scholarly journals Faunistic patterns and diversity components of leech assemblages in karst springs of Montenegro

2019 ◽  
pp. 26 ◽  
Author(s):  
Nikola Marinković ◽  
Branko Karadžić ◽  
Vladimir Pešić ◽  
Bogić Gligorović ◽  
Clemens Grosser ◽  
...  
Keyword(s):  
New Species ◽  
Environmental Factors ◽  
Environmental Variables ◽  
Aquatic Vegetation ◽  
Abiotic Factors ◽  
Forward Selection ◽  
Karst Springs ◽  
Water Parameters ◽  
The Impact ◽  
Substrate Types

The aim of this study was to reveal faunistic and diversity patterns and to assess the effects of environmental factors on the differentiation of leech communities. This study covers investigations of 82 karst springs in Montenegro from 2009–2017. The communities were analyzed in respect to five wellspring types – caves, sublacustrine, limnocrene, rheo-limnocrene and rheocrene. The percentage of substrate types and aquatic vegetation cover was recorded alongside water parameters. In total, 18 leech species were identified, of which two were recently described as new species for science (Dina minuoculataGrosser, Moritz and Pešić, 2007 andGlossiphonia balcanicaGrosser and Pešić, 2016).K-means clustering was used to classify leech assemblages into three homogenous groups. The patterns of leech communities and the components of bothalphaandbetadiversity were examined in identified groups of assemblages. The significance of environmental factors and the impact of selected factors were assessed through forward selection analysis, CCA and RDA. Our results indicate that the type of spring and the environmental variables, as well as the combination of biotic and abiotic factors in a microhabitat dictate the distribution of leeches.

scholarly journals Longitudinal sampling of external mucosae in farmed European seabass reveals the impact of water temperature on bacterial dynamics

2021 ◽  
Vol 1 (1) ◽  
Author(s):  
Daniela Rosado ◽  
Raquel Xavier ◽  
Jo Cable ◽  
Ricardo Severino ◽  
Pedro Tarroso ◽  
...  
Keyword(s):  
Environmental Factors ◽  
Microbial Diversity ◽  
Water Temperature ◽  
Abiotic Factors ◽  
Seasonal Effect ◽  
Microbial Composition ◽  
Surrounding Water ◽  
European Seabass ◽  
And Function ◽  
The Impact

AbstractFish microbiota are intrinsically linked to health and fitness, but they are highly variable and influenced by both biotic and abiotic factors. Water temperature particularly limits bacterial adhesion and growth, impacting microbial diversity and bacterial infections on the skin and gills. Aquaculture is heavily affected by infectious diseases, especially in warmer months, and industry practices often promote stress and microbial dysbiosis, leading to an increased abundance of potentially pathogenic bacteria. In this regard, fish mucosa health is extremely important because it provides a primary barrier against pathogens. We used 16 rRNA V4 metataxonomics to characterize the skin and gill microbiota of the European seabass, Dicentrarchus labrax, and the surrounding water over 12 months, assessing the impact of water temperature on microbial diversity and function. We show that the microbiota of external mucosae are highly dynamic with consistent longitudinal trends in taxon diversity. Several potentially pathogenic genera (Aliivibrio, Photobacterium, Pseudomonas, and Vibrio) were highly abundant, showing complex interactions with other bacterial genera, some of which with recognized probiotic activity, and were also significantly impacted by changes in temperature. The surrounding water temperature influenced fish microbial composition, structure and function over time (days and months). Additionally, dysbiosis was more frequent in warmer months and during transitions between cold/warm months. We also detected a strong seasonal effect in the fish microbiota, which is likely to result from the compound action of several unmeasured environmental factors (e.g., pH, nutrient availability) beyond temperature. Our results highlight the importance of performing longitudinal studies to assess the impact of environmental factors on fish microbiotas.

