The effect of pH on the release of phosphorus from Potomac estuary sediments: Implications for blue-green algal blooms

1991 ◽  
Vol 33 (4) ◽  
pp. 409-418 ◽  
Author(s):  
Sybil P. Seitzinger
Author(s):  
Mary Claire Cooperrider ◽  
Lydia Davenport ◽  
Sydney Goodwin ◽  
Landon Ryden ◽  
Nathan Way ◽  
...  

1990 ◽  
Vol 73 (3) ◽  
pp. 451-456 ◽  
Author(s):  
Fun S Chu ◽  
Xuan Huang ◽  
R D Wei

Abstract A direct competitive enzyme-linked immunosorbent assay (ELISA) for the freshwater blue-green algal toxin mlcrocystln (MCYST) In algae and water was developed. The assay Involves coating antl-MCYST-variant leuclne-arglnine (LR) antibody to the ELISA plate and the use of MCYST-LRperoxidase as the enzyme marker. The linear portion of the standard curve for MCYST in phosphate buffer containing saline (PBS) was 0.5-10.0 ng/mL (25-500 pg/assay). The minimum detection level for MCYST-LR was 0.20 ng/mL (10 pg/assay). Contaminated water could be directly used In the ELISA. The overall analytical recoveries for MCYST-LR added to water at levels of 1-20 ng/mL was 83.4%. For analysis of cellular MCYST, the toxin was first extracted from the algae with 0.1M ammonium bicarbonate, diluted with PBS to less than 0.5 mg dried algae/mL (<5.0 mg wet welght/mL) and directly used in the ELISA. C-18 reverse-phase Sep-Pak cartridges effectively adsorbed MCYST from the toxln-containlng solutions. The toxin could be recovered from the cartridge by elutlng with 60% methanol. Using this approach, an algae extract that was relatively free of MCYST was prepared and was used in a recovery study. The overall analytical recovery of MCYST added to the algae extract In the range of 0.25-20 ppm was 83% with a coefficient of variation of 11.9%. The detection limit for MCYST In dried algae was about 0.25-0.5 pg/g (0.25-0.5 ppm) lyophlllzed algae sample. This method was applied for the analysis of several naturally occurring algal blooms. Limited samples were also analyzed for MYCST by liquid chromatography. ELISA data were in general agreement with those obtainedby liquid chromatography. MCYST concentrations from 0.006 to 2.9 fig/g (6 to 2900 ppb) and from 26 to 5200 /ig/g (26 ppm to 5200 ppm) were found In water and algae (dried weight), respectively


1994 ◽  
Vol 29 (4) ◽  
pp. 169-176 ◽  
Author(s):  
G. C. White ◽  
I. C. Smalls ◽  
P. A. Bek

During December, 1991 the NSW Department of Water Resources commenced construction of an artificial wetland at the upstream end of Carcoar Dam near Blayney in central western NSW. The principal function of the wetland is to reduce nutrient inputs, especially phosphorus, from the Belubula River into Carcoar storage and consequently lower the incidence of blue-green algal blooms which occur most summers. The wetland is a multi-faceted project involving substantial research and community involvement. Construction of the wetland weir and levees was completed during April, 1992. Stage one of the wetland planting program ran from October to December, 1992 with stage two scheduled for the same period in 1993. The wetland will not be operational until December, 1993. However, even at this early point in the project, significant experience has been gained in design, construction, planting and establishment of comprehensive community involvement programs for large constructed wetlands on the flood plain. This paper outlines the background to the wetland, the design of the wetland system and its construction primarily as a nutrient removal mechanism in the Belubula River. The paper also outlines the direction of research undertaken and the role and nature of community involvement in various aspects of the project.


1990 ◽  
Vol 24 (1) ◽  
pp. 671-676 ◽  
Author(s):  
L. H. Kauppi ◽  
S. T. Knuuttila ◽  
K. O. Sandman ◽  
K. Eskonen ◽  
S. Luokkanen ◽  
...  
Keyword(s):  

Hydrobiologia ◽  
2006 ◽  
Vol 568 (1) ◽  
pp. 111-120 ◽  
Author(s):  
Kaihong Lu ◽  
Chunhua Jin ◽  
Shuanglin Dong ◽  
Binhe Gu ◽  
Stephen H. Bowen

1988 ◽  
Vol 45 (11) ◽  
pp. 1959-1967 ◽  
Author(s):  
David L. Galat ◽  
James P. Verdin

Seventy-six percent of the 1972–86 variability in remotely sensed maximum surface water biomass of Nodularia spumigena blooms in Pyramid Lake, Nevada, was explained by concentrations of surface water total nitrogen (TN) during the preceding winter circulation. Very large summer–autumn Nodularia blooms were recorded by Landsat subsequent to low early winter surface water TN concentrations, very low fluvial discharge, and fluvial TN loads as predicted, but contrary to predictions, also when fluvial discharge and TN loads were very high. The observed cause of large Nodularia blooms following high fluvial nitrogen influx was temporary meromixis produced by the large volume of freshwater transporting this nitrogen. Incomplete winter lake circulation reduced internal transport of hypolimnetic nitrogen to surface waters. Meromixis resulted in early stable summer thermal stratification and early depletion of epilimnetic inorganic nitrogen, followed by early and large Nodularia blooms. Variations in magnitude of historic Nodularia blooms in a saline desert lake support the generality of blue-green algal dominance in lakes with low nitrogen and high phosphorus concentrations (i.e. low N:P ratios). However, climatic forcing of fluvial discharge and lake mixing patterns were also shown to be important determinants of seasonal succession of phytoplankton to blue-greens.


2001 ◽  
Vol 43 (5) ◽  
pp. 137-144 ◽  
Author(s):  
W. N. Vant

The water quality of the Waikato River is currently much better than it was in the 1950s. Major improvements in the treatment of the sewage and industrial wastewaters which are discharged to the river mean that levels of indicator bacteria in the lower reaches of the river are now many times lower than in the past. Eve so, conditions are still not suitable for swimming, and blue-green algal blooms occur at times. Non-point or diffuse sources of contaminants now dominate the nutrient and pathogens budgets. Progressively-intensifying farming, particularly in lowland areas, is thought to contribute the majority of the contaminants found in the river. Future improvements in water quality will therefore depend more on activities like changes to farming practice – such as retiring the riparian margins of lowland tributaries of the river – than on further advances in wastewater treatment.


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