Comparison of an Ecological Model of Lake Ontario and Phosphorus Loading Models

1977 ◽  
Vol 34 (2) ◽  
pp. 286-290 ◽  
Author(s):  
Donald Scavia ◽  
Steven C. Chapra
Keyword(s):  
Chlorophyll A ◽  
Total Phosphorus ◽  
Ecological Model ◽  
Lake Ontario ◽  
Phosphorus Loading ◽  
Empirical Relationships ◽  
Annual Average ◽  
Phosphorus Loads

Predicted responses of Lake Ontario to phosphorus loads from two empirical relationships and an ecological model were compared. Predictions of annual average concentrations of total phosphorus and chlorophyll a by the ecological model were consistent with those predicted by the simpler models. We concluded that the use of a particular type of model is governed by the nature of the problems being addressed rather than an inherent superiority of either approach.

Assessment of Eutrophication Control Programs Using an Ecological Model for a Dimictic Lake

1991 ◽  
Vol 24 (6) ◽  
pp. 339-348 ◽  
Author(s):  
M. Hosomi ◽  
M. Okada ◽  
R. Sudo
Keyword(s):  
Dissolved Oxygen ◽  
Bottom Sediment ◽  
Chlorophyll A ◽  
Ecological Model ◽  
Phosphorus Loading ◽  
Nutrient Concentrations ◽  
Sediment Dredging ◽  
Model Calculations ◽  
Control Programs ◽  
Eutrophication Control

An ecological model of Lake Yunoko, a dimictic lake, was developed to assess various programs for eutrophication control. A multi-component dynamic model for nutrients in the bottom sediment-water system was incorporated into the model, a one-dimensional water temperature-water quality-ecological model. Good agreement between the model calculations and observed nutrients, chlorophyll-a, and dissolved oxygen concentrations in the water and nutrient concentrations in the bottom sediment was noted. The agreement between the model calculations and the measured nutrient flux from bottom sediment during the summer stagnation period was good. The effectiveness of sediment dredging, artificial circulation, and reduction of external phosphorus loading as eutrophication control programs on chlorophyll-a, PO4−P, and dissolved oxygen concentration in the water was assessed using a calibrated model.

A Comparison of Total Phosphorus, Chlorophyll a, and Zooplankton in Embayment, Nearshore, and Offshore Habitats of Lake Ontario

2003 ◽  
Vol 29 (1) ◽  
pp. 54-69 ◽  
Author(s):  
Spencer R. Hall ◽  
Nijole K. Pauliukonis ◽  
Edward L. Mills ◽  
Lars G. Rudstam ◽  
Clifford P. Schneider ◽  
...  
Keyword(s):  
Chlorophyll A ◽  
Total Phosphorus ◽  
Lake Ontario

Chlorophyll–Phosphorus Relationships for Subarctic Lakes in Western Canada

1987 ◽  
Vol 44 (4) ◽  
pp. 775-781 ◽  
Author(s):  
M. L. Ostrofsky ◽  
F. H. Rigler
Keyword(s):  
British Columbia ◽  
Chlorophyll A ◽  
Total Phosphorus ◽  
Chlorophyll Concentration ◽  
Yukon Territory ◽  
Western Canada ◽  
Subarctic Lakes ◽  
Empirical Relationships ◽  
Chl A ◽  
The Relationship

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.

Optimal sampling period for predicting phosphores and chlorophyll concentrations in north-temperate lakes

1995 ◽  
Vol 52 (8) ◽  
pp. 1812-1815 ◽  
Author(s):  
Robert L. France ◽  
Robert H. Peters ◽  
Robert H. Rishikof
Keyword(s):  
Chlorophyll A ◽  
Total Phosphorus ◽  
Trophic Status ◽  
Sampling Period ◽  
Seasonal Patterns ◽  
Optimal Sampling ◽  
Temperate Lakes ◽  
Empirical Relationships ◽  
North Temperate Lakes ◽  
Frequent Sampling

Because total phosphorus and chlorophyll a concentrations vary seasonally within north-temperate lakes, estimates of lake trophic status are usually based on several to many sampling visits. However, because such effort is not always logistically possible, the empirical relationships developed between these trophic status indicators may depend upon seasonal patterns of sampling. Clearly, it is desirable to know if some periods of the year are more likely to produce representative estimates of total phosphorus and chlorophyll a, or, alternatively, if sampling in other periods should be restricted or even avoided. Data from north-temperate lakes are used to examine the degree to which single monthly samples for total phosphorus and chlorophyll a represent seasonal means. Analyses indicate that the least precise and least accurate estimates of the means occur when single-visit synoptic surveys are conducted during April. Not until August to September do single sampling visits provide data that approximate those represented by the means garnered through more frequent sampling.

Eutrophication study of Lake Daylesford, Victoria

1980 ◽  
Vol 31 (5) ◽  
pp. 573 ◽  
Author(s):  
JL Bales ◽  
GK Curtin ◽  
IC Campbell ◽  
BT Hart
Keyword(s):  
Water Column ◽  
Chlorophyll A ◽  
Total Phosphorus ◽  
Algal Blooms ◽  
Algal Species ◽  
Early Spring ◽  
Algal Community ◽  
Phosphorus Loading ◽  
Phytoplankton Production ◽  
Early Autumn

