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- Transformation of the morphometry of Lake Osieckie – largest lake in
the Holy Cross region
Abstract: The paper presents the analysis of the transformation of Lake Osieckie, the largest lake in the Holy Cross region until 2016. It is a valley lake that according to cartographic materials had undergone no changes in the shoreline since ca. 1938. The nearby activity of a sulphur mine required building three dikes on the lake, dividing it into four independent water bodies. The paper presents the analysis of their morphometric properties in comparison to those of the original lake. Although the basins of the new lakes are of natural origin, the currently existing four lakes can be described as quasi-natural.
PubDate: Thu, 30 Dec 2021 00:00:00 GMT
- Water quality for triathlon and open water swimming competitions in
Brazilian freshwaters
Abstract: In high-performance competitive activities, there can be intense and prolonged exposure to water during swimming components of the competition. Therefore, water quality assessments with reference to standards are desirable to ensure athletes’ health. We evaluated whether the official criteria established for primary contact recreation in Brazilian freshwaters (CONAMA Directive 274/2000), and an integrated index of bathing conditions in Brazil (ICB), are consistent with the water quality standards stipulated by the International Triathlon Union (ITU). The water quality of Lake of Ingleses, an important venue for triathlon and open water swimming near Belo Horizonte, Minas Gerais, Brazil, was assessed between 2003 and 2019. Results for E. coli, cyanobacteria density, and pH were favorable for contact recreation and competitions at the lake. Of the variables considered, only turbidity, used as a proxy indicator of visual water clarity, was unsuitable during part of the monitoring period. The ICB agreed with the ITU standards for Very Good and Excellent quality classes and is recommended as a tool for screening sites considered for competitions in Brazilian freshwaters. However, the Brazilian national criteria for contact recreation only present standards for E. coli and pH, which is insufficient coverage of attributes affecting primary contact suitability of water in high-performance sports activities.
PubDate: Thu, 30 Dec 2021 00:00:00 GMT
- Predation of (Blanchard, 1897) on the invasive snail (Draparnaud, 1805) in
the presence of an alternative prey
Abstract: The North American freshwater snail Physella acuta has invaded and colonized a wide range of freshwater habitats, globally. Resembling other invasive species, P. acuta has several negative impacts on the invaded freshwater ecosystems, which calls for its regulation, preferably through biological control. The malacophagous leech Glossiphonia weberi, native to West Bengal, India, had been previously reported as a potential biocontrol agent of P. acuta. In this experiment, we observed the predation potential and prey preference of G. weberi on P. acuta in the presence of a native snail, Gyraulus convexiusculus. The results suggest that in all instances, G. weberi consumed less G. convexiusculus compared to P. acuta. In complex habitats, G. weberi showed significant prey preference to P. acuta except in the habitat characterized by the presence of pebbles. The complex habitats bear a significant (p < 0.05) negative impact only in the case of predation on P. acuta when present with conspecific but not in heterospecific prey conditions. Therefore, G. weberi qualifies as a useful biological control agent that can affect the colonization and expansion of the invasive snail P. acuta, even in the presence of alternative prey.
PubDate: Thu, 30 Dec 2021 00:00:00 GMT
- Seasonal variation of algal diversity with reference to water quality in
Jagadishpur Reservoir, Nepal
Abstract: The study of the importance of physicochemical parameters of water for algal growth and development in Jagdishpur Reservoir was carried out in the present research. Occurrence of algal species and values of water quality parameters also indicate the ecological nature and the present status of the reservoir. Water samples were collected from Jagdishpur Reservoir in Kapilvastu District (Nepal), in two seasons (wet and dry). The following physicochemical parameters of water were analyzed: temperature, pH, dissolved oxygen, alkalinity, concentration of nitrates and phosphates, free CO2, hardness, conductivity, total dissolved solids. The values of free CO2, hardness, phosphate, temperature, and dissolved oxygen were high in wet season while alkalinity, nitrate, conductivity and total dissolved solid were high in dry season. Altogether 81 algal species belonging to 53 genera and 6 classes were recorded. Higher number of algal species was recorded in the dry season rather than in the wet season. The highest number of species was noted among Chlorophyceae, followed by Cyanobacteria > Bacillariophyceae > Euglenophyceae > Crysophyceae and Dinophyceae. Cosmarium had the highest number of species (13) among all genera. During the wet season, Cosmarium, Calothrix and Phormidium were the genera with the highest number of species while Bulbochaete, Trachelomonas and Gomphonema were genera with the lowest number of species. During the dry season, Cymbella, Cosmarium and Rhopalodia were genera with highest number of species while Euglena, Gloeotrichia and Trachelomonas were genera with lowest number of species. Algal diversity was positively correlated with the increase of alkalinity, conductivity and TDS, while negatively correlated with free CO2, hardness, concerntration of phosphates and nitrates, DO, pH and temperature. Shannon–Weiner diversity index value was higher during the dry season than in the wet season.
