Identification of Critical Nutrient Levels through Field Verification of Models for Phosphorus and Phytoplankton Growth

1986 ◽  
Vol 43 (2) ◽  
pp. 379-388 ◽  
Author(s):  
Martin T. Auer ◽  
Mark S. Kieser ◽  
Raymond P. Canale

Two models for phosphorus and phytoplankton growth were field verified along a marked gradient in trophic conditions in Green Bay (Lake Michigan): one, the Monod model, relates growth rate to external (dissolved) phosphorus concentration, and the other, the Droop model, describes growth rate as a function of internal (stored) phosphorus levels. The verification provided through a satisfactory fit of model output to field measurements of phosphorus and gross photosynthesis established a conceptual foundation for empirical models relating phosphorus and trophic state parameters. Phosphorus concentrations corresponding to boundary conditions for trophic state categories were developed based on the verified models by defining oligotrophy as the region of linear response by growth rate to increases in phosphorus (<1.2 μg soluble reactive phosphorus (SRP)∙L−1, <11.5 μg total phosphorus (TP)∙L−1), mesotrophy as the transitional state (1.2–8.0 μg SRP∙L−1, 11.5–37.5 μg TP∙L−1), and eutrophy as the region where growth rate is saturated, i.e. insensitive to changes in phosphorus concentration (>8.0 μg SRP∙L−1, >37.5 μg TP∙L−1). We applied the trophic state classification scheme to several Great Lakes basins to examine their sensitivity to changes in phosphorus levels. The oligotrophic waters of Lakes Superior, Huron, and Michigan and northern Green Bay and Georgian Bay have the greatest sensitivity to increases in total phosphorus concentration. The eutrophic waters of southern Green Bay, western Lake Erie, and nearshore Lake Ontario are nutrient saturated and relatively insensitive to initial reductions in phosphorus levels. Offshore Lake Ontario, eastern and central Lake Erie, Saginaw Bay, and mid Green Bay lie in the transitional phase for sensitivity to phosphorus management.

1986 ◽  
Vol 43 (4) ◽  
pp. 788-796 ◽  
Author(s):  
N. D. Yan

A comparison of the predictive power of nine existing empirical zooplankton biomass models indicated that lake water phosphorus concentration may be a better predictor of zooplankton biomass in Canadian Shield lakes than phytoplankton biomass, chlorophyll a, midsummer epilimnetic temperature, mean surface water temperature, mean depth, and Carlson's trophic state index. To develop models specifically applicable to nutrient-poor Canadian Shield lakes, a variety of morphometric, chemical, and planktonic parameters were assessed for three consecutive years from 16 Canadian Shield lakes in south-central Ontario. Total nitrogen was the best univariate predictor of zooplankton biomass for data averaged over single ice-free seasons, but total phosphorus was the best predictor when data were averaged over the entire study period. Consideration of pH and maximum depth improved certain models. Total phosphorus is clearly a good predictor of (long-term) average zooplankton biomass in nutrient-poor lakes as it is in lakes exhibiting a wide range in trophic state.


1976 ◽  
Vol 33 (3) ◽  
pp. 520-536 ◽  
Author(s):  
N. M. Burns

Budgets for the quantities of water, chloride, and phosphorus entering and leaving Lake Erie during the year of 1970 have been developed. The phosphorus budget was broken down into basin budgets which were further subdivided into epilimnion budgets for the Central and Eastern basins. Epilimnion budgets for soluble inorganic nitrogen (SIN) and soluble reactive silica (SRS) were also developed. The average coefficients of elimination by sedimentation of the phosphorus within each basin were 4.0, 0.38, and 0.18%/day for the Western, Central, and Eastern basins, respectively. The phosphorus elimination was found to be inversely related to mean basin depth but directly related to the phosphorus concentration of the water. The epilimnion budgets showed that during the summer the internal loading of SRS to the epilimnion was greater than the uptake of SRS by phytoplankton growth. The epilimnion budget of SIN demonstrated a massive uptake of the material during the summer, which was only partially replenished. The loss rate of phosphorus from the Central and Eastern basin epilimnia decreased as the summer progressed, to the extent that there was a net gain of phosphorus in the Eastern basin epilimnion toward the end of the summer. It is believed that this resulted from significant upward transport of phosphorus from the hypolimnion to the epilimnion by flagellate species of phytoplankton.


