scholarly journals Epilithic Diatom Community Shows a Higher Vulnerability of the River Sava to Pollution during the Winter

Diversity ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 465
Author(s):  
Igor Zelnik ◽  
Tjaša Sušin
Keyword(s):  
Power Plants ◽  
Abiotic Factors ◽  
Sampling Site ◽  
Hydroelectric Power ◽  
Diatom Community ◽  
Nitrogen And Phosphorus ◽  
Sava River ◽  
Diatom Communities ◽  
Epilithic Diatom ◽  
The Sava River

The aim of the research was to investigate the influence of environmental factors on the structure of epilithic diatom communities in the Sava River from the source to the state border 220 km downstream. The river had numerous human influences along its course, such as municipal and industrial wastewater, agriculture, hydroelectric power plants, etc. The main objective of the research was to find out the influence of human pressure on the structure of the epilithic diatom community under winter and summer conditions. Winter and summer samples were taken at nine sites. At each sampling site, a set of abiotic factors was measured and another set of environmental parameters was evaluated. The analyses showed that nitrogen and phosphorus concentrations increased downstream. We identified 118 different species of diatoms. The most common taxa were Achnanthidium minutissimum and A. pyrenaicum. Planktonic species Cyclotella meneghiniana was only found in the samples of the lower part of the Sava, which is unusual for the epilithic community. The composition of the epilithic diatom community was significantly influenced by conductivity and water temperature, pH and distance from the source. The similarity between diatom communities closer to the source of the river was higher than between communities from the lower part of the Sava River. The values of the trophic and saprobic indices increased downstream and showed that the pollution of the river with nutrients and organic matter increases with the distance from the source. Both indices were significantly higher in winter and showed a more impaired river ecosystem during the winter.

scholarly journals The Effect of Monsoon Rainfall Patterns on Epilithic Diatom Communities in the Hantangang River, Korea

Water ◽  
2020 ◽  
Vol 12 (5) ◽  
pp. 1471
Author(s):  
In-Hwan Cho ◽  
Ha-Kyung Kim ◽  
Min-Hyuk Lee ◽  
Yong-Jae Kim ◽  
Hyuk Lee ◽  
...  
Keyword(s):  
Water Quality ◽  
Dominant Species ◽  
Monsoon Rainfall ◽  
Monsoon Season ◽  
Main Stream ◽  
Diatom Community ◽  
Nitrogen And Phosphorus ◽  
Diatom Communities ◽  
Polluted Sites ◽  
Epilithic Diatom

Most of Korea’s rivers and lakes are subject to physico-chemical disturbances, such as increased water quantity and flow rates, and influx of nitrogen and phosphorus, due to intense rainfall concentrated in the Asian monsoon season. To examine the influence of rainfall on epilithic diatom communities, we measured the diatom distribution and river water quality at 29 sites along the main-stream and tributaries of the Hantangang River, Korea, in the period of 2012–2015. Water quality parameters in the polluted sites had improved following rainfall, but the response of dominant species varied with water quality; the dominant species Nitzschia fonticola decreased in abundance regardless of sampling sites, and the abundance of Achnanthidium minutissimum in the clean sites and Nitzschia palea in the polluted sites increased after rainfall, respectively. The community dynamic index (CDI) showed that the most obvious shift of epilithic diatom community occurred in the mid-polluted sites in 2013 with the highest rainfall. This suggest that the effect of rainfalls on the epilithic diatom community is dependent on various parameters, such as the magnitude of rainfall, water quality and its biotic compositions of diatom communities, but it also indicates that improving the water quality of rivers is important to promote the resilience of diatom communities to extremes of precipitation. Further investigation is needed to generalize the effects of monsoon rainfall on the epilithic diatom communities, considering rivers with different environmental characteristics.

scholarly journals Seasonal dynamics of epilithic diatom community from the Vrla River (Southeastern Serbia)

