Lack of Effect of Arsenic on Phytoplankton Communities in Different Nutrient Conditions

1983 ◽  
Vol 40 (2) ◽  
pp. 156-161 ◽  
Author(s):  
Dolores Planas ◽  
Alain Lamarche
Keyword(s):  
Organic Matter ◽  
Key Words ◽  
Chlorophyll A ◽  
Bottom Sediments ◽  
Phytoplankton Biomass ◽  
Canadian Shield ◽  
Inorganic Nutrients ◽  
Phytoplankton Communities ◽  
Nutrient Conditions

One-metre diameter plastic cylinders open to bottom sediments were used to investigate the effect of 30–40 μmol∙L−1 concentrations of arsenic on phytoplankton communities of the Canadian Shield. Dissolved nutrient-rich organic matter (trypticase soy broth) and inorganic nutrients [Formula: see text] were also added in the presence or absence of arsenic. Arsenic caused little change in phytoplankton biomass, measured as chlorophyll a or as biovolumes, in any of the cylinders during the 1st week of the experiment. Thereafter the biomass increased in cylinders enriched with organic matter and nutrients (with and without arsenic).Key words: arsenic, chlorophyll a, biomass, nutrients

Differences between Nearshore and Offshore Phytoplankton Communities in Lake Ontario

1987 ◽  
Vol 44 (12) ◽  
pp. 2155-2163 ◽  
Author(s):  
I. M. Gray
Keyword(s):  
Chlorophyll A ◽  
Phytoplankton Biomass ◽  
Algal Biomass ◽  
Phytoplankton Community ◽  
Seasonal Pattern ◽  
Principal Component ◽  
Lake Ontario ◽  
Dominant Group ◽  
Phytoplankton Communities ◽  
Eutrophic Species

Differences between nearshore and offshore phytoplankton biomass and composition were evident in Lake Ontario in 1982. Phytoplankton biomass was characterized by multiple peaks which ranged over three orders of magnitude. Perhaps as a consequence of the three times higher current velocities at the northshore station, phytoplankton biomass ranged from 0.09 to 9.00 g∙m−3 compared with 0.10 to 2.40 g∙m−3 for the midlake station. Bacillariophyceae was the dominant group at the northshore station until September when Cyanophyta contributed most to the biomass (83%). Although Bacillariophyceae was the principal component of the spring phytoplankton community at the midlake station, phytoflagellates (49%) and Chlorophyceae (25%) were responsible for summer biomass, with the Chlorophyceae expanding to 80% in the fall. The seasonal pattern of epilimnetic chlorophyll a correlated with temperature. While chlorophyll a concentrations were similar to values from 1970 and 1972, algal biomass had declined and a number of eutrophic species (Melosira binderana, Stephanodiscus tenuis, S. hantzschii var. pusilla, and S. alpinus) previously found were absent in 1982.

Impacts of bioturbation by Venus clam Cyclina sinensis (Gmelin, 1791) on benthic metabolism and sediment nutrient dynamics in a shrimp-clam polyculture pond

2020 ◽  
Vol 67 (3) ◽  
Author(s):  
Regan Nicholaus ◽  
Betina Lukwambe ◽  
Eliezer Brown Mwakalapa ◽  
Wen Yang ◽  
Jinyong Zhu ◽  
...  
Keyword(s):  
Organic Matter ◽  
Chlorophyll A ◽  
Nutrient Dynamics ◽  
Inorganic Nutrients ◽  
Sediment Organic Matter ◽  
Nutrient Fluxes ◽  
Overlying Water ◽  
Shrimp Culture ◽  
Benthic Metabolism ◽  
Cyclina Sinensis

Dynamics of benthic inorganic nutrients are key biogeochemical components of sediment metabolism and ecosystems. This study investigated the roles of the bivalve Cyclina sinensis (Gmelin, 1791) and its influence on benthic metabolism, nutrient fluxes and sediment oxygen consumption (SOC) in a shrimp-clam polyculture system in comparison with shrimp culture ponds without incorporating clams, in Ningbo Zhejiang China. The benthic inorganic nutrients fluxes (ammonium-NH4+, nitrate plus nitrite-NO3-+NO2- and phosphate-PO43-) and SOC were measured across the sediment-water interface with dark incubation experiments. The results showed that there were significantly higher nutrient fluxes from the sediment into the overlying water (p<0.05) in the treatment ponds in the order of NH4+ > PO43- > NO3- + NO2-. The SOC varied significantly (p<0.05) and was three-times higher than that of the control ponds. Water quality (dissolved oxygen, pH, chlorophyll-a and salinity) recorded showed slight variations over time but were not significantly different (p>0.05) between the control and treatment ponds. Sediment organic matter and chlorophyll-a concentration measured in the shrimp-clam ponds varied significantly (p<.05) as compared to control ponds. The results of this study suggest that the bioturbation activities by C. sinensis promoted the SOC, sediment organic matter degradation and mineralisation process that increased the exchange of nutrients and oxygen uptake between the sediment and the overlying water.

