scholarly journals EARLY SUMMER ZOOPLANKTON OF LAKE VOZHE AND LACHA (VOLOGDA REGION)

2021 ◽  
pp. 56-76
Author(s):  
V. Lazareva ◽  
R. Sabitova
Keyword(s):  
Organic Pollution ◽  
Early Summer ◽  
Water Bodies ◽  
Total Biomass ◽  
Daily Production ◽  
Composition And Structure ◽  
Oligotrophic Water ◽  
Order Of Magnitude ◽  
White Sea Basin ◽  
Lake Waters

In June 2015, zooplankton (Cladocera, Copepoda, Rotifera) of lakes Vozhe and Lacha, Svid’ River and the headwaters of the Onega River (catchment of the Onega River, White Sea basin) was examined. It was found that crustaceans (mainly the copepods Mesocyclops leuckarti and Eudiaptomus gracilis) dominated the community. The biomass of zooplankton (<1 g / m3) indicated a low food supply for fish (poorly fed water bodies), compared with the beginning of the 1970s, it decreased by 4–10 times. The composition and structure of the community characterized the ecosystem status of the Lake Vozhe as eutrophic, and Lake Lacha as mesotrophic. Changes in the structure of zooplankton over 40 years testified to the eutrophication of the ecosystem of Lake Vozhe and stabilization at the level of mesotrophy of Lake Lacha. In the lakes, the dispersal and relatively high abundance of some thermophilic species (Polyarthra luminosa, Thermocyclops crassus), indicators of eutrophic conditions that were previously absent in the community, were revealed. The productivity (14–34 cal / m2 × day) and the respiration rate of zooplankton (61–122 cal / m2 × day) of the lakes corresponded to the level of northern oligotrophic water bodies. It was shown that at the beginning of summer a significant part of the zooplankton production was consumed by planktonic predators (mainly copepods). Fishes had access to about 15% of the daily production of zooplankton in Lake Vozhe and up to 43% in Lake Lacha. A small proportion of filter feeders (30–60% of the total biomass) was recorded in the modern zooplankton of lakes. By 2015, the filtration capacity of plankton from lakes Vozhe and Lacha decreased by an order of magnitude compared to that in the 1980s. The low self-cleaning ability of lake waters is discussed as the main reason for the growing organic pollution and increased silt accumulation in their ecosystems.

scholarly journals Physicochemical Characteristics of the Okomu Wetland, Edo State, Nigeria

2020 ◽  
Vol 4 (2) ◽  
pp. 398-410
Author(s):  
A.E. Ogbeibu ◽  
S.I Ehiorobo
Keyword(s):  
Physicochemical Parameters ◽  
Forest Canopy ◽  
Oxygen Demand ◽  
Water Quality Assessment ◽  
Organic Pollution ◽  
Physicochemical Characteristics ◽  
Water Bodies ◽  
Temporary Ponds ◽  
Forested Wetland ◽  
Sampling Protocols