PubDate: Thu, 30 Dec 2021 00:00:00 GMT
- The tardigrade cuticle
Abstract: Tardigrades (phylum Tardigrada) are aquatic microecdysozoans that have adapted to survive extreme conditions through the formation of cysts or ametabolic tuns. Their body is covered by a cuticle that plays an important role in their life cycle, including their response and adaptation to environmental challenges. Cuticular characteristics are a critical component of tardigrade taxonomy. Therefore, research has often been focused on the relationship between cuticular morphology and ultrastructure and the evolutionary and phylogenetic positioning of the phylum and individual species herein. However, a deeper insight into the ultrastructural characteristics and chemical composition of the tardigrade cuticle is needed. This knowledge is important not only for a better understanding of tardigrade physiology and ecology but also for the development of efficient microinjection and/or electroporation techniques that would allow for genetic manipulation, opening new avenues in tardigrade research. Here, we review data on cuticle ultrastructure and chemical composition. Further, we discuss how the cuticle is affected during moulting, encystment, cyclomorphosis, and anhydrobiosis. Our work indicates that more systematic studies on the molecular composition of the tardigrade cuticle and on the process of its formation are needed to improve our understanding of its properties and functions.
PubDate: Tue, 21 Dec 2021 00:00:00 GMT
- Light pollution affects the coastal zone of Lake Baikal
Abstract: The role of light pollution in aquatic ecosystems functioning has increased in recent times. In addition, the effect of such pollution has mostly been studied in coastal marine ecosystems, leaving freshwater ecosystems much less studied. In the p resent work, we investigated the effect of light pollution on the coastal zone of the ancient Lake Baikal ecosystem. Both a laboratory experiment and field research were conducted. The results of the experiment showed the presence of statistically significant differences (р =0.009) between fish feeding on amphipods with and without daylight conditions, while there were no such differences between daylight and artificial light conditions. At the same time, video recordings revealed both a low number of specimens and a low species diversity of amphipods near to the village with a developed system of street lights, while in the village with a nearly nonexistent light system, the species diversity and a number of amphipods were much higher. One plausible explanation for such influence of light pollution on the quality and quantity of Baikal amphipod fauna might be the sum of several factors such as high water transparency and daily vertical migrations of amphipods.
PubDate: Tue, 21 Dec 2021 00:00:00 GMT
- Hydrological modeling of rainfall-runoff of the semi-arid Aguibat Ezziar
watershed through the GR4J model
Abstract: The management of water resources requires as a first step the modeling of rainfall-runoff. It allows simulating the hydrological behavior of the basin for a good evaluation of the potentiality of this in terms of water production. There are different hydrological models used for water resource assessment, but conceptual models are still the most used due to their simple structure and satisfactory performance. In this study, t he performances of the conceptual model of rainfall and runoff (GR4J) modeled under R with the AirGR package, are used to Aguibat Ezziar the subbasin of the Bouregreg basin in Morocco. The enormous amount of data required and the uncertainty of some of the m makes these models of limited usefulness. The GR4J model allows evaluation of the runoff rates and describes the hydrological behavior of the Aguibat Ezziar watershed, which presents the aim behind writing this paper. A period from 2003 to 2017 has been selected. This period has been divided into two parts: one for calibration (2003-2006), and one for validation (2013-2016). After the calibration of the model and following the performance obtained (Nash higher than 0.72) we can say that the GR4J model behaves well in the Aguibat Ezziar catchment area.