ATP as a Measure of Living Phytoplankton Carbon in Estuaries

1979 ◽  
Vol 36 (2) ◽  
pp. 180-186 ◽  
Author(s):  
Michael Sinclair ◽  
Edric Keighan ◽  
Jerry Jones
Keyword(s):  
Cell Count ◽  
Key Words ◽  
Chlorophyll A ◽  
Phytoplankton Biomass ◽  
Constant Ratio ◽  
High Biomass ◽  
Bacterial Populations ◽  
Cell Counts ◽  
Count Method ◽  
Key Words Atp

An attempt has been made to evaluate the accuracy of ATP as a measure of living phytoplankton carbon in estuaries. Phytoplankton carbon estimated from ATP was compared to estimates from cell counts. In high biomass samples the agreement between the two estimates was quite good. In the low biomass samples the cell count method underestimated phytoplankton carbon relative to the ATP estimate. This was interpreted to be due in part to low cell counts in these samples. Contamination by microzooplankton (essentially only tintinnids) was, in 14 out of the 18 samples, < 3% of the ATP estimated carbon. However, it was as high as 19% in one case. In the lowest biomass samples (< 0.5 μg chlorophyll a/L) bacterial populations may contribute as much as 50% of the total living carbon. It is concluded that, with caution, ATP is a useful measure of living phytoplankton carbon in estuaries during periods of moderate to high biomass (> 1 μg chlorophyll a/L for the St. Lawrence). Since carbon to chlorophyll ratios in the high biomass samples varied considerably, a constant ratio appears inapplicable for transforming chlorophyll to carbon. Key words: ATP, phytoplankton biomass, estuaries, carbon to chlorophyll ratio

Influence of the Shelf-Break Front Off Nova Scotia on Phytoplankton Standing Stock in Winter

1979 ◽  
Vol 36 (10) ◽  
pp. 1228-1237 ◽  
Author(s):  
R. O. Fournier ◽  
M. Van Det ◽  
J. S. Wilson ◽  
N. B. Hargreaves
Keyword(s):  
Nova Scotia ◽  
Key Words ◽  
Chlorophyll A ◽  
Phytoplankton Biomass ◽  
Standing Stock ◽  
Euphotic Zone ◽  
Shelf Break ◽  
Growth Enhancement ◽  
Average Amount ◽  
Growth Increase

Observations made on the shelf-break front off Nova Scotia during winter on 2 successive yr show the concentration of chlorophyll a in the euphotic zone to be correlated to the inclination of the subsurface front. The steepness of the front influences the depth to which phytoplankton are mixed which in turn controls the average amount of illumination received by a given cell. The two winter observations showed the subsurface front at each of two extremes: vertical with little phytoplankton biomass and almost horizontal with significant quantities of chlorophyll. Calculations were made as to the amount of production enchancement that could result from shallowing of the mixed layer by decreased frontal inclination. They show that during the winter under ideal conditions as few as 35 d of intermittent growth increase annual production in the frontal region by 25%. Key words: front, winter production, phytoplankton, shelf-break, chlorophyll a, frontal oscillations, growth enhancement, stability, stratification

scholarly journals Responses of Phytoplankton Communities in Selected Eutrophic Lakes to Variable Weather Conditions

Water ◽  
2019 ◽  
Vol 11 (6) ◽  
pp. 1207 ◽  
Author(s):  
Tomasz Lenard ◽  
Wojciech Ejankowski ◽  
Małgorzata Poniewozik
Keyword(s):  
Chlorophyll A ◽  
Air Temperature ◽  
Vegetative Growth ◽  
Phytoplankton Biomass ◽  
Total Precipitation ◽  
Eutrophic Lakes ◽  
Growth Season ◽  
Mild Winter ◽  
Phytoplankton Communities ◽  
Total Phytoplankton