Downstream effect of a pumped-storage hydropower plant on river habitat conditions and benthic life – a case study

Biologia ◽  
2017 ◽  
Vol 72 (6) ◽  
Author(s):  
Igor Kokavec ◽  
Tomáš Navara ◽  
Pavel Beracko ◽  
Tomáš Derka ◽  
Ivana Handanovičová ◽  
...  
Keyword(s):  
Organic Matter ◽  
Environmental Variables ◽  
Life Histories ◽  
Life Cycles ◽  
Hydropower Plant ◽  
Food Sources ◽  
Forward Selection ◽  
River Continuum ◽  
Pumped Storage ◽  
The Impact

AbstractIn spite of many investigations about the impact of reservoirs on river continuum, the downstream effects of a pumped-storage hydropower plants (PSHP) still have been less known. The aim of the study was to evaluate the downstream effect of the PSHP Čierny Váh in regard to the Serial Discontinuity Concept assumptions or studies assessing more frequent types of hydropower reservoirs. We predicted that the increase of water temperature and the alteration of food sources will hierarchically be the most relevant factors determining macroinvertebrate community composition. We focused on mayflies, caddisflies and non-insect benthic invertebrates due to their appropriate responses to discontinuity. We also determined the influence of the hydropower plant on life cycles and productions of the most abundant species of mayflies and caddisflies. We recorded the unique effect of the PSHP Čierny Váh on its downstream environmental variables. According to the nested ANOVA results, temperature regime, transported organic matter, benthic fine particulate organic matter and periphyton biomass were the environmental variables significantly modified by the river discontinuum. Significant differences were also found in the case of macroinvertebrate species richness, density and diversity. Nevertheless, based on the forward selection test for predictor effects, none of the environmental variables affected the macroinvertebrate assemblages significantly. However, the redundancy analysis revealed a separated group of macroinvertebrates preferring conditions characteristic for the site immediately below the reservoir. Regarding the impact of the reservoir on life histories, we revealed the shift in hatching, emergence and duration of life cycles of the abundant mayflies (except

scholarly journals The relationship between habitat factors and aquatic macrophyte assemblages in the Danube river in Serbia

2017 ◽  
Vol 69 (3) ◽  
pp. 427-437 ◽  
Author(s):  
Dragana Vukov ◽  
Milos Ilic ◽  
Mirjana Cuk ◽  
Ruzica Igic ◽  
Georg Janauer
Keyword(s):  
Environmental Factors ◽  
Plant Species ◽  
Environmental Variables ◽  
Aquatic Vegetation ◽  
Aquatic Macrophyte ◽  
Danube River ◽  
Survey Method ◽  
Water Flow Velocity ◽  
Main River Channel ◽  
The Relationship

Our objectives were to offer insight into the characteristics of the physical environment in the River Danube in Serbia; and to show the relationship between selected environmental factors and the composition and abundance of macrophyte species. The macrophyte survey method followed the European Standard EN 14184, applying Kohler?s five-level descriptive scale. Principal component analysis was carried out to examine the variation in aquatic vegetation, and to analyze the effect of environmental variables on the aquatic vegetation, redundancy analysis was used. To build a simpler model with fewer explanatory variables, yet sufficiently explaining species variability, forward selection of environmental variables was done. Our results confirmed that physical environmental factors significantly influence the establishment and structure of macrophyte vegetation, with the level of hydrological connectivity to the main river channel being the most important, followed by the transparency of the water column, sediment texture and water-flow velocity. In order to inspect the individual relation between best-fitted plant species and each of selected environmental variables, Spearman?s rank correlation coefficients were calculated. We have distinguished plant species with preferences to specific combinations of analyzed factors. Our results provide a background for future, more specific studies on the macrophyte/habitat relationship.

scholarly journals The relation between chironomid (Diptera: Chironomidae) assemblages and environmental variables: The Kolubara River case study

2016 ◽  
Vol 68 (2) ◽  
pp. 405-415 ◽  
Author(s):  
Natasa Popovic ◽  
Jelena Djuknic ◽  
Jelena Canak-Atlagic ◽  
Maja Rakovic ◽  
Bojana Tubic ◽  
...  
Keyword(s):  
Correspondence Analysis ◽  
Environmental Variables ◽  
Environmental Changes ◽  
Ecological Status ◽  
Freshwater Ecosystems ◽  
Forward Selection ◽  
Water Parameters ◽  
Dominant Component ◽  
Chironomid Assemblages ◽  
Study Sites

Chironomid larvae respond rapidly to environmental changes in aquatic ecosystems, with different species possessing different degrees of tolerance. Consequently, this group is considered an effective and reliable indicator of the ecological status. In this study, the relation between larval chironomid assemblages and environmental variables was examined at two sites on the Kolubara River. The nonparametric Mann-Whitney U test did not confirm significant seasonal differences between samples. Correspondence analysis indicated that the study sites are distinguished by their community composition. Based on forward selection analyses, 5 out of the 28 analyzed water parameters and 3 out of the 22 sediment parameters displayed the highest levels of correlation with chironomid assemblages. Forward selection analysis revealed that inorganic pollutants in the sediment (mercury, nickel and cadmium) exerted the greatest influence on the community. Results of canonical correspondence analysis indicated that the sediment characteristics have a more significant impact on chironomid communities than the analyzed water parameters. Our study confirmed that chironomids and sediment analyzes should be obligatorily included in the monitoring of ecological status, since chironomids are often a dominant component of benthic macroinvertebrate assemblages in freshwater ecosystems, with many species inhabiting the sediment with a proclivity for intake of toxic and persistent pollutants.

