DOI: 10.3897/biorisk.24.206086

Authors: Setie Ewnetu, Zerihun Girma

Abstract: Understanding how primates adapt their foraging strategies to fluctuating environmental conditions is a central theme in behavioral ecology. The extreme Afro-alpine ecosystem presents a unique setting to test predictions of Optimal Foraging Theory and the Fallback Food Hypothesis due to its severe seasonal shifts in resource availability. This study investigated the dietary composition, seasonal variation, food preferences (dietary selectivity), and foraging plasticity of the Southern Gelada (Theropithecus gelada obscurus) in the Abune Yosef Zigit Community Conservation Area, Ethiopia. Using instantaneous scan sampling and vegetation surveys across dry and wet seasons, we recorded 761 feeding records encompassing 25 food items. Forbs dominated the diet (55.7%), followed by grasses (42.7%), and insects (1.6%). Geladas exhibited a consistent bimodal feeding pattern but demonstrated pronounced seasonal niche shifts. In the dry season, they highly expanded their dietary breadth (Shannon H' = 2.31) and relied heavily on underground roots, aligning with fallback food strategies. In the wet season, the dietary niche narrowed (H' = 1.92), with greater reliance on grass blades and young shoots. Electivity indices revealed highly dynamic, context dependent selectivity rather than fixed preferences, with preference rankings shifting between seasons. These findings highlight the remarkable behavioral plasticity of geladas and underscore their ability to dynamically adjust foraging strategies to survive in extreme, highly seasonal environments.

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DOI: 10.3897/biorisk.24.197390

Authors: Stoyan Nedkov, Katrin Parvanova, Sofia Yakovleva, Ina Vasileva, Marta Paunova

Abstract: The Integrated Valuation of Ecosystem Services and Trade-offs Habitat Quality (InVEST HQ) model offers a spatially explicit approach for assessing habitat quality utilizing relatively simple, readily available data and an intuitive interface. In this paper, we provide a literature review of the InVEST HQ application based on 61 scientific papers, which have been systematized, analysed, and interpreted using a detailed and structured original template. We identify the main trends and gaps in the model’s applications, as well as its readiness for integration into studies on human-wildlife interactions (HWI). The first trend concerns the application of the model for assessing habitat quality to address spatial discrepancies between nature conservation and other human activities. The second one shows that, although InVEST HQ is often considered more suitable for assessing biodiversity in general, our review identifies a parallel trend of using the model in species-specific studies. The third trend reveals the application of the model in combination with other models and methods, which can provide more robust and ecologically meaningful results, compensating for its reliance on expert-based parameters. We further examine the extent to which InVEST HQ applications relate to HWI, showing that although the applicability is currently limited and mostly indirect, the model’s core strengths make it a promising tool for future HWI-oriented research. These results highlight the increasing popularity of the model as a spatially explicit tool for assessing habitat quality under a wide range of contexts, and point to its widespread integration with complementary tools as a core spatial framework that requires additional modelling layers to capture ecological complexity. This is in line with current trends in integrated ecosystem services modelling, which is necessary due to the multiple trade-offs among different services and the associated challenges that ecosystem assessments aim to resolve.

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DOI: 10.3897/biorisk.24.192687

Authors: Nadezhda Nikolova, Miglena Zhiyanski

Abstract: This study investigates the spatial and temporal distribution of copper (Cu) in soils affected by long-term atmospheric emissions from a major copper smelter in the Zlatitsa–Pirdop Valley, Bulgaria. The objective is to assess how industrial activity and subsequent technological changes influenced Cu accumulation patterns over a 48-year period (1973–2021). Soil samples were collected along eastward transects at multiple distances from the smelter and analyzed using standard aqua regia digestion followed by atomic absorption spectrometry (AAS) and inductively coupled plasma optical emission spectrometry (ICP-OES) techniques. Three temporal datasets (1973, 1995 and 2021) were compared to evaluate long-term changes in Cu concentrations and spatial distribution. The results show a pronounced shift in contamination patterns over time. In 1973, Cu concentrations exhibited a clear decrease with distance from the emission source, indicating localized deposition. In contrast, data from 1995 and 2021 reveal a more complex spatial pattern, with persistently elevated Cu levels at greater distances from the smelter. This change reflects modifications in emission release height, atmospheric dispersion conditions, and long-term redistribution processes. The study demonstrates that Cu behaves as a persistent and poorly mobile contaminant in surface soils, with limited natural attenuation over decadal time scales. Despite significant improvements in emission control technologies after industrial privatization, historical deposition continues to dominate current soil contamination levels. The findings highlight the combined role of anthropogenic emissions, valley topography, meteorological conditions, and local geochemical background in controlling heavy metal distribution. This study contributes to a better understanding of long-term soil contamination dynamics in industrial mountain-valley environments and provides a basis for environmental monitoring and risk assessment strategies.

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DOI: 10.3897/biorisk.24.206801

Authors: Fantaye Fekede, Degife Asefa, Abera Uncha

Abstract: Arisaema schimperianum (Schott) is an underutilized crop grown in the Gamo highlands of Ethiopia. It supports the food security and livelihoods of local people, while its management and utilization constitute an essential component of ethnobotanical knowledge and food culture within local communities. This study was intended to document the indigenous knowledge of local people concerning the production and utilization of the crop and its uses. A mixed sampling strategy was used for data collection: purposive sampling for districts and kebeles, random sampling for household heads, and a combined purposive and snowball sampling approach to select knowledgeable elders for the study. Ethnobotanical data were collected from a total of 357 informants: 318 through semi-structured interviews, 30 through focus group discussions, and nine through key informant interviews. The results revealed that local people recognize the diversity of A. schimperianum landraces and their associated folk names and classify them. Approximately two-thirds of respondents identified landraces based on morphometric attributes; approximately four-fifths cited the plant as a food crop, and a small fraction (13%) cited it as a source of food, ethnomedicine, and ethnoveterinary medicine, while only a small minority (5%) reported it as a source of food and ethnoveterinary medicine. Planting propagules and managing the farm throughout the dormancy period highlighted growers’ tacit ecological knowledge of the plant’s phenology, while intercropping practices revealed environmentally friendly agriculture. Postharvest practices, namely pulverization and fermentation, have been pivotal traditional skills in making the crop nutritious for human consumption. The local community domesticates, manages, and continues to use the crop, which helps preserve local food traditions and biodiversity. The multiple regression output highlighted that sociodemographic factors (age, gender, education level, occupation, marital status, and family size) significantly influenced informants’ local knowledge (F = 78.507, p < 0.001). Social stigmatization, tedious culinary processes, land-use changes, and lack of promotion have been threatening the sustainability of the crop and associated traditional knowledge.

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DOI: 10.3897/biorisk.24.205627

Authors: Zerihun Girma, Azmach Tensay, Bamlaku Ayenew

Abstract: National parks in Ethiopia face the dual challenge of conserving biodiversity, while sustaining local livelihoods. However, limited empirical evidence exists on how socio-economic, cultural and institutional factors collectively shape community perceptions of conservation policy effectiveness. This study investigates these determinants in Loka Abaya National Park, Sidama Region, Ethiopia, using an integrated framework grounded in Social exchange theory (SET) and the institutional analysis and development (IAD) framework. A mixed-methods approach was employed, combining household surveys (n = 128) with key informant interviews and focus group discussions. Determinants of policy perception were analysed using an ordered logistic regression model. Results reveal that favourable perceptions are driven by higher income, larger farmland size, greater distance from the park, education and involvement in decision-making. Notably, two counter-intuitive findings emerged: prior conflict with park authorities positively predicted favourable perceptions—likely reflecting the visibility of state enforcement—while secure land tenure predicted unfavourable views, possibly due to perceived restrictions on agricultural expansion. Conversely, larger household sizes and negative economic interactions with the Park (driven by widespread resource dependence) significantly predicted unfavourable perceptions. The findings underscore that, without viable alternative livelihoods, restrictive conservation policies exacerbate local vulnerabilities. To reconcile biodiversity goals with human well-being, policy-makers must transition from exclusionary governance to participatory, rights-based co-management. Prioritising equitable benefit-sharing, tenure-sensitive boundary delineation and conservation education are essential to enhancing policy legitimacy and long-term biodiversity outcomes in Ethiopia’s protected areas.

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DOI: 10.3897/biorisk.24.189492

Authors: Sodikin, Mutiara Salsabiela, Yoga Candra Maulana

Abstract: Because they are able to absorb and store atmospheric carbon, mangrove ecosystems help combat climate change. Nevertheless, few studies combining spatial analysis of mangrove carbon stock estimation with estimation of the mangrove area required to offset anthropogenic emissions at the subdistrict level have been conducted in rapidly developing coastal regions. This research aimed to estimate the mangrove area needed to offset anthropogenic carbon emissions in the coastal areas of Gresik Regency, East Java Province, Indonesia. Transects and 10 × 10 m plots were used for field surveys conducted in seven coastal subdistricts. DBH measurements of mangroves were fitted to species-specific allometric equations to determine biomass and carbon stocks. A 2023 Landsat image was used to map mangrove distribution with the help of geographic information system (GIS)-based spatial analyses. Anthropogenic emissions were estimated based on available data for transport, livestock and poultry, liquefied petroleum gas (LPG) consumption, and electricity. The results showed that Gresik Subdistrict had the highest total emissions, at 6,795.91 t CO2-eq yr-1, and Ujungpangkah Subdistrict had the highest carbon stock value, at 264,803.16 t C. Spatial analysis showed that Kebomas, Panceng, and Gresik subdistricts needed additional mangrove areas of 52.07 ha, 50.21 ha, and 57.10 ha, respectively, to neutralize emissions under their current emission conditions. These results highlight the need for mangrove restoration as a crucial element of effective regional climate change mitigation and, thus, sustainable coastal management.

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DOI: 10.3897/biorisk.24.185920

Authors: Matewos Masne, Serekebirhan Takele, Berhanu Gebo

Abstract: Effective management of human–carnivore conflict (HCC) is essential for promoting sustainable coexistence in shared landscapes. This study investigated the patterns, economic costs, determinants, and mitigation strategies of livestock depredation in the Sirso landscape of southern Ethiopia. An agro-ecology-based stratified random sampling approach was used to select six kebeles, from which 343 households were proportionally sampled using a systematic random technique. Data were collected in 2025 through semi-structured interviews and key informant interviews (KIIs). Overall, 43.4% of respondents reported a total of 349 HCC events. Livestock depredation was the predominant form of conflict (74.5%), followed by attacks on humans (19.2%). A total of 1,280 head of livestock were lost during the study period (≈256 annually), with small stock most affected, particularly poultry (39.7%) and sheep (31.3%). The main problematic carnivores identified were spotted hyenas, leopards, jackals, cheetahs, and small carnivores. Agro-ecologically, lowland areas experienced most conflicts (65.7%); spatially, homesteads experienced most conflicts (70.8%). Temporally, conflict peaked in the wet season (77.3%) and at night (65.5%). The estimated carnivore-induced economic loss during the study period was US$118,167.2 (≈US$23,633.4 annually), and spotted hyenas (35.4%, ≈US$41,830.6) were the primary predators. Cattle depredation caused the greatest economic impact on households, amounting to US$80,580.1 during the study period. In response to depredation, most households (58.6%, n = 201) reported lethal control of predators; as a result, 110 carnivores were killed during the study period. Hunting was the most commonly employed retaliatory method (61.83%, n = 68), and spotted hyenas were the most targeted (n = 50, 45.45%). Applying physical barriers was the most common preventive strategy (40.4%), followed by active guarding (37.2%). The findings highlight the urgent need for context-specific conflict mitigation strategies, improved livestock management practices, and community-based education programs to support both wildlife conservation and rural livelihoods in human-dominated landscapes. The presence of guarding dogs, economic status, and the location of predation were key determinants of livestock depredation. To foster both sustainable wildlife conservation and rural development, effective conflict mitigation and community education are essential.