It is well-known that recent climatic changes have strongly affected aquatic ecosystems. In this study, we examined the complex factors determining the development of phytoplankton communities during the vegetative growth season in eutrophic lakes located in a temperate zone in eastern Poland. Our analysis enabled us to divide the data into two different periods: years with a cold winter and low total precipitation, and those with a mild winter and high total precipitation. The analysis showed that the soluble and total nitrogen content, concentration of chlorophyll a, total phytoplankton biomass, and biomasses of Cyanobacteria and Cryptophyceae were significantly higher in the vegetative growth season in the year after a mild winter, whereas the soluble and total phosphorus content and phytoplankton biodiversity were significantly lower in these years. Hence, climate warming indirectly led to the loss of biodiversity in the phytoplankton communities in the studied lakes of temperate zone. During this study, we also tested the effects of increases in air temperature and total precipitation on phytoplankton communities over short time periods (14 and 28 days). The results showed that the total phytoplankton biomass and the chlorophyll a concentration were only positively correlated with the air temperature. All of the features described in this study showed how sensitive lake ecosystems are to climatic fluctuations.

Preliminary Studies on the Export of Organic Matter During Phytoplankton Blooms off La Coruña (Northwestern Spain)

1998 ◽  
Vol 78 (1) ◽  
pp. 1-15 ◽  
Author(s):  
Antonio Bode ◽  
Manuel Varela ◽  
Susana Barquero ◽  
Ma Teresa Ossorio-Alvarez ◽  
Nicolás Gonzalez
Keyword(s):  
Organic Matter ◽  
Water Column ◽  
Chlorophyll A ◽  
Phytoplankton Biomass ◽  
Euphotic Zone ◽  
Phytoplankton Blooms ◽  
Coastal Site ◽  
Northwestern Spain ◽  
Western Spain ◽  
North Western

Sinking of particles was measured at a coastal site near La Coruña (north-western Spain) using sedimentation traps placed at the base of the euphotic zone during four short periods between March and June 1995. In addition, measurements of water column properties and particles were made at five stations. The cases studied were representative of the main oceanographic situations that occur in this area and were related to the wind-induced upwelling. Phytoplankton blooms (> 100 mg chlorophyll−a m−2) were observed on two occasions in April and June, both during favourable upwelling conditions. The two other cases were studied during low phytoplankton biomass concentrations in the water column.

HEAVY METAL SPECIATION IN BOTTOM SEDIMENTS OF THE VYSHNEVOLOTSKY RESERVOIR

2018 ◽  
pp. 46-54
Author(s):  
O. A. Lipatnikova
Keyword(s):  
Heavy Metal ◽  
Organic Matter ◽  
Bottom Sediments ◽  
Metal Speciation ◽  
Organic Matter Content ◽  
Water Reservoir ◽  
Matter Content ◽  
Heavy Metal Speciation ◽  
Mobile Forms ◽  
Manganese Hydroxides

The study of heavy metal speciation in bottom sediments of the Vyshnevolotsky water reservoir is presented in this paper. Sequential selective procedure was used to determine the heavy metal speciation in bottom sediments and thermodynamic calculation — to determine ones in interstitial water. It has been shown that Mn are mainly presented in exchangeable and carbonate forms; for Fe, Zn, Pb и Co the forms are related to iron and manganese hydroxides is played an important role; and Cu and Ni are mainly associated with organic matter. In interstitial waters the main forms of heavy metal speciation are free ions for Zn, Ni, Co and Cd, carbonate complexes for Pb, fulvate complexes for Cu. Effects of particle size and organic matter content in sediments on distribution of mobile and potentially mobile forms of toxic elements have been revealed.

In Vivo Fluorescence of Chlorophyll A: Estimation of Phytoplankton Biomass and Activity in Římov Reservoir (Czech Republic)

1993 ◽  
Vol 28 (6) ◽  
pp. 29-33 ◽  
Author(s):  
V. Vyhnálek ◽  
Z. Fišar ◽  
A. Fišarová ◽  
J. Komárková
Keyword(s):  
Czech Republic ◽  
Chlorophyll Fluorescence ◽  
Primary Production ◽  
Chlorophyll A ◽  
Phytoplankton Biomass ◽  
In Vivo Fluorescence ◽  
Fluorescence Of Chlorophyll A ◽  
Římov Reservoir ◽  
Natural Phytoplankton

The in vivo fluorescence of chlorophyll a was measured in samples of natural phytoplankton taken from the Římov Reservoir (Czech Republic) during the years 1987 and 1988. The fluorescence intensities of samples either with or without addition of 3-(3,4-dichlorophenyl)-1,1-dimethylurea (diuron, DCMU) were found reliable for calculating the concentration of chlorophyll a during periods when cyanobacteria were not abundant. The correction for background non-chlorophyll fluorescence appeared to be essential. No distinct correlation between a DCMU-induced increase of the fluorescence and primary production of phytoplankton was found.

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