Influence of ecological abiotic factors on human health

2020 ◽  
Vol 58 (9) ◽  
pp. 48-51
Author(s):  
Firangiz Agadadash Jabrailova ◽  
Keyword(s):  
Environmental Factors ◽  
Key Words ◽  
Human Health ◽  
Environmental Assessment ◽  
Natural Environment ◽  
Abiotic Factors ◽  
The Impact

The article considers the medical environmental assessment of the effects of abiotic factors on human health, as well as analyzes the impact of extreme environmental factors on the prevalence of disease. It is explained that rhythmic changes in the natural environment cause the spread of different diseases among people. Key words: abiotic, photosynthesis, radiation, electromagnetic, meteorological, meteoneurosis, aerophobia

scholarly journals Reindeer 24-hr within and between group synchronicity in summer versus environmental variables

Rangifer ◽  
2004 ◽  
Vol 24 (1) ◽  
pp. 25-30 ◽  
Author(s):  
Jonathan E. Colman ◽  
Ruben Eidesen ◽  
Dag Hjermann ◽  
Mathis A. Gaup ◽  
Øystein Holand ◽  
...  
Keyword(s):  
Environmental Variables ◽  
Activity Rhythm ◽  
Anthropogenic Activities ◽  
Abiotic Factors ◽  
Physiological Processes ◽  
Close Proximity ◽  
Group Synchronization ◽  
Insect Harassment ◽  
Abiotic Stimuli ◽  
The Impact

Abstract: The impact of abiotic stimuli on the circadian activity rhythm of Rangifer has long been debated. Their highly gregarious and mobile behaviour presupposes synchronized behaviour within a group, while a predominant abiotic influence would be expected to synchronize separate, independent groups subjected to the same environment. We tested within and between group synchronization of semi-domestic reindeer during summer observing 6 independent groups located in close proximity to each other. We also tested how some external environmental factors affected the animals’ behaviour. Activity of all individuals (3 females in 6 groups, n = 18 reindeer) was recorded every 10 minutes 24-hrs a day, along with weather variables and biotic factors such as insect harassment. Data were divided into two periods of 8 and 6 days, respectively, separated by a period of 6 days. Animals within a group showed highly synchronized behaviour, reflected in overlapping periods of grazing and ruminating. There was little or no synchronization between groups, reflected by little or infrequent overlapping of activities amongst some of the groups. Rarely were all 6 groups active or inactive simultaneously. There was no consistent or significant influence on the reindeers’ behaviour by any of the environmental variables recorded. Thus, and as expected, in the absence of external environmental stimuli, the activity of individuals within a group was synchronized. However, there was no synchronization amongst independent groups. This supports the claim that during summer, in the absence of disturbance from stimuli such as insect harassment or anthropogenic activities, reindeer have a 24-hr polycyclic activity rhythm independent of climatic variables. Instead of abiotic factors, such as light, reindeers’ activity rhythms were defined by internal physiological processes and intra-specific group interactions reflected in almost complete within group synchronization and lack of between group synchronization. Abstract in Norwegian / Sammendrag: Betydningen av abiotiske variabler på reinens døgnrytme har lenge vært diskutert. Med sin gruppeadferd og mobilitet forventer man samhandling innenfor ei gruppe, mens abiotiske variabler faktorer forventes å synkronisere adferden mellom adskilte grupper i samme miljø. Vi testet adferdssynkroniseringen innenfor og mellom grupper av tamrein ved å observere aktiviteteter i seks uavhengige grupper hver med tre simler. Vi testet også hvordan noen miljøvariabler påvirker dyrenes adferd. Aktiviteten til alle individene ble observert hvert tiende minutt hele døgnet sammen med klimatiske forhold og biotiske variabler som insektplage. Dyrene innenfor ei gruppe viste klart felles adferd med samme beite- og liggeperioder. Det var lite eller ingen synkronisering mellom grupper, idet det var lite eller tilfeldig sammenfall av aktiviteter. Sjelden var alle seks gruppene aktive eller inaktive samtidig. Aktiviteten til individer innenfor en gruppe var synkronisert som forventet, uten eksterne miljøvariabler. Derimot var det ingen synkronisering mellom uavhengige grupper. Dette støtter teorien at reinsdyr har en 24-t polysyklisk aktivitetsrytme uavhengig av klimatiske variabler på sommeren og uten sterke påvirkninger utenfra som parasittiske insekter eller menneskelige aktiviteter. Vårt forsøk viste at reinens aktivitetsrytme tydeligvis var definert av interne fysiologiske prosesser og interaksjoner innen gruppen.