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DOI: 10.3897/biorisk.24.189621

Authors: Mengistu Wale, Afework Bekele, Mesele Yihune

Abstract: Data on farmers’ perception of rodent pest status and management intervention are limited in Ethiopia. The study aimed to explore farmers’ perceptions of crop yield loss due to rodents, management interventions and factors influencing their perceptions. Data were collected using a semi-structured questionnaire and analysed in R. The result showed that rodents were important agricultural pests, responsible for an average of 231.7 kg/ha crop yield loss per household annually. Farmers’ perception was significantly influenced by family size, farmland size, age, education and location of the farmlands. With an increase in farmers’ family size, age and farmland size, perceived crop yield loss/kg significantly decreases. Similarly, farmers with informal education experience significantly higher crop yield loss than those with grades 1–5 completed. However, farmers with grade six and above completed experience significantly lower yield loss than those with grades 1–5 completed. Wheat and teff were more susceptible to rodent damage at the growth stage, while maize was at the threshing (harvesting) stage. Most farmers believed that rodent interventions were effective when applied at these crop developmental stages, and rodenticide was the most effective method. Farmers have substantial knowledge to identify the most vulnerable crop developmental stage and management techniques against pest rodents. However, authors recommend that farmers should adopt ecologically-based rodent pest management to reduce crop yield loss and environmental concerns of rodenticides.

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DOI: 10.3897/biorisk.24.182472

Authors: María del Pilar Herrera-Mendoza, Laura Sánchez-Castillo, Edmar Meléndez-Jaramillo, Eduardo Osorio-Hernández, Rafael Delgado-Martínez, Héctor Rodríguez-Morán

Abstract: Soil pollution by heavy metals has increased due to anthropogenic activities, particularly agriculture, where intensive agrochemical use contributes to contaminant accumulation. Evaluating metal bioavailability is essential to understand potential risks in cultivated soils. This study aimed to assess the presence of heavy metals (Cu, Cd, Cr and Pb) in orange orchard soils by analysing their bioavailable concentrations and the soil physicochemical properties influencing their bioavailability. An exploratory soil sampling was conducted, collecting 60 soil samples from six orchards in the Municipality of Hidalgo. Samples were processed using diethylenetriaminepentaacetic acid extraction and quantified by Flame Atomic Absorption Spectrophotometry. Six soil physicochemical properties were also evaluated. Descriptive statistical parameters and Spearman’s correlation analysis were applied to assess the relationship between variables. The bioavailable concentrations of HMs followed the order Cu > Cr > Pb > Cd, with ranges of 1.1–3.2, 0.1–0.8, 0.2–0.4 and 0.04–0.2 mg/kg, respectively. Significant correlations were observed between particle density and bulk density, porosity, pH and electrical conductivity and the bioavailable concentrations, suggesting a significant association between these properties and heavy metal bioavailability. These findings demonstrate that soil physicochemical properties strongly influence metal mobility and highlight the need for continuous monitoring in agricultural areas. Changes in management practices could alter these properties and increase metal bioavailability, potentially raising toxicological risks.

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DOI: 10.3897/biorisk.24.178091

Authors: Nina Arhangelova, Seniha Salim

Abstract: Radionuclide concentrations in coastal sand samples from the Bulgarian Black Sea coast were analyzed using gamma-spectrometry. The average activity concentrations for 238U, 232Th, and 40K were found to be 11.62, 6.82 and 396.55 Bq/kg, respectively, all of which are lower than global averages. Additionally, the technogenic radionuclide 137Cs was detected in 11 samples, with an average concentration of 3.16 Bq/kg. Radiation hazard coefficients were calculated, and their average values were also lower than the global benchmarks. To explore the relationships between radionuclides and radiological variables, multivariate statistical methods such as Pearson correlation, principal component analysis, and cluster analysis were used. These findings contribute to a more comprehensive understanding of the radiological condition of the environment along Bulgarian beaches.

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DOI: 10.3897/biorisk.24.176556

Authors: Anna Cieplok, Bartosz Orpych, Katarzyna Chrobak, Konrad Rusinek, Robert Czerniawski, Aneta Spyra

Abstract: Humans widely use pharmaceuticals due to their availability, effectiveness, quick pain relief, and ability to improve well-being and health conditions. Their presence in aquatic environments, even in small doses, leads to serious ecological disturbances and alterations in trophic chains. This study aimed to assess the mortality and mobility of native Gammarus pulex and invasive Gammarus tigrinus under exposure to the nonopioid analgesics paracetamol, ibuprofen, ketoprofen, and a pharmaceutical mixture, as well as to determine their acute toxicity and impact on both species. At the 24th and 96th h of exposure, the highest increase in mortality was observed, most likely linked to shock caused by the sudden appearance of pollutants and the duration of exposure. Mortality was influenced not only by exposure time but also by the type of pharmaceutical. Paracetamol was the most lethal for both native and invasive species, though 100% mortality was recorded after 96 h of exposure. At a concentration of 5000 mg/L, all organisms died within 24 h. G. tigrinus, despite its broader ecological tolerance to pollution and resistance to environmental changes, responded to the presence of pharmaceuticals like G. pulex. Regarding survival, the ibuprofen–ketoprofen mixture in a 1:1 ratio was the least lethal for G. tigrinus, while ketoprofen alone was the least lethal for G. pulex. The availability and widespread use of over-the-counter pharmaceuticals, combined with the lack of systematic monitoring of aquatic environments, pose serious challenges to aquatic organisms in the context of pharmaceutical pollution in water habitats.

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DOI: 10.3897/biorisk.24.175449

Authors: Zelalem Temesgen, Yihew Biru, Amare Gibru

Abstract: Wildlife populations outside protected areas are highly threatened by both natural and anthropogenic factors. The present study conducted from January to February 2022, aimed to assess the major wildlife threats and evaluate the local community’s willingness to participate in wildlife conservation in the Hamer District, in South Omo, Ethiopia. Questionnaire interviews were conducted among 96 sample households. As well, focus group discussions and personal observations were held to achieve the research objectives. Descriptive statistics and multiple linear regression analysis were used to analyze the data. Overall, 63.5% and 50% of the respondents ranked deforestation and overgrazing as primary and secondary threats of wildlife conservation in Hamer District, respectively. Most respondents (82.3%) reported the decreasing status of wildlife populations in their vicinity which significantly differed across sample kebeles (the lowest administration units) (χ2 = 44.152, df = 3, p = 0.000). About 90.6 percent of respondents’ showed willingness to participate in wildlife conservation efforts in the area. The multiple linear regression models indicated that sample kebeles (ß= -0.102), sex (ß= -0.544), marital status (ß= -0.378) and years of residency of respondents (ß= 0.324) are significant predictors of local community willingness to participate in wildlife conservation activities. To ensure sustainable wildlife conservation in Hamer district, the study recommended managed livestock husbandry practices and water ponds should be prepared which can be used as water sources for both livestock and wildlife during drought seasons. Community based wildlife conservation and ecotourism should be promoted, and law enforcement are needed to halt illegal activities in the Hamer district.

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DOI: 10.3897/biorisk.24.180507

Authors: Thomas Campbell, Gilbert F. Gwilliam III, Nkosi Michael Evans, Kate Peltz, Glenn Simpson, Laure Dussubieux, Emily Erazo, Kage Guare, Agnetta Krechner, Estefania Long, Stephanie Maari, Isaac Oguike, Kimberly Rice, Amanda Zinke, Chrissy Christian, Ayesha Qazi-Lampert, Joshua M. Henkin, Danny Kreider, Christopher Maves, Gary Merrill, Phoebe Moy, Yarency Rodriguez, Zoe Ryan, Matt von Konrat

Abstract: According to the Lancet Commission, air pollution is one of the single largest environmental causes of premature death in the world. Particulate matter (PM), including metals, is among the pollutants of concern. Bryophytes, especially mosses, have been used for many decades as low-cost biomonitors of environmental deposition of heavy metals. In this exploratory investigation, we use strategically placed Sphagnum moss paired with portable X-ray fluorescence (pXRF) analysis as a living biomonitor for air/particulate metal pollution in and around the city of Chicago, Illinois, U.S.A. Preliminary results reveal a correlation between urbanization and some metal particulate matter, especially iron. The study warrants further investigation and supports the use of mosses and pXRF spectrometry as a rapid, low per-sample cost, and potentially accurate alternative to conventional metal pollution monitoring.

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DOI: 10.3897/biorisk.24.183097

Authors: Asrat Alemayhu, Kebede Gizachew, Getahun Yakob, Bedilu G. Kidan, Henok Tsegaye

Abstract: The use of Eucalyptus species has long been debated due to both their positive and negative environmental impacts. Findings from previous studies and scientific literature indicate that the effects of Eucalyptus on the environment are complex, inconsistent, and highly site-specific. The objective of this study was to evaluate the growth and yield performance of maize (Zea mays L.) under Eucalyptus hedgerow agroforestry practices in Decha Woreda, southwest Ethiopia. The experiment was conducted using a Randomized Complete Block Design with three replications. The study site was selected due to the widespread practice of eucalyptus maize alley cropping, the importance of maize production in the area, suitable agro-ecological conditions, and the need to evaluate the impact of expanding eucalyptus plantations on crop productivity under smallholder agroforestry systems. Maize growth and yield parameters, including plant height, number of cobs, cob weight, 100-seed weight, biomass, and grain yield, were measured. In addition, tree growth parameters such as diameter at breast height and tree height were recorded to assess the effects of different Eucalyptus species on intercropped maize. Data were analyzed using analysis of variance, and treatment means were separated using the Least Significant Difference test at the 95% probability level. In the first cropping season, maize grain yield did not differ significantly among treatments; however, a yield advantage was observed under river red gums (Eucalyptus camaldulensis Dehn) hedgerows. In the second and third cropping seasons, grain yield differences were significant (P ≤ 0.05) and consistently declined under Eucalyptus hedgerows compared with sole maize cropping. Among the four Eucalyptus species evaluated, flooded gum (Eucalyptus grandis W.Hill ex Maiden) and Sydney blue gum (Eucalyptus saligna Sm.) significantly (P ≤ 0.05) reduced maize grain yield during the second and third cropping seasons. Regarding tree growth performance, Eucalyptus saligna and Eucalyptus grandis exhibited greater height and diameter at breast height, while comparatively reduced growth in height and diameter at breast height was recorded for Eucalyptus camaldulensis and lemon-scented gum (Eucalyptus citriodora Hook.). However, their annual growth rates were not markedly different. The study also revealed no significant effect of Eucalyptus species on soil moisture content near the hedgerows, although relatively higher soil moisture was consistently observed under Eucalyptus camaldulensis over three consecutive years. Therefore, farmers practicing maize intercropping with Eucalyptus camaldulensis in a hedgerow arrangement with sufficient spacing (8 m) between hedgerows can potentially obtain both wood and food from the same unit of land. Nevertheless, appropriate management practices are essential to minimize competition between trees and annual crops, as both are crucial for farmers’ livelihoods.

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DOI: 10.3897/biorisk.24.189994

Authors: Mateusz Wrazidlo, Lionel Hernandez, Freddy Vergara

Abstract: A team undertaking an expedition to the plateau of Mount Roraima (also known as Roraima-tepui) in Venezuela between April and May 2023 found and documented fresh traces of a fire in the central part of the summit of the mountain, which damaged a large portion of a montane Pantepui habitat with local endemic plant species. The observation has baffled scientists, park guards, and local community leaders, who have never seen a fire in this particular area and worry that the case might be an indicator of increasing threats the unique montane ecosystem could face in the near future. This article provides insight into this case, supplemented with historical records and a discussion of possible causes and consequences of uncontrolled fire occurrences in the high-tepui environment.

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DOI: 10.3897/biorisk.24.171467

Authors: Rayana M. R. Carvalho, Wesley A. C. Godoy

Abstract: In this study, we integrate population theory with experimental data from the literature and from our laboratory experiments to develop a preliminary predator–prey model. This model investigates wing polyphenism in aphids exposed to predators. We propose a system of three ordinary differential equations to simulate interactions among apterous aphids, alate aphids, and their predators. Although essential for biocontrol, predators can induce wing development, enabling aphids to disperse to previously uninfested plantations. Building on the work of Sentis et al. (2019), who found that ladybug presence increases winged offspring production (an effect dependent on the host plant) in Acyrthosiphon pisum, with stronger responses in alfalfa-specialized lineages than in clover-specialized ones, we investigated how host plant type shapes aphid responses using an analogous system with Myzus persicae on broccoli (a favorable host, akin to alfalfa for a strong response) and basil (a repellent host, akin to clover for a weak response). Our model results indicate that predator presence promotes alate formation, a response modulated by the predator’s attack rate, its conversion efficiency, and host plant effects, as plants vary in their attractiveness to different aphid morphs.

