Phosphorus–Chlorophyll Relationships under Contrasting Herbivory and Thermal Stratification: Predictions and Patterns

1994 ◽  
Vol 51 (2) ◽  
pp. 390-400 ◽  
Author(s):  
Asit Mazumder

Analyses of the relationships between total phosphorus (TP) and chlorophyll a (Chl) among a large number of temperate lake ecosystems having contrasting herbivore communities and thermal stratification reveal that systems lacking large Daphnia (SH systems) exhibit four times more Chl yields than systems having large Daphnia (LH systems) in oligotrophic as well as eutrophic and hypereutrophic systems. Mixed (MIX) systems exhibit greater Chl yields than stratified (STR) systems. Within each group of stratified and mixed systems, greater Chl yields to constant TP are observed in systems lacking large Daphnia (MIX-SH and STR-SH) than those having large Daphnia (MIX-LH and STR-LH). Consequently, a hierarchy of Chl yield patterns is produced; STR-LH and MIX-SH systems exhibit the lowest and highest Chl yields, respectively, at constant TP. These patterns may be a reflection of variable chemical (nutrients), biological (herbivory), and physical (thermal stratification) characteristics among aquatic ecosystems. Sigmoid patterns of TP–Chl relationships appear to be related to the transition from stratified to mixed systems along the TP gradient. The finding that highly variable Chl yields to TP can be summarized into a set of TP–Chl trajectories for specific types of lake ecosystems may have strong implications for lake management.

Author(s):  
Richard Iestyn Woolway ◽  
Benjamin M. Kraemer ◽  
Jakob Zscheischler ◽  
Clement Albergel

Abstract An emerging concern for lake ecosystems is the occurrence of compound extreme events i.e., situations where multiple within-lake extremes occur simultaneously. Of particular concern are the co-occurrence of lake heatwaves (anomalously warm temperatures) and high chlorophyll-a extremes, two important variables that influence the functioning of aquatic ecosystems. Here, using satellite observations, we provide the first assessment of univariate and compound extreme events in lakes worldwide. Our analysis suggests that the intensity of lake heatwaves and high chlorophyll-a extremes differ across lakes and are influenced primarily by the annual range in surface water temperature and chlorophyll-a concentrations. The intensity of lake heatwaves is even greater in smaller lakes and in those that are shallow and experience cooler average temperatures. Our analysis also suggests that, in most of the studied lakes, compound extremes occur more often than would be assumed from the product of their independent probabilities. We anticipate compound extreme events to have more severe impacts on lake ecosystems than those previously reported due to the occurrence of univariate extremes.


2013 ◽  
Vol 115 ◽  
pp. 287-294 ◽  
Author(s):  
Bryan M. Spears ◽  
Laurence Carvalho ◽  
Bernard Dudley ◽  
Linda May

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>


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

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.


2018 ◽  
Vol 16 (1) ◽  
pp. 68
Author(s):  
Anik Prihatin ◽  
Prabang Setyono ◽  
Sunarto Sunarto

