Contribution of Particulate Phosphorus (> 250 μm) to the Total Phosphorus Pool in Lake Water

1984 ◽  
Vol 41 (2) ◽  
pp. 351-363 ◽  
Author(s):  
E. E. Prepas ◽  
J. Vickery

Particulate phosphorus (PP) > 250 μm was concentrated in the euphotic zone of 17 lakes in central Alberta. When the euphotic zone extended below the epilimnion, PP >250 μm was concentrated deep in the euphotic zone. PP > 250 μm was a significant but variable portion of the total phosphorus (TP) pool in individual lakes; thus, samples should be collected from the euphotic zone on several dates to estimate the contribution of PP > 250 μm to the TP pool. As well, the contribution of this fraction varied among lakes: average summer values for the euphotic zone ranged from 3 to 19%. Among lakes, the contribution of large particles to the TP pool decreased proportionally as lake productivity (estimated by chlorophyll a (Chl a)) increased. The relative contribution of PP > 250 μm in summer accounted for a significant portion of the residual variation in the spring TP-summer Chl a relationship but not the summer TP-summer Chl a relationship in the study lakes. These apparently contradictory results can be explained by differences between lakes that mixed intermittently throughout the summer and those that remained permanently thermally stratified during this time.

1985 ◽  
Vol 42 (2) ◽  
pp. 239-249 ◽  
Author(s):  
J. Babin ◽  
E. E. Prepas

Winter oxygen depletion rates (WODR) (g O2∙m−2∙d−1) were determined for 13 lakes in central Alberta during the winter of 1982–83. Although dissolved oxygen decreased in all lakes for the first 3.5 mo after freeze-up, the decreases were nonlinear. The highest WODR were observed just after freeze-up. The nonlinear WODR were significantly correlated with two estimates of lake productivity (i.e. total phosphorus and chlorophyll a, P < 0.05) but were not significantly correlated with morphometry (e.g. mean depth). When the WODR from the Albertan lakes were treated as linear, to enable a comparison with other studies, correlations were found between WODR and morphometry, and WODR and estimates of summer productivity. These relationships were significantly different from observations by previous investigators who worked on ice-covered lakes in two other regions. When data from other ice-covered lakes were combined with this study, WODR were best predicted from a combination of mean summer TP (TPsu in mg∙m−2) in the euphotic zone and mean depth ([Formula: see text] in m):[Formula: see text]The above equation permits the prediction of WODR for a greater range of lake types than previous models.


2014 ◽  
Vol 26 (4) ◽  
pp. 442-456 ◽  
Author(s):  
Rodrigo da Rocha Andrade ◽  
Danilo Giroldo

AIM: to provide a long-term limnological characterisation of a subtropical shallow lake in addition to verifying seasonal differences, including phytoplankton variation. METHODS: monthly sampling at sites IP, SJ and MD from 2000 to 2009 to analyse temperature - T; depth - Z; the depth of the euphotic zone - Zeu; Zeu/Z (%); total suspended solids - TSS; dissolved oxygen - DO; pH; electrical conductivity - EC; N-NH3, N-NO2, N-NO3; soluble reactive phosphorus - SRP; chlorophyll a - Chl-a and phytoplankton. RESULTS: low values of Z and Zeu characterised the shallow and turbid conditions of lake and corresponded to the contribution of nano-microflagellates (Chlamydomonas sp., Spermatozopsis sp., Cryptomonas sp. and Rhodomonas sp ) and diatoms (Aulacoseira granulata). Zeu/Z (%), SRP and Chl-a were significantly different at site IP (meso-eutrophic) compared to sites SJ and MD (eutrophic). Phytoplankton density was also significantly higher at sites SJ and MD, and the largest relative contribution of Actinastrum sp., Dictyosphaerium sp., Micractinium sp., Monoraphidium sp., Scenedesmus/Desmodesmus sp. and Euglena sp. corresponded to the most polluted waters at site SJ. The significantly higher T (ºC) in summer corresponded to significantly higher Chl-a as well as a greater richness and density of phytoplankton. Cocconeis sp., Gomphonema sp. and Pinnularia sp. (pennated diatoms) were negatively correlated with temperature and were therefore more representative at the three sites in winter. Asterionella formosa was correlated with SRP and vernal blooms were recorded (2000-2001). Planktothrix isothrix and Planktothricoides raciborskii were expressive in the summer/late summer (2004-2005), and were significantly correlated with Chl-a and low SRP in water column. CONCLUSIONS: The study corroborated the sensitivity of phytoplankton in characterising different stages of eutrophication at different sites and corresponding watersheds as well as in characterising different seasons in a shallow lake in the subtropical zone of Brazil.


