scholarly journals Environmental determinants of fish abundance in the littoral zone of gravel pit lakes

Hydrobiologia ◽  
2021 ◽  
Author(s):  
S. Matern ◽  
T. Klefoth ◽  
C. Wolter ◽  
R. Arlinghaus
Keyword(s):  
Environmental Factors ◽  
Fish Species ◽  
Littoral Zone ◽  
Lake Level ◽  
Fish Abundance ◽  
Nutrient Inputs ◽  
Lake Productivity ◽  
Gravel Pit ◽  
Pit Lakes ◽  
The Impact

AbstractThe type and extent of habitats along the shoreline specify the distribution of fish in the littoral zone of lakes, but effects are likely species and size-specific and might be overwhelmed by lake-level environmental factors that drive fish abundance (e.g. trophic state). We applied a replicated transect-sampling design by electrofishing assessing fish abundance and distribution along the banks of 20 gravel pit lakes in Lower Saxony (Germany). Boosted regression trees were used to analyse the impact of different characteristic habitat types (e.g. vegetated, woody or open water zones), shoreline water depth and lake-level environmental variables on species-specific fish abundances. In contrast to earlier studies, lake-level environment and transect-level habitat type similarly influenced the abundances of differently sized fish species in the littoral zone of gravel pit lakes. The abundance of almost all fish species increased with lake productivity and extent of structured littoral habitats, mostly following non-linear relationships. Our work suggests that investments into the quality of littoral habitat, and not merely the control of nutrient inputs or other lake-level environmental factors, can promote abundance of most gravel pit lake fish species, in particular those who depend on the littoral zone for at least part of their life-cycle.

scholarly journals Enhanced Viral Activity in the Surface Microlayer of the Arctic and Antarctic Oceans

2021 ◽  
Vol 9 (2) ◽  
pp. 317
Author(s):  
Dolors Vaqué ◽  
Julia A. Boras ◽  
Jesús Maria Arrieta ◽  
Susana Agustí ◽  
Carlos M. Duarte ◽  
...  
Keyword(s):  
Environmental Factors ◽  
Food Web ◽  
Physicochemical Characteristics ◽  
The Arctic ◽  
Microbial Food Web ◽  
Surface Microlayer ◽  
Polar Regions ◽  
Nutrient Inputs ◽  
Viral Activity ◽  
The Impact

The ocean surface microlayer (SML), with physicochemical characteristics different from those of subsurface waters (SSW), results in dense and active viral and microbial communities that may favor virus–host interactions. Conversely, wind speed and/or UV radiation could adversely affect virus infection. Furthermore, in polar regions, organic and inorganic nutrient inputs from melting ice may increase microbial activity in the SML. Since the role of viruses in the microbial food web of the SML is poorly understood in polar oceans, we aimed to study the impact of viruses on prokaryotic communities in the SML and in the SSW in Arctic and Antarctic waters. We hypothesized that a higher viral activity in the SML than in the SSW in both polar systems would be observed. We measured viral and prokaryote abundances, virus-mediated mortality on prokaryotes, heterotrophic and phototrophic nanoflagellate abundance, and environmental factors. In both polar zones, we found small differences in environmental factors between the SML and the SSW. In contrast, despite the adverse effect of wind, viral and prokaryote abundances and virus-mediated mortality on prokaryotes were higher in the SML than in the SSW. As a consequence, the higher carbon flux released by lysed cells in the SML than in the SSW would increase the pool of dissolved organic carbon (DOC) and be rapidly used by other prokaryotes to grow (the viral shunt). Thus, our results suggest that viral activity greatly contributes to the functioning of the microbial food web in the SML, which could influence the biogeochemical cycles of the water column.

scholarly journals Tourists increase the contribution of autochthonous carbon to littoral zone food webs in oligotrophic dune lakes

2004 ◽  
Vol 55 (7) ◽  
pp. 701 ◽  
Author(s):  
Wade L. Hadwen ◽  
Stuart E. Bunn
Keyword(s):  
Food Webs ◽  
Littoral Zone ◽  
Algal Biomass ◽  
Carbon Sources ◽  
Nutrient Concentrations ◽  
Relative Importance ◽  
Nutrient Inputs ◽  
Oligotrophic Lakes ◽  
Dune Lakes ◽  
The Impact

