scholarly journals The state of zooplankton communities in the lower Dniester area under the conditions of river regulation and actual climatic changes

2021 ◽  
Author(s):  
Liubovi Lebedenco ◽  
◽  
Mykhailo Nabokyn ◽  
Nadejda Andreev ◽  
Svetlana Kovalyshyna ◽  
...  
Keyword(s):  
Zooplankton Community ◽  
River Regulation ◽  
Zooplankton Biomass ◽  
Individual Characteristics ◽  
The State ◽  
Current State ◽  
Zooplankton Communities ◽  
Physical And Chemical ◽  
Quantitative Indicators ◽  
Planktonic Communities

The study focuses on zooplankton communities of the Lower Dniester. The quantitative indicators of plankton are given and the annual dynamics is described. An assessment of the current state of the river according to the state of zooplankton communities is presented, together with a comparison with historical data, at different stages of river regulation. The changes that occurred in the river zooplankton since the 1950s were analyzed. The relationships between individual characteristics of planktonic communities and the physical and chemical characteristics of the river was also investigated. A comparison of actual data with those collected during 70-80s revealed no significant changes in the structure of the zooplankton community. The proportion of different groups of zooplankton organisms changed insignificantly, the saprobity indices improved slightly, and the average zooplankton biomass did not change. However, compared to the period before 1950s, prior to river regulation for hydropower purposes the role of rotifers in the community was reduced. It might be difficult to identify the main factor determining the development of zooplankton in the Lower Dniester, in order to understand the processes taking place in planktonic communities, it is necessary to analyze the complex impact of hydrological and hydrochemical factors on planktonic communities.

scholarly journals Zooplankton Community Responses to Oxygen Stress

Water ◽  
2020 ◽  
Vol 12 (3) ◽  
pp. 706 ◽  
Author(s):  
Maciej Karpowicz ◽  
Jolanta Ejsmont-Karabin ◽  
Joanna Kozłowska ◽  
Irina Feniova ◽  
Andrew R. Dzialowski
Keyword(s):  
Zooplankton Community ◽  
Oxygen Depletion ◽  
Zooplankton Biomass ◽  
Oxygen Stress ◽  
Carbon Transfer ◽  
Oxygen Conditions ◽  
Anoxic Layer ◽  
Zooplankton Communities ◽  
The Impact

Recent changes in climate and eutrophication have caused increases in oxygen depletion in both freshwater and marine ecosystems. However, the impact of oxygen stress on zooplankton, which is the major trophic link between primary producers and fish, remains largely unknown in lakes. Therefore, we studied 41 lakes with different trophic and oxygen conditions to assess the role of oxygen stress on zooplankton communities and carbon transfer between phytoplankton and zooplankton. Samples were collected from each lake at the peak of summer stratification from three depth layers (the epilimnion, metalimnion, and hypolimnion). Our results revealed that freshwater zooplankton were relatively tolerant to anoxic conditions and the greatest changes in community structure were found in lakes with the highest oxygen deficits. This caused a switch in dominance from large to small species and reduced the zooplankton biomass in lower, anoxic layers of water, but not in the upper layers of water where the oxygen deficits began. This upper anoxic layer could thus be a very important refuge for zooplankton to avoid predation during the day. However, the reduction of zooplankton in the lower water layers was the main factor that reduced the effectiveness of carbon transfer between the phytoplankton and zooplankton.

Development of the zooplankton community in the growing ponds of the Novosibirsk region when growing carp fingerlings using the probiotic “Sibmos-PRO”

2020 ◽  
pp. 44-57
Author(s):  
Elena Vital’evna Pishchenko ◽  
Irina Vladimirovna Moruzi ◽  
Valentina Sergeevna Osipova ◽  
Oksana Andreyevna Vorobyova
Keyword(s):  
Zooplankton Community ◽  
Zooplankton Biomass ◽  
Natural Food ◽  
Reservoir Temperature ◽  
Structure Changes ◽  
Quantitative Characteristics ◽  
Abiotic And Biotic Factors ◽  
Zooplankton Communities ◽  
Molecular Compounds ◽  
Secondary Link

