scholarly journals Seasonal Variations of Zooplankton, Chlorophyll-A and Nutrients in Phewa Lake, Pokhara Valley, Nepal

1970 ◽  
Vol 16 ◽  
pp. 51-57
Author(s):  
Md. Akbal Husen ◽  
Ram Prasad Dhakal
Keyword(s):  
Chlorophyll A ◽  
Phytoplankton Biomass ◽  
Dominant Species ◽  
Trophic Status ◽  
Seasonal Pattern ◽  
Zooplankton Species ◽  
Total Phosphorous ◽  
Different Seasons ◽  
Pokhara Valley ◽  
Lake Phewa

In order to understand trophic status of lake Phewa, largest lake (535 ha) in Pokhara valley, seasonal pattern of zooplanktons, chlorophyll a and nutrients level in water column was examined from January to December 2005. Total zooplanktons density was highest in January and November, showed bimodal pattern in Lake Phewa. The sequence of dominant species of zooplankton was Nauplius > Kerratella > Cyclops > Daphnia > Eodiaptomus in this lake. Correlation between zooplankton species and nutrients level was established. The Chlorophyll- a as an indicator of phytoplankton biomass peaks in November and chlorophyll-a concentration was found lower in winter months. The NH4-N ranged between zero to 0.021 mg/l with mean of 0.003 mg/l. The annual concentration of nitrate+nitrite (NO3+NO2) was found upto 0.148 mg/l (mean= 0.013 mg/l), soluble reactive phosphate (PO4-P) ranged from zero to 0.003 mg/l (mean= 0.001 mg/l), and total phosphorous ranged upto 0.052 mg/l (mean= 0.009 mg/l) in lake Phewa in 2005. Based on nutrients and chlorophyll-a dynamics, the lake varied from mesotrophic to eutrophic in different seasons. The Phewa Lake fluctuated from oligo-mesotrophic in monsoon seasons to meso-eutrophic in dry periods. Key words: Zooplanktons, nutrients, chlorophyll. DOI: 10.3126/eco.v16i0.3473ECOPRINT 16: 51-57, 2009

scholarly journals Fluctuations of the population of Daphnia laevis Birge 1878: a six-year study in a tropical lake

2012 ◽  
Vol 72 (3) ◽  
pp. 479-487 ◽  
Author(s):  
LPM. Brandão ◽  
T. Fajardo ◽  
E. Eskinazi-Sant'Anna ◽  
S. Brito ◽  
P. Maia-Barbosa
Keyword(s):  
Chlorophyll A ◽  
Total Phosphorus ◽  
Trophic State ◽  
Trophic Status ◽  
Seasonal Pattern ◽  
Ecological Research ◽  
Total Phosphorous ◽  
Long Term Ecological Research ◽  
Physical And Chemical

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.

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.

Seasonal pattern and inferred phosphorus limitation of phytoplankton biomass in two tropical reservoirs in northern Australia

2000 ◽  
Vol 51 (1) ◽  
pp. 91 ◽  
Author(s):  
Simon A. Townsend
Keyword(s):  
Chlorophyll A ◽  
Total Phosphorus ◽  
Phytoplankton Biomass ◽  
Seasonal Pattern ◽  
Phosphorus Concentration ◽  
Wet Season ◽  
Temperate Lakes ◽  
Total Phosphorus Concentration ◽  
River Reservoir ◽  
Annual Range

Manton River Reservoir (MRR) and Darwin River Reservoir (DRR) are two small impoundments in the Australian wet/dry tropics. Over an eight-year period, chlorophyll a concentrations in the mixed layer averaged 3.6 µg L−1 in DRR, and 7.1 µg L−1 in MRR. The seasonal pattern of chlorophyll a at MRR was influenced by wet season wash-out (February average 4.8 µg L−1 ), and dry season destratification and nutrient enrichment of the surface waters (July average 8.4 mg L−1 ). In contrast, DRR exhibited near uniform chlorophyll a concentrations over the year. The seasonal patterns of DRR and MRR chlorophyll a are typical of tropical water bodies which tend to have a smaller annual range than temperate lakes, though this can be modified by significant wash-out. Empirical evidence suggests that the phytoplankton biomass of each reservoir is phosphorus limited, relative to the potential provided by other nutrients and light energy. This conclusion is based on a regression of total phosphorus and chlorophyll a concentrations of pooled DRR and MRR data (P < 0.001; r2 = 0.90), and the high total-nitrogen to total-phosphorus concentration ratios (by weight) of 50 and 37 in DRR and MRR, respectively. Annual chlorophyll a and total phosphorus concentrations for both reservoirs are in accord with the OECD regression for temperate lakes and reservoirs.