ABSTRAKEkosistem mangrove merupakan suatu interaksi yang terjadi antara tanaman – tanaman mangrove dengan faktor lingkungan perairan mangrove sehingga dapat menyebabkan terjadinya kesuburan perairan dan sebagai tempat mencari makan alami bagi biota – biota perairan. Tujuan penelitian ini adalah untuk mengetahui sebaran klorofil-a, nitrat dan fosfat serta plankton pada ekosistem mangrove yang berguna untuk kelestarian hidup biota – biota perairan Mangrove. Penelitian ini dilaksanakan bulan Oktober – November 2017 di Mangrove Tapak Tugurejo Semarang. Hasil penelitian ini didapatkan kandungan klorofil a rata – rata 0,165 mg/l, kandungan nitrat rata – rata 2,188 mg/l dan kandungan fosfat rata – rata 0,045 mg/l. Kelimpahan fitoplankton ditemukan sebanyak 23 spesies dan zooplankton ditemukan sebanyak 5 spesies. Berdasarkan status indeks trofik perairan Mangrove Tapak Tugurejo Semarang termasuk dalam kategori perairan mesotrofik, yakni unsur hara dan nutrien dalam perairan mangrove kurang tersedia banyak atau sedang dan belum tercemar. Kondisi kesuburan ekosistem mangrove terpantau cukup baik bila dibandingkan dengan kandungan – kandungan unsur hara, klorofil a dan plankton yang melimpah di perairan penelitian, sehingga memungkinkan banyak terdapat kehidupan biota – bioata perairan. Kesimpulan dari penelitian ini adalah kandungan unsur hara (nitrat dan fosfat) dan klorofil a serta plankton diperairan mangrove sangat mempengaruhi kesuburan ekosistem perairan, serta plankton yang mendominasi tempat penelitian ialah dari kelas Baccilariophyceae sebanyak 21 spesies.Kata kunci: Status trofik, Plankton, Ekosistem Mangrove,  Mangrove Tapak Tugurejo Semarang.ABSTRACTMangrove ecosystem is an interaction that occurs between mangrove plants with environmental factors of mangrove waters that can cause the occurrence of water fertility and as a place of natural foraging for aquatic biota. The purpose of this research is to know the distribution of chlorophyll a, nitrate and phosphate and plankton in mangrove ecosystem which is useful for the preservation of biota life of Mangrove waters. This research was conducted in October - November 2017 at Tapak Mangrove Tugurejo Semarang. The results of this study obtained an average chlorophyll-1 content of 0.165 mg / l, an average nitrate content of 2.188 mg / l and an average phosphate content of 0.045 mg / l. Abundance of phytoplankton found as many as 23 species and zooplankton found as many as 5 species. Based on the trophic index status of Mangrove waters Tapak Tugurejo Semarang included in the category of mesotrophic waters, the nutrients and nutrients in the mangrove waters are less available or moderate and not contaminated. The condition of mangrove ecosystem fertility is observed quite well when compared with nutrient content, chlorophyll-a and plankton abundant in research waters, thus allowing many life biota - bioata waters. The conclusion of this research is the content of nutrients (nitrate and phosphate) and chlorophyll a and plankton in mangrove waters greatly affect the fertility of aquatic ecosystems, and the plankton that dominate the research site is from the Baccilariophyceae class of 21 species.Keywords : Trophic Status, Plankton, Mangrove Ecosystem, Mangrove Tapak Tugurejo SemarangCitation: Prihatin, A, Setyono, P dan Sunarto (2018). Sebaran Klorofil-a, Nitrat, Fosfat dan Plankton Sebagai Indikator Kesuburan Ekosistem di Mangrove Tapak Tugurejo Semarang. Jurnal Ilmu Lingkungan, 16(1), 68-77, doi:10.14710/jil.16.1.68-77


2019 ◽  
Vol 31 ◽  
Author(s):  
Jéssica Nayara de Carvalho Leite ◽  
Vanessa Becker

Abstract Aim The aim of this study was to analyze the water quality of a tropical, semi-arid reservoir after a reflooding. In terms of impact on water quality after a drought event, it is expected that there will be improvements with the reflooding. Less algal biomass, increased water transparency, decreased turbidity and low nutrient concentration. Methods This study was performed in a tropical, semi-arid man-made lake (Dourado Reservoir), during an extended drought period. This study consisted of a comparison of three distinct periods determined by water accumulation. The limnological variables, including water transparency, turbidity, electrical conductivity, pH, total phosphorus, soluble reactive phosphorus, and chlorophyll-a were analyzed. A principal component analysis (PCA) was also performed to verify the patterns of the variables in relation to the sample units in the studied periods. Results After water renewal, there was an expressive reduction in chlorophyll-a. Electrical conductivity, pH, and turbidity variables also reduced after the reflooding, indicating an improvement in water quality. There was no reduction in total phosphorus and soluble reactive phosphorus after the reflooding compared to the previous periods. Conclusions The significant reduction in algal biomass after reflooding in Dourado indicates water quality improvement in terms of eutrophication due to the change of the trophic state from eutrophic to mesotrophic.


