Empirical study of cyanobacterial toxicity along a trophic gradient of lakes

2005 ◽  
Vol 62 (9) ◽  
pp. 2100-2109 ◽  
Author(s):  
A Giani ◽  
D F Bird ◽  
Y T Prairie ◽  
J F Lawrence
Keyword(s):  
Nitrogen Concentration ◽  
Phosphorus Concentration ◽  
Limited Effect ◽  
Total Phosphorus Concentration ◽  
Toxic Species ◽  
Microcystin Concentration ◽  
Toxic Cyanobacteria ◽  
Total Nitrogen Concentration ◽  
Cyanobacterial Toxicity ◽  
Trophic Range

A series of 22 lakes in southern Quebec spanning a wide trophic range were sampled to develop models of changes in cyanobacterial abundance and toxicity. All lakes contained toxic cyanobacteria, and epilimnetic toxin content, expressed as microcystin equivalents, was best predicted by total nitrogen concentration and total phosphorus concentration (TP). Although phytoplankton biomass increased linearly with increases in TP among lakes, toxigenic biomass increased as greater than the squared power of TP. The only potentially toxigenic genera whose biomass was correlated with microcystin concentration were Microcystis and Anabaena. Surprisingly, the best model for toxic-species biomass was based on epilimnetic nitrogen. The level of the hepatotoxin microcystin per unit biomass in these organisms did not vary markedly among lakes, supporting the idea that environmental factors control the occurrence, but have only a limited effect on the toxicity, of potentially toxic species.

scholarly journals A novel submerged Rotala rotundifolia, its growth characteristics and remediation potential for eutrophic waters

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Chaoguang Gu ◽  
Feifei Li ◽  
Jibo Xiao ◽  
Shuyi Chu ◽  
Shuang Song ◽  
...  
Keyword(s):  
Total Phosphorus ◽  
Nitrogen Concentration ◽  
Biomass Accumulation ◽  
Ammonium Nitrogen ◽  
Phosphorus Concentration ◽  
Nitrogen And Phosphorus ◽  
Overlying Water ◽  
Total Phosphorus Concentration ◽  
Submerged Aquatic Plant ◽  
Nitrogen Contents

Abstract The vegetative growth and remediation potential of Rotala rotundifolia, a novel submerged aquatic plant, for eutrophic waters were investigated on different sediments, and under a range of nitrogen concentrations. Rotala Rotundifolia grew better on silt than on sand and gravel in terms of plant height, tiller number and biomass accumulation. Percent increment of biomass was enhanced at low water nitrogen (ammonium nitrogen concentration ≤10 mg/L). The maximum total nitrogen and total phosphorus removals in the overlying water were between 54% to 66% and 42% to 57%, respectively. Nitrogen contents in the sediments increased with increasing water nitrogen levels, whereas, nitrogen contents in the plant tissues showed no apparent regularity, and the greatest value was obtained at ammonium nitrogen concentration 15 mg/L. Both phosphorus contents in the sediments and tissues of plants were not affected significantly by additional nitrogen supply. Direct nitrogen uptake by plants was in the range of 16% to 39% when total phosphorus concentration was 1.0 mg/L. These results suggested that Rotala Rotundifolia can be used to effectively remove nitrogen and phosphorus in eutrophic waters.

Prediction of Chlorophyll a Concentrations in Florida Lakes: Importance of Aquatic Macrophytes

1984 ◽  
Vol 41 (3) ◽  
pp. 497-501 ◽  
Author(s):  
Daniel E. Canfield Jr. ◽  
Jerome V. Shireman ◽  
Douglas E. Colle ◽  
William T. Haller ◽  
Curtis E. Watkins II ◽  
...  
Keyword(s):  
Chlorophyll A ◽  
Aquatic Macrophytes ◽  
Nitrogen Concentration ◽  
Potential Effect ◽  
Phosphorus Concentration ◽  
Secchi Disc ◽  
Total Phosphorus Concentration ◽  
Florida Lakes ◽  
Wide Range ◽  
Using Data