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DOI: 10.3897/biorisk.24.175866

Authors: Kebebush Mulat, Ayalew Wondie, Minwyelet Mingist

Abstract: Cyperus papyrus is the cornerstone of Lake Tana’s buffer zone, a vital ecosystem supplying the Blue Nile. However, this critical area is under siege from excessive sediment runoff, primarily due to deforestation and unsustainable agricultural practices in the surrounding watershed. The lack of research on papyrus’s response to varying sediment levels has hindered restoration efforts. To address this knowledge gap, a study was conducted between May and October 2020 near Lake Tana. Twelve experimental wetlands were constructed, each divided into four sediment treatments: control (0 cm), low (1 cm), medium (5 cm), and high (10 cm). Papyrus growth parameters, including height, diameter, new shoot count, and above and below-ground biomass, were monitored every two weeks. Results unequivocally indicate that sediment load significantly impacts papyrus growth. Plants subjected to high sediment levels exhibited stunted growth, with reduced height, diameter, and new shoot production compared to those in lower sediment or control conditions. Biomass measurements also revealed a substantial decline in both above and belowground plant matter under high sediment stress. These findings highlight the urgent need for sediment management strategies to protect and restore the papyrus-dominated wetlands of Lake Tana.

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DOI: 10.3897/biorisk.23.173254

Authors: Laura Sanchez-Castillo, Edmar Melendez-Jaramillo, Santos Daniel Chicas, Ma. Teresa de Jesus Segura Martinez, Marisol Gonzalez-Delgado

Abstract: Shallow landslides and erosional problems in mountain areas are a recurrent issue that can represent a threat to human life and impact landscape ecology in many ways. Soil bioengineering is an approach that uses biological and ecological knowledge and engineering design principles to restore shallow-landslide-affected slopes. Tree species can be used as elements of soil bioengineering to reduce erosion and provide reinforcement through their roots. For this reason, we estimated the mechanical properties of thin tree roots from three vegetation communities along an elevational gradient. Our results showed that Piper amalago and Pinus teocote consistently exhibited higher mechanical properties than all species analyzed. The absence of a consistent altitudinal trend suggests that local site conditions and species-specific traits have a stronger influence on root mechanics than elevation alone.

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DOI: 10.3897/biorisk.23.139718

Authors: Pavel Dmitrievich Timkin, Yusufjon Gafforov, Mengcen Wang, Kun Qiao, Alisher Baxtibaevich Ajiev, Igor Eduardovich Pamirsky, Kirill Sergeevich Golokhvast

Abstract: The development of new pesticides as well as new approaches in their application are important challenges for food security. Currently, bioinformatics methods are useful for searching and designing models of molecular target structures, including antiviral, fungicidal, bactericidal, insecticidal, herbicidal drugs and plant growth regulators, which have been recently used in agrochemical research. In this article, we present the findings of a study investigating the molecular mechanisms underlying the binding of fungicides (fluopicolide, propamocarb) to target proteins (cytochrome P450, glutathione-S-transferases) of Phytophthora infestans. Virtual three-dimensional complexes of pesticides and their targets have been created using bioinformatics methods. A new approach for identifying the cavity parameters of binding sites using machine learning technology has been proposed. Rigid docking of pesticides with targets has been carried out and the binding energy calculation showed a high degree of stability of ligand-protein complexes. Our proposed in silico approach may be useful for studying the molecular mechanisms of fungicides action on Phytophthora proteins.

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DOI: 10.3897/biorisk.23.163073

Authors: Zelalem Temesgen, Yihew Biru, Amare Gibru, Kebebew Hundie

Abstract: Understanding local communities’ attitudes towards wildlife conservation is important for policymakers and conservationists in implementing sustainable wildlife conservation strategies. The present study was undertaken to assess local communities’ attitudes towards wildlife conservation and the types of human–wildlife conflict (HWC) in the Konta Special District (KSD). A total of 95 household respondents were randomly selected for questionnaire interviews from two study kebeles. In addition, focus group discussions (FGD) and personal observations were used to collect qualitative data. Descriptive statistics and the chi-square test were applied to analyze the data. Overall, 51.6% of the respondents reported both crop damage and livestock depredation as the main types of HWC. The respondents ranked baboons (95.8%) and monkeys (65.5%) as the principal wildlife responsible for property damage. Habitat loss (75.6%) was reported as the main threat to wildlife existence. A total of 91.6% of the respondents expressed a positive attitude towards wildlife conservation, and there was no statistically significant difference between study kebeles, sex, or education level of respondents. Guarding (75.8%) was identified as the dominant traditional method used to reduce damage. Development activities should not compromise wildlife conservation goals. Employing effective protection methods and providing alternative livelihoods such as ecotourism, beekeeping, and livestock fattening were recommended to ensure coexistence between humans and wildlife and to promote sustainable development in the KSD.

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DOI: 10.3897/biorisk.23.156866

Authors: Kebebush Mulat Alem

Abstract: Denbiq Wetland, located in Bure Woreda of West Gojam, Ethiopia, provides essential ecosystem services that support local livelihoods and biodiversity. This study assessed the wetland’s ecological functions, the socio-economic factors contributing to its degradation, and community-driven conservation strategies. Primary data were collected through structured questionnaires, interviews, focus group discussions, and field observations from a randomly selected sample of 202 households. Descriptive statistics and binary logistic regression were used for analysis. The findings show that the wetland offers diverse ecosystem services, including provisioning (freshwater, fodder, fruits), regulating (water purification, temperature control), cultural (recreation, tourism), and supporting (habitat, organic matter accumulation) functions. Logistic regression revealed statistically significant influences (p < 0.01): household size was negatively associated with wetland condition, while landholding size and age had positive impacts. Key drivers of degradation include agricultural expansion, overgrazing, reduced upland crop productivity, and limited grazing land. The local community showed strong awareness of, and support for, interventions such as awareness campaigns, establishing buffer zones, and grazing control. These findings underscore the need for integrated, community-based and policy-supported wetland management to maintain ecosystem function while supporting rural livelihoods.

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DOI: 10.3897/biorisk.23.151538

Authors: Isabella Bueno, João Vitor Mendes Ferraz de Toledo, Lucas Santos Canuto, Wesley Augusto Conde Godoy

Abstract: This study presents an extended mathematical model, originally developed to explore biomass dynamics in Acromyrmex ants and their symbiotic fungus, which has been adapted to investigate biomass growth in Atta sexdens and its fungal partner. The model incorporates ant grooming as a defence against entomopathogenic fungi, building on experimental data where self-grooming and allogrooming were quantified across three groups: Metarhizium anisopliae, Escovopsis phialicopiosa, and a control. A second chamber was introduced to simulate biomass transfer between compartments. Inflection points in growth curves were identified to detect shifts in population dynamics, and bifurcation diagrams explored key parameters affecting system stability, namely worker allocation to fungal cultivation, ant mortality, and fungal mortality. Metarhizium anisopliae significantly reduced both ant and fungal biomass, even under optimal grooming conditions, owing to its direct virulence to workers. In contrast, E. phialicopiosa, an opportunistic pathogen, had minimal impact unless fungal mortality exceeded a critical threshold. Self-grooming proved more effective than allogrooming in mitigating M. anisopliae effects, likely owing to prioritisation of individual defences under high pathogen pressure. Spatial dynamics enhanced resilience: one-way transfer between chambers redistributed biomass, delaying inflection points and bolstering structural stability. Bifurcation analysis revealed that extreme proportions of workers cultivating the symbiotic fungus reduced the biomass for both partners, whilst ant and fungal mortality rates led to non-linear declines in most simulations. These findings underscore the role of multi-chamber architecture in mitigating pathogen impacts in Atta colonies and suggest potential applications for biological control strategies by identifying behavioural and structural factors that may limit or enhance the effectiveness of pathogenic fungi in field settings. The model provides a useful framework for understanding epidemiological dynamics in natural nests, integrating behavioural defences and spatial strategies to safeguard this mutualism.

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DOI: 10.3897/biorisk.23.141404

Authors: Gebreegziabher Hailay Gebrenariam

Abstract: African butterflies play vital ecological roles but face numerous threats. Their protection requires aligning biodiversity conventions with butterfly-specific conservation goals. This review examines how to optimize regional and international conventions for enhanced African butterfly conservation. Through systematic assessment of relevant conventions, their provisions, success stories, and implementation effectiveness, I identify strategies to strengthen conservation outcomes. A comprehensive search of academic databases and official convention resources, using rigorous selection criteria, revealed that international frameworks support butterfly conservation through diverse mechanisms. The Convention on Biological Diversity (CBD) provides a foundational framework for biodiversity protection, including population monitoring and conservation. The African Convention on the Conservation of Nature and Natural Resources (ACCNNR) supports butterfly conservation indirectly through sustainable resource use and habitat protection. While climate change remains a significant threat, the UN Framework Convention on Climate Change (UNFCCC) offers mitigation tools. The Convention on International Trade in Endangered Species (CITES) regulates butterfly trade, with potential for greater impact through expanded species coverage and aligned strategies. The Ramsar Convention’s wetland focus benefits butterflies when butterfly species are recognized as bioindicators in site management plans, while the World Heritage Convention protects critical habitats. Collectively, these conventions advance butterfly conservation through habitat protection, sustainable practices, awareness-raising, and international cooperation. However, their effectiveness is constrained by resource limitations and data deficiencies. To address these challenges, three key recommendations are proposed: (1) integrating butterfly-specific targets into national biodiversity strategies, (2) strengthening research capacity and enforcement mechanisms, and (3) creating a Pan-African conservation network for coordinated regional action. Additionally, promoting the use of butterflies as bioindicators in climate and land-use policies would simultaneously enhance conservation efforts and support broader ecosystem protection objectives.

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DOI: 10.3897/biorisk.22.124897

Authors: Agus Sabdono, Diah Permata Wijayanti, Muhammad Hilmi, Eridhani Dharma Satya

Abstract: The Karimunjawa Marine National Park, situated in the Java Sea, Indonesia, is renowned for its rich biodiversity and lively coral reefs. However, amidst the backdrop of this natural beauty, concerns have been raised regarding the potential impacts of shipping activities on the health and diversity of these fragile ecosystems. The increase in maritime traffic, including commercial vessels, tourist boats, and fishing vessels, traversing through the Karimunjawa Marine National Park, raises significant environmental concerns. The movement of these vessels, especially along specific shipping routes, has the potential to disturb and damage coral reefs through various mechanisms. Hence, this study aimed to investigate the possible impacts of shipping routes on the coral abundance and diversity and the coral health in the Karimunjawa Islands, Java Sea, Indonesia. This study categorized ship routes into West Route, East Route, and Non-Route and assessed coral health and diversity across 15 islands. Key metrics analyzed included coral disease prevalence, coral cover, diversity index, species richness, relative abundance, and evenness, using 15 × 2 m belt transects at 3 and 8 m depths with three repetitions each. Statistical analysis revealed significant differences in coral abundance and species richness among ship-route groups, but no significant depth-related differences. These results suggest that while shipping routes affect certain aspects of coral health and diversity, other factors may be more influential in shaping coral disease prevalence and overall diversity in Karimunjawa reefs.

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DOI: 10.3897/biorisk.22.125194

Authors: Stoyan Nedkov, Vanya Stoycheva, Hristina Prodanova, Ivaylo Ananiev, Yordan Yordanov

Abstract: The ecosystem services (ES) concept has established itself in recent years as the predominant paradigm for framing environmental research and policy-making. The EU Biodiversity Strategy to 2020 with its task for member countries to map and assess the state of ecosystems and their services has contributed vastly to the development of the ES studies in the European countries. Bulgaria was among the countries that made substantial progress in its implementation and the contribution of the geographers was of vital importance. This paper aims to provide an overview and analysis of the ES research in Bulgaria focusing on the contributions of the geographers and the spatial aspects of the studies. The information on the ES research was performed through a literature review by collecting all available published works that address the main objectives of the study. To systematize and characterize the content of the reviewed papers, a special database with a standard nomenclature was constructed. The findings from the review allowed us to identify both achievements and research gaps in the ES studies conducted by Bulgarian geographers. This enabled us to define the main research priorities of the coming years which can trace the future directions of ES research in the country. They include the development of the spatial aspects in the methodological frameworks for mapping and assessment of ES, better use of GIS-based tools for mapping ES alongside models’ integration, and improvement of the publication's quality and increase of the papers published in highly rated indexed journals.

