Macedonian Journal of Ecology and Environment

Microhabitat utilisation and coexistence strategies of sucker fish Garra mullya (Sykes, 1839) and zodiac loach Mesonoemacheilus triangularis (Day, 1865) in a wooded hill stream of Southern Kerala, India

Ruby Thomas, Raju Thomas K. — Wed, 25 Dec 2024 00:00:00 +0200

The habitat requirements of fishes vary with their biological and physiological processes. In this study conducted from March 2019 to February 2020, we focused on Garra mullya (Sykes, 1839) and Mesonoemacheilus triangularis (Day, 1865) in a wooded hill stream of the Pamba river basin in southern Kerala, India. These species were selected due to their ecological significance and prevalence within the freshwater ecosystems of the region. Our investigation aimed to identify and quantify microhabitat availability, utilisation patterns, and niche partitioning mechanisms influenced by trophic requirements, morphological and physiological characteristics, and stream biochemical conditions. Our focus was on fifteen environmental descriptors and attributes that operate on the microhabitat scale. Principal Component Analysis (PCA) and Pearson correlation were employed to reveal the habitat selectivity and association of species with multiple environmental variables at the focal point position of each observed fish. Microhabitat selection in G. mullya and M. triangularis was driven by trophic requirements, morphological and physiological characteristics of the fish, and biochemical conditions of the stream. G. mullya inhabited cobble and rubble-dominated microhabitats and favoured closer proximity to shelter and banks. M. triangularis, on the other hand, preferred gravel-filled microhabitats and was found to use locations near banks and shelters, more frequently. The coexistence of G. mullya and M. triangularis along the water column can be attributed to resource allocation and substrate variability.

Enumeration and antimicrobial activity of bacterial isolates from undisturbed and contaminated soils in North Macedonia

Wed, 25 Dec 2024 00:00:00 +0200

Particularly in temperate regions, seasonal change has an effect on microbial communities directly through climatic function. The microbial populations of an undisturbed and contaminated soil undergo temporal change over the course of four seasons. Eight soil samples were collected from different regions in North Macedonia. The undisturbed soil was collected from mountain Karadzica (protected area Jasen) and the contaminated soil was collected around the factory OHIS, operating in the chemical industry. The samples were collected using sterile bags along with sterile spatula. All the samples were transffered to the Microbiology laboratory, under sterile conditions. Bacillus spp. and Actinobacteria were isolated from the samples using a dillution method, based on the use of heat pretreatment for the isolation of Bacillus spp. and a selective media for the isolation of Actinobacteria. Confirmation was carried out by Gram staining method of all isolates. Soil samples corresponding to the autumnal season showed the greatest number of antimicrobial strains, 30 in total from both regions. Soil pH and moisture contents and as well as the concentration of organic carbon were determined for all soil samples. We found an inverse correlation between the organic carbon content and the number of isolates from undisturbed soil and a positive correlation between the both parameters in contaminated soil. Antimicrobial assays of the isolates were carried out against six bacteria and three fungi, using the agar well diffusion method. Bacillus strains from the undisturbed soil samples showed greater antimicrobial activity against Gram negative test microorganisms from the winter samples, while Bacillus strains from the summer contaminated soil samples demonstrated larger activity. In comparison, Actinobacteria strains demonstrated antagonistic activities only from the autumn season from both samples. The findings of this study show that the relationship between of the microbial communities and their ecosystem depend on the presence of anthropogenic contamination.

Habitat and humidity preferences of ground-beetle community (Coleoptera, Carabidae) on Belasica Mt.

Wed, 25 Dec 2024 00:00:00 +0200

This paper presents functional traits - habitat and humidity preferences of ground-beetles along altitudinal gradient on Belasica Mt, thus contributing in the knowledge of the ground-beetle responses to environmental changes.

The research was carried on Belasica Mt. in the period April-November 2010, by using pitfall traps.

Four categories of ground-beetles were recorded according to the habitat preferences: forest generalists, forest specialists, eurytopic species and open-area species, as well as five categories of ground-beetles according to the humidity preferences: xerophiles, mesoxerophiles, mesophiles, mesohygrophiles and hygrophiles.

Forest generalists as well as mesohygrophiles dominated throughout the entire gradient. Higher abundance of forest generalists and specialists, relatively low share of eurytopic forms and the absence of open space individuals indicate existence of well-preserved oak forest habitats in the lower altitudinal belt of Belasica Mt. In contrast, the absence of forest specialists in montane beech forests is a clear indicator of forest degradation.