Water quality assessment was carried out within the 202 km2 Okomu National Park located within the 1,082km2Okomu Forest Reserve between January 2017 and December 2018. Water sampling was carried in ten compartments of approximately 1.6km2 each, covering Ponds, Stream and River, based on easy accessibility. No such study has been carried out for the Okomu Wetlands in the past three decades. Sampling protocols, laboratory analysis and quality control/quality assurance measures followed standard procedures. All physicochemical parameters showed significant (P < 0.001) spatial variations. The maximum and minimum values obtained for physicochemical parameters of the Okomu Wetland are 23.6 and 38.0°C air temperature; 21.0 – 38°C water temperature; 0.15 – 1.02m water level; 16.7 – 150.7mg/l total dissolved Solids (TDS); 0.5 – 18.8mg/l total suspended Solids (TSS); 0.2 – 14.8mg/l turbidity; 40. 0 – 307.4µS/cm electrical conductivity (EC); 4.4 – 6.7 pH; 0.02 – 0.14mg/l salinity; 0.7 – 5.5mg/l dissolve oxygen (DO); 0.5 – 3.8mg/l biochemical oxygen demand (BOD); 1.5 – 120.2mg/l chemical oxygen demand (COD); 23.8 – 593.6mg/l bicarbonates (HCO3); 69.9 – 245.3mg/l Chlorine (Cl); 0.02 – 0.59mg/l nitrite (NO2); 0.11 – 2.34mg/l nitrate (NO3); 0.04 – 2.11mg/l ammonium-nitrogen (NH4N); 0.05 – 2.96mg/l sulphate (SO4); 0.09 – 9.2mg/l phosphorus (P); 0.20 – 2.72mg/l sodium (Na), 0.03 – 1.32mg/l potassium (K); 0.88 – 5.88mg/l calcium (Ca); 0.13 – 3.1mg/l magnesium (Mg); 5.8 – 18.9mg/l iron (Fe); 0.04 – 1.1mg/l manganese (Mn); 0.02 – 0.09mg/l copper (Cu); 0.93 – 6.0mg/l zinc (Zn); 0.01 – 2.9mg/l lead (Pb); 0.01 – 0.18mg/l cadmium (Cd); 0.06 – 4.0mg/l chromium (Cr); 0.01 – 0.15mg/l nickel (Ni); 0.01 – 11mg/l vanadium (V). Air and water temperatures were mostly influenced by forest canopy cover. pH levels indicate that the water bodies within the forested wetland are slightly acidic. Higher DO values were recorded in the Arhakhuan Stream and Okomu River (Agekpukpu and Iron bridge) than in the temporary ponds. BOD levels of greater than 1mg/l were observed which is indicative of slight levels of organic pollution. Higher concentrations of TDS, TSS, turbidity, EC, Colour, HCO3, NH4N, NO2, NO3, P, Na, K, Ca Mg and heavy metals were recorded in the temporary ponds than in the Stream and River. Research on water bodies within wetlands should be carried out routinely in order to monitor changes in the water conditions that could occur overtime whether natural or anthropogenic. This becomes even more pertinent in the light of glaring impacts of climate change and increasing environmental modifications.

scholarly journals GENETIC IDENTIFICATION OF AQUATIC INVERTEBRATES OF KAZAKHSTAN AS INDICATORS OF ORGANIC POLLUTANTS

2018 ◽  
pp. 139-148
Author(s):  
Alexandr Anatoljevich Volkov ◽  
Larisa Anatoljevna Kovaljova ◽  
Tatjana Timofeevna Troshina ◽  
Zhanara Omirbekovna Mazhibaeva ◽  
Dmitrij Valerjevich Pilin ◽  
...  
Keyword(s):  
Dna Barcoding ◽  
Phylogenetic Trees ◽  
Aquatic Invertebrates ◽  
Species Abundance ◽  
Ecological Status ◽  
Taxonomic Status ◽  
Organic Pollution ◽  
Water Bodies ◽  
Genetic Identification ◽  
Morphological Identity

The article deals with carrying out DNA barcoding of aquatic invertebrates of Kazakhstan to identify their taxonomic status as organic pollution indicators. 33 species of the Balkhash-Alakol basin and the Zhayik river were analyzed. 21 species correlate (95-100%) with previously published sequences of invertebrates with well-known classifications in the GenBank and BOLD databases. The taxonomic discrepancy in morphometric and genetic parameters in certain species has been revealed. The discrepancy may be caused by the morphological identity in chironomids at a larval stage. The phylogenetic trees of the investigated species within the families Chironomidae and Moinidae have been indicated. Chironomids are represented by ten clades of different types of genetic polymorphism of DNA gene. Genetic links of Moinidae are detected in four groups including a cryptic species from Lake Alakol. It has been stated that in distribution of cryptic taxons in Moina family factors of salinity and depth of the lake are important, as well as differences in depth. Molecular DNA-barcoding of invertebrates of Kazakhstan should be continued with covering a greater number of species and several replications, with qualified primary fixation of subjects of research and a sufficient number of samples. Authenticity of composition defining, species abundance, species characteristics of aquatic invertebrates from the water bodies of poorly explored arid regions is necessary for using them as indicators of the ecological status of water bodies.