PubDate: Tue, 21 Dec 2021 00:00:00 GMT
- Current state of bacterial community of Lake Ladoga
Abstract: The data are presented on a quantitative assessment of the bacterioplankton community of Lake Ladoga and total bacterial numbers dynamic in the period from 2009 to 2019. The trophic state of the lake and water quality in different areas have been characterized by microbiological parameters. Maximum concentrations of microorganisms and highest water temperatures were commonly observed in the shallow coastal area (Volkhov Bay, up to 6.40 ×106 cells ml−1), and minimum – in the deepest part of the lake (ca. 0.45 ×106 cells cm−3). The bacterial abundances correlate with water temperatures both within each year of observations and over the whole study period. The trophic state of the lake expressed by the total bacterial numbers during summer seasons closely matches the state during the first decade of the 21st century. In the period of 2009-2019, the trophic state varied from oligo-mesotrophic in the hypolimnion of deep-water areas to mesotrophic eutrophic in the shallow southern coastal area, which corresponds to the trophic state indicated by chlorophyll-a concentrations. Within the previous decade (2000-2008), the waters of Lake Ladoga were “clean” and “especially clean”, while during the 2017-2019 period, water masses all over the lake can be identified as “especially clean”. From 2017 to 2019 the coccoid forms of bacterial cells prevailed over rod-shaped cells comprising 57.6 ±5.1% (2017), 64.4 ±4.5% (2018), 61.1 ±4.6% (2019), which imply the high quality of the waters.
PubDate: Tue, 21 Dec 2021 00:00:00 GMT
- Aquatic tardigrades in Poland – a review
Abstract: The diversity, distribution and ecology of aquatic Tardigrada in Poland remain poorly known. We reviewed the literature focused on tardigrades in Poland and recognized only 15 aquatic taxa which were reported from various freshwater and marine habitats. Among them, 12 are freshwater and three are marine taxa. Hypsibius dujardini is Poland’s most widely-distributed hygrophilous species, but it re presents rather a complex of cryptic species and their diagnosis requires integrative approaches. Most reports of aquatic tardigrades in Poland are accidental findings mostly from water bodies in Tatra Mountains or from lakes in Masurian Lake District. Some species were also reported from small ponds or wastewater treatment plants in other regions like Małopolska or Wielkopolska Provinces.
PubDate: Tue, 21 Dec 2021 00:00:00 GMT
- Phosphorus in the shallow, urban lake subjected to restoration - case
study of Lake Domowe Duże in Szczytno
Abstract: The paper presents the results of the research on the restoration of the shallow Lake Domowe Duże in Szczytno (area 0.6 km2, average depth 3.4m). Restoration treatments were carried out in the years 2010-2012 and consisted in the inactivation of phosphorus using polyaluminium chloride. Technical restoration was supported by biomanipulation treatments consisting in stocking the lake with predatory fish. Water quality study were carried out before remediation and annually for a decade (2010-2019) during and after the application of coagulant. It was shown that the efficiency of removing excess phosphorus from water column was high (decrease from 0.23 mgP L-1 to 0.05 mgP L-1). The effects achieved during the coagulant application were maintained for 5 years after the end of the project. Currently, the phosphorus pool is still twice as low as before the treatments, but it is gradually increasing. The main external factor limiting permanent improvement of water quality is the open hydrological system and transport of biogenic matter by surface inflows draining anthropogenically transformed areas. Maintaining permanent improvement of water quality will require continuation of restoration measures.
