scholarly journals Charophyte variation in sensitivity to eutrophication affects their potential for the trophic and ecological status indication

2021 ◽  
pp. 30
Author(s):  
Agnieszka Kolada
Keyword(s):  
Water Quality ◽  
Significant Contribution ◽  
Ecological Status ◽  
Taxonomic Diversity ◽  
Trophic Gradient ◽  
Eutrophic Lakes ◽  
Trophic Conditions ◽  
Index Approach ◽  
The Mean

Charophytes (stoneworts) form a group of macrophytes that are considered sensitive to eutrophication. The high indicator value of charophytes toward eutrophication results in their wide use in the bioassessment systems. I explored the variability of stonewort communities' requirements for trophic conditions in lowland temperate lakes and attempted to determine the role of individual syntaxa in assessing the ecological status of lakes in Poland. The position of charophyte communities' niches along the trophic gradient was analysed using the Outlying Mean Index approach. A few stonewort communities, i.e., Nitelletum opacae, N. mucronatae, N. flexilis and Charetum filiformis appeared to be specialised concerning water quality and may be considered indicators of habitats less eutrophic than the “mean” trophic conditions in the study domain. Most stonewort communities were relatively common in European waters. Four of them, i.e., Charetum tomentosae, C. asperae, C. contrariae and Nitellopsidetum obtusae, can be classified as ‘generalists’ with low marginality and broad ecological tolerance. Most stonewort communities appeared in a broad range of ecological status classes. In the case of 15 communities, 6 to 25% of occurrences were observed in lakes representing a less than good status, and they cannot be considered indicative of good ecological conditions. However, the high taxonomic diversity and extensive phytolittoral zone were most likely to occur when the phytocoenoses of stoneworts were present. In lowland naturally eutrophic lakes inhabited by eurytopic species, the extraordinary role of charophytes in the assessment of the ecological status can be interpreted through their significant contribution to the development of the littoral.

Effects of Fe addition on sediment P dynamics in a eutrophic lake

2021 ◽  
Author(s):  
Melanie Münch ◽  
Rianne van Kaam ◽  
Karel As ◽  
Stefan Peiffer ◽  
Gerard ter Heerdt ◽  
...  
Keyword(s):  
Water Quality ◽  
Organic Matter ◽  
Surface Water ◽  
Water Column ◽  
Sediment Cores ◽  
Surface Water Quality ◽  
Water Interface ◽  
Eutrophic Lakes ◽  
Fe Addition

<p>The decline of surface water quality due to excess phosphorus (P) input is a global problem of increasing urgency. Finding sustainable measures to restore the surface water quality of eutrophic lakes with respect to P, other than by decreasing P inputs, remains a challenge. The addition of iron (Fe) salts has been shown to be effective in removing dissolved phosphate from the water column of eutrophic lakes. However, the resulting changes in biogeochemical processes in sediments as well as the long-term effects of Fe additions on P dynamics in both sediments and the water column are not well understood.</p><p>In this study, we assess the impact of past Fe additions on the sediment P biogeochemistry of Lake Terra Nova, a well-mixed shallow peat lake in the Netherlands. The Fe-treatment in 2010 efficiently reduced P release from the sediments to the surface waters for 6 years. Since then, the internal sediment P source in the lake has been increasing again with a growing trend over the years.</p><p>In 2020, we sampled sediments at three locations in Terra Nova, of which one received two times more Fe during treatment than the other two. Sediment cores from all sites were sectioned under oxygen-free conditions. Both the porewaters and sediments were analysed for their chemical composition, with sequential extractions providing insight into the sediment forms of P and Fe. Additional sediment cores were incubated under oxic and anoxic conditions and the respective fluxes of P and Fe across the sediment water interface were measured.</p><p>The results suggest that Fe and P dynamics in the lake sediments are strongly coupled. We also find that the P dynamics are sensitive to the amount of Fe supplied, even though enhanced burial of P in the sediment was not detected. The results of the sequential extraction procedure for P, which distinguishes P associated with humic acids and Fe oxides, as well as reduced flux of Fe(II) across the sediment water interface in the anoxic incubations, suggest a major role of organic matter in the interaction of Fe and P in these sediments.</p><p>Further research will include investigations of the role of organic matter and sulphur in determining the success of Fe-treatment in sequestering P in lake sediments. Based on these data in combination with reactive transport modelling we aim to constrain conditions for successful lake restoration through Fe addition.</p>

scholarly journals Factors Influencing Abundances and Population Size Structure of the Threatened and Endemic Cyprinodont Aphanius iberus in Mediterranean Brackish Ponds

