scholarly journals Limnological characterisation and phytoplankton seasonal variation in a subtropical shallow lake (Guaiba Lake, Brazil): a long-term study

2014 ◽  
Vol 26 (4) ◽  
pp. 442-456 ◽  
Author(s):  
Rodrigo da Rocha Andrade ◽  
Danilo Giroldo
Keyword(s):  
Shallow Lake ◽  
Soluble Reactive Phosphorus ◽  
Late Summer ◽  
Euphotic Zone ◽  
Subtropical Zone ◽  
Chl A ◽  
Relative Contribution ◽  
Long Term Study ◽  
Reactive Phosphorus

AIM: to provide a long-term limnological characterisation of a subtropical shallow lake in addition to verifying seasonal differences, including phytoplankton variation. METHODS: monthly sampling at sites IP, SJ and MD from 2000 to 2009 to analyse temperature - T; depth - Z; the depth of the euphotic zone - Zeu; Zeu/Z (%); total suspended solids - TSS; dissolved oxygen - DO; pH; electrical conductivity - EC; N-NH3, N-NO2, N-NO3; soluble reactive phosphorus - SRP; chlorophyll a - Chl-a and phytoplankton. RESULTS: low values of Z and Zeu characterised the shallow and turbid conditions of lake and corresponded to the contribution of nano-microflagellates (Chlamydomonas sp., Spermatozopsis sp., Cryptomonas sp. and Rhodomonas sp ) and diatoms (Aulacoseira granulata). Zeu/Z (%), SRP and Chl-a were significantly different at site IP (meso-eutrophic) compared to sites SJ and MD (eutrophic). Phytoplankton density was also significantly higher at sites SJ and MD, and the largest relative contribution of Actinastrum sp., Dictyosphaerium sp., Micractinium sp., Monoraphidium sp., Scenedesmus/Desmodesmus sp. and Euglena sp. corresponded to the most polluted waters at site SJ. The significantly higher T (ºC) in summer corresponded to significantly higher Chl-a as well as a greater richness and density of phytoplankton. Cocconeis sp., Gomphonema sp. and Pinnularia sp. (pennated diatoms) were negatively correlated with temperature and were therefore more representative at the three sites in winter. Asterionella formosa was correlated with SRP and vernal blooms were recorded (2000-2001). Planktothrix isothrix and Planktothricoides raciborskii were expressive in the summer/late summer (2004-2005), and were significantly correlated with Chl-a and low SRP in water column. CONCLUSIONS: The study corroborated the sensitivity of phytoplankton in characterising different stages of eutrophication at different sites and corresponding watersheds as well as in characterising different seasons in a shallow lake in the subtropical zone of Brazil.

scholarly journals Long-Term Study of Soluble Reactive Phosphorus Concentration in Fall Creek and Comparison to Northeastern Tributaries of Cayuga Lake, NY: Implications for Watershed Monitoring and Management

Water ◽  
2019 ◽  
Vol 11 (10) ◽  
pp. 2075 ◽  
Author(s):  
O’Leary ◽  
Johnston ◽  
Gardner ◽  
Penningroth ◽  
Bouldin
Keyword(s):  
Flow Rate ◽  
Algal Blooms ◽  
Soluble Reactive Phosphorus ◽  
Phosphorus Concentration ◽  
Term Study ◽  
Long Term Study ◽  
Cayuga Lake ◽  
Significant Difference ◽  
Reactive Phosphorus