scholarly journals Does the Tichi Haf dam construction affect dragonfly and damselfly (Odonata : Insecta) assemblages of the Boussellam watercourse (central north Algeria)? A preliminary study

2020 ◽  
Vol 30 (30) ◽  
pp. 37-47
Author(s):  
Abdelmadjid Chelli ◽  
Riadh Moulaï ◽  
Abdelhadi Djemai
Keyword(s):  
Nineteenth Century ◽  
New Species ◽  
Riparian Vegetation ◽  
Dam Construction ◽  
Water Parameters ◽  
Negative Effect ◽  
Preliminary Study ◽  
The Impact ◽  
North Algeria ◽  
Extant Population

This paper reports a pioneer study dealing with the impact of dam construction on Odonata communities, because no similar study has been undertaken in Algeria and the consequences of this artificialization on the Odonata assemblages have rarely been studied elsewhere. The main purpose of this study was to determine if the Tichi Haf dam is really having a negative effect on the Odonata communities living on the Boussellam watercourse, as there has hitherto been a lack of knowledge about its odonatofauna and aquatic microinvertebrates. This study showed that changes due to the construction of this dam, involving riparian vegetation, bank aspect and water parameters, affected the Odonata assemblages inhabiting both sides of the dam wall. The richness and abundance of dragonflies and damselflies found upstream from the dam is quite different from those found downstream from the dam. The survey also identified four new species for the Bejaia region. Among these, we report on the rediscovery of the critically endangered (EN) Calopteryx exul in Algeria, recorded in the nineteenth century and deemed to have been extinct after an absence of more than a century. The presence of an extant population C. exul in this location does not correspond to any historical locality reported for this species.

Characterizing the impact of recovering sea otters on commercially important crabs in California estuaries

2020 ◽  
Vol 655 ◽  
pp. 123-137
Author(s):  
TM Grimes ◽  
MT Tinker ◽  
BB Hughes ◽  
KE Boyer ◽  
L Needles ◽  
...  
Keyword(s):  
Abiotic Factors ◽  
Sea Otter ◽  
Dungeness Crab ◽  
Sea Otters ◽  
Elkhorn Slough ◽  
Enhydra Lutris Nereis ◽  
Crab Abundance ◽  
Population Sizes ◽  
Commercially Important ◽  
The Impact

Protective legislation and management have led to an increase in California’s sea otter Enhydra lutris nereis population. While sea otter recovery has been linked to ecosystem benefits, sea otter predation may negatively affect commercially valuable species. Understanding the potential influence of sea otters is of particular importance as their range expands into estuaries that function as nurseries for commercially valuable species like Dungeness crab Metacarcinus magister. We consider how sea otter predation has affected the abundance and size of juvenile Dungeness crab in Elkhorn Slough, California, USA, and analyzed cancrid crab abundance and size across 4 California estuaries with and without sea otters to understand how biotic and abiotic factors contribute to observed variation in crab size and abundance. We compared trends in southern sea otters relative to Dungeness crab landings in California to assess whether increasing sea otter abundance have negatively impacted landings. In Elkhorn Slough, juvenile Dungeness crab abundance and size have declined since 2012, coinciding with sea otter population growth. However, the impact of sea otters on juvenile Dungeness crab size was habitat-specific and only significant in unvegetated habitat. Across estuaries, we found that cancrid crab abundance and size were negatively associated with sea otter presence. While abiotic factors varied among estuaries, these factors explained little of the observed variation in crab abundance or size. Although we found evidence that sea otters can have localized effects on cancrid crab populations within estuaries, we found no evidence that southern sea otters, at recent population sizes, have negatively impacted Dungeness crab landings in California from 2000-2014.

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.

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