scholarly journals The impact of economic activity on the ecological state of the water reservoirs of Ishim

2018 ◽  
Vol 7 (3) ◽  
pp. 98-103
Author(s):  
Natalia Evgenievna Suppes
Keyword(s):  
Private Sector ◽  
Coastal Zone ◽  
Visual Assessment ◽  
Organic Pollution ◽  
The State ◽  
Water Bodies ◽  
Economic Activities ◽  
Water Reservoirs ◽  
Anthropogenic Pressures ◽  
The Impact

This article analyzes the problem of the state of the water bodies in Ishim by anthropogenic pressures. The study shows that the water reservoirs are negatively influenced by the economic activities of the population. The author defines their main directions: industrial wastewater discharge to the city water bodies, construction and operation of engineering constructions, activity in the private sector. To assess the state of the water bodies the author uses the results of the visual assessment of the state of the riverbeds and their coastal zone, the organoleptic water indicators (turbidity, color and smell), the analysis of the hydrobiological studies (determination of the degree of saprobity of the water bodies as indicators ciliated infusoria). The study showed the satisfactory condition of all the water reservoirs and the non-critical impact. As the enterprises for light manufacturing and food industries in Ishim are not sources of chemical, organic and other pollution the visual assessment didn't reveal significant deformations of the riverbeds and any changes in the coastal zone. The impact of the private sector is local and not the significant cause of organic pollution.

A model for predicting sediment-water partition of toxic chemicals in aquatic environments

2002 ◽  
Vol 46 (11-12) ◽  
pp. 437-442 ◽  
Author(s):  
H. Shimazu ◽  
E. Ohnishi ◽  
N. Ozaki ◽  
T. Fukushima ◽  
O. Nakasugi
Keyword(s):  
Organic Matter ◽  
Partition Coefficient ◽  
Water Bodies ◽  
Toxic Chemicals ◽  
Published Data ◽  
Aquatic Environments ◽  
Inorganic Matter ◽  
Water Partition Coefficient ◽  
Japanese Water ◽  
Order Of Magnitude

In order to investigate the characteristics of sediment-water partition of chemicals in aquatic environments using published data, we developed a model for predicting the sediment-water partition coefficient (Kp) as the sum of sorption to sediment organic matter and sorption to sediment inorganic matter. This model is so successful that the differences between Kp (median for a variety of Japanese water bodies) and pre-Kp (predicted Kp) are within one order of magnitude in 24 out of 28 chemicals.

scholarly journals Semiannual and annual variations in the height of the ionospheric F2-peak

2000 ◽  
Vol 18 (3) ◽  
pp. 285-299 ◽  
Author(s):  
H. Rishbeth ◽  
K. J. F. Sedgemore-Schulthess ◽  
T. Ulich
Keyword(s):  
Solar Activity ◽  
Computational Models ◽  
Annual Variation ◽  
Late Summer ◽  
Early Summer ◽  
Atmospheric Composition ◽  
Annual Variations ◽  
Composition And Structure ◽  
Semiannual Variation ◽  
Quiet Day