Chlorophyll a concentrations in Lake Pearl, Florida, increased as the percentage of the lake's total volume infested with aquatic macrophytes decreased. Using data from 32 Florida lakes having a wide range of limnological characteristics, we demonstrated that predictions of chlorophyll a concentrations could be improved by including a term for the percentage of the lake's total volume infested with macrophytes in existing nutrient–chlorophyll models. Our best-fit multivariate regression equation was[Formula: see text]where CHLA is the chlorophyll a concentration (milligrams per cubic metre), TN is the total nitrogen concentration (milligrams per cubic metre), TP is the total phosphorus concentration (milligrams per cubic metre), and PVI is the percentage of the lake's total volume infested with macrophytes. By use of this equation, we assessed the potential effect of aquatic macrophytes on chlorophyll yields and Secchi disc transparencies in lakes of different trophic status.

Response of summer chlorophyll concentration to reduced total phosphorus concentration in the Rhine River (Netherlands) and the Sacramento – San Joaquin Delta (California, USA)

2007 ◽  
Vol 64 (11) ◽  
pp. 1529-1542 ◽  
Author(s):  
Erwin E Van Nieuwenhuyse
Keyword(s):  
Total Phosphorus ◽  
Nitrogen Concentration ◽  
Chlorophyll Concentration ◽  
Water Systems ◽  
Phosphorus Loading ◽  
Phosphorus Concentration ◽  
Flowing Water ◽  
Rhine River ◽  
Total Phosphorus Concentration ◽  
Fold Reduction

Reductions in wastewater loading led to significant declines in mean summer total phosphorus (TP) and chlorophyll concentration (Chl) in two large flowing water systems despite their initially shallow (<2 m) euphotic depth and continually high (>40 mg·m-3) soluble reactive P concentration. In the Rhine River, a gradual 2.7-fold reduction in TP resulted in a 4-fold decline in Chl. In the Sacramento – San Joaquin Delta, an abrupt 1.5-fold reduction in TP led to an equally abrupt 2.6-fold reduction in Chl. Neither response could be attributed to coincidental changes in flow, light, or nitrogen concentration. The slope of the response (Chl:TP) in both systems paralleled the average trajectory calculated using an among-system TP–Chl relationship for a broad cross section of flowing waters. The results suggest that TP was the principal determinant of Chl in both systems and that control of phosphorus loading may be an effective tool for managing eutrophication in other flowing water systems with relatively high (10–100 mg·m-3) soluble reactive P concentrations.

Lake Paranoá, Brasília, Brazil: Integrated Management Plan for its Restoration

1992 ◽  
Vol 27 (2) ◽  
pp. 271-286 ◽  
Author(s):  
Sonia Paulino Mattos ◽  
Irene Guimarães Altafin ◽  
Hélio José de Freitas ◽  
Cristine Gobbato Brandão Cavalcanti ◽  
Vera Regina Estuqui Alves
Keyword(s):  
Total Phosphorus ◽  
Drainage Basin ◽  
Integrated Management ◽  
Algal Growth ◽  
Nutrient Content ◽  
Management Plan ◽  
Cylindrospermopsis Raciborskii ◽  
Phosphorus Concentration ◽  
Limiting Factor ◽  
Total Phosphorus Concentration