Water ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 3264
Author(s):  
Serena Sgarzi ◽  
Sandra Brucet ◽  
Mireia Bartrons ◽  
Ignasi Arranz ◽  
Lluís Benejam ◽  
...  
Keyword(s):  
Water Quality ◽  
Total Nitrogen ◽  
Size Structure ◽  
Ecological Status ◽  
Maximum Size ◽  
Structured Populations ◽  
Negative Effect ◽  
The Mean ◽  
Abiotic And Biotic Factors

Aphanius iberus is an endemic cyprinodontoid fish species of Mediterranean ponds in danger of extinction. In this study, we studied some abiotic and biotic factors that can influence A. iberus’s size structure and density in Mediterranean brackish ponds. We sampled fish using fyke nets in 10 ponds of Empordà (Spain) during the spring season. Our results showed that a better ecological status (according to the Water Quality of Lentic and Shallow Ecosystems (QAELS) index), pond’s depth and pond’s isolation (reflected by an increase in total nitrogen) were related to larger individual sizes and more size-diverse populations. Increasing the salinity is known to help the euryhaline A. iberus acting as a refuge from competitors. Nevertheless, our results showed that higher conductivities had a negative effect on A. iberus’s size structure, leading to a decrease in the mean and maximum size of the fish. Fish abundance (expressed as captures per unit of effort (CPUE)) seemed to increase with increasing the pond’s depth and total nitrogen (the latter reflecting pond isolation). In conclusion, our results suggest that achieving a better pond ecological status may be important for the conservation of endangered A. iberus, because better size-structured populations (i.e., larger mean and average lengths) were found at higher water quality conditions.

Exercise training-induced hypervolemia in greyhounds: role of water intake and renal mechanisms

1985 ◽  
Vol 248 (4) ◽  
pp. R422-R425 ◽  
Author(s):  
K. H. McKeever ◽  
W. A. Schurg ◽  
V. A. Convertino
Keyword(s):  
Exercise Training ◽  
Water Intake ◽  
Significant Contribution ◽  
Free Water ◽  
Work Intensity ◽  
Water Reabsorption ◽  
Free Water Clearance ◽  
Primary Mechanism ◽  
The Mean

The purpose of this study was to determine if the chronic hypervolemia that accompanies endurance exercise training is due only to an increase in the rate of water intake or if there were contributions from renal mechanisms. Four greyhound dogs, previously sedentary for 3 yr, were utilized. During the 28-day experiment each dog was trained on a treadmill ergometer for 14 consecutive days at 65% of its pretraining maximal work intensity. After training, plasma volume increased 472 ml (27.5%, P less than 0.05). The rate of water intake increased 328 ml/day (33%, P less than 0.05), whereas urine output increased 87 ml/day (20.8%, P less than 0.05). The mean resting 24-h values for clearance of sodium increased 0.29 ml/min (90.3%, P less than 0.05), and clearance of potassium decreased 1.51 ml/min (16.1%, NS). Glomerular filtration rate, free water clearance, and osmotic clearance were not significantly altered. These data suggest that the primary mechanism for the exercise training-induced hypervolemia in dogs is a net positive water balance via increased water consumption without significant contribution from an increase in renal water reabsorption.

scholarly journals The role of alkalinity in setting water quality metrics: phosphorus standards in United Kingdom rivers

2018 ◽  
Vol 20 (10) ◽  
pp. 1361-1372
Author(s):  
Alan D. Tappin ◽  
Alba Navarro-Rodriguez ◽  
Sean D. W. Comber ◽  
Paul J. Worsfold
Keyword(s):  
Water Quality ◽  
European Union ◽  
United Kingdom ◽  
Water Framework Directive ◽  
Reference Conditions ◽  
Ecological Status ◽  
Quality Metrics ◽  
The European Union ◽  
Reactive Phosphorus

UK implementation of the European Union Water Framework Directive (for the 2015–2021 cycle) Ecological Status (ES) classification for river phosphorus is based on the calculation of reference conditions for reactive phosphorus (RP) using river alkalinity measurements.