Abstract. Ionosonde data from sixteen stations are used to study the semiannual and annual variations in the height of the ionospheric F2-peak, hmF2. The semiannual variation, which peaks shortly after equinox, has an amplitude of about 8 km at an average level of solar activity (10.7 cm flux = 140 units), both at noon and midnight. The annual variation has an amplitude of about 11 km at northern midlatitudes, peaking in early summer; and is larger at southern stations, where it peaks in late summer. Both annual and semiannual amplitudes increase with increasing solar activity by day, but not at night. The semiannual variation in hmF2 is unrelated to the semiannual variation of the peak electron density NmF2, and is not reproduced by the CTIP and TIME-GCM computational models of the quiet-day thermosphere and ionosphere. The semiannual variation in hmF2 is approximately "isobaric", in that its amplitude corresponds quite well to the semiannual variation in the height of fixed pressure-levels in the thermosphere, as represented by the MSIS empirical model. The annual variation is not "isobaric". The annual mean of hmF2 increases with solar 10.7 cm flux, both by night and by day, on average by about 0.45 km/flux unit, rather smaller than the corresponding increase of height of constant pressure-levels in the MSIS model. The discrepancy may be due to solar-cycle variations of thermospheric winds. Although geomagnetic activity, which affects thermospheric density and temperature and therefore hmF2 also, is greatest at the equinoxes, this seems to account for less than half the semiannual variation of hmF2. The rest may be due to a semiannual variation of tidal and wave energy transmitted to the thermosphere from lower levels in the atmosphere.Key words: Atmospheric composition and structure (thermosphere - composition and chemistry) - Ionosphere (mid-latitude ionosphere)

Seasonal succession of diatom epiphyton on dense mats of Lemna minor

1985 ◽  
Vol 63 (12) ◽  
pp. 2332-2339 ◽  
Author(s):  
L. G. Goldsborough ◽  
G. G. C. Robinson
Keyword(s):  
Lemna Minor ◽  
Algal Growth ◽  
Seasonal Succession ◽  
Ambient Air ◽  
Early Spring ◽  
Early Summer ◽  
Algal Community ◽  
Light Limitation ◽  
Total Biomass

Annual sequences of biomass, species diversity, and community composition of epiphytic diatoms on a dense mat of Lemna minor L. growing in a freshwater marsh are described. In 2 successive years, maximum biomass occurred in early spring prior to occlusion of the water surface by the mat, while diversity reached relative maxima in the early summer (during a period of declining total biomass) and late fall. Ambient air temperature (possibly through a relationship with in situ metabolic activity and nutrient availability) was significantly correlated with community ordination scores on a temporal basis. Depth profile maxima of diatom abundance on vertically positioned artificial substrata occurred below the mat, suggesting that light limitation of algal growth within dense mats may be of lesser importance. Dominant diatom species in the spring and fall were generally ubiquitous in the surrounding marsh, while the major taxa in midsummer, Achnanthes hungarica, Amphora veneta, and Navicula twymaniana, may be specific to the Lemna microhabitat. The development of algal community specificity within a defined seasonal range is discussed in terms of the relative importance of host exudates versus exogenous nutrients as the basis for algal-substratum associations.

Interpretation of Radiophosphate Dynamics in Lake Waters

1992 ◽  
Vol 49 (2) ◽  
pp. 252-258 ◽  
Author(s):  
T. R. Fisher ◽  
D. R. S. Lean
Keyword(s):  
Steady State ◽  
Membrane Filtration ◽  
Cell Damage ◽  
Gel Filtration ◽  
Turnover Time ◽  
Steady State Distribution ◽  
State Distribution ◽  
Order Of Magnitude ◽  
Lake Waters ◽  
Functional Components

Models of planktonic phosphorus dynamics over the last 30–40 yr depend on the steady-state distribution of isotope for the determination of compartment size. Radiophosphate data for P-deficient lakes in summer have shown a steady-state distribution of 1–15% of 32P in the filtrate within 0.5–5 h. To explain this, a phosphate back-flux term from the particulate fraction has been widely accepted (phosphate is believed to be released from the internal pools of phosphate consumers and by excretion from herbivores and bacterivores). We show that dialysis of lake water at isotopic steady state provides values for the dissolved [32P]PO4 compartment up to an order of magnitude lower than those obtained by membrane filtration and gel filtration chromatography. This apparently occurs as a result of minor cell damage during filtration when most of the [32P]PO4 is in the particulate pool. Consequently, the size of the phosphate pool and the magnitudes of phosphate uptake and back-flux may have been overestimated by up to a factor of 10. Furthermore, the turnover time of the particulate compartment lengthens from ~ 40 min to > 1 d, which is more consistent with models describing P fluxes between functional components of the plankton.