Quantitative characteristics of the zooplankton community in cyprinid growth ponds were studied. As a method of stimulating the growth and development of hydrobionts, the introduction of probiotic into water and feed was used. It was taken into account that zooplankton is the main and significant part of the natural food base for young carp grown in ponds. At the early stages of ontogenesis, the activity of digestive enzymes in carp is extremely low, the larva practically does not assimilate high-molecular compounds [7]. At the same time, zooplankton is a secondary link in the food chain of aquatic ecosystems, and plays an important role in their functioning and structure. Changes in plankton fauna can lead to modification of the aquatic ecosystem [18]. The development and existence of zooplankton pond communities during the growing season is influenced by a combination of abiotic and biotic factors, in particular: the composition and abundance of ichthyofauna, fluctuations in the water level in the reservoir, temperature, «flowering» of water, etc. Due to a set of indicators, and the strengthening or weakening of certain factors, it is possible to observe changes in the seasonal dynamics of zooplankton communities, which are more uneven than progressive. In the conducted research on the use of the probiotic Sibmos-Pro-antimicrobial feed concentrate based on mananoligosaccharides (obtained from yeast cell walls) in combination with the bacteria Bacillus Subtilis and Bacillus Licheniformis. Its introduction was carried out both in feed and in feed and water. Studies have shown that, judging by the productivity of carp and zooplankton biomass, the probiotic is absorbed by hydrobionts and affects the increase in the number and productivity of crustaceans. The level of development of the natural food supply increases, which ensures an increase in fish production. The structure of the zooplankton community changes under the influence of probiotics.

Cladoceran- and copepod-dominated zooplankton communities graze at similar rates in low-productivity lakes

1998 ◽  
Vol 55 (2) ◽  
pp. 414-422 ◽  
Author(s):  
Hélène Cyr
Keyword(s):  
Zooplankton Community ◽  
Grazing Rate ◽  
Taxonomic Composition ◽  
Zooplankton Biomass ◽  
Phytoplankton Assemblage ◽  
Different Types ◽  
The Difference ◽  
Zooplankton Communities ◽  
Copepod Biomass

Many studies suggest that the taxonomic composition of a zooplankton community should determine its grazing rate and selectivity for different types of particles. It is generally believed that copepod-dominated communities should (i) have lower grazing rates and (ii) consume larger particles than communities dominated by large cladocerans. I tested these hypotheses in situ by comparing zooplankton grazing in 19 communities from low-productivity lakes where the zooplankton ranged from >99% copepod biomass to >90% large cladoceran biomass (Holopedium gibberum, Daphnia spp.). The zooplankton grazed 1-14% of total chlorophyll per day and 0-17% of the chlorophyll in algae <35 µm per day. Grazing rates increased with increasing zooplankton biomass (r2 = 0.34, P < 0.01), but once the effect of zooplankton biomass was accounted for, similar grazing rates were found in copepod- and in cladoceran-dominated communities. The difference in grazing rates on small algae and on the whole phytoplankton assemblage, on the other hand, varied systematically with zooplankton taxonomic composition. Holopedium-dominated communities were most efficient at grazing algae <35 µm, Bosmina-dominated communities had similar grazing rates on algae <35 µm and on the whole phytoplankton assemblage, and copepod-dominated communities had similar or slightly higher grazing rates on the whole phytoplankton assemblage. Qualitative differences in grazing selectivity of different zooplankton taxa are observed in complex natural communities.

Planktivory by the predacious cladoceran Bythotrephes longimanus: effects on zooplankton size structure and abundance

1999 ◽  
Vol 56 (10) ◽  
pp. 1865-1872 ◽  
Author(s):  
Eva Wahlström ◽  
Erika Westman
Keyword(s):  
Size Structure ◽  
Zooplankton Community ◽  
Zooplankton Biomass ◽  
Zooplankton Abundance ◽  
Large Species ◽  
Bythotrephes Longimanus ◽  
Total Zooplankton ◽  
Natural Systems ◽  
Phytoplankton Communities ◽  
Zooplankton Communities