2021 ◽  
pp. 109-122
Author(s):  
Olga Jakovljević ◽  
Slađana Popović ◽  
Ivana Živić ◽  
Katarina Stojanović ◽  
Jelena Krizmanić
Keyword(s):  
Seasonal Dynamics ◽  
Sampling Site ◽  
Winter Period ◽  
Diatom Community ◽  
The Third ◽  
Four Seasons ◽  
Seasonal Analysis ◽  
The Relationship ◽  
Epilithic Diatom ◽  
Southeastern Serbia

Seasonal analysis of epilithic diatom community from the Vrla River was performed in four seasons a year (six times) at six sampling sites. Between the second (VR2) and the third sampling site (VR3) was located a trout fish farm. The highest number of diatom taxa was recorded in spring (149) and the lowest in autumn (93). The number of taxa that were found to be dominant during all four seasons was twenty-four. The relationship between 45 the best-fitted diatom taxa, which showed conspicuous seasonal dynamics, and seasons in which these taxa were recorded was illustrated using canonical correspondence analysis (CCA). The large number of taxa was identified in all four seasons or in winter period only. Few taxa were present only in spring and summer.

scholarly journals Comparison of benthic diatom community structures on natural and artificial substrates in marine lake (Adriatic Sea)

2021 ◽  
Vol 62 (1) ◽  
pp. 21-44
Author(s):  
Ana Car ◽  
Cüneyt Nadir Solak ◽  
Stijepo Ljubimir ◽  
Aydin Kaleli ◽  
Iris Dupčić Radić ◽  
...  
Keyword(s):  
Adriatic Sea ◽  
Sampling Site ◽  
Microscopic Analysis ◽  
Dead Sea ◽  
Artificial Substrates ◽  
Diatom Community ◽  
Shallow Marine ◽  
Diatom Communities ◽  
Light Microscopic Analysis ◽  
First Time

In this study, the diatoms of three alternative habitats (epilithon, epiphyton and artificial sub-strate) were compared to understand the differences in composition on artificial and natural sub-strates. For this purpose, the samples were collected weekly between 11th August and 2nd Septem-ber 2016 at a sampling site in a shallow marine lake, Mrtvo More (Dead Sea) on Lokrum Island near Dubrovnik (South Adriatic, Croatia). In addition to detailed light microscopic analysis, ultrastructural analysis of benthic diatoms from Lake Mrtvo More was performed for the first time using scanning electron microscopy (SEM). A total of 97 taxa were identified in 12 samples. Cocconeis scutellum Ehrenberg and Halamphora coffeiformis (C.Agardh) Levkov were the most frequent taxa in the samples. Shannon-Wiener diver-sity index (H’) values varied from 1.78 (in September on Padina sp.) to 4.52 (in August on glass). According to non-metric multidimensional scaling ordination, there were two groups: epilithon and artificial glass substrate as Group1 and macroalgae as Group2. The results of the analysis showed that the diatom communities developing on artificial sub-strates accurately correspond to the diatom community of a rock substrate and thus can be used as a representative alternative tool for studies of epilithic diatoms in further experiments.

Epilithic diatoms of the Clyde Estuary

1986 ◽  
Vol 90 ◽  
pp. 151-156
Author(s):  
R. O. McLean ◽  
T. A. K. Gow ◽  
J. Webster ◽  
A. Arthur ◽  
D. J. Curtis
Keyword(s):  
Species Diversity ◽  
Dominant Species ◽  
Niche Breadth ◽  
High Tide ◽  
Diatom Community ◽  
Valve Morphology ◽  
Epilithic Diatoms ◽  
Species Succession ◽  
Diatom Communities ◽  
Epilithic Diatom