Distribution of chemical elements in river sediments and alluvial soils from the Strumica River basin, North Macedonia

Trajče Stafilov, Robert Šajn, Katerina Trajanova — Wed, 25 Dec 2024 00:00:00 +0200

The distribution of 20 chemical elements (Ag, Al, Ba, Ca, Cd, Co, Cr, Cu, Fe, K, Li, Mg, Mn, Na, Ni, P, Pb, Sr, V and Zn) in river sediments and alluvial soils from the Strumica River basin in North Macedonia is presented. A total of 12 sediment and 24 soil samples were collected, from four locations of the Strumica River and eight locations of its main tributaries (Bansko, Dabile, Turija, Vodoča, Radoviška River and Injevska River). The content of the analysed elements was determined using inductively coupled plasma - atomic emission spectrometry (ICP-AES). All data obtained for the analysed samples were statistically processed using Stat Soft 11.0 software, whereby a descriptive statistical analysis of the element content values was performed. The maps of the spatial distribution of the content for each element with a minimum and maximum value of the content for each element were also created. The matrix of correlation coefficient for the sediments and soil samples from the entire study area shows that there is a strong correlation between the contents of the elements: V-Fe (0.97), V-Cr (0.94), Fe-Cr (0.91), Mn-Fe (0.85), Sr-Ba (0.83), Mg-Ca (0.83), Mg-Li (0.82), Ni-Cr (0.81) and P-Sr (0.80). There are three factors in the matrix of loading factors for the elements in the sediment and soil samples. Factor 1 includes the chemical elements V, Cr, Ge, P, Cu, Ni and Pb, Factor 2 comprises the chemical elements Sr, Ba, Al, Zn and Mn and Factor 3 includes Mg, Li and Ca. The comparative statistics using three methods [t-test, F-ratio and R(T/B)] showed no difference between the distribution of the different chemical elements in the topsoil and subsoil samples. The results obtained show that the content of potentially toxic elements in the river sediments and alluvial soil is low and it can be concluded that the Strumica catchment is not polluted with heavy metals.

Econometric modeling and forecasting of environmental conditions of cities and population health problems: Case study of Navoi and Zarafshan cities

Wed, 25 Dec 2024 00:00:00 +0200

In this research work, the problems of connection between various harmful substances emitted into the atmosphere and population morbidity indicators were analyzed in Navoi and Zarafshan, two important cities of the Navoi region, located in the industrialized and arid climate region of the Republic of Uzbekistan, located in the Central Asian region. The obtained results show that in the city of Navoi, there is a high correlation between diseases related to the respiratory system, diseases of the blood and blood-forming organs and immune system, diseases of the nervous system, and annual harmful substances released into the atmosphere. In the city of Zarafshan, there is a strong direct connection between the harmful substances released into the atmosphere and diseases related to the digestive organs, that is, the increase or decrease of various harmful substances in a certain amount, as mentioned above It can also increase or decrease the mentioned diseases. In conclusion, there is a direct correlation between the environmental conditions of industrialized and arid climate regions and the issues of public health, and the increase or decrease of one affects the trend of the other directly. It is more important than ever to develop the necessary measures with a proper understanding of this causal effect. Taking into account all the above points, we have developed some suggestions and recommendations.

The impact of lithology in the recharge area on the hydrochemical properties of the Slatinski Izvor spring (North Macedonia)

Biljana Gichevski, Slavčo Hristovski — Wed, 25 Dec 2024 00:00:00 +0200

The Slatinski Izvor spring is located in the Poreče basin, in the Slatinska Reka river valley in the central part of the Treska river basin. Hydrochemical characteristics of water from the karst spring Slatinski Izvor were analysed in the period between June 2013 and June 2014. The results showed that the lithology of the catchment area of the spring is reflected in the chemical composition of the water. All used methods showed that spring belongs to calcium bicarbonate water type. The spring had typical shallow and fresh water and short residence time of the water in the karst aquifer. All water samples had low concentration of nutrients and heavy metals and can be considered as potential for water supply and irrigation.