In order to study density-dependent effects of invertebrate planktivory, four different densities of Bythotrephes longimanus were inoculated into mesocosm enclosures with a mixed zooplankton community. Changes in size structure and abundance of zooplankton and phytoplankton communities were recorded over a period of 3 weeks. High densities of Bythotrephes were able to reduce total zooplankton abundance, which was mainly due to a decrease in the density of the relatively large species Holopedium gibberum. The density of the smaller species Bosmina longirostris was also reduced with increasing densities of Bythotrephes, whereas rotifer abundance remained largely unaffected. The mean size of Holopedium increased with increasing densities of Bythotrephes. Despite the decrease in total zooplankton biomass in high-Bythotrephes treatments, no effect of Bythotrephes density on primary producers was observed. Our experiment shows that predacious cladocerans may reduce macrozooplankton biomass, large as well as small species. Predation from invertebrate planktivores results in a zooplankton community consisting of larger individuals. Comparing our experimental densities with densities of Bythotrephes found in natural systems suggests that invertebrate planktivores may influence size structure and abundance of zooplankton communities even in lakes with planktivorous fish.

Zooplankton as Water Quality Indicator in Shallow Lakes

2019 ◽  
Vol 16 (11) ◽  
pp. 4486-4490
Author(s):  
Olga Yurjevna Derevenskaya ◽  
Evgenia Sergeevna Prytkova ◽  
Elena Nikolaevna Unkovskaya
Keyword(s):  
Shallow Lakes ◽  
Trophic Status ◽  
Zooplankton Community ◽  
Biosphere Reserve ◽  
Physicochemical Studies ◽  
Taxonomic Groups ◽  
Zooplankton Communities ◽  
Quantitative Indicators ◽  
Individual Mass

Long-term studies (1998–2018) of shallow lakes Krugloe and Krutoe (Russia) were carried out. The trophic status of the lakes was estimated using physicochemical parameters of water and the indicators of zooplankton. Physicochemical studies of Krugloe and Krutoe lake water make it possible to classify these reservoirs as eutrophic according to their trophic status. The lakes are characterized by low water transparency, a high content of organic substances in water, the “blooming” of water is observed periodically, accompanied by the increase of pH to 8–9 units. The zooplankton communities of Krugloe and Krutoe lakes are characterized by relatively low species richness, the dominance of a small number of species, and the predominance of species that are indicators of eutrophic waters. Quantitative indicators of zooplankton are characterized by significant fluctuations in values over the years, the prevalence of rotifers. They showed that zooplankton community is a good indicator of the trophic state of lakes. Such indicators of zooplankton communities as the composition of dominant species, their number, the presence of indicator species, the quantitative indicators of zooplankton and individual taxonomic groups, and the average individual mass of the zooplankton can be used to characterize the trophic status of lakes. They can be recommended for use during monitoring of the lake condition in the Volga-Kama State Natural Biosphere Reserve.

scholarly journals Zooplankton communities as eutrophication bioindicators in tropical reservoirs

2014 ◽  
Vol 14 (4) ◽  
Author(s):  
Antonio José Gazonato Neto ◽  
Lidiane Cristina da Silva ◽  
Angelo Augusto Saggio ◽  
Odete Rocha
Keyword(s):  
Trophic State ◽  
Zooplankton Community ◽  
Water Level Fluctuations ◽  
System Productivity ◽  
Monitoring Tools ◽  
Chemical Measurements ◽  
Water Quality Change ◽  
Zooplankton Communities ◽  
Physical And Chemical

Eutrophication is a process characterized by an increase in the aquatic system productivity, which causes profound changes in the structure of its communities. Owing to the high environmental sensitivity of planktonic species, the study of their communities can indicate the deterioration of the environment. The Jaguari and Jacareí reservoirs are part of the Cantareira System, supplying water to São Paulo inhabitants and that has been affected by several forms of continuous human interference. Here we analyze some properties of the zooplankton community as bioindicators of eutrophication and water quality change. In situ physical and chemical measurements were carried out, water was collected for analysis and quantitative zooplankton samples were taken at eight sites in the two reservoirs, in both seasons, dry and rainy. Species were identified and their numerical abundances and biomasses were determined and used to estimate two biological indices. The overall trophic state and zooplankton structure, the Calanoida/Cyclopoida ratio and the k-dominance curves were associated with the disturbance levels, mainly represented by nutrient river inputs and by water level fluctuations. The Jaguari Reservoir was more eutrophicated than the Jacareí Reservoir, as evidenced by the obtained indices values. The zooplankton community properties used as indicators of the reservoir trophic state were useful monitoring tools.