1994 ◽  
Vol 30 (2) ◽  
pp. 73-80 ◽  
Author(s):  
Yu-Ming Wang ◽  
Ming-Chun Wu ◽  
Jan-Tai Kuo

This paper describes the development and application of uncertainty analysis to evaluate the risk of eutrophication for Te-Chi Reservoir, Taiwan. Two methods, probabilistic model and first-order analysis of uncertainty (FOAU), were used to quantify the expected variability of the total phosphorus concentration in the reservoir. Based on the load-resistance analysis, these two methods were applied and compared to calculate the risk of eutrophication for Te-Chi Reservoir. An approach is also proposed herein to evaluate the trophic state in the future. Since the trophic state for Te-Chi Reservoir is strongly dependent on hydrologic conditions, incorporating an annual ARM A inflow model with the empirical total phosphorus model developed in previous work, the trophic state in the future was investigated. The significant advantage of the proposed approach is that it provides a simplified and useful procedure to evaluate the risk of eutrophication for the reservoir in the future.


1995 ◽  
Vol 52 (6) ◽  
pp. 1202-1209 ◽  
Author(s):  
Ruth E. Holland ◽  
Thomas H. Johengen ◽  
Alfred M. Beeton

Concentrations of soluble reactive phosphorus, ammonium-nitrogen, nitrate-nitrogen, silica, and chloride have all increased since the establishment of the zebra mussel (Dreissena polymorpha) in Hatchery Bay, western Lake Erie, in 1988. Total phosphorus concentrations have changed little. These results are from 188 samples collected weekly and year round before the establishment of Dreissena (1984–1987) and 192 samples post-Dreissena (1990–1993). The mean annual total phosphorus concentration for the three complete post-Dreissena years was 35 μg∙L−1 strikingly similar to the concentration of 36 μg∙L−1, which in 1959 helped to define the waters of Lake Erie as eutrophic. The relative steadiness in total phosphorus may reflect sediment reflux, because Hatchery Bay is a polymictic system. The slight increase in the biologically conservative ion, chloride, in the 1990s, is probably due to the increased precipitation and runoff in the western Lake Erie watershed. Decreased phytoplankton and associated increased water clarity caused by efficient filtering by D. polymorpha, have lessened symptoms of eutrophication and produced a situation where nutrients are not fully utilized, i.e., biological oligotrophy.


1981 ◽  
Vol 38 (11) ◽  
pp. 1421-1427 ◽  
Author(s):  
Ralph E. H. Smith ◽  
Jaap Kalff

The inducible enzyme alkaline phosphatase (APA) was used to quantify phosphorus limitation of freshwater phytoplankton growth in situ. Natural phytoplankton communities from oligotrophic–eutrophic Lake Memphremagog were grown at phosphorus-limited rates of 0.06–0.93 per day in continuous, lake water cultures. APA varied inversely with phosphorus-limited growth rate and was little influenced by the community composition changes that occurred in culture. Compared to cultures, average in situ APA in Lake Memphremagog during the ice-free season was low, and suggested phosphorus-limited growth rates greater than 0.6 per day in even the most oligotrophic parts of the lake. Although algal abundance varies with total phosphorus among most north-temperate zone lakes, including Lake Memphremagog, our data show that average community growth rates are normally high and change relatively little over a fourfold range of total phosphorus concentration.Key words: alkaline phosphatase, phytoplankton, growth rate, phosphorus


2017 ◽  
Vol 19 (2) ◽  
pp. 113
Author(s):  
Kusuma Wardani Laksitaningrum ◽  
Wirastuti Widyatmanti