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DOI: 10.3897/biorisk.22.117668

Authors: Stephany Toschkova, Sevginar Ibryamova, Darina Ch. Bachvarova, Teodora Koynova, Elitca Stanachkova, Radoslav Ivanov, Nikolay Natchev, Tsveteslava Ignatova-Ivanova

Abstract: One of the main problems of the world's oceans, reported by many scientific studies, is the microplastic pollution. Within the Black Sea, one of the main sources of pollution is the same, which is caused by the diverse anthropogenic activities. The present study demonstrated detailed microplastics contamination of in five fish species important for the commercial fishing (Garfish, Мullet, Knout goby, Pontic shad and Mediterranean horse mackerel). They were collected from the Sozopol area on the Bulgarian Black Sea coast. Within each microplastic morphological group, three size classes were recognised: 100–200 µm, 25–100 µm and ≤ 25 µm. Microplastics were found in all studied tissues of the fish, but in varying proportions of pellets, fibres and fragments. Pellets were most frequently isolated, followed by irregularly-shaped fragments and fibres were the least numerous. The bulk of insulated plastics are made of polyethylene (PE) and polyethylene terephthalate (PET). Our results pointed out serious pollution with plastic particles in the Bulgarian Black Sea aquatory, which, in the future, may seriously affect the health of the fish population and also human health.

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DOI: 10.3897/biorisk.22.120802

Authors: Dinesh C. Nautiyal, Kumar Manish

Abstract: Studies documenting anthropogenic disturbance-driven changes in forest communities of the Eastern Himalaya, a global biodiversity hot spot, are largely lacking. We studied six forest sites of tropical semi-evergreen forests in Arunachal Pradesh in the Eastern Himalaya to understand the effects of varying disturbance intensities on the forest community structure and composition. Based on the magnitude of disturbance, forest sites were classified as experiencing low, moderate and high disturbance. Mean species richness (SR) of trees and shrubs decreased from low disturbance to high disturbance. Mean SR of herbs was maximum in moderately disturbed forest sites. Maximum values of the Shannon-Wiener Diversity Index (SD) were recorded for trees at sites with low disturbance, for shrubs at sites with high disturbance and for herbs in moderately disturbed forests. Pilelou Evenness Index (EI) values were maximum for trees at sites with high disturbance, while maximum EI values for shrubs and herbs were recorded in the forest sites with low disturbance. The number of tree families decreased from 18 to 13 in the forests with low and high disturbance, respectively. Moderate disturbance led to increased herb species richness and diversity, while increasing disturbance produced contrasting effects on trees. High anthropogenic disturbance led to low species richness, but high diversity amongst shrubs. Our investigations suggest that the magnitude of disturbance elicits differential responses in different physiognomic classes in the forest ecosystems and further our understanding of the effects of disturbance in tropical forest ecosystems of a global biodiversity hotspot.

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DOI: 10.3897/biorisk.21.111253

Authors: Sevginar F. Ibryamova, Stephany Toschkova, Darina Ch. Bachvarova, Elitca Stanachkova, Radoslav I. Ivanov, Nikolay D. Natchev, Tsveteslava V. Ignatova-Ivanova

Abstract: In the present work, we investigated the dynamics of the microbial communities in the wedge clam Donax trunculus (Linnaeus, 1758) from the Bulgarian coastal waters of the Black Sea. The samples were collected in the period of January 2020 until December 2022 from Arkutino, Ahtopol, Obzor and Tsarevo. The BIOLOG system was used for microbiological determination. In our investigation were isolated the following microorganisms: Enterococcus cancerogenus, Enterococcus hirae, Escherichia vulneris, Citrobacter farmeri, Acinetobacter gyllenbergii, Enterococcus hirae, Escherichia vulneris, Enterobacter cloacae, Escherichia hermannii, Pseudomonas mendocina, Pseudomonas fulva, Pseudomonas alcaligenes, Pseudomonas putida, Acinetobacter johnsonii, Acinetobacter gyllenbergii, Enterococcus hirae, Escherichia vulneris, Enterococcus gallinarum, Citrobacter sedakii, Pseudomonas putida, Streptococcus lugdunensis, Enterococcus casseliflavus, Vibrio cincinnatiensis, Vibrio alginolyticus, Vibrio parahaemolyticus, Enterococcus hirae, Streptococcus aureus, Staphylococcus lugdunensis and Enterococcus casseliflavus. During the winter period, we detected the presence of Pseudomonas sp. – P. alcaligenes, P. putida, and A. gyllenbergii. In the autumn months we isolated C. sedakii, C. farmeri, A. gyllenbergii, A. johnsonii, P. fulva and E. casseliflavus. In the spring, E. cancerogenus, E. hirae and Pseudomonas mendocina were found. During the summer, the highest biodiversity of microorganisms - E. hirae, E. vulneris, E. cloacae, E. gallinarum, P. putida, V. cincinnatiensis, V. alginolyticus, V. parahaemolyticus, S. aureus, E. hermannii and S. lugdunensis were registered. Although our three-year research showed that some species are permanent and others are transient, we tend to accept the conclusion that there is only a transient microbiota in mussels and it changes depending on environmental conditions or is a result of pollution of the Black Sea.

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DOI: 10.3897/biorisk.21.111983

Authors: Aleksandrs Petjukevičs, Inta Umbraško, Natalja Škute

Abstract: This study describes an express method for identifying microorganisms: Pseudomonas aeruginosa by standard Raman spectroscopy, without surface-enhanced Raman spectroscopy (SERS). The short-wavelength 514 nm Ar-Ion laser was used for P. aeruginosa spectral identification in the Raman shift range from 3200 cm−1 to 200 cm−1. The research results showed a high analytical and diagnostic sensitivity of the technology to the express identification of P. aeruginosa and can be used as one of the reliable methods. The proven technology is promising for further research of other microorganisms due to several significant advantages of the method. It does not require long-term cultivation of bacteria and special sample preparation, additional expensive reagents or consumables.

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DOI: 10.3897/biorisk.21.108551

Authors: Carmine Colacino

Abstract: Three sites in the southern Italian Apennines were selected to assess correlation between forest structure and bryophyte flora. In two of the sites, the Index of Air Purity (IAP)–based on cover data of epiphytic bryophytes–was evaluated. The results show that bryophyte populations–and consequently IAP–are affected by forest structure and development, and that studies including different sites require a precise assessment of silvicultural characteristics to allow comparisons. Indicator values of mosses and liverworts were also taken into consideration in characterizing ecologically the three sites.

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DOI: 10.3897/biorisk.21.101171

Authors: Wojciech Ciesielski, Henryk Kołoczek, Zdzisław Oszczęda, Wiktor Oszczęda, Jacek A. Soroka, Piotr Tomasik

Abstract: Background: Recognising effects of static magnetic field (SMF) of varying flux density on flora and fauna is attempted. For this purpose, the influence of static magnetic field is studied for molecules of five complex lipids i.e. such as β-carotene, sphingosine, ceramide, cholesterol and phosphatidylcholine. Methods: Computations of the effect of real SMF 0.0, 0.1, 1, 10 and 100 AMFU (Arbitrary Magnetic Field Unit; here 1AMFU > 1000 T) flux density were performed in silico (computer vacuum), involving advanced computational methods. Results: SMF polarises molecules depending on applied flux density. Only β-carotene survives exposure to SMF of 10 and 100 AMFU without radical splitting of some valence bonds. Molecules of remaining lipids suffered radical cleavage of some bonds on exposure to SMF of 10 and 100 AMFU. Manipulation with applied flux density provides either inhibition or stimulation of biological functions of the lipids under study. Conclusions: SMF destabilises complex lipids to the extent depending applied flux density. Biological functions of β-carotene are fairly sensitive to SMF, whereas only slight response to the effect of SMF is observed in case of sphingosine, ceramide and cholesterol. Enzymatic hydrolysis of phosphatidylcholine is stimulated by SMF regardless of the catalysed enzyme employed.

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DOI: 10.3897/biorisk.20.97534

Authors: Borislav Grigorov, Nikolay Velev, Assen Assenov, Momchil Nazarov, Beloslava Genova, Kiril Vassilev

Abstract: The current study aims at revealing the forest habitat diversity of Godech Municipality, according to the EUNIS habitat classification. Initial data was collected from the Ministry of Environment and Water and the Forestry Management Plans. Subsequently, 418 vegetation plots (relevés) and 3422 verification points were collected during the fieldwork seasons of 2019 and 2020. The research territory is situated in Western Bulgaria in close proximity to the country’s border with the Republic of Serbia. Forests cover a total of 144.85 km2. Their phytocoenoses are dominated by Fagus sylvatica L. (59.22 km2), Quercus cerris L. (14.85 km2), Carpinus betulus L. (4.94 km2), Quercus dalechampii Ten. (2.39 km2), Q. frainetto Ten. (2.99 km2). There are plantations with Pinus nigra J. F. Arnold (20.87 km2), P. sylvestris L. (16.06 km2) and Picea abies H. Karst (11.65 km2) also. Forests are experiencing some major threats, such as logging, pollution and fires.

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DOI: 10.3897/biorisk.20.97604

Authors: Venislava Spasova, Daniela Simeonovska-Nikolova, Krastio Dimitrov, Gabriela Petrova, Kalina Pachedjieva, Rossen Tzonev

Abstract: Plant communities of two peat-shrub species – Spiraea salicifolia and Potentilla fruticosa were studied in the Rhodope Mts., with emphasis on their use as a resource for the mammals associated with them. These shrubs are boreal relicts among the dominant coniferous forests. The field surveys were conducted in the spring-autumn period of 2021–2022. In both study areas, the species composition of the mammals was studied by camera traps for medium and large mammals, and by Sherman live traps for small mammals. The species registered were roe deer (Capreolus capreolus), red fox (Vulpes vulpes), wild boar (Sus scrofa), pine marten (Martes martes), European hare (Lepus europaeus), red squirrel (Sciurus vulgaris), bank vole (Myodes glareolus) and yellow-necked mouse (Apodemus flavicollis). Having in mind that small mammals are vital prey base for avian and mammalian predators, it is not surprising that M. glareolus and A. flavicollis individuals were captured in the habitats that they probably use as shelters. The pine marten inhabits the forests by which the community of P. fruticosa is surrounded, but probably feeds on the rodents in the shrub. In this way, it probably provides it with an alternative to the forest food base and hunting ground. From the presented results, it seems that the L. europaeus uses P. fruticosa shrubs as food. Therefore, the plant communities of the two relict peat-shrub species studied probably provide shelter and food for the mammals. Their importance is established for at least one species of mammal with conservation significance at national and European level – M. martes. Therefore, it is necessary to continue and expand the future monitoring on mammal diversity of these relict communities.

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DOI: 10.3897/biorisk.20.97322

Authors: Plamen M. Kirov, Metody Karadjov, Hristo K. Hristov, Radostina Alexandrova

Abstract: There have been multiple types of research focusing on the relationship between feed ingredients and metal content in the egg white due to their role in human nutrition. The aim of the present study is to determine the metal concentration in hens’ eggs and, in particular, to compare the metal concentration in egg albumen originating from industrial poultry farms with that of backyard and free-range hens. All samples were collected in Romania from five separate counties and 10 different farms, over a period of two weeks and, as a result, a total of 50 were collected, 10 from each housing system (batteries/cages, litter/soil, free-range, organic and backyard). The measurements of the metals were taken by Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES), with a wide range of elements reported. For the essential elements, we measured Cr, Cu, Fe, Mn and Zn; Al, Cd, Ni and Pb for the heavy metals and, in addition, we measured B, Ba, Sr, Ca and Mg. The present study revealed that the metals in eggs from free-range hens are richer in essential elements with mean concentrations as follows: 1.528 mg/kg for Fe, 3.278 mg/kg for Zn, 0.058 mg/kg for Mn and 1.362 mg/kg for Cu. We concluded that the egg quality is closely connected with the housing system and nutrition. Furthermore, the results demonstrate that eggs from backyard housing are no better than those from free-range hens in terms of essential metal composition. The heavy and non-essential metal contents, present in the albumen of all the examined eggs, were much lower than the maximum allowed concentration and, therefore, egg consumption does not pose any risk to human health.