1980 ◽  
Vol 37 (1) ◽  
pp. 111-114 ◽  
Author(s):  
Martin Bergmann ◽  
Robert Henry Peters

This paper describes a new method to measure total sestonic pigment based on the reduction in the amount of light reflected from a membrane filter after a given volume of lake water has passed through the filter. For a sample of 30 lakes, this index of "reflectance" gave a better regression on total phosphorus than did chlorophyll which suggests that part of the variation in published phosphorus–chlorophyll relationships results from the association of phosphorus with pigments other than chlorophyll. But the residual variation suggests both that the amount of pigment developed per unit of phosphorus varies among lakes and that the index does not completely represent the seston. Relationships between reflectance and concentration of chlorophyll, phosphorus, and seston are good enough to suggest that this rapid, easy analysis may find application as an adjunct to more traditional analyses whereever membrane filters are routinely used in the analysis of lake water.Key words: Total pigment analysis, seston, phosphorus–chlorophyll


2006 ◽  
Vol 63 (5) ◽  
pp. 1115-1129 ◽  
Author(s):  
David C Depew ◽  
Stephanie J Guildford ◽  
Ralph E.H Smith

Planktonic primary production, chlorophyll a (chl a), underwater light climate, and total phosphorus were measured at 18 stations during 2001 and 2002 in eastern Lake Erie to characterize spatial and seasonal patterns in this system colonized by dreissenid mussels (Dreissena spp.). Areal production rates and chl a displayed a seasonal pattern typical of the Laurentian Great Lakes, with highest production in the early and late summer. Daily and seasonal (May–October) primary production was significantly lower nearshore than offshore. Although light attenuation was similar between nearshore and offshore, the nearshore light climate was generally more favorable for phytoplankton because of shallower mixing depths. However, chl a was significantly lower nearshore, which accounted for most of the depression in production rates. Nearshore chl a was lower than predicted from relationships with total phosphorus in comparable dreissenid-free systems. Offshore, subepilimnetic communities contributed up to 67% of daily production but only up to 19% of seasonal production. The depression of chl a and primary production in the nearshore was a reversal from historic patterns in eastern Lake Erie and from the pattern traditionally expected in large lakes. Decreased external nutrient loading and dreissenid colonization may both have contributed to this new spatial pattern, but dreissenids appear to be key agents.


2008 ◽  
Vol 65 (12) ◽  
pp. 2644-2655 ◽  
Author(s):  
Amy M. Kamarainen ◽  
Freya E. Rowland ◽  
Reinette Biggs ◽  
Stephen R. Carpenter

Zooplankton grazing is important in resolving residual variation around the total phosphorus – chlorophyll a relationship. In empirical studies, zooplankton body size is often a better predictor of residual variation than zooplankton biomass. We investigate whether higher measurement error associated with zooplankton biomass may explain its lower predictive ability. We collected five replicate zooplankton biomass samples in 19 lakes, allowing us to quantify measurement error in volumetric zooplankton biomass with greater precision than in previous studies. A hierarchical Bayesian model was used to assess the predictive ability of volumetric zooplankton biomass and mean individual zooplankton length, corrected for measurement error. We found consistent effects of total zooplankton biomass, but not zooplankton length, on chlorophyll a. This finding does not appear to be related to the higher precision with which total zooplankton biomass was measured in our study, but rather to ecological factors. Interlake variation outweighed the effects of measurement error in estimating the strength of relationships between zooplankton variables and chlorophyll a. Our findings therefore suggest that studies to estimate zooplankton effects on phytoplankton should allocate resources to study a larger range of lakes over different time periods than to process replicate samples to reduce measurement error.


1987 ◽  
Vol 44 (4) ◽  
pp. 775-781 ◽  
Author(s):  
M. L. Ostrofsky ◽  
F. H. Rigler

Concentrations of total phosphorus and chlorophyll a were measured weekly in 49 lakes in the vicinity of Yellowknife, N.W.T., Canada, from May to September 1977. The relationship between [TPspr] and [Chl asu] was significantly different from the Dillon–Rigler model, but similar to relationships developed for lakes in Alberta, British Columbia, and the Yukon Territory. Empirical relationships were developed between [TPspr] and maximum chlorophyll a concentrations and the probability of exceeding critical concentrations of chlorophyll a. These models may be potentially more useful than models which predict only a mean summer chlorophyll concentration.