<p align="center"><strong>ABSTRAK</strong></p><p class="abstrak">Waduk Gajah Mungkur (WGM) adalah bendungan buatan yang memiliki luas genangan maksimum 8800 ha, terletak di Desa Pokoh Kidul, Kecamatan Wonogiri, Kabupaten Wonogiri. Kondisi perairan WGM dipengaruhi oleh faktor klimatologis, fisik, dan aktivitas manusia yang dapat menyumbang nutrisi sehingga mempengaruhi status trofiknya. Tujuan dari penelitian ini adalah mengkaji kemampuan citra Landsat 8 OLI untuk memperoleh parameter-parameter yang digunakan untuk menilai status trofik, menentukan dan memetakan status trofik yang diperoleh dari citra Landsat 8 OLI, dan mengevaluasi hasil pemetaan dan manfaat citra penginderaan jauh untuk identifikasi status trofik WGM. Identifikasi status trofik dilakukan berdasarkan metode <em>Trophic State Index</em> (TSI) Carlson (1997) menggunakan tiga parameter yaitu kejernihan air, total fosfor, dan klorofil-a. Model yang diperoleh berdasar pada rumus empiris dari hasil uji regresi antara pengukuran di lapangan dan nilai piksel di citra Landsat 8 OLI. Model dipilih berdasarkan nilai koefisien determinasi (R<sup>2</sup>) tertinggi. Hasil penelitian merepresentasikan bahwa nilai R<sup>2</sup> kejernihan air sebesar 0,813, total fosfor sebesar 0,268, dan klorofil-a sebesar 0,584. Apabila nilai R<sup>2 </sup>mendekati 1, maka semakin baik model regresi dapat menjelaskan suatu parameter status trofik. Berdasarkan hasil kalkulasi diperoleh distribusi yang terdiri dari kelas eutrofik ringan, eutrofik sedang, dan eutrofik berat yaitu pada rentang nilai indeks 50,051 – 80,180. Distribusi terbesar adalah eutrofik sedang. Hal tersebut menunjukkan tingkat kesuburan perairan yang tinggi dan dapat membahayakan makhluk hidup lain.</p><p><strong>Kata kunci: </strong>Waduk Gajah Mungkur, citra Landsat 8 OLI, regresi, TSI, status trofik</p><p class="judulABS"><strong>ABSTRACT</strong></p><p class="Abstrakeng">Gajah Mungkur Reservoir is an artificial dam that has a maximum inundated areas of 8800 ha, located in Pokoh Kidul Village, Wonogiri Regency. The reservoir’s water conditions are affected by climatological and physical factors, as well as human activities that can contribute to nutrients that affect its trophic state. This study aimed to assess the Landsat 8 OLI capabilities to obtain parameters that are used to determine its trophic state, identifying and mapping the trophic state based on parameters derived from Landsat 8 OLI, and evaluating the results of the mapping and the benefits of remote sensing imagery for identification of its trophic state. Identification of trophic state is based on Trophic State Index (TSI) Carlson (1997), which uses three parameters there are water clarity, total phosphorus, and chlorophyll-a. The model is based on an empirical formula of regression between measurements in the field and the pixel values in Landsat 8 OLI. Model is selected on the highest value towards coefficient of determination (R<sup>2</sup>). The results represented that R<sup>2</sup> of water clarity is 0.813, total phosphorus is 0.268, and chlorophyll-a is 0.584. If R<sup>2</sup> close to 1, regression model will describe the parameters of the trophic state better. Based on the calculation the distribution consists of mild eutrophic, moderate eutrophic, and heavy eutrophic that has index values from 50.051 to 80.18. The most distribution is moderate eutrophication, and it showed the high level of trophic state and may harm other living beings.</p><p><strong><em>Keywords: </em></strong><em>Gajah Mungkur Reservoir, </em><em>L</em><em>andsat 8 OLI satellite imagery, regression, TSI, trophic state</em></p>


1996 ◽  
Vol 31 (2) ◽  
pp. 411-432 ◽  
Author(s):  
Michael E. Comba ◽  
Janice L. Metcalfe-Smith ◽  
Klaus L.E. Kaiser