This study focuses on soluble reactive phosphorus (SRP), a key driver of eutrophication worldwide and a potential contributor to the emerging global environmental problem of harmful algal blooms (HABs). Two studies of tributary SRP concentrations were undertaken in sub-watersheds of Cayuga Lake, NY, the subject of a total maximum daily load (TMDL) development process, due to phosphorus impairment of its southern shelf. The long-term study compared SRP concentration in Fall Creek in the 1970s with that in the first decade of the 2000s, thus spanning a period of change in phosphorus sources, as well as in regional climate. The spatial study used data collected between 2009 and 2018 and compared SRP concentrations in Fall Creek to levels in northeastern tributaries that flow into the lake close to areas where HABs have been problematic. SRP was measured using standard procedures. Flow-weighted mean SRP concentration ranged between 15.0 µg/L and 30.0 µg/L in all years studied in both the 1970s and 2000s, with the exception of 2010. Annual discharge in Fall Creek showed no trend between 1970 and 2018, but a higher proportion of high streamflow samples was captured in the 2000s compared to the 1970s, which resulted in proportionally increased SRP concentration in the latter time period. There was no significant difference in the SRP concentration—flow rate relationship between the two time periods. Adjusted for flow rate, SRP concentrations in Fall Creek have not changed over many decades. Increasing phosphorus contributions from growing population and urbanization since the 1970s may have been counterbalanced by improvements in wastewater treatment and agricultural practices. Mean SRP concentration in northeastern tributaries was significantly (p < 0.001) higher than in Fall Creek, likely reflecting more intense agricultural use and higher septic system density in the watersheds of the former. This finding justifies continued monitoring of minor northern tributaries. Future monitoring must emphasize the capture of high flow conditions. Historical stability and highly variable hydrology will slow the watershed response to management and confound the ability to detect changes attributable to decreased phosphorus inputs. Large scale monitoring on decadal timescales will be necessary to facilitate watershed management.

scholarly journals Phosphorus Inactivation in Lake Sediments Using Calcite Materials and Controlled Resuspension—Mechanism and Efficiency

Minerals ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 223
Author(s):  
Agnieszka Bańkowska-Sobczak ◽  
Aurelia Blazejczyk ◽  
Elisabeth Eiche ◽  
Uwe Fischer ◽  
Zbigniew Popek
Keyword(s):  
Adsorption Capacity ◽  
Soluble Reactive Phosphorus ◽  
High Dose ◽  
Eutrophic Lakes ◽  
Precipitated Calcium Carbonate ◽  
Anoxic Conditions ◽  
P Fraction ◽  
Reactive Phosphorus ◽  
High Doses

The efficiency and mechanism of orthophosphate—soluble reactive phosphorus (SRP)—inactivation in eutrophic lakes using controlled resuspension and calcite application into the sediment were investigated in this study. Two calcite materials, industrially produced precipitated calcium carbonate (PCC) and natural ground limestone (GCC), were tested in short-term batch experiments and long-term sediment incubations under oxic and anoxic conditions. Maximum SRP adsorption capacity calculated using Langmuir model for PCC (3.11 mg PO43− g−1) was 6 times higher than of GCC (0.43 mg PO43− g−1), reflecting substantial difference in the surface area of calcite materials (12.36 and 1.72 m2 g−1, respectively). PCC applied into the sediment during controlled resuspension reduced SRP release by 95% (oxic) and 78% (anoxic incubation) at medium dose (0.75 kg m−2) and suppressed it completely at high dose (1.5 kg m−2) for at least 3 months, irrespectively of incubation conditions. The maximum achieved reduction of SRP release using GCC was also meaningful: 78% under oxic and 56% under anoxic conditions, but this required very high doses of this material (6 kg m−2). Mechanisms of SRP inactivation by calcites were: (1) adsorption of SRP during application into the resuspended sediment and (2) precipitation of calcium-phosphate compounds (Ca-PO4) during subsequent incubation, which was reflected in a substantial increase in the HCl-P fraction (phosphorus extractable in 0.5 M HCl) in sediments enriched with calcite, irrespectively of oxygen presence. However, anoxia strongly promoted the formation of this fraction: the rise of HCl-P was 2–6 times higher in anoxic than in oxic conditions, depending on the dose and form of calcite applied. The results showed that SRP inactivation using the controlled resuspension method is only successful if highly efficient reactive materials are used, due to large amount of SRP being released from sediment during resuspension. Thus, calcite materials exhibiting high adsorption capacity should be used in this lakes’ restoration technology to ensure fast and sufficient SRP inactivation. The rise in the HCl-P fraction in sediment suggests SRP inactivation through precipitation of relatively stable Ca-PO4 minerals, which makes calcite a suitable agent for sustainable, long term SRP inactivation. As anoxic conditions promoted formation of these compounds, calcite seems to be a promising SRP inactivation agent in highly reductive sediments.

