Empirical Prediction of Crustacean Zooplankton Biomass in Nutrient-Poor Canadian Shield Lakes

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.

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>


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.


1983 ◽  
Vol 40 (10) ◽  
pp. 1813-1819 ◽  
Author(s):  
J. S. Bays ◽  
T. L. Crisman

Zooplankton, including ciliated protozoans, were collected from 39 Florida lakes of widely ranging trophic state. Annual mean biomass values for different zooplankton groups were regressed against Carlson's Trophic State Index based on annual mean chlorophyll a concentration. Whereas total zooplankton biomass yielded a significant regression with increasing trophic state, microzooplankton (ciliates, rotifers, and nauplii) accounted for more of the relationship than macrozooplankton (cladocera, calanoids, and cyclopoids). Within the microzooplankton, the regression improved with decreasing body size. Macrozooplankton biomass exhibited a weak statistical relationship with lake trophic state, but the different component groups were variable in their response. The dominance within the zooplankton community shifts from macrozooplankton to microzooplankton with increasing trophic state, and the microzooplankton can constitute between 50 and 90% of the total zooplankton biomass in eutrophic lakes. Changes in zooplanktivore community structure with increasing trophic state show that whereas total fish biomass increases, dominance shifts from visually oriented predators, such as bass and bluegill, to pump filter-feeding planktivores, such as gizzard shad (Dorosoma cepedianum). While Florida zooplankton communities are similar in size structure to tropical communities, no statistically significant differences were found between empirical equations of crustacean zooplankton biomass and trophic state determined from temperate and Florida data bases.


2016 ◽  
Vol 18 (2) ◽  
pp. 19-28
Author(s):  
Roumen Kalchev ◽  
Árpád Berczik ◽  
Michaela Beshkova ◽  
Mária Dinka ◽  
Hristina Kalcheva ◽  
...  

Abstract The phytoplankton limitation conditions in a few Bulgarian and Hungarian wetlands and in two more sampling sites, one for each Danube stretch, were investigated by means of trophic state index of Carlson (1977) for phytoplankton chlorophyll-a (CHL), Secchi disk depths (SD), total phosphorus (TP), and total nitrogen (TN) concentrations. Phytoplankton of both river sites was not limited by non-algal turbidity, nor was they phosphorus and nitrogen limited. In summer months the studied wetlands were predominantly nitrogen limited, while in spring and autumn limitation by non-algal turbidity prevailed.


2002 ◽  
Vol 2 ◽  
pp. 284-307 ◽  
Author(s):  
Ray W. Drenner ◽  
Ray K. David Hambright

The concept of cascading trophic interactions predicts that an increase in piscivore biomass in lakes will result in decreased planktivorous fish biomass, increased herbivorous zooplankton biomass, and decreased phytoplankton biomass. Though often accepted as a paradigm in the ecological literature and adopted by lake managers as a basis for lake management strategies, the trophic cascading interactions hypothesis has not received the unequivocal support (in the form of rigorous experimental testing) that might be expected of a paradigm. Here we review field experiments and surveys, testing the hypothesis that effects of increasing piscivore biomass will cascade down through the food web yielding a decline in phytoplankton biomass. We found 39 studies in the scientific literature examining piscivore effects on phytoplankton biomass. Of the studies, 22 were confounded by supplemental manipulations (e.g., simultaneous reduction of nutrients or removal of planktivores) and could not be used to assess piscivore effects. Of the 17 nonconfounded studies, most did not find piscivore effects on phytoplankton biomass and therefore did not support the trophic cascading interactions hypothesis. However, the trophic cascading interactions hypothesis also predicts that lake systems containing piscivores will have lower phytoplankton biomass for any given phosphorus concentration. Based on regression analyses of chlorophyll�total phosphorus relationships in the 17 nonconfounded piscivore studies, this aspect of the trophic cascading interactions hypothesis was supported. The slope of the chlorophyll vs. total phosphorus regression was lower in lakes with planktivores and piscivores compared with lakes containing only planktivores but no piscivores. We hypothesize that this slope can be used as an indicator of “functional piscivory” and that communities with extremes of functional piscivory (zero and very high) represent classical 3- and 4-trophic level food webs.