Abstract Built in 1959, Lake Paranoá, in Brasilia, Brazil, has been undergoing an accelerated process of nutrient enrichment, due to inputs of inadequately treated raw sewage, generated by a population of 600,000 inhabitants. Consequently, it shows high nutrient content (40 µg/L of total phosphorus and 1800 µg/L of total nitrogen), low transparency (0.65 m) and high levels of chlorophyll a (65 µg/L), represented mainly by Cylindrospermopsis raciborskii and sporadic bloom of Microcystis aeruginosa, which is being combatted with copper sulphate. With the absence of seasonality and a vertical distribution which is not very evident, the horizontal pattern assumes great importance in this reservoir, in which five compartments stand out. Based on this segmentation and on the identification of the total phosphorus parameter as the limiting factor for algal growth, mathematical models were developed which demonstrate the need for advanced treatment of all the sewage produced in its drainage basin. With this, it is expected that a process of restoration will be initiated, with a decline in total phosphorus concentration to readings below 25 µg/L. Additional measures are proposed to accelerate this process.

scholarly journals Phytase-Producing Rahnella aquatilis JZ-GX1 Promotes Seed Germination and Growth in Corn (Zea mays L.)

2021 ◽  
Vol 9 (8) ◽  
pp. 1647
Author(s):  
Gui-E Li ◽  
Wei-Liang Kong ◽  
Xiao-Qin Wu ◽  
Shi-Bo Ma
Keyword(s):  
Seed Germination ◽  
Plant Growth ◽  
Biomass Accumulation ◽  
Root Surface ◽  
Phosphorus Concentration ◽  
Maize Seedlings ◽  
Total Phosphorus Concentration ◽  
Rahnella Aquatilis ◽  
Maize Seeds

Phytase plays an important role in crop seed germination and plant growth. In order to fully understand the plant growth-promoting mechanism by Rahnella aquatilis JZ-GX1，the effect of this strain on germination of maize seeds was determined in vitro, and the colonization of maize root by R. aquatilis JZ-GX1 was observed by scanning electron microscope. Different inoculum concentrations and Phytate-related soil properties were applied to investigate the effect of R. aquatilis JZ-GX1 on the growth of maize seedlings. The results showed that R. aquatilis JZ-GX1 could effectively secrete indole acetic acid and had significantly promoted seed germination and root length of maize. A large number of R. aquatilis JZ-GX1 cells colonized on the root surface, root hair and the root interior of maize. When the inoculation concentration was 107 cfu/mL and the insoluble organophosphorus compound phytate existed in the soil, the net photosynthetic rate, chlorophyll content, phytase activity secreted by roots, total phosphorus concentration and biomass accumulation of maize seedlings were the highest. In contrast, no significant effect of inoculation was found when the total P content was low or when inorganic P was sufficient in the soil. R. aquatilis JZ-GX1 promotes the growth of maize directly by secreting IAA and indirectly by secreting phytase. This work provides beneficial information for the development and application of R. aquatilis JZ-GX1 as a microbial fertilizer in the future.

Phosphorus and land-use changes are significant drivers of cladoceran community composition and diversity: an analysis over spatial and temporal scales

2010 ◽  
Vol 67 (8) ◽  
pp. 1262-1273 ◽  
Author(s):  
Marc Richard Albert ◽  
Guangjie Chen ◽  
Graham K. MacDonald ◽  
Jesse C. Vermaire ◽  
Elena M. Bennett ◽  
...  
Keyword(s):  
Land Use ◽  
Community Composition ◽  
Time Series Data ◽  
Temporal Analysis ◽  
Phosphorus Loading ◽  
Series Data ◽  
Phosphorus Concentration ◽  
Total Phosphorus Concentration ◽  
Watershed Disturbance ◽  
Subfossil Cladoceran

We conducted paleolimnological studies over spatial and temporal gradients to define the responses of subfossil cladoceran community composition and diversity to changes in land use and phosphorus concentrations in shallow lakes. We predicted that watershed disturbance by humans, through its impact on water quality, would explain significant variation in cladoceran diversity and composition. Across lakes, water-column total phosphorus concentration was a significant (p < 0.05) predictor of the subfossil cladoceran community composition. Chydorid diversity was also found to be related significantly to phosphorus concentration (r = –0.55, p < 0.05) and the proportion of disturbed land in the watershed (r = –0.47, p < 0.05). However, net load of phosphorus to the watershed rather than proportion of watershed disturbance was a significant predictor of chydorid diversity (r = –0.86, p < 0.001) in our temporal analysis of an eutrophying lake. Given that phosphorus loading to surface waters is often related to phosphorus concentrations in soils, we suggest that the net phosphorus load to the watershed is a more sensitive metric of land-use change and necessary for detecting ecological responses in time series data.

