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

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.

2001 ◽  
Vol 58 (2) ◽  
pp. 421-436 ◽  
Author(s):  
E E Prepas ◽  
B Pinel-Alloul ◽  
D Planas ◽  
G Méthot ◽  
S Paquet ◽  
...  

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.


1982 ◽  
Vol 14 (4-5) ◽  
pp. 397-406 ◽  
Author(s):  
H Bernhardt ◽  
J Clasen

The elimination of the phosphorus compounds from the River Wahnbach (100 - 150 µg/l Ptot) at the point where it flows into the Wahnbach Reservoir down to a figure of 5 µg/l Ptot has decreased the total phosphorus concentration in the Wahnbach Reservoir to 8 - 10 µg/l Ptot. As a result of this, the impoundment which had been in an eutrophic state became oligotrophic to mesotrophic within 3 years. The blue-green algae which had been predominant disappeared and diatoms grow again every spring. Algal growth has been reduced to such an extent that the transparency has gone up to a Secchi-depth of 10 m and was 6 m on an annual average. This was solely produced by eliminating phosphorus and without eliminating nitrogen at the same time (the annual average N-concentration of all tributaries was 5 mg/l).


1989 ◽  
Vol 21 (2) ◽  
pp. 111-118 ◽  
Author(s):  
A. H. Arthington ◽  
G. J. Miller ◽  
P. M. Outridge

The water quality and trophic status of two Queensland dune lakes are compared in the context of assessing the impacts of recreational use and other human activities. Lake Freshwater, Cooloola, has a mean total phosphorus concentration of 12.1 ± 3.3 µg l−1 and is approaching mesotrophic status, whereas Blue Lagoon, Moreton Island, is oligotrophic. Natural loadings of total phosphorus, ranging from 0.2 to 0.35 g m−2 yr−1, are consistent with the progression of Lake Freshwater from oligotrophic to mesotrophic status. The phosphorus loadings predicted by Vollenweider's (1976) one-compartment model, for two values of mean lake depth, also indicate that Lake Freshwater is tending towards eutrophic conditions. The management implications of phosphorus loadings and budgets are discussed.


2019 ◽  
Vol 19 (5) ◽  
pp. 1500-1506 ◽  
Author(s):  
I. Melendez-Pastor ◽  
E. M. Isenstein ◽  
J. Navarro-Pedreño ◽  
M-H. Park

Abstract Cyanobacteria bloom events have been associated with eutrophication processes, along with hydrologic and climate factors. Missisquoi Bay is a portion of Lake Champlain (USA–Canada) that is highly eutrophic and prone to cyanobacteria blooms and cyanotoxins. This study assessed the spatial–temporal influence of nutrients, turbidity and temperature in cyanobacteria distributions during a bloom event in the summer of 2006. Correlations, generalized linear models (GLMs), geostatistics and local indications of spatial association (LISA) autocorrelation analysis tested the influence of nutrient and non-nutrient explanatory variables in cyanobacteria biovolume. Total phosphorus exhibited a high direct correlation with cyanobacteria biovolume. The best performing GLMs included total phosphorus, total nitrogen, Secchi depth (as turbidity) and temperature as explanatory variables of cyanobacteria biovolume. Variogram analysis of those variables resulted in a better understanding of the underlying spatial variation process of the cyanobacteria bloom event. The LISA test revealed a moderate but stable autocorrelation between cyanobacteria biovolume and total phosphorus from 180 to 1,000 m of weight distance, suggesting the possibility of up-scaling the current results to coarse-resolution satellite imagery for more frequent monitoring of bloom events. The LISA test also revealed the spatial–temporal dynamic (movement of cyanobacteria scums) of high cyanobacteria blooms with high total phosphorus concentration.


1989 ◽  
Vol 29 (3) ◽  
pp. 433 ◽  
Author(s):  
NA Maier ◽  
KA Potocky-Pacay ◽  
CMJ Williams

We studied the effect of rate of applied phosphorus on total phosphorus concentration (17 sites) and acetic acid soluble phosphorus concentration (12 sites) in petioles of youngest fully expanded leaves of potatoes (cvv. Kennebec, Coliban and Exton) when their largest tubers were 5-10 mm long. We showed that the internal requirements for phosphorus are similar for the cvv. Kennebec and Coliban. Taken over all sites, mean total phosphorus concentrations and acetic acid soluble phosphorus concentrations ranged from 0.22 to 0.84% and 0.10 to 0.63%, respectively depending on phosphorus supply. For each site a coefficient of determination (r2) was calculated based on the mean total phosphorus concentration versus acetic acid soluble phosphorus concentration data for all treatments. The r2 values varied from 0.969 (site 14) to 0.997 (site 17). On the pooled data for all sites, the Cate-Nelson separation and the Mitscherlich and Smith-Dolby bent-hyperbola models were used to investigate the correlations between relative yield [(mean treatment yields/maximum treatment yie1d)x 100] and total phosphorus concentration (n = 16 1, 17 sites) and acetic acid soluble phosphorus concentration (n = 112, 12 sites) and to calculate the critical values. Depending on the model fitted the critical total phosphorus concentrations varied from 0.41 (r2 = 0.62) to 0.53% (r2 = 0.72). The critical acetic acid soluble phosphorus concentrations varied from 0.29 (r2 = 0.62) to 0.52% (r2 = 0.72). Critical concentration ranges of 0.41-0-53% for total phosphorus and 0.29-0.52% for acetic acid soluble phosphorus have been proposed to assist in the assessment of the phosphorus status of irrigated potato crops in South Australia. Based on sensitivity, reproducibility and sharpness of the transition zone between adequacy and deficiency we found no advantage in determining acetic acid soluble phosphorus concentration rather than total phosphorus concentration to assess the phosphorus status of potato plants.


2020 ◽  
Vol 41 (20) ◽  
pp. 7993-8013
Author(s):  
Chenggong Du ◽  
Yunmei Li ◽  
Heng Lyu ◽  
Naisen Liu ◽  
Zhubin Zheng ◽  
...  

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