Strategy for Phosphorus Control from Estimated Phosphorus Loads and Predicted Total Phosphorus Concentration in Penetang Bay, Georgian Bay, 1973 to 1992

1995 ◽  
Vol 30 (4) ◽  
pp. 619-634
Author(s):  
R. Keith Sherman ◽  
Sharon L. Brown

Abstract Cultural eutrophication has affected Penetang Bay, in southeastern Georgian Bay, since the 1960s. External sources of phosphorus were estimated and open water total phosphorus concentration was predicted in order to establish a rationale for an effective source control strategy for the bay. Seasonal loadings are greatest in the spring due mainly to the watershed sources, with 33-58% of the total annual load entering during the March to May period. Apart from this period, the two sewage plant effluent discharges are the largest sources of phosphorus loading to the bay. On an annual basis, the largest source of phosphorus to the bay is from treated sewage effluent (60%), followed by watershed, shoreline development and urban storm water, respectively. More than 80% of the estimated total annual loads was from sewage effluent, watershed and urban storm sources alone. These sources were estimated annually for the historical period of record (1973-1992). The trophic model predicted the long-term average total phosphorus concentration ([TP]) reasonably well. Predictions of [TP]Bay for individual years were within 1-49% of the measured [TP]Bay. The model predicted [TP]Bay to within 20% of measured values for 14 of the 20 years of record. The model as applied to Penetang Bay is sensitive to changes in sewage plant effluent loading and watershed loading. Model predictions indicate that significant reductions in open water [TP] can be expected following implementation of proposed source control actions. Total loading of phosphorus to the Bay of less than 1,000 kg/year should result in open water [TP]Bay of less than 15 µg/L.

1974 ◽  
Vol 31 (11) ◽  
pp. 1771-1778 ◽  
Author(s):  
P. J. Dillon ◽  
F. H. Rigler

The total phosphorus budgets for a number of lakes in the Haliburton–Kawartha region of southern Ontario were measured over a 20-mo period. These data, combined with the lakes' morphometry and water budgets, were used to test a simple nutrient budget model similar to that proposed by Vollenweider (1969) purporting to predict the total phosphorus concentration in lakes. Except in the case of two very shallow lakes [Formula: see text], the concentrations predicted by the model were very close to those measured in the lakes at spring overturn. Additional data from the literature supported the belief that this model could be used effectively for oligotrophic and mesotrophic lakes. Its value lies in the fact that quantitative changes in phosphorus loading can be interpreted in terms of changes in phosphorus concentration, which in turn, can be related to changes in parameters that reflect the lake's trophic state such as summer chlorophyll a concentration.


1981 ◽  
Vol 38 (4) ◽  
pp. 414-423 ◽  
Author(s):  
Daniel E. Canfield Jr. ◽  
Roger W. Bachmann

A model for the prediction of total phosphorus was developed and tested using data on 704 nautral and artificial lakes including 626 lakes in the U.S. Environmental Protection Agency (EPA) National Eutrophication Survey. A statistical analysis showed that the best estimate for the sedimentation coefficient (σ) in the Vollenweider equation was[Formula: see text]for artificial lakes where L is the areal phosphorus loading rate (mg∙m−2∙yr−1) and z is the mean depth (m). The model yields unbiased estimates of phosphorus concentrations over a wide range of lake types and has a 95% confidence interval of 31–288% of the calculated total phosphorus concentration. Other models are less precise. Though total phosphorus concentrations can be predicted equally well in natural and artificial lakes, predictions of algal densities and water transparency are less reliable in artificial lakes, as the phosphorus–chlorophyll and chlorophyll–Secchi depth relationships are less precise. This seems to be due to the influence of nonalgal particulate materials.Key words: phosphorus models, eutrophication, lake trophic state


1985 ◽  
Vol 36 (2) ◽  
pp. 157 ◽  
Author(s):  
JM Ferris ◽  
PA Tyler

Linear regression of chlorophyll concentration on total phosphorus concentration for phosphorus- limited Lake Burragorang, N.S.W., yields regression coefficients within the range reported for individual lakes in the Northern Hemisphere. Some variation in slope of published regressions is attributable to the choice of different regression subvariables (e.g. annual mean or annual maximum). The extent of this variation is quantified. Data from Lake Burragorang and other sites indicate that chlorophyll-phosphorus relationships in the Southern Hemisphere are concordant with those in the north if turbid waters are excluded from consideration. This is obviously significant in Australia, with so many turbid waters. The notion of 'growing season', as applied to Northern Hemisphere studies, is inappropriate for the warm temperate conditions of Lake Burragorang, and it was necessary instead to use the annual maximum chlorophyll concentration. Prediction of annual maximum chlorophyll concentration is of particular significance to water-quality management. Despite highly significant regressions, 95% confidence intervals and 95% prediction limits are wide, so that prediction of chlorophyll concentration from single values of total phosphorus, using double-In regressions, gives a wide arithmetic range. Use of annual mean total phosphorus concentration as the predictor variable limits the forecasting ability of the Lake Burragorang regressions but facilitates future coupling with a phosphorus loading model. This would assist in the assessment of projected management plans and the formulation of protective loading criteria.


2007 ◽  
Vol 64 (11) ◽  
pp. 1529-1542 ◽  
Author(s):  
Erwin E Van Nieuwenhuyse

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.


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.


2010 ◽  
Vol 67 (8) ◽  
pp. 1262-1273 ◽  
Author(s):  
Marc Richard Albert ◽  
Guangjie Chen ◽  
Graham K. MacDonald ◽  
Jesse C. Vermaire ◽  
Elena M. Bennett ◽  
...  

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.


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.


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.


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