scholarly journals The role of land use types and water chemical properties in structuring the microbiomes of a connected lakes system

2018 ◽  
Author(s):  
Sophi Marmen ◽  
Lior Blank ◽  
Ashraf Al-Ashhab ◽  
Assaf Malik ◽  
Lars Ganzert ◽  
...  
Keyword(s):  
Water Quality ◽  
Land Use ◽  
Microbial Communities ◽  
Drainage Basin ◽  
Chemical Properties ◽  
Early Summer ◽  
Water Bodies ◽  
Drainage Basins ◽  
Ecological Changes ◽  
Freshwater Bodies

Lakes and other freshwater bodies are intimately connected to the surrounding land, yet to what extent land-use affects the quality of freshwater and the microbial communities living in various freshwater environments is largely unknown. We address this question through an analysis of the land use surrounding 46 inter-connected lakes located within 7 different drainage basins in northern Germany, and the microbiomes of these lakes during early summer. Lake microbiome structure was not determined by the specific drainage basin or by basin size, and bacterial distribution did not seem to be limited by distance. Instead, land use within the drainage basin could predict, to some extent, NO2+NO3 concentrations in the water, which (together with temperature, chlorophyll a and total phosphorus) affected water microbiome structure. Land use directly surrounding the water bodies, however, had little observable effects on water quality or the microbiome. Several microbial lineages, including environmentally important Cyanobacteria and Verrucomicrobia, were differentially partitioned between the lakes. As the amount of available data on land use (e.g. from remote sensing) increases, identifying relationships between land use, aquatic microbial communities and their effect on water quality will be important to better manage freshwater resources worldwide, e.g. by systemically identifying water bodies prone to ecological changes or the presence of harmful organisms.

scholarly journals CDOM Absorption Properties of Natural Water Bodies Along Extreme Environmental Gradients

2020 ◽  
Author(s):  
Jakob J. Stamnes ◽  
Ciren Nima ◽  
Børge Hamre ◽  
Øyvind Frette ◽  
Yi-Chun Chen ◽  
...  
Keyword(s):  
Environmental Gradients ◽  
Lake Victoria ◽  
Eutrophic Lake ◽  
Mean Value ◽  
Water Bodies ◽  
Spectral Slope ◽  
Uv Spectrum ◽  
Absorption Properties ◽  
Oligotrophic Water ◽  
The Mean