In Vivo Fluorescence of Chlorophyll A: Estimation of Phytoplankton Biomass and Activity in Římov Reservoir (Czech Republic)

1993 ◽  
Vol 28 (6) ◽  
pp. 29-33 ◽  
Author(s):  
V. Vyhnálek ◽  
Z. Fišar ◽  
A. Fišarová ◽  
J. Komárková
Keyword(s):  
Czech Republic ◽  
Chlorophyll Fluorescence ◽  
Primary Production ◽  
Chlorophyll A ◽  
Phytoplankton Biomass ◽  
In Vivo Fluorescence ◽  
Fluorescence Of Chlorophyll A ◽  
Římov Reservoir ◽  
Natural Phytoplankton

The in vivo fluorescence of chlorophyll a was measured in samples of natural phytoplankton taken from the Římov Reservoir (Czech Republic) during the years 1987 and 1988. The fluorescence intensities of samples either with or without addition of 3-(3,4-dichlorophenyl)-1,1-dimethylurea (diuron, DCMU) were found reliable for calculating the concentration of chlorophyll a during periods when cyanobacteria were not abundant. The correction for background non-chlorophyll fluorescence appeared to be essential. No distinct correlation between a DCMU-induced increase of the fluorescence and primary production of phytoplankton was found.

scholarly journals Spatiotemporal Variability of Surface Phytoplankton Carbon and Carbon-to-Chlorophyll a Ratio in the South China Sea Based on Satellite Data

2020 ◽  
Vol 13 (1) ◽  
pp. 30
Author(s):  
Wenlong Xu ◽  
Guifen Wang ◽  
Long Jiang ◽  
Xuhua Cheng ◽  
Wen Zhou ◽  
...  
Keyword(s):  
South China Sea ◽  
Chlorophyll A ◽  
South China ◽  
Satellite Data ◽  
Phytoplankton Biomass ◽  
The South China Sea ◽  
Spatiotemporal Variability ◽  
The South ◽  
Chl A ◽  
China Sea

The spatiotemporal variability of phytoplankton biomass has been widely studied because of its importance in biogeochemical cycles. Chlorophyll a (Chl-a)—an essential pigment present in photoautotrophic organisms—is widely used as an indicator for oceanic phytoplankton biomass because it could be easily measured with calibrated optical sensors. However, the intracellular Chl-a content varies with light, nutrient levels, and temperature and could misrepresent phytoplankton biomass. In this study, we estimated the concentration of phytoplankton carbon—a more suitable indicator for phytoplankton biomass—using a regionally adjusted bio-optical algorithm with satellite data in the South China Sea (SCS). Phytoplankton carbon and the carbon-to-Chl-a ratio (θ) exhibited considerable variability spatially and seasonally. Generally, phytoplankton carbon in the northern SCS was higher than that in the western and central parts. The regional monthly mean phytoplankton carbon in the northern SCS showed a prominent peak during December and January. A similar pattern was shown in the central part of SCS, but its peak was weaker. Besides the winter peak, the western part of SCS had a secondary maximum of phytoplankton carbon during summer. θ exhibited significant seasonal variability in the northern SCS, but a relatively weak seasonal change in the western and central parts. θ had a peak in September and a trough in January in the northern and central parts of SCS, whereas in the western SCS the minimum and maximum θ was found in August and during October–April of the following year, respectively. Overall, θ ranged from 26.06 to 123.99 in the SCS, which implies that the carbon content could vary up to four times given a specific Chl-a value. The variations in θ were found to be related to changing phytoplankton community composition, as well as dynamic phytoplankton physiological activities in response to environmental influences; which also exhibit much spatial differences in the SCS. Our results imply that the spatiotemporal variability of θ should be considered, rather than simply used a single value when converting Chl-a to phytoplankton carbon biomass in the SCS, especially, when verifying the simulation results of biogeochemical models.

scholarly journals Sebaran Klorofil a, Nitrat, Fosfat dan Plankton Sebagai Indikator Kesuburan Ekosistem Mangrove Tugurejo Semarang