Abstract Zebra mussels were collected from 24 sites in Lake Erie, Lake Ontario and the St. Lawrence River between 1990 and 1992. Composite samples of whole mussels (15 sites) or soft tissues (9 sites) were analyzed for residues of organochlo-rine pesticides and PCBs to evaluate zebra mussels as biomonitors for organic contaminants. Mussels from most sites contained measurable quantities of most of the analytes. Mean concentrations were (in ng/g, whole mussel dry weight basis) 154 ΣPCB, 8.4 ΣDDT, 3.5 Σchlordane, 3.4 Σaldrin, 1.4 ΣBHC, 1.0 Σendosulfan, 0.80 mirex and 0.40 Σchlorobenzene. Concentrations varied greatly between sites, i.e., from 22 to 497 ng/g for ΣPCB and from 0.08 to 11.6 ng/g for ΣBHC, an indication that mussels are sensitive to different levels of contamination. Levels of ΣPCB and Σendosulfan were highest in mussels from the St. Lawrence River, whereas mirex was highest in those from Lake Ontario. Overall, mussels from Lake Erie were the least contaminated. These observations agree well with the spatial contaminant trends shown by other biomoni-toring programs. PCB congener class profiles in zebra mussels are also typical for nearby industrial sources, e.g., mussels below an aluminum casting plant contained 55% di-, tri- and tetrachlorobiphenyls versus 31% in those upstream. We propose the use of zebra mussels as biomonitors of organic contamination in the Great Lakes.


1995 ◽  
Vol 30 (4) ◽  
pp. 565-592 ◽  
Author(s):  
A.F. Gemza

Abstract Severn Sound continues to exhibit signs of eutrophication despite initial identification of the problem in 1969 and the construction of several sewage treatment plants since then. In general, improvements in trophic state indicators have been marginal, suggesting that the sewage treatment plants have had limited success in controlling phosphorus concentrations. These discharges likely contributed to the increased total phosphorus levels and consequently the higher phytoplankton densities of the nearshore waters. Phytoplankton biovolumes were on average one order of magnitude higher than in the open waters of Lake Huron with mean summer biovolumes as high as 8.0 mm/L. Algal biovolumes were most dense in Penetang Bay, which experienced limited exchange with the main waters of the sound. No significant long-term trends were observed. Water clarity was declining significantly, however, at a rate of -0.60 to -0.78 m/year throughout the sound except in Sturgeon Bay. Total phosphorus levels were highly variable from year to year; however, concentrations from a 20-year perspective were declining in the open waters at a rate of 0.70 µg/L/year, but response was limited in nearshore areas. In Sturgeon Bay, mean annual euphotic zone total phosphorus as well as soluble reactive phosphorus levels declined by as much as 50% following the construction of a sewage treatment plant with tertiary treatment. Phytoplankton genera typical of eutrophic waters continued to dominate the algal assemblage but members indicative of mesotrophic conditions have become apparent in some areas of the sound.


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.


1998 ◽  
Vol 37 (2) ◽  
pp. 177-185 ◽  
Author(s):  
Hany Hassan ◽  
Keisuke Hanaki ◽  
Tomonori Matsuo

Global climate change induced by increased concentrations of greenhouse gases (especially CO2) is expected to include changes in precipitation, wind speed, incoming solar radiation, and air temperature. These major climate variables directly influence water quality in lakes by altering changes in flow and water temperature balance. High concentration of nutrient enrichment and expected variability of climate can lead to periodic phytoplankton blooms and an alteration of the neutral trophic balance. As a result, dissolved oxygen levels, with low concentrations, can fluctuate widely and algal productivity may reach critical levels. In this work, we will present: 1) recent results of GCMs climate scenarios downscaling project that was held at the University of Derby, UK.; 2) current/future comparative results of a new mathematical lake eutrophication model (LEM) in which output of phytoplankton growth rate and dissolved oxygen will be presented for Suwa lake in Japan as a case study. The model parameters were calibrated for the period of 1973–1983 and validated for the period of 1983–1993. Meterologic, hydrologic, and lake water quality data of 1990 were selected for the assessment analysis. Statistical relationships between seven daily meteorological time series and three airflow indices were used as a means for downscaling daily outputs of Hadley Centre Climate Model (HadCM2SUL) to the station sub-grid scale.


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