2019 ◽  
Vol 21 (2) ◽  
pp. 730-744
Author(s):  
Francisco Bruno Monte Gomes ◽  
Davis Pereira De Paula

A pesquisa teve como objetivo analisar o índice de estado trófico no rio Acaraú localizado em Sobral-Ceará-Brasil. A metodologia consistiu em revisões bibliográficas, análises de campo, delimitação de cinco pontos amostrais ao longo do trecho fluvial, culminando na coleta de amostras de água e avaliação dos parâmetros de Clorofila “A” e Fósforo Total, no período de março/2015 a março/2016. O trecho do rio Acaraú no espaço urbano de Sobral foi dividido em cinco trechos principais, abrangendo entrada e saída. A Clorofila “A” apresentou uma crescente nas estações PT-3 (40,0 µg/L), PT-4 (32,0 µg/L), nos meses de setembro/15 e PT-5 (12,5 µg/L), para o mês de março/16, os menores resultados foram nas estações PT-1 (6,2 µg/L a 9,0 µg/L), PT-2 (6,7 µg/L a 8,0 µg/L). O Fósforo Total variou entre 0,02 mg/l em agosto/15 na estação PT-1 a 22,5 mg/l em dezembro/15 da estação de coleta PT-5. O cálculo do IET (Índice de Estado Trófico) se mostrou com nível de predominância no grau mesotrófico nos pontos PT-1, PT-3 e PT-5, entre agosto/15 a dezembro/15. O grau hipereutrófico foi resultado nos pontos PT-3, PT-4 e PT-5, afetados significativamente pelas elevadas concentrações de matéria orgânica e nutrientes. Portanto, conclui-se que as águas no rio Acaraú apresentaram vulnerabilidades aos processos de eutrofização, se fazendo necessária a implantação de um planejamento urbano eficiente.Palavras-chave: Eutrofização; Poluição hídrica; Qualidade de água; Rio urbano. ABSTRACTThe aim of this research was analyze the trophic state index in the Acaraú river located in Sobral-Ceará-Brazil. The methodology consisted of bibliographic reviews, field recognition, delimitation of five sampling points along the river, culminating in the water sampling and evaluation of the parameters of Chlorophyll "A" and Total Phosphorus, from March/2015 to March/2016. The section of the Acaraú River in the urban space of Sobral was divided into five main sections, including entrance and exit. Chlorophyll "A" increased in PT-3 (40.0 μg/L), PT-4 (32.0 μg/L) in September/15 and PT-5 (12.5 μg/L), for the month of  March/16, the lowest results were in PT-1 (6.2 μg/L at 9.0 μg/L), PT-2 (6.7 μg/L at 8.0 μg/L). Total Phosphorus ranged from 0.02 mg/L to 22.5 mg/L (August/15– December/15) at the PT-5 sampling point. The TSI (Trophic State Index) showed that there was predominance on mesotrophic degree at points PT-1, PT-3 and PT-5among August/15 and December/15. The hypereutrophic degree that was found in points PT-3, PT-4 and PT-5, were the results of a significant influence by high concentrations of organic matter and nutrients. Therefore, it is concluded that the waters in Acaraú River presents vulnerabilities to the eutrophication processes, and it is necessary to implement efficient urban planning.Keywords: Eutrophication; Water pollution; Water quality; Urban river. RESUMENLa investigación tuvo como objetivo analizar el índice de estado trófico en el río Acaraú ubicado en Sobral-Ceará-Brasil. La metodología consistió en revisiones bibliográficas, análisis de campo, delimitación de cinco puntos de muestreo a lo largo de la sección del río, que culminó con la recolección de muestras de agua y la evaluación de los parámetros de Clorofila "A" y Fósforo Total, de marzo/2015 a marzo/2016. El tramo del río Acaraú en el espacio urbano de Sobral se dividió en cinco tramos principales, que incluyen la entrada y la salida. La clorofila “A” presentó un crecimiento en las estaciones PT-3 (40.0 µg/L), PT-4 (32.0 µg/L) en septiembre/15 y PT-5 (12.5 µg/L). L), para el mes de marzo/16, los resultados más bajos fueron en PT-1 (6.2 µg/L a 9.0 µg/L), PT-2 (6.7 µg/L a 8.0 µg/L). El fósforo total varió de 0.02 mg/l en agosto/15 en la estación PT-1 a 22.5 mg/l en diciembre/15 desde la estación de recolección PT-5. El cálculo del EIT (Índice de estado trófico) fue predominantemente mesotrófico en PT-1, PT-3 y PT-5, del 15 de agosto al 15 de diciembre. El grado hipereutrófico se obtuvo en los puntos PT-3, PT-4 y PT-5, significativamente afectados por las altas concentraciones de materia orgánica y nutrientes. Por lo tanto, se concluye que las aguas del río Acaraú presentan vulnerabilidades a los procesos de eutrofización, lo que hace necesaria la implementación de una planificación urbana eficiente.Palabras clave: Eutrofización; Contaminación del agua; Calidad del agua; Río urbano.


