scholarly journals Состав водорослей весенне-летнего планктона озера Арахлей (Забайкальский край)

2019 ◽  
Vol 5 (1) ◽  
pp. 47-52
Author(s):  
N. A. Tashlykova
Keyword(s):  
Fragilaria Crotonensis

По материалам гидробиологического обследования оз. Арахлей весной и летом 2017 г. представлены: таксономическая структура, список идентифицированных микроводорослей, а также состав доминирующего комплекса. Установлено, что фитопланктон озера насчитывает 97 таксонов рангом ниже рода. Его основу (86,6 %) составляют представители четырех отделов: диатомовые, зеленые, золотистые и цианобактерии. К наиболее часто встречаемым видам относились: Lindavia comta, Fragilaria crotonensis, F. radians, Ulnaria ulna, Cocconeis placentula, Nitzschia graciliformis, Chrysococcus rufescens, Dinobryon cylindricum, D. divergens, D. sertularia, Kephyrion spirale, Oocystis marssonii.

Paleolimnological analyses of cultural eutrophication patterns in British Columbia lakes

2000 ◽  
Vol 78 (7) ◽  
pp. 873-888 ◽  
Author(s):  
Euan D Reavie ◽  
John P Smol ◽  
Ian D Sharpe ◽  
Lisa A Westenhofer ◽  
Anne-Marie Roberts
Keyword(s):  
Water Quality ◽  
British Columbia ◽  
Total Phosphorus ◽  
Human Intervention ◽  
Cultural Eutrophication ◽  
High Productivity ◽  
Planktonic Diatoms ◽  
Stratigraphic Analysis ◽  
Fragilaria Crotonensis ◽  
Fossil Diatoms

Diatom-based paleolimnological approaches were used to determine the effects of cultural impacts on eutrophication histories in four lakes from central British Columbia. Stratigraphic analysis of fossil diatoms in 210Pb-dated cores and inferences of past total phosphorus concentrations using diatom-based models were used to reconstruct the nutrient histories of Takysie, Tchesinkut, Francois, and Tyhee lakes. Diatom microfossils indicate that these lakes are probably naturally productive, but some nutrient enrichment has likely occurred in response to human development (since A.D. 1850), particularly in Tyhee Lake. However, in Tchesinkut and Francois lakes, some reduction in total phosphorus may have occurred in recent decades. Takysie, Tchesinkut, and Francois lakes have been dominated by planktonic diatoms indicative of high productivity (e.g., Stephanodiscus, Asterionella, Fragilaria crotonensis, Aulacoseira). Tyhee Lake has been dominated by benthic Fragilaria species, but Stephanodiscus minutulus has increased in recent decades. These data were pooled with previously published paleolimnological data from British Columbia to summarize cultural eutrophication patterns in this region. Out of 11 British Columbia lakes considered, 10 were productive before human intervention, but 7 eutrophied further as a result of human activities. One lake exhibited no obvious post-1850 change in diatom assemblage, suggesting little human impact on water quality. In three of the lakes, recent improvements in water quality may have occurred in response to recent mitigation efforts.Key words: eutrophication, paleolimnology, British Columbia, diatoms, lakes, mining.

Extracellular phosphatase activity of freshwater phytoplankton exposed to different in situ phosphorus concentrations

2005 ◽  
Vol 56 (4) ◽  
pp. 417 ◽  
Author(s):  
A. Ŝtrojsová ◽  
J. Vrba ◽  
J. Nedoma ◽  
K. Ŝimek
Keyword(s):  
Enzyme Activity ◽  
Phosphatase Activity ◽  
Microcystis Aeruginosa ◽  
Image Cytometry ◽  
Phosphorus Concentration ◽  
Phytoplankton Species ◽  
Freshwater Phytoplankton ◽  
Fragilaria Crotonensis ◽  
Species Specific

Extracellular phosphatase production and biomass change were investigated in phytoplankton species transplanted from the phosphorus-limited dam area of a eutrophic reservoir and exposed to the phosphorus-sufficient inflow part and vice versa. Extracellular phosphatase activity was studied using the enzyme-labelled fluorescence (ELF) technique, allowing for direct microscopic detection of enzyme activity and, moreover, its quantification using image cytometry. Several phytoplankton species (e.g. Anabaena planctonica, Microcystis aeruginosa, Fragilaria crotonensis, Ankyra ancora and Planktosphaeria gelatinosa) regulated phosphatase activity according to external phosphorus concentration. On the contrary, picocyanobacteria and several green algae (Coelastrum microporum, Crucigeniella sp., Pediastrum tetras, and Staurastrum planctonicum) did not produce extracellular phosphatases at all. The species-specific extracellular phosphatase activity of F. crotonensis, A. ancora, and P. gelatinosa ranged between 0.02 and 3.5 fmol μm−2 h−1.