2018 ◽  
Vol 16 (1) ◽  
pp. 68
Author(s):  
Anik Prihatin ◽  
Prabang Setyono ◽  
Sunarto Sunarto
Keyword(s):  
Environmental Factors ◽  
Chlorophyll A ◽  
Aquatic Ecosystems ◽  
Trophic Status ◽  
Nutrient Content ◽  
Mangrove Ecosystem ◽  
Nitrate Content ◽  
Aquatic Biota ◽  
Phosphate Content ◽  
Trophic Index

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

The Deep Chlorophyll Maximum: Comparing Vertical Profiles of Chlorophyll a

1982 ◽  
Vol 39 (5) ◽  
pp. 791-803 ◽  
Author(s):  
John J. Cullen
Keyword(s):  
Chlorophyll A ◽  
Phytoplankton Biomass ◽  
Physiological Adaptation ◽  
Organic Carbon Content ◽  
Deep Chlorophyll Maximum ◽  
Vertical Profiles ◽  
In Vivo Fluorescence ◽  
Chlorophyll Maximum ◽  
Vertical Distributions

The relationship between chlorophyll a and phytoplankton biomass (organic carbon content) is highly variable as is the yield of in vivo fluorescence per unit chlorophyll. Thus, vertical profiles of chlorophyll or in vivo fluorescence must be interpreted with caution if their ecological significance is to be established. Although the variability of carbon-to-chlorophyll ratios and fluorescence yield is large, much of it can be anticipated, corrected for, and usefully interpreted. Vertical profiles from different regions of the sea are presented; each has a deep chlorophyll maximum, but the probable mechanisms of their formation and maintenance differ widely. Most vertical distributions of chlorophyll can be explained by the interaction between hydrography and growth, behavior, or physiological adaptation of phytoplankton with no special consideration of grazing by herbivores, even though vertical distributions of epizooplankton are not uniform. The interaction between vertical profiles of zooplankton and chlorophyll will be better understood when the relationships between chlorophyll and phytoplankton biomass in those profiles is determined.Key words: chlorophyll a, fluorescence, phytoplankton, vertical structure

Change in biomass of benthic and planktonic algae along a disturbance gradient for 24 Great Lakes coastal wetlands

2003 ◽  
Vol 60 (6) ◽  
pp. 676-689 ◽  
Author(s):  
Sheila A McNair ◽  
Patricia Chow-Fraser
Keyword(s):  
Water Quality ◽  
Great Lakes ◽  
Chlorophyll A ◽  
Total Variation ◽  
Coastal Wetlands ◽  
Phytoplankton Biomass ◽  
Wetland Management ◽  
Percent Cover ◽  
Planktonic Algae ◽  
Wide Range

We quantified the chlorophyll a content of planktonic algae and benthic algae in periphyton on acrylic rods and in epiphyton growing on macrophytes in 24 coastal wetlands in all five Laurentian Great Lakes. Sites were selected to represent a wide range of environmental conditions ranging from nutrient-poor, clear-water marshes with abundant macrophytes to nutrient-enriched, turbid systems devoid of aquatic vegetation. Water quality and species and percent cover of submergent macrophytes were measured in each wetland. Principal components analysis (PCA) showed that total phosphorus, turbidity, and suspended solids, variables associated with human-induced degradation, were most strongly correlated with PC axis 1 (PC1), accounting for 69% of the total variation. The PC1 site score was significantly related to both periphyton and phytoplankton biomass, respectively accounting for 54 and 70% of the total variation in periphyton and phytoplankton data, whereas PC1 only accounted for 18% of the variation in epiphyton biomass. Periphytic and epiphytic biomass were negatively correlated with percent cover and species richness of submergent macrophytes, but phytoplankton biomass was not. We conclude that periphytic and planktonic chlorophyll a biomass are good indicators of human-induced water-quality degradation and recommend that both benthic and planktonic algal biomass should be routinely monitored as part of an effective wetland management program.

Phytoplankton biomass and chlorophyll-a in some shallow lakes in central Europe

Hydrobiologia ◽  
1991 ◽  
Vol 215 (2) ◽  
pp. 111-119 ◽  
Author(s):  
Lajos Vörös ◽  
Judit Padisák
Keyword(s):  
Chlorophyll A ◽  
Central Europe ◽  
Shallow Lakes ◽  
Phytoplankton Biomass
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