Tourists can adversely influence the ecology of oligotrophic lakes by increasing algal production via direct nutrient inputs and/or re-suspension of sediments. To assess the influence of tourists on food web dynamics, we used the natural abundance of stable isotopes of carbon and nitrogen to calculate the relative importance of autochthonous and allochthonous carbon sources to littoral zone food webs across five variously visited perched dune lakes on Fraser Island, Australia. The relative importance of autochthonous (phytoplankton and periphyton) carbon to littoral zone consumers was highly variable across taxa and lakes. Despite the potential influence of algal biomass, ambient nutrient concentrations and tannin concentrations on the contribution of autochthonous carbon to littoral zone food webs, none of these variables correlated to the per cent contribution of autochthonous carbon to consumer diets. Instead, autochthonous sources of carbon contributed more to the diets of aquatic consumers in heavily visited lakes than in less visited lakes, suggesting that tourist activities might drive these systems towards an increased reliance on autochthonous carbon. The assessment of the contribution of autochthonous carbon to littoral zone food webs may represent a more robust indicator of the impact of tourists in oligotrophic lakes than standard measures of nutrient concentrations and/or algal biomass.

Assessing the sustainability of the Siberian Federal District regions

2020 ◽  
Vol 18 (5) ◽  
pp. 891-908
Author(s):  
T.A. Smirnova
Keyword(s):  
Sustainable Development ◽  
Environmental Factors ◽  
Regional Development ◽  
Federal District ◽  
Integrated Approach ◽  
Siberian Federal District ◽  
The Sustainable Development ◽  
The Impact ◽  
Empirical Analyses

Subject. This article deals with the issues of functioning of the region as a system. Objectives. The article aims to identify the problems of the region's functioning as a system, develop methodological tools to monitor the sustainable development of the Siberian Federal District territories, and determine the the impact of socio-economic and environmental factors on the sustainable development of the region as a whole. Methods. For the study, I used the methods of theoretical, statistical, and empirical analyses taking into account an integrated approach. Results. The article reveals the impact of some individual components of regional development on the sustainability of the territorial system as a whole. Relevance. The results of the study can be used to analyze the sustainability of regions' development.

Directions of Accounting Environmental Factors for Forecasting Formation of Agroecosystems

2020 ◽  
pp. 31-35
Author(s):  
L.Z. Khalishkhova ◽  
◽  
A. Kh. Temrokova ◽  
I.R. Guchapsheva ◽  
K.A. Bogаtyreva ◽  
...  
Keyword(s):  
Sustainable Development ◽  
Comparative Analysis ◽  
Environmental Factors ◽  
Environmental Safety ◽  
Logical Analysis ◽  
Management Decisions ◽  
The Sustainable Development ◽  
The Impact

Ensuring the sustainable development of agroecosystems requires research into the justification of the impact of environmental factors on the formation of territorial agroecosystems and identifies ways to take them into account in order to justify management decisions and ensure environmental safety. The main goal of the research within the article is to identify the most significant environmental factors in predicting the formation of agroecosystems. Provisions are devoted to the study of the laws governing the functioning of agroecosystems in order to increase their stability. The methods of comparative analysis, generalization, abstraction, logical analysis are applied. A number of provisions are formulated regarding ways to account for the influence of factors on the formation of key elements of agroecosystems.

scholarly journals Assessment of the Impact of Small Hydropower Plants on the Ecological Status Indicators of Water Bodies: A Case Study in Lithuania

Water ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 433
Author(s):  
Laima Česonienė ◽  
Midona Dapkienė ◽  
Petras Punys
Keyword(s):  
Water Quality ◽  
Benthic Macroinvertebrates ◽  
Suspended Solids ◽  
Ecological Status ◽  
Fish Abundance ◽  
Water Bodies ◽  
Small Hydropower ◽  
Hydropower Plants ◽  
Physico Chemical ◽  
The Impact

Hydropower plants produce renewable and sustainable energy but affect the river’s physico-chemical characteristics and change the abundance and composition of the aquatic organisms. The impact of large HPPs on the ecological conditions of surface water bodies have been extensively studied, but less attention has been paid to environmental impact studies of small hydropower plants (SHPs). The impact of hydropeaking on both the river flow regime and ecosystems has been well-studied for peaking mode plants, mainly medium to large-sized ones. However, for small hydroelectric power plants, and especially for those in lowland rivers, the available information on water quality, benthic macroinvertebrates communities and fish abundance, and biomass is not sufficient. Ten small hydropower plants were selected, and the ecological status of water bodies was assessed in different parts of Lithuania. The studies were performed at the riverbed upstream from the SHPs, where the hydrological regime has not changed, and downstream from the SHPs. It was found that the small hydropower plants do not affect the physico-chemical values of the water quality indicators. This study demonstrated that the total number of benthic macroinvertebrates taxa (TS) is influenced by the concentration of nitrogen and suspended solids, the water flow, the river area, and the current speed; the number of EPT (Ephemeroptera (mayflies), Plecoptera (stoneflies), and Trichoptera (caddisflies)) taxa is influenced by the concentration of nitrogen and suspended solids. The studied indicators do not have a significant impact on biomass. The SHPs affect the fish abundance and biomass. The Lithuanian fish index (LFI) is influenced by the average depth and area of the river. Some SHPs operating in lowland areas may yield somewhat significant hydrograph ramping but more detailed investigation is needed to support the significance of this impact on the biological indices.