Sorption of Cadmium and its Effect on Growth and the Utilization of Inorganic Carbon and Phosphorus of Two Freshwater Diatoms

1979 ◽  
Vol 36 (5) ◽  
pp. 579-586 ◽  
Author(s):  
H. Lee Conway ◽  
Susan C. Williams
Keyword(s):  
Growth Rate ◽  
Inorganic Carbon ◽  
Cadmium Toxicity ◽  
Cadmium Concentration ◽  
Cadmium Content ◽  
Site Location ◽  
Key Words Cadmium ◽  
Asterionella Formosa ◽  
Freshwater Diatoms ◽  
Fragilaria Crotonensis

Cadmium was rapidly sorbed by Asterionella formosa and Fragilaria crotonensis during the first 5–10 min of exposure (0.05 to ~9 μg Cd∙L−1), followed by a hyperbolic increase in the cellular cadmium content as a function of time. Results obtained from experiments conducted in the light and dark, experiments using live and dead populations, and cellular site location studies imply that the sorption of cadmium by A. formosa is partially an active process, but for F. crotonensis it appears to be passive. Populations of A. formosa exhibited a corresponding decrease in the growth rate as the ambient cadmium concentration was increased from ~2 to ~9 μg∙L−1. In contrast, the growth rate of F. crotonensis was unaffected at levels ranging from ~0.05 to ~9 μg Cd∙L−1. The utilization of inorganic carbon by A. formosa was unaffected at ~4 μg Cd∙L−1, but reduced 45% at ~9 μg Cd∙L−1. The utilization rates of carbon and phosphorus by F. crotonensis were reduced at the lower cadmium concentrations and enhanced at the highest. Key words: cadmium, toxicity, sorption, diatom, Asterionella formosa, Fragilaria crotonensis

Influence of a Hexachlorobiphenyl in Great Lakes Phytoplankton in Continuous Culture

1982 ◽  
Vol 39 (3) ◽  
pp. 388-394 ◽  
Author(s):  
Timoth C. Lederman ◽  
G-Yull Rhee
Keyword(s):  
Great Lakes ◽  
Continuous Culture ◽  
Dry Weight ◽  
Initial Response ◽  
Inhibitory Effect ◽  
Dose Response Relationship ◽  
Chl A ◽  
Ankistrodesmus Falcatus ◽  
Fragilaria Crotonensis ◽  
C Assimilation

The influence of 2,4,5,2′,4′,5′-hexachlorobiphenyl (HCB) on the growth of Great Lakes phytoplankters Fragilaria crotonensis, Ankistrodesmus falcatus, and Microcystis sp. was investigated in continuous culture under nutrient-sufficient and phosphate (P) limited conditions. Growth rate (μ) was inhibited only in F. crotonensis at cellular HCB concentrations as low as 4 × 10−8 ng/cell (0.8 μg/g dry weight) in nutrient-sufficient cultures; there appeared to be a dose–response relationship between cellular HCB and μ. Microcystis sp. and A. falcatus showed no inhibitory effect at cellular HCB levels up to 5 × 10−8 ng/cell (3.6 μg/g dry weight) and 30 × 10−8 ng/cell (11.5 μg/g dry weight), respectively. Under P-limited conditions HCB also affected F. crotonensis but not A. falcatus. The initial response of F. crotonensis to HCB addition was a significant increase in μ, followed by a sharp decline. In both nutrient-rich and P-limited F. crotonensis the cellular chlorophyll a (chl a) concentration decreased with the accumulation of HCB, yet the 14C assimilation rate per unit chl a increased. Cellular P concentration in the P-limited cells also decreased with the accumulation of HCB. Such responses were not observed in the other species.Key words: polychlorinated biphenyls, hexachlorobiphenyl, bioconcentration. Great Lakes, algae, continuous culture

Sign in / Sign up

Export Citation Format

Share Document