Total nitrogen concentration in leaves of potatoes (Solanum tuberosumL.) as an index of nutritional status

1976 ◽  
Vol 87 (2) ◽  
pp. 293-296 ◽  
Author(s):  
A. Gupta ◽  
M. C. Saxena
Keyword(s):  
Total Nitrogen ◽  
Tuber Yield ◽  
Critical Concentration ◽  
Nitrogen Concentration ◽  
Curvilinear Relationship ◽  
N Application ◽  
Total N ◽  
Potato Plants ◽  
N Concentration ◽  
Total Nitrogen Concentration

SummaryLeaf samples were collected, at weekly intervals, throughout the growing season, from potato (Solanum tuberosumL.) plants supplied with varying amounts of nitrogen (0, 60, 120, 180 and 240 kg N/ha) and analysed for total N. Application of nitrogen increased the N concentration in the green leaves at all stages of growth. There was a significant curvilinear relationship between the final tuber yield and the total N concentration in the leaves at 48–90 days after planting in 1968–9 and at 79–107 days after planting in 1969–70. The N concentration at 70–90 days after planting was consistently related to the final tuber yield in both years. Thus this period was ideal for assessing the nitrogen status of potato plants. The critical concentration of total nitrogen generally decreased with advance in age. It ranged from 4·65% at 76 days to 3·30% at 90 days during 1968–9, whereas in 1969–70 it ranged from 4·20% at 79 days to 3·80% at 93 days. During the period from 83 to 86 days the critical percentage was around 3·6% in both the years.

Forest harvest impacts on water quality and aquatic biota on the Boreal Plain: introduction to the TROLS lake program

2001 ◽  
Vol 58 (2) ◽  
pp. 421-436 ◽  
Author(s):  
E E Prepas ◽  
B Pinel-Alloul ◽  
D Planas ◽  
G Méthot ◽  
S Paquet ◽  
...  
Keyword(s):  
Total Phosphorus ◽  
Drainage Basin ◽  
Zooplankton Biomass ◽  
Phosphorus Concentration ◽  
Zooplankton Abundance ◽  
Total Phosphorus Concentration ◽  
Buffer Strip ◽  
Stratified Lakes ◽  
Lake Volume ◽  
Order Of Magnitude

Eleven headwater lakes in Alberta's Boreal Plain were monitored for nutrients and plankton 2 years before and 2 years after variable watershed harvesting (harvesting mean 15%, range 0-35%). After harvesting, variations in annual precipitation resulted in lake water residence times that differed by an order of magnitude from one year to the next. During the first posttreatment year, total phosphorus concentrations increased (overall 40%) in most lakes; however, response was most consistent in lakes that were shallow and the water column mixed or weakly thermally stratified. Chlorophyll a, cyanobacteria (Aphanizomenon-Anabaena), and cyanotoxins (microcystin-LR) increased after harvesting, primarily in shallow lakes. Zooplankton abundance and biomass decreased after harvesting, particularly in stratified lakes where edible phytoplankton biomass declined. In the weakly or nonstratified lakes, declines in zooplankton biomass were associated with higher cyanobacterial biomass and cyanotoxins. Posttreatment change in total phosphorus concentration was strongly related to weather (greatest response in a wet year) and relative drainage basin size (drainage basin area to lake volume, r2 = 0,78, P << 0,01). There was no evidence that buffer strip width (20, 100, and 200 m) influenced lake response. These results suggest that activities within the entire watershed should be the focus of catchment-lake interactions.

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