SynopsisEpilithic diatom communities of the Clyde Estuary demonstrated no spring or autumn bloom. Species diversity and dominance were stable at the ends of the estuary and fluctuated through the year in midestuary. Species succession differed from regions where one species dominated throughout the year, e.g. Opephora martyi Heribaud at Bowling (high tide), to those where the dominant species was constantly changing e.g. Erskine (low tide). In all 307 species were recorded, twenty-nine very rare, 172 rare, nineteen were abundant, some e.g. Opephora martyi, Navicula mutica var. cohnii (Hilse) Grun. having wide niche breadth (B>60). others being restricted in their distribution e.g. Nitzschia paleacea Kütz. (B=10.4), Navicula pseudocomoides Hendey (B = 14–8). N. mutica var. cohnii and var. mutica Kütz. were difficult to distinguish in terms of valve morphology, as intermediate forms existed. In the estuary, smaller valves occurred towards the freshwater end. Two clones, originating from a 12/μm and a 26 nm valve (length) corresponding to descriptions of var. cohnii and var. mutica respectively, behaved similarly in culture throughout a range of salinity, in terms of size expression, suggesting no taxonomic difference. Diatom community photosynthesis was affected by salinity, reflecting the site of origin.

scholarly journals Organochlorine Pesticides in Freshwater Fish from the Zagreb Area

2007 ◽  
Vol 58 (2) ◽  
pp. 187-193 ◽  
Author(s):  
Jasna Bošnir ◽  
Dinko Puntarić ◽  
Zdenko Šmit ◽  
Maja Klarić ◽  
Matijana Grgić ◽  
...  
Keyword(s):  
Freshwater Fish ◽  
Organochlorine Pesticides ◽  
Sampling Site ◽  
Fish Family ◽  
Fish Samples ◽  
Sava River ◽  
Zagreb Area ◽  
Concentration Limits ◽  
The Sava River ◽  
Group 1

Organochlorine Pesticides in Freshwater Fish from the Zagreb AreaThe aim of this study was to determine the level of organochlorine pesticides in freshwater fish from the Zagreb area, Croatia. The study included 215 freshwater fish samples from three sites: the Sava River, Lake Jarun, and five fishponds from the Zagreb surroundings. Organochlorine pesticides DDT and derivates, HCH, HCB, lindane, aldrin, dieldrin, endrin, heptachlor with epoxide, and methoxychlor were determined using the GC-ECD method. The determined amounts of organochlorine pesticides were within allowed concentration limits in all analysed fish samples. Median values ranged from below the detection limit of 0.01 μg kg-1 for dieldrin and metoxychlor to 2.00 μg kg-1 for DDT in the Cyprinidae fish family from the Sava River, Zagreb sampling site (group 1).This study has confirmed pesticide persistence in the overall ecosystem in our country despite the ban of some thirty years ago, like in many other parts of the world.

scholarly journals Lost Energy of Water Spilled over Hydropower Dams

2021 ◽  
Vol 13 (16) ◽  
pp. 9119
Author(s):  
Andrej Predin ◽  
Matej Fike ◽  
Marko Pezdevšek ◽  
Gorazd Hren
Keyword(s):  
Power Plants ◽  
Flood Events ◽  
Energy Potential ◽  
Climate Conditions ◽  
Hydropower Plants ◽  
Hydropower Dams ◽  
Sava River ◽  
Analytical Assessment ◽  
The Sava River

The present paper presents a view of water spilled over hydropower plants as an energy loss. In the current climate conditions, flood events are becoming more frequent due to human impact on the environment; water spills are also more frequent, which means more and more energy is lost. How much water is spilled and, consequently, how much energy is lost is shown in the present article on the chain of power plants on the Sava River in the five years from 2015 to 2019. An analytical assessment of the current situation in the lock was carried out, which showed that the available water through the locks could be used efficiently. The paper presents a case study of one overflow event lasting 48 h. The calculated theoretical losses of energy (of spilled water) and possible technical implementation for capturing losses are given. The proposed technical implementation is based on established technology, so we could expect that the approach is feasible. The results show that the estimated spilled water energy potential reaches about 40% of the actual spilled water or energy lost.

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