scholarly journals Sediment phosphorus fractionation and flux in a tropical shallow lake

2021 ◽  
Vol 33 ◽  
Author(s):  
Jéssica Papera ◽  
Fabiana Araújo ◽  
Vanessa Becker
Keyword(s):  
Shallow Lake ◽  
Organic Phosphorus ◽  
Soluble Reactive Phosphorus ◽  
Oxygen Depletion ◽  
Phosphorus Fractionation ◽  
P Fractions ◽  
P Release ◽  
Water And Sediment ◽  
Mobile Fraction ◽  
Reactive Phosphorus

Abstract: Aim The aim of the present study is to evaluate the potential phosphorus (P) release from the sediment to the water column of a tropical shallow lake in the northeast of Brazil, based on the sediment P fractions and on the flux of P between water and sediment. Methods We used a sequential extraction method to analyse the different P fractions of the sediment of Lake Extremoz. We also carried out a 40-day microcosm experiment to analyse the flux of P between water and sediment. We did so by flooding 200g of sediment from the lake with 800 mL of 1.2 µm filtered lake water in 1 L beakers. Every 5 days we analysed: soluble reactive phosphorus (SRP), total phosphorus (TP), organic phosphorus (Org-P), dissolved oxygen (DO), temperature, and pH of the water. Results The largest fraction of P in the sediment of Lake Extremoz is Refractory-P, which is non-mobile. The main mobile fraction of this lake’s sediment is composed of P bound to Fe and Mn oxides (BD-P) which is redox sensitive. During the P flux experiment, the water was always oxic and with nearly neutral pH, however the temperature increased by almost 4 °C due to the increase of the temperature of the air. SRP, TP and Org-P concentrations in the water had a general decrease in the first 20 days. But, on the second half of the experiment, those concentrations increased and the fluxes of P from sediment to water, mainly Org-P, were positive. Even with this increase in concentrations, indicating a period of P release, overall fluxes were negative. Conclusions The main mobile fraction of the sediment is redox sensitive, therefore it has the potential to be released in case of oxygen depletion. Under current conditions, most of the P released by the sediment is in organic forms, indicating that, in the presence of oxygen, the balance of P between water and sediment is controlled by the effects of organisms on P as well as temperature.

scholarly journals Phytoplankton in relation to water quality of Tanguar Haor ecosystem, Bangladesh: I. Rauar station

2019 ◽  
Vol 28 (2) ◽  
pp. 131-138
Author(s):  
Mohammad Azmal Hossain Bhuiyan ◽  
SAM Shariar Islam ◽  
Abu Kowser ◽  
Md Rasikul Islam ◽  
Shahina Akter Kakoly ◽  
...  
Keyword(s):  
Water Quality ◽  
Air Temperature ◽  
Environmental Variables ◽  
Secchi Depth ◽  
Soluble Reactive Phosphorus ◽  
Organic Pollution ◽  
Quality Data ◽  
Water Quality Data ◽  
Chl A ◽  
Reactive Phosphorus