The occurrence of algal blooms in Lake Daylesford (area 11.6 ha; maximum depth 9 m) each summer in recent years was investigated. Surface water temperature of the lake varied from 7 to 25�C. The lake which is fed by Wombat Creek, a small permanent stream, was cheimomictic with stratification occurring between summer and early autumn. In most years classical 'turnover' would be unlikely; rather, epilimnetic water would be flushed from the lake by inflowing creek waters approximately 12 times per year. Surface waters were always well oxygenated but the hypolimnion was anoxic between December 1976 and March 1977. Transparency was greatest in winter and early spring and least in summer and early autumn, this reduction being caused by autochthonously produced algal matter and allochthonously derived suspended material. Incommon withmany other Australian lakes, Lake Daylesford had ashallow euphoticzone 1-2 m deep that would limit phytoplankton production. In March and June 1977, over 99% of the incident visible light was absorbed in the top 1 m of the water column. The lake was classified as eutrophic on the basis of chlorophyll a levels. productivity, total phosphorus loadings and algal species. Chlorophyll a levels ranged from < 1 �g 1-1 in June 1977 to 79 �g 1-1 in February 1977; the productivity maximum was 210 mg C m-3 day-1 (560 mg O2, m-3 day-1) in March 1977 and the estimated total phosphorus loading was 2.8 g P m-2 year-1. The algal community was dominated by three genera: the blue-green alga Anabaena, the euglenoid Trachelomonas and the diatom Asterionella. Evidence suggests that reduction of the phosphorus loading to the lake will do much to eliminate the annual algal blooms. Provision of sewerage facilities for the township of Daylesford may achieve the required reduction. The lake sediments contain elevated levels of phosphorus, mainly a result of past discharges of waste material from a potato-processing factory; the contribution of this sediment phosphorus to the water column is unknown but should be investigated.

APLIKASI CITRA LANDSAT 8 OLI UNTUK IDENTIFIKASI STATUS TROFIK WADUK GAJAH MUNGKUR WONOGIRI, JAWA TENGAH

2017 ◽  
Vol 19 (2) ◽  
pp. 113
Author(s):  
Kusuma Wardani Laksitaningrum ◽  
Wirastuti Widyatmanti
Keyword(s):  
Chlorophyll A ◽  
Total Phosphorus ◽  
Trophic State ◽  
Water Clarity ◽  
Coefficient Of Determination ◽  
Physical Factors ◽  
Landsat 8 ◽  
Trophic State Index ◽  
Landsat 8 Oli ◽  
State Index

<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>

scholarly journals Effect of red algal bloom on growth and production of carps

Our Nature ◽  
2018 ◽  
Vol 16 (1) ◽  
pp. 48-54
Author(s):  
Ram Bhajan Mandal ◽  
Sunila Rai ◽  
Madhav Kumar Shrestha ◽  
Dilip Kumar Jha ◽  
Narayan Prasad Pandit
Keyword(s):  
Water Quality ◽  
Body Weight ◽  
Chlorophyll A ◽  
Total Nitrogen ◽  
Total Phosphorus ◽  
Algal Bloom ◽  
Total Dissolved Solids ◽  
Dissolved Solids ◽  
Aquaculture Farm ◽  
Red Algal

An experiment was carried to assess the effect of red algal bloom on growth and production of carp, water quality and profit from carp for 120 days at Aquaculture Farm of Agriculture and Forestry University, Chitwan. The experiment included two treatments: carp polyculture in non-red pond and carp polyculture in red pond with algal bloom each with three replicates. Carp fingerlings were stocked at 1 fish/m2 and fed with pellet containing 24% CP at 3% body weight. Net yield of rohu was found significantly higher (p<0.05) in non-red ponds (0.38±0.01 t ha-1) than red ponds (0.24±0.05 t ha-1). Survival of rohu (84.9±1.4%), bighead (95.2±2.0%) and mrigal (88.1±14.4%) were also significantly higher (p<0.05) in non-red ponds than red ponds. Red algal bloom affected DO, nitrate and chlorophyll-a, nitrite, total nitrogen, total phosphorus, total dissolved solids and conductivity. However, overall carp production and profit from carp remained unaffected.

Differences between Nearshore and Offshore Phytoplankton Communities in Lake Ontario

1987 ◽  
Vol 44 (12) ◽  
pp. 2155-2163 ◽  
Author(s):  
I. M. Gray
Keyword(s):  
Chlorophyll A ◽  
Phytoplankton Biomass ◽  
Algal Biomass ◽  
Phytoplankton Community ◽  
Seasonal Pattern ◽  
Principal Component ◽  
Lake Ontario ◽  
Dominant Group ◽  
Phytoplankton Communities ◽  
Eutrophic Species

Differences between nearshore and offshore phytoplankton biomass and composition were evident in Lake Ontario in 1982. Phytoplankton biomass was characterized by multiple peaks which ranged over three orders of magnitude. Perhaps as a consequence of the three times higher current velocities at the northshore station, phytoplankton biomass ranged from 0.09 to 9.00 g∙m−3 compared with 0.10 to 2.40 g∙m−3 for the midlake station. Bacillariophyceae was the dominant group at the northshore station until September when Cyanophyta contributed most to the biomass (83%). Although Bacillariophyceae was the principal component of the spring phytoplankton community at the midlake station, phytoflagellates (49%) and Chlorophyceae (25%) were responsible for summer biomass, with the Chlorophyceae expanding to 80% in the fall. The seasonal pattern of epilimnetic chlorophyll a correlated with temperature. While chlorophyll a concentrations were similar to values from 1970 and 1972, algal biomass had declined and a number of eutrophic species (Melosira binderana, Stephanodiscus tenuis, S. hantzschii var. pusilla, and S. alpinus) previously found were absent in 1982.

Impacts of Phosphorus Loading Temporal Pattern on Benthic Algae Growth in Lake Ontario

2021 ◽  
pp. 126449
Author(s):  
Yuan Hui ◽  
Zhenduo Zhu ◽  
Joseph F. Atkinson ◽  
Angshuman M. Saharia
Keyword(s):  
Temporal Pattern ◽  
Lake Ontario ◽  
Benthic Algae ◽  
Phosphorus Loading ◽  
Algae Growth
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