scholarly journals GPS Coordinates for Modelling Correlated Herd Effects in Genomic Prediction Models Applied to Hanwoo Beef Cattle

Animals ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 2050
Author(s):  
Beatriz Castro Dias Cuyabano ◽  
Gabriel Rovere ◽  
Dajeong Lim ◽  
Tae Hun Kim ◽  
Hak Kyo Lee ◽  
...  
Keyword(s):  
Environmental Factors ◽  
Genomic Prediction ◽  
Prediction Models ◽  
Phenotypic Expression ◽  
Genetic Evaluation ◽  
Genomic Breeding ◽  
Breeding Values ◽  
Korean Cattle ◽  
Evaluation Programs ◽  
The Impact

It is widely known that the environment influences phenotypic expression and that its effects must be accounted for in genetic evaluation programs. The most used method to account for environmental effects is to add herd and contemporary group to the model. Although generally informative, the herd effect treats different farms as independent units. However, if two farms are located physically close to each other, they potentially share correlated environmental factors. We introduce a method to model herd effects that uses the physical distances between farms based on the Global Positioning System (GPS) coordinates as a proxy for the correlation matrix of these effects that aims to account for similarities and differences between farms due to environmental factors. A population of Hanwoo Korean cattle was used to evaluate the impact of modelling herd effects as correlated, in comparison to assuming the farms as completely independent units, on the variance components and genomic prediction. The main result was an increase in the reliabilities of the predicted genomic breeding values compared to reliabilities obtained with traditional models (across four traits evaluated, reliabilities of prediction presented increases that ranged from 0.05 ± 0.01 to 0.33 ± 0.03), suggesting that these models may overestimate heritabilities. Although little to no significant gain was obtained in phenotypic prediction, the increased reliability of the predicted genomic breeding values is of practical relevance for genetic evaluation programs.

scholarly journals Are Bacterio- and Phytoplankton Community Compositions Related in Lakes Differing in Their Cyanobacteria Contribution and Physico-Chemical Properties?

Genes ◽  
2021 ◽  
Vol 12 (6) ◽  
pp. 855
Author(s):  
Mikołaj Kokociński ◽  
Dariusz Dziga ◽  
Adam Antosiak ◽  
Janne Soininen
Keyword(s):  
Environmental Factors ◽  
Community Composition ◽  
Phytoplankton Community ◽  
Heterotrophic Bacteria ◽  
Bacterial Community Composition ◽  
Physical Factors ◽  
Research Attention ◽  
Phytoplankton Community Composition ◽  
The Impact ◽  
Bacteria Communities

Bacterioplankton community composition has become the center of research attention in recent years. Bacteria associated with toxic cyanobacteria blooms have attracted considerable interest. However, little is known about the environmental factors driving the bacteria community, including the impact of invasive cyanobacteria. Therefore, our aim has been to determine the relationships between heterotrophic bacteria and phytoplankton community composition across 24 Polish lakes with different contributions of cyanobacteria including the invasive species Raphidiopsis raciborskii. This analysis revealed that cyanobacteria were present in 16 lakes, while R. raciborskii occurred in 14 lakes. Our results show that bacteria communities differed between lakes dominated by cyanobacteria and lakes with minor contributions of cyanobacteria but did not differ between lakes with R. raciborskii and other lakes. Physical factors, including water and Secchi depth, were the major drivers of bacteria and phytoplankton community composition. However, in lakes dominated by cyanobacteria, bacterial community composition was also influenced by biotic factors such as the amount of R. raciborskii, chlorophyll-a and total phytoplankton biomass. Thus, our study provides novel evidence on the influence of environmental factors and R. raciborskii on lake bacteria communities.

scholarly journals Seasonal feeding plasticity can facilitate coexistence of dominant omnivores in Neotropical streams

2021 ◽  
Author(s):  
Mayara P. Neves ◽  
Pavel Kratina ◽  
Rosilene L. Delariva ◽  
J. Iwan Jones ◽  
Clarice B. Fialho
Keyword(s):  
Seasonal Variation ◽  
Fish Species ◽  
Resource Availability ◽  
Seasonal Changes ◽  
Dry Season ◽  
Diet Overlap ◽  
Isotopic Niche ◽  
Neotropical Streams ◽  
Feeding Plasticity ◽  
The Impact