The water quality at Rauar station of Tanguar Haor, Sunamganj was assessed studying phytoplankton and associated environmental variables. The environmental variables were monitored over a period of one year, collecting samples at two months interval between March, 2017 and March, 2018. Air temperature, rainfall, and humidity ranged from 22.6 - 32.1°C, 48 - 76% and 8 - 930 mm, respectively. Air temperature showed a direct relationship with water temperature which varied from 22.4 - 31.0°C during the study period. The water transparency remained relatively constant throughout the year having a mean Secchi depth (Zs) value of 2.48 m. Total dissolved solids (TDS), conductivity, and pH of the water ranged from 51 - 85 mg/l, 60 - 110 μS/cm, and 7.2 - 9.7, respectively. In December, because of a temperature fall, the dissolved oxygen (DO) concentration of the water reached its maximum value of 6.09 mg/l. In the rest of the period, the concentration remained between 2.44 and 4.80 mg/l. The value of alkalinity ranged from 0.43 - 1.35 meq/l. Among the nutrients, soluble reactive phosphorus (SRP), soluble reactive silicate (SRS), and NO3-N ranged from 5.43 - 36.43 μg/l, 4 - 14.58 mg/l, and 0.06 - 0.31 mg/l, respectively. The concentration of NH4+ ranged from 238 - 1230 μg/l. The highest concentrations (905 and 1230 μg/l) occurred between September and December, 2017. This might be attributed to the higher density of migratory birds during that period. The phytoplanktonic biomass expressed as chlorophyll-a (Chl-a) ranged from 1.35 - 8.45 μg/l while its degraded product phaeophytin concentration ranged from 0.08 - 3.5 μg/l. The standing crop of phytoplankton ranged from 397 - 2480 × 103 individuals/l of haor water exhibiting its maximum abundance in September. This parameter showed a highly significant positive correlation with SRP. From the correlation analysis, the degradation of chl-a to phaeophytin was found to be temperature dependent. Considering the different physicochemical and biological water quality data, it could be said that the Tanguar Haor is still free from organic pollution. However, the range of soluble reactive phosphorus data (5.43 - 36.43 μg/l) show that the Haor has been passing a meso-eutrophic state. Dhaka Univ. J. Biol. Sci. 28(2): 131-138, 2019 (July)

Contribution of Particulate Phosphorus (> 250 μm) to the Total Phosphorus Pool in Lake Water

1984 ◽  
Vol 41 (2) ◽  
pp. 351-363 ◽  
Author(s):  
E. E. Prepas ◽  
J. Vickery
Keyword(s):  
Chlorophyll A ◽  
Total Phosphorus ◽  
Lake Water ◽  
Euphotic Zone ◽  
Particulate Phosphorus ◽  
Lake Productivity ◽  
Chl A ◽  
Relative Contribution ◽  
Residual Variation ◽  
Large Particles

Particulate phosphorus (PP) > 250 μm was concentrated in the euphotic zone of 17 lakes in central Alberta. When the euphotic zone extended below the epilimnion, PP >250 μm was concentrated deep in the euphotic zone. PP > 250 μm was a significant but variable portion of the total phosphorus (TP) pool in individual lakes; thus, samples should be collected from the euphotic zone on several dates to estimate the contribution of PP > 250 μm to the TP pool. As well, the contribution of this fraction varied among lakes: average summer values for the euphotic zone ranged from 3 to 19%. Among lakes, the contribution of large particles to the TP pool decreased proportionally as lake productivity (estimated by chlorophyll a (Chl a)) increased. The relative contribution of PP > 250 μm in summer accounted for a significant portion of the residual variation in the spring TP-summer Chl a relationship but not the summer TP-summer Chl a relationship in the study lakes. These apparently contradictory results can be explained by differences between lakes that mixed intermittently throughout the summer and those that remained permanently thermally stratified during this time.