Economic Development of Bangladesh: The Role of IBBL

IIUC Studies ◽  
2015 ◽  
Vol 9 ◽  
pp. 323-334
Author(s):  
Shafiqur Rahman ◽  
Nicholas McDonald
Keyword(s):  
Economic Development ◽  
Content Analysis ◽  
Foreign Trade ◽  
Rural Economy ◽  
Significant Contribution ◽  
Annual Report ◽  
Housing Sector

This paper presents the role of Islami Bank Bangladesh Limited (IBBL) to the recent economic development in Bangladesh. The study analyses published texts, articles, websites and annual report of this bank through a content analysis. Key findings of this study manifest the contribution of this bank in different areas of economic development in Bangladesh like generating employment, earning foreign remittance, strengthening rural economy, promoting ecology and green banking, boosting industrialization, developing the SMEs, assisting in foreign trade (import-export), developing the housing sector etc. This study also identifies IBBL’s significant contribution to the national exchequer. This paper contributes to the field of economic development of Bangladesh and the role of IBBL behind it and fills the gap of literature in this specific area.IIUC Studies Vol.9 December 2012: 323-334

IDENTIFYING THE MOST SUITABLE AREAS FOR SURFACE FLOW WETLAND CONSTRUCTION IN LITHUANIA

2015 ◽  
Author(s):  
Antanas DUMBRAUSKAS ◽  
Nijolė BASTIENĖ ◽  
Petras PUNYS
Keyword(s):  
Constructed Wetlands ◽  
Ecological Status ◽  
Surface Flow ◽  
Gis Analysis ◽  
Proximity Analysis ◽  
Wetland Construction ◽  
The Mean ◽  
Two Phases ◽  
Terrain Features ◽  
Surface Flow Constructed Wetlands

GIS-based approach to find the suitable sites for surface flow constructed wetlands was employed for the Lithuanian river basins with low ecological status. According to the nature of the analysed criteria the flowchart consists of two phases. Criteria used include hydrographical network, soil properties, terrain features, land use, etc. Some of them have strictly defined values (constraints), and other ranges within certain limits (factors). Limited criteria were analysed using rejection principle and influencing factors using proximity analysis and overlay methods. Selecting the potential sites using standard GIS analysis tools there was estimated about 3286 sites for possible wetlands with the mean area of inflow basin about 4 km2 in the basins of water bodies at risk.

Participation of ABCA1 transporter in development of chronic obstructive pulmonary disease

2020 ◽  
Vol 28 (3) ◽  
pp. 360-370
Author(s):  
Stanislav N. Kotlyarov ◽  
Anna A. Kotlyarova
Keyword(s):  
Chronic Obstructive Pulmonary Disease ◽  
Pulmonary Disease ◽  
Significant Contribution ◽  
Modern Medicine ◽  
Lipid Homeostasis ◽  
Chronic Obstructive ◽  
Obstructive Pulmonary Disease ◽  
Reverse Transport ◽  
Current Paradigm

Despite all achievements of the modern medicine, the problem of chronic obstructive pulmonary disease (COPD) does not lose its relevance. The current paradigm suggests a key role of macrophages in inflammation in COPD. Macrophages are known to be heterogeneous in their functions. This heterogeneity is determined by their immunometabolic profile and also by peculiarities of lipid homeostasis of cells. Aim. To analyze the role of the ABCA1 transporter, a member of the ABC A subfamily, in the pathogenesis of COPD. The expression of ABCA1 in lung tissues is on the second place after the liver, which shows the important role of the carrier and of lipid homeostasis in the function of lungs. Analysis of the literature shows that participation of the transporter in inflammation consists in regulation of the content of cholesterol in the lipid rafts of the membranes, in phagocytosis and apoptosis. Conclusion. Through regulation of the process of reverse transport of cholesterol in macrophages of lungs, ABCA1 can change their inflammatory response, which makes a significant contribution to the pathogenesis of COPD.