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DOI: 10.3897/biorisk.20.97581

Authors: Gloria Georgieva, Trayana Nedeva, Marina Badalova, Veronika Deleva, Valentin Savov

Abstract: Plant Growth Promoting Rhizobacteria (PGPR) represent a microbial community that exerts growth-promoting capabilities in plants by various mechanisms. Among the PGPR genera, Pseudomonas spp. deserves special attention. It is due to its characteristic traits, like the production of phytohormones and siderophores, solubilization of minerals and phosphates, and plant protection from biotic and abiotic stress. These PGPR properties depend on the microorganism and its plant counterpart. The use of microbial strains as bioinoculants must consider the physiological and economic aspects of the process, and the plant growth stimulating effect has to be checked and proved. This study aimed to explore the PGP capacity of Pseudomonas putida 1046 strain in a model plant system of the economically important corn culture (Zea mays). The effect of the strain’s metabolic status on the plant germination capacity was evaluated. Bacterial cultures, grown 16 h and 48 h, were explored for the treatment of the corn seeds at three experimental concentrations: 0.1, 0.2, and 0.4%, and monitoring of their germination capacity through the growth indicators length of the radicle, length of the coleoptile, and the number of lateral roots. The data obtained outline the positive effect of Pseudomonas putida 1046 on the germination capacity of corn when applied at 0.2% concentration. The in vitro treatment of the model plants with 0.2% suspension resulted in a 22.87%–28.33% increase in the length of the radicle, a 35.96%–49.56% increase in the length of the coleoptile, and a 5.41–16.67% increase in the number of the lateral roots. High values of the vigour index (2125 for 16 h and 2721 for 48 h culture) were also registered. The strain’s ability to produce siderophores of hydroximate type and exhibit phosphate solubilizing activity is proved. The optimal treatment parameters of the corn seeds comprise the application of 0.2% suspension of 16 h grown Pseudomonas putida 1046 strain for five days.

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DOI: 10.3897/biorisk.20.97566

Authors: Vladimir Ilinkin, Boryanka Traykova, Marina Stanilova

Abstract: Dalmatian pyrethrum Tanacetum cinerariifolium (Trevir.) Sch. Bip. (Asteraceae) is a perennial herb endemic to the eastern coast of the Adriatic Sea. The species is widely cultivated in many countries for its bioactive compounds pyrethrins, which are used as natural insecticides. Plants derived from seeds vary greatly in pyrethrin content; therefore, the vegetative propagation of high-quality individuals is very important for the establishment of agricultural pyrethrum crops. The present study deals with rapid in vitro multiplication of pyrethrum, ex vitro adaptation of selected clones and creation of an ex situ collection, as a first step towards introducing the species into agriculture in Bulgaria. Seeds from a private ex situ collection in Bulgaria and from a natural Croatian population were used as initial material for in vitro cultures initiation. Basal MS medium (Murashige and Skoog 1962) or MS supplemented with different concentrations of kinetin and indole-3-butyric acid were used for seed germination and multiplication of one-seed derived clones by consecutive subcultivations. The propagation effectiveness was evaluated as a number of new plants obtained per initial shoot. Considerable losses were noticed due to both endophytic contaminations and necrosis, especially on media supplemented with plant growth regulators. These problems were overcome by medium optimization: adding an antibiotic and modifying the medium to increase the calcium concentration using CaCO3. In the best medium variant (basal MS + 200 mg/L Medaxone + 75 mg/L Ca) no more infected plants were observed, and the percentage of necrotic plants decreased threefold, which resulted in formation of 38.06±10.11 new plants per initial shoot for a period of 7 months. Three hundred and sixty plants were ex vitro adapted in a phytotron (88% surviving rate), then 16 plants from 4 selected clones were transferred to the ex situ collection and bloomed twice from the very first growing season (June and September). The number of the flower heads increased in the second year of field cultivation and an average of 328±138 capitula per plant were counted for the best clone. The first trials to establish a pilot plantation of pyrethrum are promising.

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DOI: 10.3897/biorisk.20.97616

Authors: Boyana Angelova, Gabriela Atanasova, Nikolay Atanasov, Momchil Paunov, Maria Gurmanova, Margarita Kouzmanova

Abstract: The growing use of wireless communication devices has been significantly increasing the level of high frequency electromagnetic fields (EMFs) in the environment, which raises a concern for possible deleterious effects on living organisms. Long lasting exposure to low-intensity EMFs can cause effects on the molecular and cellular level, and a number of morphological and physiological changes. The aim of this work was to investigate the effects of 2.41 GHz EMF emitted by wireless communication systems on human erythrocytes after in vitro irradiation. The amount of the hemoglobin released from the cells was measured as an indicator for membrane destabilization. Effects of different exposure times (20 min or 4 h) and time elapsed after exposure to 2.41 GHz pulsed or continuous EMFs with different intensities, emitted from a textile (0.213–0.238 V/m) or a dipole (5, 20, 40 and 180 V/m) antenna, were investigated. The obtained results showed that the low intensity EMF had no significant effect on the hemoglobin release from irradiated cells; even a slight tendency for membrane stabilization was noticed 3–4 hours after the end of 20-min exposure to 0.213–0.238 V/m, 2.41 GHz EMF. There was no difference in the effects of continuous and pulsed EMFs. Increased hemoglobin release was observed only during the 4-hour exposure to 180 V/m, 2.41 GHz continuous EMF. Under these conditions, the temperature of the cell suspension had been rising, so we compared the results obtained under EMF with the effects of conventional heating. Moreover, after 1-hour exposure to 180 V/m the released hemoglobin level was a bit higher than the control one but the difference disappears within an hour after terminating the irradiation. In conclusion, the in vitro exposure to 2.41 GHz EMF emitted by wireless communication devices with power density below the reference level for population exposure does not change the stability of the cell membrane of human erythrocytes.

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DOI: 10.3897/biorisk.20.97557

Authors: Zlatina V. Peteva, Stanislava K. Georgieva, Bernd Knock, Thomas Max, Mona D. Stancheva, Simona Valkova

Abstract: Marine biotoxins are produced by certain phytoplankton species and used to accumulate in filter-feeding marine organisms. The occurrence of marine biotoxins in all aquatic environments and latitudes is variable in time and space. Thus, it is an essentially natural phenomenon, but the occurrence of toxigenic phytoplankton cannot be completely avoided or eliminated. A serious concern appears if these substances accumulate at high levels in seafood. If it is consumed by mammals including humans, severe illness of consumers of intoxicated seafood may result. The aim of this study is to assess the presence of marine biotoxins in plankton samples taken in 2021 and to compare the determined levels with a previous period. Plankton samples (n = 21) were collected in 2021 along the whole Bulgarian coastline (Black Sea). The presence of hydrophilic (domoic acid (DA)) and lipophilic toxins (okadaic acid, dinophysis toxin – 1, dinophysis toxin -2, azaspiracid-1, goniodomin A, pectenotoxin-2 (PTX2), yessotoxin, spirolide-1 and gymnodimine A) was investigated via liquid chromatography – tandem mass spectrometry (LC-MS/MS). Results indicated the presence of only DA in three samples and PTX2 in two samples. The positive samples were sporadically distributed throughout the study period. During 2016–2019, LC-MS/MS analysis confirmed the presence of DA, PTX2, YTX, SPX-1 and GDA in plankton net samples collected from the same locations reported here. The matching toxins (DA and PTX2) were at comparable levels in both periods of investigation, thus lower than in other European waters where harmful algal blooms are registered. These results show the persistent appearance of some marine biotoxins in Bulgarian waters. Although levels were low in the monitored periods, a constant monitoring is required in order that toxic events by seafood consumption be avoided.

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DOI: 10.3897/biorisk.20.97555

Authors: Stanislava K. Georgieva, Zlatina V. Peteva, Mona D. Stancheva

Abstract: Plastic pollution in seawaters is ubiquitous, but quantitative estimates on the floating microplastics in the Black Sea are still limited. Plastics may adsorb persistent environmental contaminants, thus representing a potential risk for marine organisms. Aim: Thе aim of the study was evaluation of the presence and characteristics of microplastic particles (MPs) in waters from the Black Sea coast of Bulgaria. Materials and methods: Samples of coastal waters were collected from March 2021 to April 2022 from different stations on the Black Sea coast, including protected, aquaculture and industrial areas. In order to determine the number of plastic particles, 23 samples were collected from the surface waters at depth of 1–3 m close to the Bulgarian shore. Samples were treated with H2O2, plastic particles were isolated by density separation and filtered over a membrane filter. Identification analysis of micro particles (< 5 mm) was performed visually by microscopy. Main results: Results indicated widespread presence of microplastics in coastal waters. Mean MPs concentration was calculated 7.3 ± 4.9 pt/l. The comparison of the North, Varna and South sampling area showed that there is no significant difference in the abundance of plastic particles. The most dominant type forms were fibres followed by fragments. The most abundant size class of fragments was 101–500 μm Ferret diameter. Conclusion: Further studies are needed in order to fill knowledge gap and to evaluate distribution of plastic particles in the Black Sea and their potential ecological risk.

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DOI: 10.3897/biorisk.20.97598

Authors: Teodora Ivanova Todorova, Petya Nikolaeva Parvanova, Krassimir Plamenov Boyadzhiev, Martin Dimitrov Dimitrov, Stephka Georgieva Chankova

Abstract: The aim of the study was to throw more light on the PbCl2 mode of action (MoA) depending on the genotype by the application of three model organisms and microbiological, biochemical, and molecular approaches. Three model systems – Chlamydomonas reinhardtii strain 137C – wild type (WT), Saccharomyces cerevisiae strain D7ts1, and Pisum sativum L. cultivar Ran1 and two experimental schemes – short- and long-term treatments were used. C. reinhardtii and S. cerevisiae cell suspensions (1×106 cells/ml) at the end of the exponential and the beginning of a stationary phase of growth were treated with various PbCl2 concentrations (0.45–3.6 mM) for 2 hours. Lower PbCl2 concentrations (0.03–0.22 mM) were also tested on C. reinhardtii 137C. Short-term treatment for up to 2 days with PbCl2 concentrations in the range of 0.45–3.6 mM and long-term treatment for up to 10 days with concentrations in the range of 0.45–2.7 mM was performed on P. sativum L. seeds and plants, respectively. Long-term treatment with a PbCl2 concentration of 3.6 mM was not tested because of the very strong toxic effect (plant death). The following endpoints were used – for C. reinhardtii: cell survival, “visible” mutations, DNA double-strand breaks (DSBs), malondialdehyde (MDA), intracellular peroxides (H2O2), and photosynthetic pigments; for S. cerevisiae – cell survival, gene conversion, reverse mutation, mitotic crossing-over, DSBs, superoxide anions, MDA and glutathione (GSH); P. sativum L. – germination and root length (short-term treatment), pro-oxidative markers – MDA, H2O2 and photosynthetic pigments (long-term treatment). Genotype differences between C. reinhardtii (0.047 mM) and S. cerevisiae (1.66 mM) were observed by two endpoints: concentrations inducing 50% lethality (LD50) and DSB induction. By contrast, no mutagenic effect was found for both unicellular test models. A slight toxic capacity of PbCl2, measured as inhibition of Pisum sativum L. seed germination and around 20% root length reduction was revealed after the treatment with concentrations equal to or higher than 1.8 mM. The variety of stress responses between the two plant test models was demonstrated by comparing MDA and H2O2. A dose-dependent increase in H2O2 levels and a minor increase of MDA levels (around 9–15%) were measured when C. reinhardtii cells were treated with concentrations in the range of LD20–LD80 (0.03–0.11 mM). Analyzing the kinetics of MDA and H2O2 in pea leaves, the most pronounced effect of concentration was shown for 2.7 mM. A decrease in the photosynthetic pigments was detected in the two experimental designs – short-term on C. reinhardtii and long-term on P. sativum treatments. The pro-oxidative potential was also proven in S. cerevisiae based on increased levels of MDA and superoxide anions and decreased GSH. New information is gained that PbCl2 can affect the DNA molecule and photosynthetic pigments via induction of oxidative stress. Our study revealed that the magnitude of stress response towards PbCl2 is genotype-specific. Our finding that Chlamydomonas reinhardtii is a sensitive test system towards PbCl2 contributes to good strategies for revealing very low levels of contaminants present chronically in main environmental matrices. This is the first report, as far as we know, affirming that PbCl2 can induce DSBs in Chlamydomonas reinhardtii and Saccharomyces cerevisiae.