Heavy metal stress response in the diazotroph, Rhizobium petrolearium

Anwuli U. Osadebe, Amarachi Durunna — Wed, 25 Dec 2024 00:00:00 +0200

Heavy metals occur at elevated concentrations in the environment mainly due to anthropogenic activities. The response of the hydrocarbon-degrading, diazotroph, Rhizobium petrolearium, to varying concentrations of the heavy metals – lead, cadmium and chromium(VI) – was investigated by establishing the effect of loading concentrations of 1 mM to 15 mM on its growth and enzymatic activity with increasing exposure time. The findings revealed a decline in growth and enzymatic activity with increasing heavy metal concentration and increasing exposure period. Mean reductions in abundance of 42.0% – 100.0%, 52.1% – 100.0% and 54.4% – 100.0% for different concentrations of lead, cadmium and chromium(VI) respectively were obtained. For lead and cadmium, no growth (100% decline) was seen by the end of the study at 10mM and 15mM exposure concentrations. There was no growth at the Cr(VI) concentrations of 5mM – 15mM by the end of the study. Statistically significant differences (p≤0.05) were seen in growth reduction between the different application concentrations. The results inferred the order of toxicity against R. petrolearium based on growth response to be chromium(VI) > cadmium > lead. At higher concentrations of 10 mM and 15 mM, all three heavy metals inhibited α-amylase and protease activity but had only minimal impact on oxidase, catalase and cellulase activities. Only Pb and Cr(VI) inhibited protease activity at higher concentrations of 10mM and 15mM. Based on the enzymatic activity inhibition tests, the order of toxicity was Cd > Cr(VI) > Pb. The findings suggest that at high concentrations, the heavy metals, lead, cadmium and chromium(VI) could impact negatively on abundance and interrupt enzymatic activity in soil bacteria like R. petrolearium.

Isolation and screening of biosurfactant producing strains of Bacillus spp. from soils on selected sites in North Macedonia

Wed, 25 Dec 2024 00:00:00 +0200

Biosurfactants are eco-friendly, biodegradable, and versatile compounds with extensive industrial applications, notably in environmental bioremediation. Biosurfactants are known for lowering surface and interfacial tension within aqueous and hydrocarbon mixtures. Their primary application lies in the oil industry, where they enhance oil quality and assist in extraction processes, making oil recovery more efficient. Despite their diverse uses, the environmental distribution of biosurfactant-producing bacteria remains largely unexplored. This research focused on exploring the presence of biosurfactant-producing bacteria in both uncontaminated and polluted settings. Soil samples, totaling eight from polluted areas and four from undisturbed sites, were cultured on nutrient agar, and bacterial isolates were subsequently analyzed for their distinctive macroscopic and microscopic features, especially highlighting those with biosurfactant potential. Confirmation was carried out by Gram staining method of all isolates. Additionally, geochemical parameters of the soil samples were measured to emphasize the relevance of these strains for industrial applications and underscore their ecological role within soil environments. The biosurfactant potential of the 37 bacterial isolates was assessed utilizing the oil spread technique and hemolysis assay. Twenty of the isolates exhibited biosurfactant activity, primarily representing samples from contaminated soil environments. Bacterial isolates demonstrating significant biosurfactant production capabilities can be utilized for the bioremediation of contaminated soils. This application harnesses their natural properties to enhance the degradation of pollutants in affected environments.

Investigating the feasibility of reusing the effluent from the urban sewage treatment plant (Case study: South Tehran treatment plant)

Fatemeh Ahmadinezhad, Nasser Mehrdadi, Alireza Talebi — Wed, 25 Dec 2024 00:00:00 +0200

The current study was carried out with the aim of measuring the feasibility of reusing the effluent from the wastewater treatment plant in south Tehran. For this purpose, pH, BOD5, COD, NO₃-, PO₄^3-, SO₄^2-, TDS, TSS, Turbidity, EC, fecal coliform and total coliform were investigated during 6 stages of sampling from the incoming wastewater and the outgoing wastewater from the treatment plant. The average pH, BOD5, COD, NO₃-, PO₄^3-, SO₄^2-, TDS and TSS entering the treatment plant are 7.19, 211.4, 392, 68.8, 12.4, 464, 793.4, 217.8 mg/liter respectively, Turbidity 126.25 NTU, EC 1006.6 Micro mouse/cm, fecal coliform was 1200 MPN and total coliform was 1254 MPN, the highest organic load entering the treatment plant was in May and August 2020. The average total removal efficiency for pH, BOD5, COD, NO₃-, PO₄^3-, SO₄^2-, TDS, TSS, which is equal to 6.9, 15, 31.16, 6.06, 2.99, 83, 465.13, 7.5 mg/L, respectively. Turbidity was 6.21 NTU, EC was 762.83 micro mouse/cm, fecal coliform was 8.75 MPN and total coliform was 63.5 MPN. By comparing the results of the quality parameters with the standards of the Environmental Protection Organization, it was found that the effluent of the treatment plant is in a favorable condition for discharge to surface water, absorbent wells and irrigation and agricultural uses, which indicates the correct operation of the treatment plant and compliance with the established rules and standards. Also, the efficiency of the sewage treatment system using the activated sludge method in this treatment plant is favorable.