AbstractCoexistence of ecomorphologically similar species in diverse Neotropical ecosystems has been a focus of long-term debate among ecologists and evolutionary biologists. Such coexistence can be promoted by trophic plasticity and seasonal changes in omnivorous feeding. We combined stomach content and stable isotope analyses to determine how seasonal variation in resource availability influences the consumption and assimilation of resources by two syntopic fish species, Psalidodon aff. gymnodontus and P. bifasciatus, in the Lower Iguaçu basin. We also tested the impact of seasonality on trophic niche breadth and diet overlap of these two dominant omnivores. Seasonal changes in resource availability strongly influenced the consumption and assimilation of resources by the two fish species. Both species exhibited high levels of omnivory, characterized by high diversity of allochthonous resources in the wet season. Terrestrial invertebrates were the main component of diet during this season. However, in the dry season, both species reduced their isotopic niches, indicating diet specialization. High diet overlap was observed in both seasons, but the isotopic niche overlap was smaller in the dry season. Substantial reduction in the isotopic niche of P. bifascistus and a shift toward aquatic invertebrates can facilitate coexistence during this season of resource shortage. Feeding plasticity allows omnivorous fish to adjust their trophic niches according to seasonality, promoting the exploitation of different resources during periods of greater resource diversity. This seasonal variation could be an important mechanism that contributes to the resource partitioning and coexistence of dominant omnivores in Neotropical streams.

scholarly journals The impact of environmental variables on the spread of COVID-19 in the Republic of Korea

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Yong Kwan Lim ◽  
Oh Joo Kweon ◽  
Hye Ryoun Kim ◽  
Tae-Hyoung Kim ◽  
Mi-Kyung Lee
Keyword(s):  
Environmental Factors ◽  
Virus Disease ◽  
Environmental Parameters ◽  
Environmental Data ◽  
Republic Of Korea ◽  
Metropolitan Region ◽  
Health Concern ◽  
Ozone Level ◽  
The Republic ◽  
The Impact

AbstractCorona virus disease 2019 (COVID-19) has been declared a global pandemic and is a major public health concern worldwide. In this study, we aimed to determine the role of environmental factors, such as climate and air pollutants, in the transmission of COVID-19 in the Republic of Korea. We collected epidemiological and environmental data from two regions of the Republic of Korea, namely Seoul metropolitan region (SMR) and Daegu-Gyeongbuk region (DGR) from February 2020 to July 2020. The data was then analyzed to identify correlations between each environmental factor with confirmed daily COVID-19 cases. Among the various environmental parameters, the duration of sunshine and ozone level were found to positively correlate with COVID-19 cases in both regions. However, the association of temperature variables with COVID-19 transmission revealed contradictory results when comparing the data from SMR and DGR. Moreover, statistical bias may have arisen due to an extensive epidemiological investigation and altered socio-behaviors that occurred in response to a COVID-19 outbreak. Nevertheless, our results suggest that various environmental factors may play a role in COVID-19 transmission.

scholarly journals Research on the Relationship between Shared Leadership and Individual Creativity-Qualitative Comparative Analysis on the Basis of Clear Set

2021 ◽  
Vol 13 (10) ◽  
pp. 5445
Author(s):  
Muyun Sun ◽  
Jigan Wang ◽  
Ting Wen
Keyword(s):  
Comparative Analysis ◽  
Environmental Factors ◽  
Shared Leadership ◽  
Management Practices ◽  
Qualitative Comparative Analysis ◽  
Necessary Condition ◽  
The Individual ◽  
The Impact ◽  
The Relationship ◽  
Sufficient And Necessary Condition

Creativity is the key to obtaining and maintaining competitiveness of modern organizations, and it has attracted much attention from academic circles and management practices. Shared leadership is believed to effectively influence team output. However, research on the impact of individual creativity is still in its infancy. This study adopts the qualitative comparative analysis method, taking 1584 individuals as the research objects, underpinned by a questionnaire-based survey. It investigates the influence of the team’s shared leadership network elements and organizational environmental factors on the individual creativity. We have found that there are six combination of conditions of shared leadership and organizational environmental factors constituting sufficient combination of conditions to increase or decrease individual creativity. Moreover, we have noticed that the low network density of shared leadership is a sufficient and necessary condition of reducing individual creativity. Our results also provide management suggestions for practical activities during the team management.

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