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DOI: 10.3897/biorisk.20.97795

Authors: Michaella Petkova, Nadezhda Nankova, Viktoriya Kancheva, Silvena Boteva, Anelia Kenarova, Galina Radeva

Abstract: This study presents the distribution of bacterial and fungal abundances in long-term copper (Cu) contaminated soils in Topolnitsa-Pirdop valley – a highly industrialized zone with a number of mines and processing plants for copper and other non-ferrous metals. The bacterial (16S rRNA gene copies) and fungal (ITS rRNA gene copies) were estimated using quantitative PCR technique in five topsoils, differently Cu contaminated (ranging from 28.05 to 198.9 mg kg-1). Bacterial abundance varied in a range of 1.68 × 1011 to 3.24 × 101116S rRNA genes, whereas fungi amounted from 1.95 × 108 to 6.71 × 108 ITS rRNA genes. Fungal and bacterial abundances were significantly (fungi) and insignificantly (bacteria) influenced by Cu contamination. The fungal/bacterial ratio related negatively with soil Cu, which shifted microbial communities’ structure towards bacterial dominance. Since the ratio between bacteria and fungi are vital in explaining many soil functions, the calculated changes in this ratio indicated deterioration in soil quality, being of primary importance for plant production.

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DOI: 10.3897/biorisk.20.97569

Authors: Stephka G. Chankova, Nadezhda P. Yurina, Teodora I. Todorova, Petya N. Parvanova

Abstract: Genotype resistance to oxidative stress, induced by various physical/chemical stimuli has been the focus of scientists for the last decades, with several aspects – ecological (the formation of the genetic elite of population), agricultural and medical (radio-chemotherapy). Genotype resistance to oxidative stress is regarded as the integration of different morphological, physiological, biochemical, metabolic and genetic characteristics. Currently, it is supposed that the mechanisms involved in the formation of genotype resistance to oxidative stress are inter-correlated and inter-dependent, comprising changes in genes, proteins, enzymes, different metabolic pathways and/or biological networks. According to the present state of knowledge, various cellular targets, resulting in genotoxic stress, induction of DNA damage, mutations, genomic instability or apoptosis can trigger different signal transduction pathways, activating DNA repair, antioxidant and chaperone defence systems. Till now, a lot of experimental data have been accumulated concerning the contribution of DNA repair to the formation of genotype resistance to oxidative stress. At the same time, genotype resistance of organisms is largely determined by the ability of molecular chaperones to maintain conformational homeostasis of proteins (folding – misfolding – refolding or aggregation – degradation). The role of chaperones in protein homeostasis and cell death, especially in apoptosis, is well discussed in literature, but much less is known about their function in DNA repair. In this regard, here we addressed the question of whether the overproduction of chaperone proteins contributes to the repair of DNA damage caused by oxidative stress.

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DOI: 10.3897/biorisk.20.104660

Authors: Kalina Danova

Abstract:

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DOI: 10.3897/biorisk.19.96250

Authors: Wojciech Ciesielski, Henryk Kołoczek, Zdzisław Oszczęda, Jacek A. Soroka, Piotr Tomasik

Abstract: Background: We attempt to recognise the effects of static magnetic field (SMF) of varying flux density on flora and fauna. For this purpose, the influence of static magnetic field is studied for molecules of octadecanoic (stearic), cis-octadec-9-enoic (oleic), cis,cis-octadec-9,12-dienoic (linoleic), all cis-octadec-6,9.12-trienoic (linolenic), trans-octadec-9-enoic – (elaidic), cis-octadec-11-enoic (vaccenic) and all trans-octadec-6,9,12-trienoic (trans-linolenic) acids as well as 1- and 2-caproyl monoglycerides, 1,2- and 1,3-caproyl diglycerides and 1,2,3-caproyl triglyceride. In such a manner we attempt to develop an understanding of the interactions of living cells with SMF on a molecular level. Methods: Computations of the effect of real SMF 0.0, 0.1, 1, 10 and 100 AMFU (Arbitrary Magnetic Field Unit; here 1AMFU > 1000 T) flux density were performed in silico (computer vacuum), involving advanced computational methods. Results: SMF polarises molecules depending on applied flux density It neither ionises nor breaks valence bonds at 0.1 and 1 AMFU. In some molecules under consideration flux density of 10 and 100AMFU some C-H and C-C bonds were broken. Some irregularities were observed in the changes of positive and negative charge densities and bond lengths against increasing flux density. They provide evidence that molecules slightly change their initially fixed positions with respect to the force lines of the magnetic field. The length of some bonds and bond angles change with an increase in the applied flux density providing, in some cases, polar interactions between atoms through space. Conclusions: SMF destabilizes lipid acids and caproyl glycerides irregularly against increasing flux density. That irregularity results from the ability of those molecules to twist out of the initially established SMF plain and squeeze molecules around some bonds. In some molecules SMF flux density of 10 AMFU and above breaks some valence bonds and only in case of elaidic acid the trans-cis conversion is observed. Depending on the structure and applied flux density SMF either stimulates or inhibits metabolic processes of the lipids under study.

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DOI: 10.3897/biorisk.18.87433

Authors: Katarína Fogašová, Peter Manko, Jozef Oboňa

Abstract: Tiny pieces of plastic, or microplastics, are one of the emerging pollutants in a wide range of different ecosystems. However, they have, thus far, not been confirmed from phytotelmata – specific small water-filled cavities provided by terrestrial plants. The authors confirmed microplastics (141 μm – 2.4 mm long fibres of several colour and blue and orange fragments with diameters of 9–81 μm) in quantities from 101 to 409 per ml in Dipsacus telmata from two different periods. The phytotelmata, therefore, appear to be possible indicators of current and future microplastic pollution of the environment. However, further research is needed to obtain accurate information and verify the methodology for possible assessment of the local environmental burden of microplastics.

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DOI: 10.3897/biorisk.18.86616

Authors: Wojciech Ciesielski, Tomasz Girek, Zdzisław Oszczęda, Jacek A. Soroka, Piotr Tomasik

Abstract: Background: An attempt to recognize the effects of a static magnetic field (SMF) of varying flux density on flora and fauna.. For this purpose the influence of static magnetic field upon molecules of Mg(II), Fe(II), Fe(III), Co(II), Co(III) and Cu(II) metalloporphyrins is studied. Methods: Computations of the effect of real SMF 0.0, 0.1, 1, 10 and 100 AFU (Arbitrary Magnetic Field Unit; here 1AMFU > 1000 T) flux density were performed in silico (computer vacuum) involving advanced computational methods. Results: The static magnetic field (SMF) decreased the stability of the metalloporphyrine molecules. This effect depended on the situation of the molecule in respect to the direction of the SMF of the Cartesian system. An increase in the value of heat of formation was accompanied by an increase in the dipole moment. It was an effect of deformations of the molecule which involved pyrrole rings holding the hydrogen atoms at the ring nitrogen atoms and the length of the C-H and N-H bonds. As a consequence, that macrocyclic ring lost its planarity. Conclusions: SMF even of the lowest, 0.1 AMFU flux density influences the biological role of metalloporphyrines associated with their central metal atoms. This effect is generated by changes in the electron density at these atoms, its steric hindering and polarization of particular bonds from pure valence bonds possibly into ionic bonds.

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DOI: 10.3897/biorisk.18.80357

Authors: Sevginar Ibryamova, Stephany Toschkova, Borislava Pavlova, Elitca Stanachkova, Radoslav Ivanov, Nikolay Natchev, Nesho Chipev, Tsveteslava Ignatova-Ivanova

Abstract: This paper presents a study on the microbial status of different fish species and their habitats in the Bulgarian Black Sea area. The samples were collected in the period of January 2021 until March 2021. The fish species we used in this study were Black Sea turbot (Scophthalmus maximus), round goby (Neogobius melanostomus), shore rockling (Gaidropsarus mediterraneus) and European anchovy (Engraulis encrasicolus). The BIOLOG system was used for microbiological determination. From the different fish species, different species of microorganisms were isolated (using selective nutrient media). From the torbut, we isolated species Enterococcus villorum with 24 × 103 cells in 1 ml, Moraxella nonliquefaciens with 70 × 103 cells in 1 ml and Pseudomonas synxantha with 123 × 103 cells. Pseudomonas putida was isolated from the round goby with 20 × 103 cells in 1 ml. The species Streptococcus entericus with 123 × 103 cells in 1 ml was isolated from the shore rockling. Pseudomonas fulva with 60 × 103 cells in 1 ml was isolated from the European anchovy. A total of 223 × 103 cells in 1 ml of Pseudomonas agarici were isolated from Trachinus draco. Pseudomonas tolaasii with 145 × 103 cells in 1 ml were isolated from Merlangius merlangus. A different species of bacteria of the genus Pseudomonas was found for each of the investigated species of Black Sea fish. Apparently, the species Pseudomonas is characteristic of marine Teleostei and is important for the life and metabolism of these vertebrates. These microorganisms probably are resident species and developed not as result of pollution or environmental change.

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DOI: 10.3897/biorisk.18.80607

Authors: Wojciech Ciesielski, Tomasz Girek, Zdzisław Oszczęda, Jacek A. Soroka, Piotr Tomasik

Abstract: Background: Recognizing effects of static magnetic field (SMF) of varying flux density on flora and fauna is attempted. For this purpose the influence of SMF upon the porphine molecule is studied. Methods: Computations of the effect of static magnetic field (SMF) of 0.0, 0.1, 1, 10 and 100 AFU (1 AFU > 1000 T) flux density were performed in silico for SMF changes distribution of the electron density in that molecule. HyperChem 8.0 software was used together with the AM1 method for optimization of the conformation of the molecule of porphine. The computations of polarizability, charge distribution, potential and dipole moment for molecules placed in SMF were performed for molecule situated subsequently in the x-y, y-z and x-z planes of the Cartesian system. The computations involved the DFT 3-21G method. Results: Static magnetic field (SMF) decreased stability of the porphine molecule. This effect depended on the situating the molecule in respect to the direction of SMF of the Cartesian system. An increase in the value of heat of formation was accompanied by an increase in dipole moment. Conclusions: Observed effects resulted from deformations of the molecule which involved pyrrole rings holding the hydrogen atoms at the ring nitrogen atoms and the length of the C–H and N–H bonds. In a consequence that macrocyclic ring lost its planarity.

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DOI: 10.3897/biorisk.18.76997

Authors: Wojciech Ciesielski, Tomasz Girek, Zdzisław Oszczęda, Jacek A. Soroka, Piotr Tomasik

Abstract: Background: Recognising effects of static magnetic field (SMF) of varying flux density on flora and fauna is attempted. For this purpose, the influence of static magnetic field upon molecules of lower alkanols i.e. methanol, ethanol, propan-1-ol, propan-2-ol, butan-1-ol, S-butan-2-ol, isobutanol and tert-butanol is studied. Methods: Computations of the effect of real SMF 0.0, 0.1, 1, 10 and 100 AFU (Arbitrary Field Unit; here 1AFU > 1000 T) flux density were performed in silico (computer vacuum), involving advanced computational methods. Results: SMF polarises molecules depending on applied flux density, but it neither ionises nor breaks valence bonds. Some irregularities in the changes of positive and negative charge densities and bond lengths provide evidence that molecules slightly change their initially fixed positions with respect to the force lines of the magnetic field. Length of some bonds and bond angles change with an increase in the applied flux density, providing, in some cases, polar interactions between atoms through space. Conclusions: Since SMF produced and increase in the negative charge density at the oxygen atom of the hydroxyl group and elongated the –O-H bond length, these results show that SMF facilitates metabolism of the alkanols.

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DOI: 10.3897/biorisk.18.77001

Authors: Wojciech Ciesielski, Tomasz Girek, Henryk Kołoczek, Zdzisław Oszczęda, Jacek A. Soroka, Piotr Tomasik

Abstract: Background: Recognising effects of static magnetic field (SMF) of varying flux density on flora and fauna is attempted. For this purpose, the influence of SMF upon molecules of α- and β-D-glucose, α- and β-D-galactose, α- and β-fructopyranoses, α- and β-fructofuranoses and α- and β-D-xylofuranoses and α and β-D-xylopyranoses is studied. Methods: Computations of the effect of static magnetic field (SMF) of 0.0, 0.1, 1, 10 and 100 AFU (1 AFU > 1000 T) flux density were performed in silico for SMF changes distribution of the electron density in these molecules. Hyper-Chem 8.0 software was used together with the AM1 method for optimisation of the conformation of the molecules of monosaccharides under study. Then polarisability, charge distribution, potential and dipole moment for molecules placed in SMF were calculated involving DFT 3-21G method. Results: Application of SMF induced polarisability of electrons, atoms and dipoles, the latter resulting in eventual re-orientation of the molecules along the applied field of the molecules and the electron density redistribution at particular atoms. Increase in the field strength generated mostly irregular changes of the electron densities at particular atoms of the molecules as well as polarisabilities. Energy of these molecules and their dipole moments also varied with the SMF flux density applied. Conclusions: Saccharides present in the living organisms may participate in the response of the living organisms to SMF affecting metabolism of the molecules in the body fluids by fitting molecules to the enzymes. Structural changes of saccharide components of the cell membranes can influence the membrane permeability.