PubDate: Tue, 20 Jul 2021 00:00:00 GMT
- Preliminary hydrochemical characteristics of an urban lake restored using
a sequential application of iron and aluminum coagulants
Abstract: A study was carried out on Lake Mielenko in Kartuzy. It is a small and shallow waterbody (7.8 ha, max. depth 1.8 m), whose morphometric conditions qualify it as a polymictic lake (the first lake in a river - lake system). Before the reclamation began, the lake was characterized by a high concentration of chlorophyll-a (16.4 mg m−3 in spring to 33 mg m−3 in summer) and low visibility. The purpose of the study was to determine the impact of the first stage of restoration of Lake Mielenko by phosphorus inactivation using a combination of aluminum and iron coagulants (PIX and PAX). After coagulant dosing into the lake, a significant decrease in chlorophyll-a was observed, which resulted in improving water transparency in the lake and decreasing concentrations of both nutrients (nitrogen and phosphorus). The total concentration of nutrients was dominated by organic forms (constituting 71-95%). Maximum nutrient concentrations were 0.273±0.01 mg P L−1 and 5.52±0.1 mg N L-1 (in the summer period before the restoration activities were performed).
PubDate: Tue, 20 Jul 2021 00:00:00 GMT
- Lakes restoration approaches
Abstract: Preventive and curative intervention become an imperative to encounter the recent dilemmas of lakes and its ecosystem, eutrophication, external contaminants load and the internal load and hydrological cycle disruption, lakes drought or flood as a result of the global warning are some of these dilemmas which mainly caused anthropogenic activities. At present, mechanical and chemical treatment approaches are the most popular applied techniques for lakes remediation with an escalating pace of biological methods are implemented as biomanipulation; which consider an efficient eco-technique. As experience has proven, desirable reclamation result is achieved by implementing combination of the restoration methods.
PubDate: Tue, 20 Jul 2021 00:00:00 GMT
- Were there any changes in zooplankton communities due to the limitation of
restoration treatments'
Abstract: Zooplankton is a good indicator of water quality state. Analysing the species composition and abundance, it is possible to assess the condition of the water body and predict the direction of changes. The aim of the study was to analyse the zooplankton in a shallow urban lake, in which restoration was limited to one method, i.e. wind-aeration. The results were compared with the earlier data obtained during sustainable restoration (three methods: wind-aeration, phosphorus inactivation, biomanipulation) and before the restoration period. The zooplankton was sampled monthly in 2015 and 2016 in the deepest place of the lake from the surface to the bottom. The trophic state was determined based on rotifer trophic state index for lakes (TSIROT). Although the species composition of zooplankton communities varied very little among the restoration periods (Keratella cochlearis f. tecta mainly dominated), significant changes in the abundance of zooplankton were found in the analysed lake. The maximum of total abundance was noted in 2015, almost 5500 ind. L−1, and in the next year its decrease was almost 3-fold, to ca. 1800 ind. L-1. Based on TSIROT, the water was still eutrophic. Leaving only one method of restoration (namely, oxygenation of the bottom waters) proved insufficient to support the development of crucial organisms as cladocerans. The changes in the abundance could have resulted more from seasonal changes than from the effects of aeration. A reduction in species number and maintaining a high proportion of rotifers typical for a high trophic state indicated a return of the ecosystem to its pre-restoration state. High variability in the rotifer abundance indicated a continuous imbalance of the ecosystem. Previous restoration treatments using several methods simultaneously showed better effectiveness. The change of strategy of restoration before obtaining a stable improvement of water quality destroyed previously achieved effects.
PubDate: Tue, 20 Jul 2021 00:00:00 GMT
- Deformations of upper soil slopes of retaining structures and shores with
violated reinforced concrete fastening in riverbed reservoirs in Belarus
Abstract: The conditions of wind waves influence on the ground upper soil slopes of retaining structures and natural shores that are fixed in the form of reinforced concrete fastening with deformations are considered. The results of modeling the regime of intra-water currents and field surveys of artificial water bodies are shown. A criterion for assessing the stability of ground slopes and coastal slopes with reinforced concrete fastening with a broken structure is proposed and the conditions for its applicability are determined. Measures for engineering protection of the reservoir shores are proposed via using a criterion for the stability of fixed slopes Пк. It is assumed that at Пк ≥ 1 the slope profile with fastening plates deformed during operation acquires the contour of the dynamic equilibrium profile adopted for the calculated type of soil as a result of the destruction of the slope by waves.