2012 ◽  
Vol 72 (3) ◽  
pp. 479-487 ◽  
Author(s):  
LPM. Brandão ◽  
T. Fajardo ◽  
E. Eskinazi-Sant'Anna ◽  
S. Brito ◽  
P. Maia-Barbosa

The fluctuation of the population of Daphnia laevis in Lake Jacaré (Middle River Doce, Minas Gerais) was monitored monthly (at one point in the limnetic region) for six years (2002-2007) as part of the Program of Long-Term Ecological Research (LTER/UFMG). The following parameters were also monitored: water temperature, pH, electrical conductivity, dissolved oxygen, chlorophyll a, total phosphorus, phosphate, total nitrogen, nitrate, nitrite, ammonia, and densities of Chaoborus and ephippia of Daphnia laevis in the sediment. A seasonal pattern was observed in the fluctuation of D. laevis, with higher densities recorded during periods of circulation (May-August). A significant correlation was found between the density of D. laevis and temperature (r = -0.47, p = 0.0001), chlorophyll-a (r = -0.32, p = 0.016) and indicators of the lake's trophic status (total phosphorus, r = 0.32, p = 0.007 and trophic state, r = 0.36, p = 0.003), as well as Chaoborus density (r = 0.43 and p = 0.002). These results indicate that changes in the physical and chemical characteristics of the water related with stratification and circulation of the lake may have a direct (temperature, total phosphorous) or an indirect (food availability, presence of predators, ephippia eclosion) influence on the fluctuation of the D. laevis population.


2018 ◽  
Vol 60 (2) ◽  
pp. 135-142 ◽  
Author(s):  
Antonella LUGLIÈ ◽  
Yelda AKTAN ◽  
Paola CASIDDU ◽  
Nicola SECHI

The purpose of this paper was to assess the effect of the diversion of wastewater on the trophic status of Lake Bidighinzu, a hypertrophic man-made lake in Northern Sardinia, used as a drinking water reservoir. There have been problems with potabilization since the early years of the diversion operation, particularly in the summer-autumn period. Data available (August 1978, February 1979 and March 1985) before the reservoir (1987) were compared with those collected during a study carried out in the annual cycle immediately after (1988-1989) and after some years (1994 and 1996-1997). The study examined the dynamics of temperature, main nutrients (total phosphorus, nitrate and ammonia), chlorophyll-a and phytoplanktonic biomass. No particular variation in the water nutrient availability emerged from the comparison between these two situations - especially for total phosphorus, whose annual mean concentrations were similar in the two annual cycles (386 mg P m-3 in 1988-1989 and 305 mg P m-3 in 1996-1997). Chlorophyll-a and biomass were high during each period of study (annual mean values were 17 mg m-3and 3.7 mg l-1 in 1988-1989 and 11 mg m-3and 4.6 mg l-1 in 1996-1997). However, peaks were never higher than values recorded in August 1978 (112 mg m-3and 133 mg l-1) due to an extraordinary bloom of Ceratium hirundinella (O.F. Müller). Species composition of phytoplankton was typical of highly trophic conditions and was frequently characterised by the presence of Cyanophyceae and Bacillariophyceae. Results demonstrated that, ten years after construction of the by-pass, the lake had shown no improvement in its trophic status. This might depend on many factors, among which the most likely might be the non-use or partial use of the diversion system, which allows the sewage to continue to flow into the lake and keep its trophic status almost unchanged.


2020 ◽  
Vol 13 ◽  
pp. 117862211989842
Author(s):  
Hwan Kim ◽  
Inseol Yeo ◽  
Chan-Gyu Park

Water sources are currently facing great challenges from rapid population growth and industrial developments. Investigations into how to remove algal organic matter (AOM) are thus of great importance from an environmental point of view because most lakes and reservoirs in South Korea suffer from algae problems, especially in the summer. Many efforts have been made to remove AOM from the aquatic environment in South Korea. In this study, we focus on development of a new AOM removal system, utilizing waste oyster shells and ferrihydrite as the media of the filtration system. Using this system, the removal rate of AOM was investigated regarding the concentrations of chlorophyll a, total phosphorus, and alginate. It was found that about 92% of the total phosphorus was removed through this system when raw oyster shell powders were heated at 900°C to convert them into calcium oxide powders. The use of a continuous system also led to a reduction of 94.2% in total phosphorus, 78.8% in chlorophyll a, and 43.6% in alginate.


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