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DOI: 10.3897/biorisk.18.78548

Authors: Vanya Stoyanova Boneva, Nadezhda Traycheva Petkova

Abstract: The Bulgarian members of Chenopodiaceae are mainly ruderal and weed species; another part are halophytes. Over the last two decades, phylogenetic molecular studies have led to a number of taxonomic changes in the above mentioned family. Changes have also occurred in one of the largest genera – Chenopodium. The aim of the present study is to review the research on Bulgarian members of the Chenopodiaceae family. The data available in the literature on the taxonomic composition, chorology, morphological features and karyological variability of the species from their Bulgarian populations has been studied. A review of the phytochemical studies of Chenopodiaceae plants from their Bulgarian populations has been made. The systematized data is presented in chronological order, which allows for tracing the current level of study on the family in Bulgaria and opportunities for new research.

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DOI: 10.3897/biorisk.18.76114

Authors: Maria Zh. Kaschieva, Nikolay P. Nedyalkov

Abstract: The meadow violet (Viola pumila Chaix) is an endangered species which is regionally extinct in many European countries. This is a stenobiontic species with a very limited distribution in Bulgaria. Only a few populations have been detected, and they consist of several tens to several hundreds of specimens. The meadow violet has limited reproductive abilities and weak competitiveness. The species is exposed to various anthropogenic threats, as the most significant of them are related to ploughing, conversion of the mesophilic meadows into arable lands, changes in the water regime of the habitats, the expansion of highly competitive species from the group of tufted cereal grasses and infrastructure construction. To date, information concerning the relocation of rare and endangered plant species in Bulgaria is rather scarce. In the present study we provide a protocol on our activities during a successful establishment of a new locality as part of our effort to successfully relocate one particular population of the meadow violet. The observations made after the relocation of the species over a two-year period (2020 and 2021) provided data on the successful relocation, and the creation of a new locality for the species. We discuss the conservation measures needed for this rare and endangered species, and efforts to increase its population, as well as the measures needed for effective management of the habitats of V. pumila (mainly 6510 “Lowland hay meadows”).

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DOI: 10.3897/biorisk.17.77523

Authors: Tsvetan Tsenov, Stanislav Donchev, Christomir Christov

Abstract: The models described in this study are of high importance in the development of thermodynamic database needed for nuclear waste geochemical storage as well as for technology for extracting cesium resources from saline waters. In this study we developed new not concentration restricted thermodynamic models for solution behavior and solid-liquid equilibrium in CsF-H2O CsOH-H2O and Cs2SO4-H2O systems at 25 °C. To parameterize models we used all available experimental osmotic coefficients data for whole concentration range of solutions and up to saturation point. The new models are developed on the basis of Pitzer ion interactions approach. The predictions of new developed here models are in excellent agreement with experimental osmotic coefficients data (ϕ) in binary solutions from low to extremely high concentration (up to 21.8 mol.kg-1 for CsOH-H2O and up to 35.6 mol.kg-1 for CsF-H2O). The previously developed by Christov by Christov and co-authors and by other authors Pitzer approach based thermodynamic models for five (5) cesium binary systems (CsCl-H2O CsBr- H2O CsI-H2O CsNO3-H2O and Cs2SeO4- H2O) are tested by comparison with experimental osmotic coefficients data and with recommendations on activity coefficients (γ±) in binary solutions. The models which give the best agreement with (ϕ)- and (γ±) -data from low to high concentration up to m(sat) are accepted as correct models which can be used for solubility calculations in binary and mixed systems and determination of thermodynamic properties of precipitating cesium solid phases. The thermodynamic solubility products (ln Kosp) and the Deliquescence Relative Humidity (DRH) of solid phases precipitating from saturated cesium binary solutions (CsF(cr) CsCl(cr) CsBr(cr) CsI(cr) CsOH(cr) CsNO3(cr) Cs2SO4(cr) and Cs2SeO4(cr)) have been determined on the basis of evaluated and accepted binary parameters and using experimental solubility data. The reported mixing parameters [θ(Cs M2+) and ψ(Cs M2+ X)] evaluated by solubility approach for 15 cesium mixed ternary systems (CsCl-MgCl2-H2O CsBr-MgBr2-H2O CsCl-NiCl2-H2O CsBr-NiBr2-H2O CsCl-MnCl2-H2O CsCl-CoCl2-H2O CsCl-CuCl2-H2O CsCl-CsBr-H2O CsCl-RbCl-H2O Cs2SO4-CoSO4-H2O Cs2SeO4-CoSeO4-H2O Cs2SO4-NiSO4-H2O Cs2SeO4-NiSeO4-H2O Cs2SO4-ZnSO4-H2O and Cs2SeO4-ZnSeO4-H2O) are tabulated.

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DOI: 10.3897/biorisk.17.77487

Authors: Stanislav Donchev, Tsvetan Tsenov, Christomir Christov

Abstract: The main purpose of this study is to develop new thermodynamic models for solution behavior and solid-liquid equilibrium in 10 nitrate binary systems of the type 2–1 (Mg(NO3)2-H2O, Ca(NO3)2-H2O, Ba(NO3)2-H2O, Sr(NO3)2-H2O, and UO2(NO3)2-H2O), 3–1 (Cr(NO3)3-H2O, Al(NO3)3-H2O, La(NO3)3-H2O, Lu(NO3)3-H2O), and 4–1 (Th(NO3)4-H2O) from low to very high concentration at 25 °C. To construct models, we used different versions of standard molality-based Pitzer approach. To parameterize models, we used all available raw experimental osmotic coefficients data (φ) for whole concentration range of solutions, and up to supersaturation zone. The predictions of developed models are in excellent agreement with φ-data, and with recommendations on activity coefficients (γ±) in binary solutions from low to very high concentration. The Deliquescence Relative Humidity (DRH), and thermodynamic solubility product (as ln K°sp) of 12 nitrate solid phases, precipitating from saturated binary solutions have been calculated. The concentration-independent models for nitrate systems described in this study are of high importance for development of strategies and programs for nuclear waste geochemical storage.

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DOI: 10.3897/biorisk.17.77466

Authors: Dimitar Zhelev, Rumen Penin

Abstract: The article depicts the geochemical properties of the landscapes in the Ada Tepe gold mine area before its launching. The research is conducted by examining the heavy metals (Cu, Pb, Zn, Co, Cr, Mn and Ni) content in samples of river sediments in the local landscapes. The research aims to analyse the concentration of heavy metals before the launch of gold mining. The study implements the coefficient of Clarke concentration. The deviation from the background concentrations is a ratio between the element concentration in the collected environmental samples and the Clarke value of the element. The coefficient has a scale from 0 to a particular positive value, corresponding to the level of enrichment of the sample in comparison to the background Clarke value. The values corresponding to the Clarke concentration are equal to 1, the lower values are between 0 and 1 (dispersion) and any value higher than 1 is a case of concentration (enrichment). The obtained results display the researched territory as a natural background area. The content of heavy metals in the river sediments of the researched area (mg/kg, median value) by chemical elements is Cu (15), Zn (72), Pb (17), Mn (461), Ni (35), Co (8) and Cr (60). That is the reason it could be defined as not impacted by human activities and it is not influenced by natural geochemical anomalies. Heavy metals do not pollute the researched landscapes before mining. This outcome is obtained by the geochemical content of the investigated heavy metals in the river sediments.

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DOI: 10.3897/biorisk.17.77388

Authors: Borislav Grigorov, Nikolay Velev, Assen Assenov, Momchil Nazarov, Beloslava Genova, Kiril Vassilev

Abstract: The current study aims to uncover the forest habitat diversity of Breznik municipality, following the EUNIS Classification. Initial data was collected from the Ministry of Environment and Water and the Forestry Management Plans. Forest habitat polygons were spatially processed with the use of the ArcGIS 10.8.1 software package. Field studies were performed to add more detailed information to the analysis. The phytocoenoses of the forest habitats are dominated by Quercus dalechampii, Q. frainetto, Fagus sylvatica, Carpinus betulus. Some artificial plantations with Pinus nigra and P. sylvestris were also present, as well as with non-native species, such as Robinia pseudacacia and Quercus rubra. The results of this study could be used for more in-depth research of the Breznik municipality vegetation.

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DOI: 10.3897/biorisk.17.77484

Authors: Desislava Mantovska, Detelina Petrova, Lybomira Yocheva, Zhenya Yordanova

Abstract: Stachys thracica Davidov – Thracian woundwort is a Balkan endemic plant included in The Red Data Book of Bulgaria with conservational status “rare”. The plants from genus Stachys have a long history of use to treat various diseases, inflammatory conditions, coughs, ulcers, genital tumors, and infected wounds. Due to its limited distribution the information on the biological activity and chemical composition of S. thracica is rather scarce. The aim of the present research is the comparative determination of the antimicrobial activity of methanolic extracts obtained from in situ wild, in vitro cultivated and ex vitro adapted S. thracica plants. The in vitro shoot culture of the Thracian woundwort was maintained in hormone-free MS medium under controlled environmental conditions. The methanolic extracts from in situ, in vitro cultivated and ex vitro adapted S. thracica plants were active mainly against Gram-negative bacteria. All three extracts showed equal activity against Acinetobacter calcoaceticus. The establishment of in vitro shoot culture and its subsequent adaptation in ex vitro conditions was an appropriate alternative approach for the ex situ conservation of S. thracica as well as for the study of its biological activity.

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DOI: 10.3897/biorisk.17.77368

Authors: Eleonora Fikovska, Dimitar Kozuharov, Marieta Stanachkova

Abstract: The aim of the present study was to trace the influence of some environmental factors (w.temperature, wind, transparency, depth) on the distribution of zooplankton communities in the system Reservoir Mandra and the ecotone zones formed at the confluence of rivers Fakiyska, Sredetska, Izvorska and Rusokastrenska. Four samplings were performed at seven sites between February 2020 and January 2021. After determining the species composition and abundance, the results were subjected to structural analysis and Canonical Correspondence Analysis (CCA). A total of 67 taxa were identified, constituting about 48% of the Rotifera group, 27% of Cladocera and 19% of the Copepoda and only 6% from Protozoa. The Shannon-Weaver index for individual species diversity was between 2.37 and 0.62. The positive and negative correlation of zooplankton distribution in CCA shows that the relative abundance of any species depends on specific environmental variables. Analysis showed that temperature and wind had the strongest impact on the distribution of zooplankton.

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DOI: 10.3897/biorisk.17.77454

Authors: Ivaylo Todorov, Toshko Ljubomirov, Vlada Peneva

Abstract: Parasitoid wasps belonging to the family Pteromalidae are widespread and abundant members of the insect communities in the temperate regions of the world. As many other chalcids do, pteromalids serve as natural enemies of the pests in various crops and play an important role in the biological control of these harmful insects. Here we present the results of a field study in Bulgaria which was focused on the diversity of family Pteromalidae in ten oilseed rape fields. All samples were collected by sweep netting on the border line or inside the crop field. A total of 93 pteromalid specimens belonging to 26 taxa were gathered. The most abundant genus was Mesopolobus – 67% of the sampled pteromalids. The most numerous species in the samples was Mesopolobus morys – a well-known key parasitoid of the cabbage seed weevil, Ceutorhynchus obstrictus, in Europe. One species – Halticoptera patellana, is recorded for the first time in Bulgarian fauna. Clearfield oilseed rape fields had relatively higher parasitoid abundance and richness than the fields treated by conventional technology. In the present work we discuss the overall species composition of Pteromalidae obtained from the studied areas and present our point of view on the perspectives for biological control of oilseed rape pests.