1978 ◽  
Vol 35 (3) ◽  
pp. 300-304 ◽  
Author(s):  
W. A. Scheider

Phosphorus and hydrological budgets were constructed for four small lakes with Precambrian drainage in Algonquin Park, Ontario. Lake outflow discharge ranged from 21.7 × 105 to 177 × 105 m3∙yr−1. Annual phosphorus input to the lakes from terrestrial drainage and precipitation totaled 36.3–188 kg∙yr−1. The lakes retained 16–41% of the annual input. These data were used to test a series of models that predict the spring total phosphorus concentration in lake water and the mean summer chlorophyll a. The predicted spring phosphorus concentration agreed well with measured values (within 1.3 mg∙m−3) except where human-associated phosphorus input may have contributed to the phosphorus budget of the lake. Agreement between predicted and measured chlorophyll a was not as close. A figure of 0.48 kg P∙capita−1∙yr−1 was calculated as the human-associated supply. Key words: phosphorus budget, chlorophyll a, predictive model, Precambrian lake


1985 ◽  
Vol 42 (4) ◽  
pp. 831-835 ◽  
Author(s):  
E. T. Riley ◽  
E. E. Prepas

Data from the literature were used to calculate separate regressions of summer chlorophyll a concentration ([Chl a]) on spring total phosphorus concentration ([TP]) for lakes that remain thermally stratified during the summer and lakes that mix intermittently during the summer. Significant differences were found in the spring [TP] – summer [Chl a] relationships for the two lake types (P < 0.05). The mean ratios of summer [TP] to spring [TP] were also significantly different in stratified and mixed lakes (P < 0.001); this difference is the explanation offered for why the spring [TP] – summer [Chl a] relationships were different in stratified and mixed lakes.


1988 ◽  
Vol 45 (5) ◽  
pp. 910-914 ◽  
Author(s):  
E. E. Prepas ◽  
M. E. Dunnigan ◽  
A. M. Trimbee

In response to the recent attention given to picoplankton, many researchers have switched from GF/C to GF/F glass-fiber filters for chlorophyll a (Chl a) analyses; GF/F filters have a smaller pore size and are more expensive than GF/C filters. In this study, Chl a was measured with both Whatman GF/F and GF/C glass-fiber filters on euphotic zone water from 28 mesotrophic to hypereutrophic lakes (Chl a ranged from 2 to 175 μg∙L−1) in central Alberta. The differences between paired Chl a estimates with the two grades of filter paper were remarkably small; there was no evidence that GF/F filters collected more Chl a than GF/C filters (P > 0.2). Hence there is no justification for switching from GF/C to GF/F filters for routine Chl a analyses on productive lakes.


2020 ◽  
Vol 12 (13) ◽  
pp. 2087 ◽  
Author(s):  
Vassiliki Markogianni ◽  
Dionissios Kalivas ◽  
George P. Petropoulos ◽  
Elias Dimitriou

Assessing chlorophyll-a (Chl-a) pigments in complex inland water systems is of key importance as this parameter constitutes a major ecosystem integrity indicator. In this study, a methodological framework is proposed for quantifying Chl-a pigments using Earth observation (EO) data from Landsat 7 Enhanced Thematic Mapper Plus (ETM+) and 8 Operational Land Imager (OLI) sensors. The first step of the methodology involves the implementation of stepwise multiple regression (MLR) analysis of the available Chl-a dataset. Then, principal component analysis (PCA) is performed to explore Greek lakes’ potential interrelationships based on their Chl-a values in conjunction with certain criteria: their characteristics (artificial/natural), typology, and climatic type. Additionally, parameters such as seasonal water sampling and the date difference between sampling and satellite overpass are taken into consideration. Next, is implemented a stepwise multiple regression analysis among different groups of cases, formed by the criteria indicated from the PCA itself. This effort aimed at exploring different remote sensing-derived Chl-a algorithms for various types of lakes. The practical use of the proposed approach was evaluated in a total of 50 lake water bodies (natural and artificial) from 2013–2018, constituting the National Lake Network Monitoring of Greece in the context of the Water Framework Directive (WFD). All in all, the results evidenced the suitability of Landsat data when used with the proposed technique to estimate log-transformed Chl-a. The proposed scheme resulted in the development of models separately for natural (R = 0.78; RMSE = 1.3 μg/L) and artificial lakes (R = 0.76; RMSE = 1.29 μg/L), while the model developed without criteria proved weaker (R = 0.65; RMSE = 1.85 μg/L) in comparison to the other ones examined. The methodological framework proposed herein can be used as a useful resource toward a continuous monitoring and assessment of lake water quality, supporting sustainable water resources management.


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