Midsummer plankton development along a large temperate river: the St. Lawrence River

2000 ◽  
Vol 57 (S1) ◽  
pp. 7-15 ◽  
Author(s):  
Ben K Basu ◽  
J Kalff ◽  
B Pinel-Alloul
Keyword(s):  
Zooplankton Community ◽  
Lake Ontario ◽  
Zooplankton Biomass ◽  
Longitudinal Patterns ◽  
Chl A ◽  
Longitudinal Pattern ◽  
Temperate River ◽  
Total Zooplankton Biomass ◽  
St Lawrence River ◽  
Planktonic Communities

Midsummer planktonic communities were sampled in 1997 along a 425-km reach of the St. Lawrence River between Lake Ontario and Trois-Rivières (Quebec) to describe longitudinal patterns of plankton development. Chlorophyll a (Chl a) quickly declined as water flowed from Lake Ontario into the river. Thereafter, in the reach upstream from Montreal, Chl a was ~1 µg·L-1 and total phosphorus (TP) was ~10 µg·L-1. Downstream from Montreal, TP increased to 20-40 µg·L-1 and Chl a rose to 2-5 µg·L-1. Although Chl a increased concomitant with TP, phytoplankton may have been light limited at the more turbid downstream stations. Zooplankton biomass decreased from 40 µg dry mass·L-1 in Lake Ontario to 16 µg dry mass·L-1 at Brockville, 90 km downstream. Zooplankton biomass continued to decline and downstream from Montreal remained <10 µg dry mass·L-1, despite the increased TP and Chl a. Rotifers dominated the zooplankton community, but as in other temperate rivers, total zooplankton biomass was low (<10 µg dry mass·L-1). There was no longitudinal pattern in heterotrophic bacterial or flagellate abundance. A comparison of the inflow and outflow biomass of two fluvial lakes showed the lakes to contribute little to the downstream river plankton during summer.

scholarly journals SPATIAL-TEMPORAL DYNAMICS OF LITTORAL ZOOPLANKTON COMMUNITY OF THE OLEKSANDRIVKA RESERVOIR

2016 ◽  
Vol 72 (2) ◽  
pp. 75-80
Author(s):  
V. Trokhymets ◽  
D. Lukashov
Keyword(s):  
Seasonal Changes ◽  
Temporal Dynamics ◽  
Zooplankton Community ◽  
Qualitative And Quantitative ◽  
Species Complexes ◽  
Quantitative Development ◽  
Spatio Temporal ◽  
Density And Biomass ◽  
Zooplankton Communities ◽  
Quantitative Indicators

The analysis results of spatio-temporal dynamics of zooplankton communities from littoral of the Oleksandrivka reservoir are presented. The features of the seasonal changes in species composition, faunal and ecological spectrums, quantitative indicators (density and biomass) and the dominant species complexes of littoral zooplankton was revealed. The analysis of seasonal dynamics of qualitative and quantitative development of zooplankton in the littoral zone within the upper, middle and lower parts of the Oleksandrivka reservoir was conducted.

scholarly journals The current state and promising innovative directions to development methods for bioimplant sterilization

2019 ◽  
Vol 47 (7) ◽  
pp. 634-646
Author(s):  
V. V. Rozanov ◽  
I. V. Matveychuk
Keyword(s):  
Radiation Dose ◽  
State Of The Art ◽  
Optimal Solution ◽  
The State ◽  
Radiation Sterilization ◽  
Individual Factor ◽  
Current State ◽  
Chemical Factors ◽  
Physical And Chemical ◽  
Development Methods

