanobacterial blooms (Aphanizomenon flos-aquae and Anabaena flos-aquae) in 1989. Historically, mean summer Chl a and total phosphorus (TP) concentrations in the euphotic zone (0-6 m) of the treated basin were 15.9 ± 1.6 and 33.5 ± 1.5 µg ·L-1, respectively, indicating a eutrophic lake. In 1988 and 1989, mean summer Chl a (10.0 ± 0.6 and 8.1 ± 0.7 µg ·L-1, respectively) and TP concentrations (29.0 ± 0.5 and 22.5 ± 0.9 µg ·L-1, respectively) in this stratum were lower than historic values (P < 0.05), indicating that the trophic status of Amisk Lake had shifted towards mesotrophy.

scholarly journals North-South asymmetry in the modeled phytoplankton community response to climate change over the 21st century

2013 ◽  
Vol 27 (4) ◽  
pp. 1274-1290 ◽  
Author(s):  
Irina Marinov ◽  
Scott C. Doney ◽  
Ivan D. Lima ◽  
K. Lindsay ◽  
J. K. Moore ◽  
...  
Keyword(s):  
Climate Change ◽  
21St Century ◽  
Phytoplankton Community ◽  
Community Response ◽  
South Asymmetry

scholarly journals Assessing the role of dust deposition on phytoplankton ecophysiology and succession in a low-nutrient low-chlorophyll ecosystem: a mesocosm experiment in the Mediterranean Sea

2012 ◽  
Vol 9 (12) ◽  
pp. 19199-19243 ◽  
Author(s):  
V. Giovagnetti ◽  
C. Brunet ◽  
F. Conversano ◽  
F. Tramontano ◽  
I. Obernosterer ◽  
...  
Keyword(s):  
Mediterranean Sea ◽  
Phytoplankton Community ◽  
Phytoplankton Bloom ◽  
Community Response ◽  
Mesocosm Experiment ◽  
Saharan Dust ◽  
Dust Deposition ◽  
Layer System ◽  
Pigment Analysis ◽  
The Mediterranean

Abstract. In this study, we investigate the phytoplankton community response, with emphasis on ecophysiology and succession, after two experimental additions of Saharan dust in the surface layer of a low-nutrient low-chlorophyll ecosystem in the Mediterranean Sea. Three mesocosms were amended with evapocondensed dust to simulate realistic Saharan dust events while three additional mesocosms were kept unamended and served as controls. Experiments consisted in two consecutive dust additions and samples were daily collected at different depths (−0.1, −5 and −10 m) during one week, starting before each addition occurred. Data concerning HPLC pigment analysis on two size classes (< 3 and > 3 µm), electron transport rate (ETR) versus irradiance curves, non-photochemical fluorescence quenching (NPQ) and phytoplankton cell abundance (measured by flow cytometry), are presented and discussed in this paper. Results show that picophytoplankton mainly respond to the first dust addition, while the second addition leads to an increase of both pico- and nano-/microphytoplankton. Ecophysiological changes in the phytoplankton community are revealed, and an increase in NPQ development, as well as in pigment concentration per cell, follows the dust additions. ETR does not show large variations between dust-amended and control conditions, while biomass increases in response to the dust additions. Furthermore, the biomass increase observed during this mesocosm experiment allows us to attempt a quantitative assessment and parameterization of the onset of a phytoplankton bloom in a nutrient-limited ecosystem. These results are discussed focusing on the adaptation of picophytoplankton to such a nutrient-limited mixed layer system, as well as on size-dependent competition ability in phytoplankton.

scholarly journals No Clear Response in the Stormwater Phytoplankton Community to Biocide Contamination

Water ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 3120
Author(s):  
Greta Minelgaite ◽  
Diana A. Stephansen ◽  
Márta Simon ◽  
Morten L. Fejerskov ◽  
Jes Vollertsen
Keyword(s):  
Statistical Analysis ◽  
Phytoplankton Community ◽  
Taxonomic Composition ◽  
Community Response ◽  
The Other ◽  
Phytoplankton Communities ◽  
Mesocosm Experiments ◽  
Laboratory Microcosm ◽  
Stormwater Pond ◽  
Natural Phytoplankton

This study investigated the responses of natural phytoplankton communities of an urban stormwater pond to biocide contamination. The biocides carbendazim, terbutryn, diuron, and irgarol 1051, and their mixture, were used in two laboratory microcosm and one outdoor mesocosm studies at concentrations of 10, 100, and 1000 ng L−1. The water samples were collected in a pond receiving significant biocide contamination. The mesocosm study was carried out in the same pond. The phytoplankton community response was evaluated after 10–15 days of exposure, with respect to its taxonomic composition, abundance and biovolume. No significant changes were observed in any of the experiments. Only at the highest applied terbutryn concentration were lower numbers of taxa identified in both microcosm and mesocosm experiments. Additionally, increases in Chlorophyta abundance and biovolume, along with an increase in irgarol concentration, were observed throughout the three experiments. Nevertheless, the statistical analysis did not confirm any significant differences among the biocide treatments. These results suggest that the biocide concentrations probably were below the harmful or toxic threshold to the stormwater pond phytoplankton. On the other hand, as the investigated pond phytoplankton taxa face biocide inputs throughout the year, they could have already adapted to the tested biocide contamination.

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