Major controls of base flow soluble reactive phosphorus losses in humid temperate headwater streams

2020 ◽  
Author(s):  
Michael Rode ◽  
Remi Dupas
Keyword(s):  
Land Use ◽  
Headwater Streams ◽  
Soluble Reactive Phosphorus ◽  
Low Flow ◽  
Temperate Climate ◽  
Redox Processes ◽  
Temperature Dependent ◽  
P Release ◽  
Reactive Phosphorus

&lt;p&gt;Long-term Soluble Reactive Phosphorus (SRP) monitoring in headwater streams in central Europe revealed a seasonal pattern of SRP concentrations during low flow periods, with highest concentrations in summer and lowest in winter. These seasonal concentration amplitudes often exceed the eutrophication threshold during the summer eutrophication-sensitive period. It is assumed that temperature dependent biogeochemical processes control the underlying P release mechanism, where redox processes may be responsible for this increase. Several studies have highlighted the crucial role of reactive zones such as riparian wetlands in controlling solute export regimes. Moreover especially in forest headwater streams, in-stream assimilatory uptake shows a distinct seasonal behaviour because of varying shading conditions. This can also lead to seasonal SRP amplitudes. Furthermore sorption and desorption processes are temperature dependent which may alter in-stream SRP release during the year.&lt;/p&gt;&lt;p&gt;Often SRP concentrations are higher in agricultural streams than in more pristine headwaters. It is not clear how land use (e.g. P status of soils) may impact the baseline SRP concentrations and which factors control the seasonal change in SRP stream concentration (riparian groundwater heads and redox processes, temperature, in-stream release and uptake processes). Therefore the objective of this study is to disentangle land use impacts from hydrological and biogeochemical controls of low flow SRP losses.&amp;#160; A comparative study on seasonal SRP concentration patterns will be presented comprising around 53 long term monitored headwater catchments in humid temperate climate of northern Europe and the United States. Based on hydrological and SRP headwater signals and catchment properties, P release processes are discussed. The results of the study will allow to target SRP mitigation strategies based on knowledge of the dominating control of SRP loss from headwater streams.&amp;#160;&lt;/p&gt;

scholarly journals Limnology of lake Rainkhyongkain of Bangladesh with a new record of Marchantia polymorpha L. var. aquatica Nees

2014 ◽  
Vol 42 (2) ◽  
pp. 223-229 ◽  
Author(s):  
Md Almujaddade Alfasane ◽  
Md Sharif Ullah ◽  
Moniruzzaman Khondker
Keyword(s):  
Phytoplankton Biomass ◽  
New Record ◽  
Soluble Reactive Phosphorus ◽  
Total Dissolved Solids ◽  
Marchantia Polymorpha ◽  
Mean Values ◽  
Chl A ◽  
The Mean ◽  
Reactive Phosphorus ◽  
First Time

In lake Rainkhyongkain, water temperature, pH, conductivity and total dissolved solids (TDS) were recorded 33.5°C, 7.39, 308 ?S/cm and 49 mg/l, respectively. The mean values (n = 4) of dissolved oxygen content (DO), alkalinity, soluble reactive phosphorus (SRP), soluble reactive silicate (SRS) and NO3-N were 7.93 ± 0.78 mg/l, 1.70 ± 0.12 meq/l, 17.25 ± 0.62 ?g/l, 10.44 ± 0.72 mg/l and 34.00 ± 4.00 ?g/l, respectively. The phytoplankton biomass as chlorophyll a (chl a) was found very low (4.93 ± 0.51 ?g/l) with a phaeopigment concentration of 1.97 ± 0.51 ?g/l. A total of 16 phytoplankton taxa were recorded of which Cyclotella comensis (V. Keissler) Lemm. was dominant followed by Protoperidinium conicum (Gran) Balech, Coelosphaerium kuetzingianum Näg., Euglena spp. and Mallomonas paxillata Bardley. For the first time in Bangladesh Marchantia polymorpha L. var. aquatica Nees was found to grow in masses in the shallow littoral of the lake. Among the dominant macrophytes of the littoral, Nymphaea stellata Willd., Nymphoides indicum (L.) O. Kuntze and Monochoria hastata (L.) Solms were common. DOI: http://dx.doi.org/10.3329/bjb.v42i2.18023 Bangladesh J. Bot. 42(2): 223-229, 2013 (December)

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