PubDate: Sat, 03 Jul 2021 00:00:00 GMT
- The exotic gastropod (von dem Busch, 1847) as a predator of freshwater
gastropods: a threat to native biota in India'
Abstract: The carnivorous snail Clea (Anentome) helena (von dem Busch, 1847) (Gastropoda: Nassariidae), commonly called as the “assassin snail” is sold worldwide including India for aesthetics and the ability to kill pest snails in aquaria. Assuming invasion as a fair possibility, the predation potential of C. helena on seven native freshwater snails was assessed. The exotic predator consumed all the native snail species provided in the experiment and prey consumption varied with the prey species identity, the prey density and the prey size class. Future colonization and establishment of C. helena in Indian freshwater ecosystems may reduce the abundance of the native gastropod snails, in absence of suitable intervention.
PubDate: Sat, 03 Jul 2021 00:00:00 GMT
- River minimum flow changes under dammed reservoir conditions
Abstract: The main aim of this study was to assess what range of downstream low flow changes is caused by dam construction directly. An investigation was based on the assumption that the difference in change ratio of flow between gauging cross-sections located downstream and upstream position of dammed reservoir identifies the scope of changes determined by dam construction. Three dammed reservoirs located on Polish rivers were selected for analysis. They were different in size, hydrological regime and water management purposes. For each reservoir pair of water, gauges were selected. The input data were daily discharge series collected by the Polish Institute of Meteorology and Water Management. For each time series 20-year period before and after dam construction was established. Comparison of annual minimum flow ratios for these peri-ods as well as analysis of low flow dynamics and inertia allowed to identify range and direction of changes caused by investigated reservoirs.
PubDate: Sat, 03 Jul 2021 00:00:00 GMT
- Estimation methodology and the significance of the atmospheric water
exchange flux in the river-lake systems of selected lobelia lakes in the
vicinity of the Tri-City in Poland
Abstract: The article aims to present the methodology of estimating the atmospheric water exchange components in the lake. In the absence of direct precipitation and evaporation measurements, these water balance elements need to be estimated. However, the inadequate selection of precipitation and evaporation estimation methods causes the incorrect determination of the hydrological function of the lake and the effect it has on the formation of river drainage. Determination of the evaporation from the lake’s surface was based on the Davidov formula, which considered the monthly average surface temperature of a given lake. The saturated water vapour pressure under the lake’s monthly mean surface water temperature (TWP) was calculated according to ISO 13788 standard. The interpolation method, which is the inverse-distance deterministic method (IDW), was used to calculate precipitation reaching the lake surface. The calculations were made for three hydrological years diverse in terms of humidity and thermal conditions. The methodology for estimating the components of atmospheric water exchange was presented on a small river-lake system of the upper Gościcina River catchment, an example of a postglacial lake district area. The lake elements of this system are lobelia lakes, poorly known in terms of water circulation. At the beginning of the twenty-first century, unjustified activities regarding assessing the water circulation conditions in this river-lake system led to changes in water relations, causing environmental, financial and social losses.