Long-term dynamics and destruction of marsh vegetation in the Kolokolkova Bay of the Barents Sea

2012 ◽  
pp. 66-77 ◽  
Author(s):  
I. A. Lavrinenko ◽  
O. V. Lavrinenko ◽  
D. V. Dobrynin
Keyword(s):  
Species Composition ◽  
Plant Communities ◽  
Barents Sea ◽  
Mean Value ◽  
Marsh Vegetation ◽  
Composition And Structure ◽  
The Mean ◽  
Species Composition And Structure

The satellite images show that the area of marshes in the Kolokolkova bay was notstable during the period from 1973 up to 2011. Until 2010 it varied from 357 to 636 ha. After a severe storm happened on July 24–25, 2010 the total area of marshes was reduced up to 43–50 ha. The mean value of NDVI for studied marshes, reflecting the green biomass, varied from 0.13 to 0.32 before the storm in 2010, after the storm the NDVI decreased to 0.10, in 2011 — 0.03. A comparative analysis of species composition and structure of plant communities described in 2002 and 2011, allowed to evaluate the vegetation changes of marshes of the different topographic levels. They are fol­lowing: a total destruction of plant communities of the ass. Puccinellietum phryganodis and ass. Caricetum subspathaceae on low and middle marches; increasing role of halophytic species in plant communities of the ass. Caricetum glareosae vic. Calamagrostis deschampsioides subass. typicum on middle marches; some changes in species composition and structure of plant communities of the ass. Caricetum glareosae vic. Calamagrostis deschampsioides subass. festucetosum rubrae on high marches and ass. Parnassio palustris–Salicetum reptantis in transition zone between marches and tundra without changes of their syntaxonomy; a death of moss cover in plant communities of the ass. Caricetum mackenziei var. Warnstorfia exannulata on brackish coastal bogs. The possible reasons of dramatic vegetation dynamics are discussed. The dating of the storm makes it possible to observe the directions and rates of the succession of marches vegetation.

Seasonal trends in the stable isotopic composition of snow and meltwater runoff in a subarctic catchment at Okstindan, Norway

2004 ◽  
Vol 35 (2) ◽  
pp. 119-137 ◽  
Author(s):  
S.D. Gurney ◽  
D.S.L. Lawrence
Keyword(s):  
Isotopic Composition ◽  
Mean Value ◽  
Mean Values ◽  
Stable Isotopic Composition ◽  
Meltwater Runoff ◽  
Stable Isotopic ◽  
The Mean ◽  
The Difference ◽  
Δ18o And Δd

Seasonal variations in the stable isotopic composition of snow and meltwater were investigated in a sub-arctic, mountainous, but non-glacial, catchment at Okstindan in northern Norway based on analyses of δ18O and δD. Samples were collected during four field periods (August 1998; April 1999; June 1999 and August 1999) at three sites lying on an altitudinal transect (740–970 m a.s.l.). Snowpack data display an increase in the mean values of δ18O (increasing from a mean value of −13.51 to −11.49‰ between April and August), as well as a decrease in variability through the melt period. Comparison with a regional meteoric water line indicates that the slope of the δ18O–δD line for the snowpacks decreases over the same period, dropping from 7.49 to approximately 6.2.This change points to the role of evaporation in snowpack ablation and is confirmed by the vertical profile of deuterium excess. Snowpack seepage data, although limited, also suggest reduced values of δD, as might be associated with local evaporation during meltwater generation. In general, meltwaters were depleted in δ18O relative to the source snowpack at the peak of the melt (June), but later in the year (August) the difference between the two was not statistically significant. The diurnal pattern of isotopic composition indicates that the most depleted meltwaters coincide with the peak in temperature and, hence, meltwater production.

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