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.


1987 ◽  
Vol 44 (8) ◽  
pp. 1510-1515 ◽  
Author(s):  
R. L. France

Spatial variability in amphipod (Hyalella azteca) density was examined in 17 Canadian Shield Lakes in south-central Ontario. Aggregation was measured by the exponent of the power relationship between density and variance. The average b index was 1.45, although this value varied depending on lake and habitat type. Whereas this should indicate the use of a fourth-root transformation, neither this nor the logarithmic transformation was as effective as the square-root in stabilizing variance. A literature review suggests that if a universal transformation is sought for benthos data, it should not be the commonly used log transformation. The observation that the square-root transformation seemed to work better on average than the fourth-root transformation, even in the region suggested by theory for the latter, suggests that complications may arise in the uncritical use of Taylor's Power Law.


Author(s):  
Linh Nguyen Thuy ◽  
Ha Nguyen Thi Thu ◽  
Thao Nguyen Thien Phuong ◽  
Vinh Pham Quang

The water quality of Suoi Hai reservoir, the largest reservoir in Hanoi city, is being threatened by human activities of the surrounding area, as reported by the press. The trophic status of the reservoir is the result of both natural eutrophication and nutrient inputs from anthropogenic sources, particularly the leachate from a lakeside waste treatment plant. This study aims to identify the trophic status of the Suoi Hai reservoir and the changes of water trophic state over space and time. Data of chlorophyll-a concentration, total phosphorus, and Secchi disk depth from 51 sites during three field campaigns in October 2019, August 2020, and March 2021 was used to calculate Carlson’s trophic state index (CTSI). Resultant CTSI (ranged from 60 to 72) allows classifying Suoi Hai reservoir as highly eutrophic water. Its variations in space and time provided evidence for an influence of anthropogenic activities on the reservoir trophic state. Analysis of the trophic state index deviations suggested that total phosphorus is the key factor that influenced the reservoir trophic state. Therefore, managing the anthropogenic nutrient inputs load to the reservoir should be a critical task to control eutrophication in Suoi Hai Reservoir at present. 


2019 ◽  
Author(s):  
Farnaz Nojavan A. ◽  
Betty J Kreakie ◽  
Jeffrey W Hollister ◽  
Song S Qian

Lake trophic state classifications provide information about the condition of lentic ecosystems and are indicative of both ecosystem services (e.g., clean water, recreational opportunities, and aesthetics) and disservices (e.g., cyanobacteria blooms). The current classification schemes have been criticized for developing indices that are single-variable based (vs. a complex aggregate of multi-variables), discrete (vs. a continuum), and/or deterministic (vs. an inherent randomness). We present an updated lake trophic classification model using a Bayesian multilevel ordered categorical regression. The model consists of a proportional odds logistic regression (POLR) that models ordered, categorical, lake trophic state using Secchi disk depth, elevation, nitrogen concentration (N), and phosphorus concentration (P). The overall accuracy, when compared to existing classifications of trophic state index (TSI), for the POLR model was 0.68 and the balanced accuracy ranged between 0.72 and 0.93. This work delivers an index that is multi-variable based, continuous, and classifies lakes in probabilistic terms. While our model addresses all the limitations of the current approach to lake trophic classification, the addition of uncertainty quantification is important, because the trophic state response to predictors varies among lakes. Our model successfully addresses concerns with the current approach and performs well across trophic states in a large spatial extent.


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