PubDate: Sat, 03 Jul 2021 00:00:00 GMT
- Responses and Tolerance Mechanisms of Mangrove Trees to the Ambient
Salinity along the Egyptian Red Sea Coast
Abstract: Due to the importance of mangrove forests to the ecological system, environment, climate change adaptation, mitigation and ecosystem services, it is necessary to understand the status of the mangroves in Egypt (ecology and physiology). The present study aimed to obtain the basic information needed to evaluate the photosynthetic pigments and proline mechanisms of Avicennia marina and Rhizophora mucronata mangrove to the ambient salinity. The results reached that the free proline accumulated appreciably in leaves. The functional role of proline accumulation appears to be as a cytoplasmic osmoticum to lower cell water potential, provide hydration to bipolymer and serve as an energy source under high salinity environmental conditions. Mangroves showed variations in proline content between the two species. The highest value of proline was recorded 23.56 mg/g dry wt for R. mucronata and the minimum value was recorded 17 mg/g dry wt for A. marina. In addition, the mean value of proline was recorded 18.57 mg/g dry wt for A. marina and 23.98 mg/g dry wt for R. mucronata. The contents of chlorophyll-a in different analyzed mangroves was ranged from 4.46 to 6.05 mg/gf.wt. for A. marina, and from 3.69 to 4.29 mg/gf.wt. for R. mucronata. In addition, the chlorophyll-b content was ranged from 1.46 to 1.83 mg/gf.wt. for A. marina, and from 1.27 to 1.65 mg/gf.wt. for R. mucronata. The carotenoids contents in mangroves ranged from 2.94 to 2.29 mg/gf.wt for A. marina and from 2.04 to 2.09 mg/gf.wt for R. mucronata. In the present study, A. marina was relatively more tolerant and adapted to salinity, low rainfall and extreme temperature conditions than R. mucronata. This explains the more significant local distribution of A. marina in Egypt compared to R. mucronata.
PubDate: Sat, 03 Jul 2021 00:00:00 GMT
- Inventory: The pesticides application and its risk assessment in the
irrigated perimeter of Tadla-Morocco
Abstract: The industrialization of the agricultural sector increases the use of pesticides, which are composed of chemical substances, such as herbicides, fungicides, insecticides, acaricides, nematicides, and rodenticides, that are adapted to the control of undesirable plants and animals. All these phytosanitary products have varying degrees of toxicity, which risks human life. This study aimed to make an inventory of the pesticides used in the irrigated perimeter of Beni Moussa and Beni Aamir in the Beni Mellal-Khenifra region. The data collection through questionnaires took place between January and February 2016 and covered all the study areas. The questionnaires are focused on the mode of packaging management, sale and purchase of pesticides. The results demonstrated the existence of different pesticides and active substances used for crop protection in the region. Among 63 molecules, 14 active substances were detected, where the active substances are not approved by the world health organization, which considers it as carcinogenic substances. During phytosanitary treatments by farmers, these active substances come into direct contact with the soil, presenting a permanent risk to the environmental compartments, including groundwaters.
PubDate: Sat, 03 Jul 2021 00:00:00 GMT
- Alternative prey influence the predation of mosquito larvae by three water
bug species (Heteroptera: Nepidae)
Abstract: The indirect interactions among multiple prey sharing a common predator characterize apparent competition. In conservation biological control involving mosquitoes and controphic prey against generalist insect predators, apparent competition may be a crucial factor determining the extent of success. The possible influence of apparent competition on mosquito prey consumption by three water bugs (Heteroptera: Nepidae): Ranatra elongata, Ranatra filiformis, and Laccotrephes griseus was assessed under laboratory conditions. Tadpoles (Duttaphrynus melanostictus), chironomid larvae, snails (Racesina luteola) and fish fingerlings (Labeo rohita) were considered as alternative prey under two prey or multi prey conditions against instar IV larvae of Culex quinquefasciatus as target prey. Under two prey conditions all the predators exhibited a preference (significant Manly’s α) for mosquito larvae, against fish fingerlings by R. filiformis. In the presence of multiple prey, mosquito larvae were selected by the predators. Using the ratio of mosquito selectivity in two prey and multi-prey conditions as a measure of apparent competition, chironomid larvae had greatest effect in suppressing mosquito selectivity for R. elongata, and fish fingerlings for R. filiformis and L. griseus. It seems that the prey preference of R. elongata, R. filiformis and L. griseus may differentially evoke apparent competition among the prey. In the aquatic community where these predators and prey coexist, mosquito larvae may benefit from apparent competition that reduces their vulnerability to predators. The identity of the alternative prey appears to be an important factor for shielding the vulnerability of mosquito prey to the generalist insect predators.
PubDate: Thu, 31 Dec 2020 00:00:00 GMT
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