&lt;p&gt;We present absorption properties of colored dissolved organic matter (CDOM) sampled in six different water bodies along extreme altitudinal, latitudinal, and trophic state gradients. Three sites are in Norway: the mesotrophic Lysefjord (LF), Samnangerfjord (SF), and R&amp;#248;st Coastal Water (RCW); two sites are in China: the oligotrophic Lake Namtso (LN) and the eutrophic Bohai Sea (BS); and one site is in Uganda: the eutrophic Lake Victoria (LV).&lt;/p&gt;&lt;p&gt;&amp;#160;&lt;/p&gt;&lt;p&gt;The site locations ranged from equatorial to subarctic regions, and they included water types from oligotrophic to eutrophic and altitudes from 0 m to 4700 m. The mean CDOM absorption coefficients at 440 nm [a&lt;sub&gt;CDOM&lt;/sub&gt;(440)] and 320 nm [a&lt;sub&gt;CDOM&lt;/sub&gt;(320)] varied in the ranges 0.063&amp;#8211;0.35 m&lt;sup&gt;-1&lt;/sup&gt; and 0.34&amp;#8211;2.28 m&lt;sup&gt;-1&lt;/sup&gt;, respectively, with highest values in LV, Uganda and the lowest in the high-altitude LN, Tibet.&lt;/p&gt;&lt;p&gt;&amp;#160;&lt;/p&gt;&lt;p&gt;The mean spectral slopes S&lt;sub&gt;280-500&lt;/sub&gt; and S&lt;sub&gt;350-500&lt;/sub&gt; were found to vary in the ranges of 0.017&amp;#8211;0.032 nm&lt;sup&gt;-1&lt;/sup&gt; and 0.013&amp;#8211;0.015 nm&lt;sup&gt;-1&lt;/sup&gt;, respectively. The highest mean value for S&lt;sub&gt;280-500&lt;/sub&gt; as well as the lowest mean value for S&lt;sub&gt;350-500&lt;/sub&gt; were found in LN. Scatter plots of S&lt;sub&gt;280-500&lt;/sub&gt; versus a&lt;sub&gt;CDOM&lt;/sub&gt;(440) and a&lt;sub&gt;CDOM&lt;/sub&gt;(320) values ranges revealed a close connection between RCW, LF, and SF on one side, and BS and LV on the other side.&lt;/p&gt;&lt;p&gt;&amp;#160;&lt;/p&gt;&lt;p&gt;CDOM seems to originate from terrestrial sources in LF, SF, BS, and LV, while RCW is characterized by autochthonous-oceanic CDOM, and LN by autochthonous CDOM. Photobleaching of CDOM is prominent in LN, demonstrated by absorption towards lower wavelengths in the UV spectrum. We conclude that high altitudes, implying high levels of UV radiation and oligotrophic water conditions are most important for making a significant change in CDOM absorption properties.&lt;/p&gt;&lt;p&gt;Considering all study sites, we find a strong negative linear relationship between the base-10 logarithm of a&lt;sub&gt;CDOM&lt;/sub&gt;(440) and the spectral slope S&lt;sub&gt;280-500&lt;/sub&gt;, and also between the base-10 logarithm of a&lt;sub&gt;CDOM&lt;/sub&gt;(320) and the spectral slope S&lt;sub&gt;280-500&lt;/sub&gt;.&lt;/p&gt;

Spatial and Temporal Distribution of Chlorophyll a and Pheopigments in Surface Waters of Lake Erie

1974 ◽  
Vol 31 (3) ◽  
pp. 265-274 ◽  
Author(s):  
Walter A. Glooschenko ◽  
James E. Moore ◽  
Richard A. Vollenweider
Keyword(s):  
Chlorophyll A ◽  
Surface Waters ◽  
Lake Erie ◽  
Degradation Products ◽  
Temporal Distribution ◽  
Water Bodies ◽  
Zooplankton Abundance ◽  
Central Basin ◽  
Western Basin ◽  
Oligotrophic Water

Chlorophyll a analyses including pheopigments were made on water samples taken on 10 cruises on Lake Erie between April and December, 1970. The highest mean chlorophyll a values of approximately 11 μg/liter occurred in the mid-Western Basin, with a second maximum of 6 μg/liter off Erie, Pennsylvania. The southern shore is also characterized by high values of chlorophyll to the east of Cleveland, Ohio. The lowest yearly means were found in the eastern portion of the Central Basin and most of the Eastern Basin (approximately 3 μg/liter.) Ratios of chlorophyll a between the Eastern, Central, and Western basins have a yearly mean of 1:1.4:2.8, respectively; with maximum differences in the summer, i.e. late August, the ratio was 1:1.5:7.2.Pheopigment concentration in the surface waters reached a maximum in late October corresponding to the fall overturn of the lake and subsequent resuspension of organic matter containing degradation products from the bottom of the lake. No significant correlation was found between zooplankton abundance and pheopigment concentration as in other water bodies studied. This may indicate that zooplankton food chains are primarily detrital in Lake Erie, with grazing of living phytoplankton playing a lesser role compared with more oligotrophic water bodies.

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