We have analyzed the state-of-the-art methods for sterilization of bone implants. The problem of finding effective bioimplant sterilization methods is still far from its optimal solution and remains as urgent as before. The factors limiting further development of the main biomaterial sterilization methods include limitations related to each existing method and the use of technologies with sterilizing effect. Comparative analysis of the main techniques for bioimplant sterilization that are used in medical and biological areas (treatment with ethylene oxide, radiation, wet warmth, liquid media, and ozone) allows for a conclusion on the advantages of the radiation sterilization. However, the choice is challenged by the dilemma: higher radiation dose would increase the sterilization effect, but at the same time can lead to multiple morphological abnormalities in the tissues, deterioration of their mechanical characteristics, destruction of morphogenetic proteins and consequently to lower efficacy of the reparative bone formation. As a  result, the material can become unsuitable for clinical use. One of the real approaches to solve this problem is to use as low absorbed radiation dose as possible during irradiation of biomaterials, at least to 15 kGy. The developments made by the authors within the last years have shown that such a  result can be achieved by the use of combines sterilization techniques based on combines effects of a  number of physical and chemical factors on the biomaterial being sterilized. Mutual enhancement of the sterilizing effects of these factors creates prerequisites for their synergy, whereby the intensity of each factor can be reduced. This makes it possible to decrease the degree of harmful adverse events associated with each individual factor with higher total effect. The search for innovative solutions for the urgent problems of the bone bioimplant sterilization, for the development of the state-of-the-art health-sparing technologies can be successful only with unification of the efforts by specialists from related sciences. This would allow for creating of breakthrough technologies for sterilization and for optimization of this procedure with achievement of its high efficacy.

Features of the formation of zooplankton of the upper Ob in the conditions of the influence of the megapolis

2021 ◽  
pp. 21-31
Author(s):  
Lyubov Semyonovna Vizer ◽  
Alexander Mikhailovich Vizer ◽  
Iuliia Vital’evna Tsygankova Iuliia Vital’evna Tsygankova ◽  
Andrey Valeryevich Tsapenkov
Keyword(s):  
Species Diversity ◽  
Zooplankton Community ◽  
Organic Pollution ◽  
Zooplankton Biomass ◽  
Organic Contamination ◽  
Saprobity Index ◽  
Ob River ◽  
Annual Biomass ◽  
Quantitative Indicators ◽  
The City

Journal: Рыбоводство и рыбное хозяйство №8 2021, №8, 2021 Based on the data obtained in the study of some hydrobiological sections of the Ob River, located above and below the city. The qualitative and quantitative characteristics of the zooplankton community were considered, and the saprobity index was calculated. The species composition is represented by 34 species from three systematic groups, of which 12 are rotifers (Rotifera), 14 are branchial crustaceans (Cladocera), and 10 are copepods (Copepoda). The highest species diversity was observed above the city — 34 taxa, the lowest below the city — 14. The average number of zooplankton above the city of Novosibirsk is insignificant and reached 761 copies/m³ per year. Most (49%) were copepods (Copepoda). The number of rotifers (Rotifera) was 34% of the total. In the summer, the number of zooplankton was slightly higher than the annual one and amounted to 871 copies/m³. The average annual biomass of zooplankton had low values and was 35.0 mg/m³. The maximum summer values reached 180 mg/m³. In the study area of the Ob River below Novosibirsk, the average number of zooplankton increases to 2,4 thousand copies/m³. The group of oar-footed crustaceans dominated in number, its share reached 91%. The number of branchiform crustaceans was 7%. The average annual zooplankton biomass in the river below the city limits was 99.53 mg/m³. The value of the saprobity index in the area above Novosibirsk was 1.6, which indicates the presence of weak organic contamination and corresponds to beta-mesosaprobic conditions. In the zone below Novosibirsk, the saprobity index was 2.0, which indicates an increase in organic pollution and corresponds to beta-mesosaprobic conditions. An increase in the level of eutrophication contributes to a change in the structure of zooplankton. This is reflected in a significant decrease (2.4 times) in the species diversity of zooplankton and a significant increase in quantitative indicators: abundance — 3.2 times, biomass — 2.8 times.

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