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DOI: 10.3897/biorisk.17.76577

Authors: Ekaterina Kozuharova, Vasil Simeonov

Abstract: Ever increasing data continue to indicate the decline of bumblebee populations. The key factors causing declines in their abundance and diversity are: 1) habitat destruction, 2) loss of floral resources, 3) emerging diseases, 4) increased use of pesticides (particularly neonicotinoids). The aim of this study is to monitor bumblebee visits to Gentiana asclepiadea L, recording pollinator species, and taking measurements of seed set. This plant species is chosen for two reasons: 1) similar data is available from our previous research in the 1990’s and 2) this montane plant species is supposed to be less exposed to hazards from pesticides and habitat destruction. Three study sites were chosen in Mt. Vitosha (SW Bulgaria) where natural populations of G. asclepiadea occur in 1990. The observations of bumblebee activity in the flowers of G. asclepiadea were conducted during the flowering seasons (August and September) of 2017 – 2020 at the same study sites and compared to the data obtained in the previous period (1990–1994). The free pollination fruit set was tested by monitoring of 100 G. asclepiadea flowers each year for development of fruit capsules. The seed set was tested by counting the matured seeds and non-fertilised ovules of 10 fruit capsules each year. A slight decline in bumblebee activity was recorded in 2017 – 2020 in comparison to 1990–1994. This is reflected in the fruit set and the seed set. Our data demonstrates that even in a mountain habitat, where there are fewer direct hazards to bumblebees, that pollination effectiveness has been suppressed over time. This corresponds to a research study which provides evidence that insect biomass fell by 76% in German nature reserves between 1989 and 2016.

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DOI: 10.3897/biorisk.17.77052

Authors: Borislav Georgiev, Milena Nikolova, Ina Aneva, Anatoli Dzhurmanski, Boriana Sidjimova, Strahil Berkov

Abstract: Acetylcholinesterase (AChE) inhibitors are widely used in Alzheimer’s treatment, but they are also crucial for their action on organophosphorus insecticides. The latter exert their toxicity by inhibiting the AChE enzyme in insects, leading to their death. Amaryllidaceae alkaloids have been proven to be potent AChE inhibitors. In the present study methanolic extracts and essential oils being obtained from species of Asteraceae, Lamiaceae, Brassicaceae and Amaryllidaceae were evaluated in vitro for AChE inhibitory activity. Ellman’s colourimetric method, with modifications, was used for AChE activity evaluation. According to the activity level, the tested plant products were divided into three categories. First: plant products with strong activity comparable to that of galanthamine; second: plant products with medium activity, with IC50 value about 1 mg/ml and the last group with low activity, with IC50 value greater than 1 mg/ml. Essential oils of Origanum vulgare subsp. hirtum Ietswaart., Satureja pilosa Vel., Monarda fistulosa L., Thymus longedentatus (Degen & Urum.) Ronniger and the methanolic extract of Leucojum aestivum L. showed the most potent activity and were referred to as the first group. Carvacrol was identified as the main component of the most active essential oils. In L. aestivum extract, galanthamine was found as the main alkaloid. The obtained results indicate that essential oils and alkaloid-rich plant extracts possess the strongest AChE inhibitory activity. This gives us a reason to recommend these plant products to be tested for insecticidal activity in the future.

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DOI: 10.3897/biorisk.17.77364

Authors: Hristo Valchev, Zdravko Kolev, Bilyana Stoykova, Ekaterina Kozuharova

Abstract: Lavender essential oil is widely used in pharmacy, perfumery and the food industry. It is one of the key essential oils in aromatherapy due to its valuable pharmacological properties. The producers of lavender essential oil are well aware that the greatest quantity of oil is obtained near the end of the inflorescence anthesis and that oil quantity is correlated with the pollination as unpollinated flowers drop down. In addition, it has been demonstrated that oil quality is also highest at the end of the flowering period, related to the gradual increase of monoterpenes (particularly the valuable linalool) and the decrease of sesquiterpenes during flower ontogenesis. The aim of this preliminary study was to measure the occurrence of spontaneous self-pollination in Lavandula angustifolia Mill. and to identify external pollinators. The field experiments were performed in a lavender plantation near Gorna Lipnitza Village, north Bulgaria and in the ex-situ lavender collection in the experimental plot of the Botanical Garden of Sofia University. It was revealed that spontaneous self-pollination did not occur in flowers from which external pollinators had been excluded. Exposed flowers were pollinated by polylectic insects, such as honeybees, several species of bumblebees and butterflies. Wild pollinators (particularly bumblebees) dominated over honeybees at both study sites. Our observations showed that all pollinators actively collected nectar. The pollen baskets of most bees were full, indicating the active consolidation of pollen adhering to the pollinators’ bodies. Although lavender growers tend to place beehives in the fields for optimal essential oil production, it is also crucial to conserve wild pollinators.

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DOI: 10.3897/biorisk.17.77398

Authors: Plamen M. Kirov, Radostina I. Alexandrova

Abstract: Whereas early organic farming was mainly focused on plant production, in the last decade, the number of organically-managed poultry farms within the European Union has increased significantly. Similar to organic crop production, organic animal farming is based on the same principles: welfare-friendly, sustainable production and resource utilisation without or with very little addition of synthetic substances, such as antibiotics and antiparasitic treatments. These practices, as well as the access to wild animals, make the free-range poultry production systems predisposed to different viral diseases and, thus, associated with potentially higher public health risks or reduction in production quality. On the other hand, intensive farming amplifies the impact of viral diseases due to high density, low genetic diversity and elevated immunodeficiency. The aim of this analytical study is to compare free-range with intensive poultry systems and the occurrence of different viral diseases in these types of farms in the EU over the past decade. The research is based on official data from the statistical office of the European Union, as well as official data from the Member countries. The results were similar in each country and demonstrate that free-range production has a higher incidence of viral diseases with high zoonotical potential. This makes year-round surveillance absolutely necessary, as well as the need for implementation of additional criteria and requirements towards free-range systems.

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DOI: 10.3897/biorisk.17.77488

Authors: Mima Todorova, Ana Dobreva, Nadezhda Petkova, Neli Grozeva, Mariya Gerdzhikova, Petya Veleva

Abstract: The aim of this study was to establish whether the type of the agricultural system has any influence on the essential oil production and antioxidant activity of industrial cultivated Rosa damascena Mill. in the Rose valley, Bulgaria. Six private farms from Kazanlak (Rose) Valley, Southern Bulgaria were included in the study conducted in the period 2019–2020. The first three selected farms are designated within the conventional farming and the other three are certificated as organic farms. GC/FID and GC/MS analyses were performed; the contents of total polyphenols and flavonoids in the methanol extracts from rose petals were determined. Additionally, the antioxidant activity of rose extracts was evaluated by four reliable methods: 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2´-azino-bis-3-ethylbenzthiazoline-6-sulphonic acid (ABTS), ferric reducing antioxidant power (FRAP), and cupric reducing antioxidant capacity (CUPRAC) assays. The impact of the agricultural system on the essential oil composition and antioxidant activity was evaluated by ANOVA statistical analysis. The results obtained showed that organic farming produced essential oil with a higher linalool and geraniol content and lower β-citronellol + nerol concentrations than conventional farming. It was found that organic farming production demonstrated a better antioxidant activity evaluated by the three DPPH, ABTS, and CUPRAC methods according to the averaged data for two years, 806.82, 797.66 and 1534.40 mM TE/g dw versus 510.34, 521.94 and 917.48 mM TE/g dw for CF, respectively, with high statistical significance for the DPPH and ABTS analyses. Consequentially, the rose extracts from the organic farming accumulated more phenolic compounds that corresponded to the higher antioxidant potential of the organic roses.

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DOI: 10.3897/biorisk.17.75988

Authors: Ivan Pandourski, Vesela Evtimova, Lyubomir Kenderov

Abstract: Antarctic environments are exposed to high levels of ultraviolet radiation (UVR) that are often detrimental to their biota. Recent studies suggest that the genus Boeckella (Copepoda, Calanoida) has a high level of plasticity in terms of its reaction to UVR, which enables its wide distribution in various water bodies in Antarctica. Boeckella poppei is common in freshwater habitats of all three main biogeographic regions in Antarctica: sub-Antarctic islands, maritime and continental. We present for the first time a specific photoprotective response in populations of B. poppei from Livingston Island, Maritime Antarctica. In non-ovigerous females and in males, we observed uniform distribution of carotenoids in the body, while these pigments were almost entirely concentrated in the ovisacs of mature females. We consider this as a means of progeny protection from the teratogenic influence of the high level of UVR in Antarctic environments. Unequivocally, such adaptation would facilitate the expansion of B. poppei on the continent through colonisation and survival in shallow freshwater habitats. Given that the Antarctic environment is dynamically changing over the past decades and the accelerated retreat of permanent ice cover is a premise for the formation of shallow ponds, B. poppei could be a suitable indicator for reflecting the ongoing global environmental changes in Antarctica.

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DOI: 10.3897/biorisk.17.77097

Authors: Sevginar Ibryamova, Borislava Pavlova, Elitca Stanachkova, Seniha Salim, Aysel Lyatif, Dimitar Dimitrov, Darina Bachvarova, Nesho Chipev, Nikolay Natchev, Tsveteslava Ignatova-Ivanova

Abstract: The main goal of the present study was to investigate the impact of the state of the environment on the microbiota of the wedge clam Donax trunculus (Linnaeus, 1758) from the region of Arkutino (Bulgarian Black Sea aquatory). The species Enterococcus hirae was isolated during the summer (from May to August). The species P. mendocina prefers the warmer months and the species P. alcaligenes the colder ones. The temperature followed a course of decrease during the period September 2020 to January 2021, followed by a slow increase from February 2021. Comparing May 2020 with May 2021, it became evident that in 2021 the temperature was 1.5 °C lower. We can say that the number of the species P. alcaligenes was twice as high in May 2021. It is likely that this species preferred lower optimum temperatures and constant other parameters. For the species Enterococcus hirae such dependence was not observed - the number remained constant in May, but with increasing temperature the number of microorganisms decreased during the summer months. The species seemed to preferably develop at pH 7.78. The species A. gyllenbergii preferably grows at temperatures between 20.3–25.7 °C and the optimal temperature was 25.7 °C. For C. farmeri the optimum conditions were temperature 26.2 °C and pH 7.3. The species E. vulneris was probably related not only to the increase in water temperature, but also to the anthropogenic factor, as it was found only in July.

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DOI: 10.3897/biorisk.17.77279

Authors: Elina Tsvetanova, Almira Georgieva, Nesho Chipev, Albena Alexandrova

Abstract: The pro/antioxidant status of marine macrozoobentic organisms is being increasingly applied in environmental monitoring and conservation programs. The oxidative stress level in marine bivalves can provide valuable information not only on the health of the organisms and their populations, but also on the current state of habitats and ecosystems. The aim of the present study was to make the first comprehensive investigation of the seasonal changes in the antioxidant activity in different organs (gills, digestive gland and foot) of M. galloprovincialis from representative Bulgarian Black Sea coastal habitats. The lipid peroxidation and glutathione levels, as well as activities of the antioxidant enzymes catalase, superoxide dismutase, glutathion peroxidase, glutathion reductase, glucose-6-phosphate dehydrogenase and glutathione-S-transferase of the organs were measured spectrophotometrically. Our hypothesis was that enhanced environmental pressure during the summer season, induced by multiple factors (biogenic, abiogenic and anthropogenic) led to weakening of the antioxidant protection in mussels at the beginning of autumn. The reaction of the mussel organism to the multiple stress factors was specific for the target organ and the type of the biomarker. Significant differences were present in the activity of the antioxidant system in mussels from the northern and southern coastal locations. The seasonal changes in the pro/antioxidant status of mussels were primarily due to specific seasonal changes in factors concerning the marine environment at the concrete locality. Further research is obviously needed to confirm the present results and provide a more complete data of seasonal and spatial changes in the antioxidant defense system of mussels from the Bulgarian Black Sea coastal area and their implementation in biomonitoring programs.

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DOI: 10.3897/biorisk.17.77465

Authors: Iva Doycheva

Abstract: Drought, salinization and heavy metal pollution of soils are main stress factors with an increasing impact on the deterioration of soil quality, yield and crop quality. Seed priming shows good results in improving seed germination, seedling growth and plant development. Proline (Pro) and metyl jasmonate (MeJA) show stimulating activity and help plants overcome stress. The study investigated the effect of Pro, MeJA and hydropriming on seeds sown on water agar supplemented with different concentrations of heavy metals (Cd, Pb, Zn) (HM), NaCl or Polyethylene glycol 6000 (PEG 6000). Chelidonium majus is a medicinal species which is grown as a crop in some parts of Europe. It is an ingredient in some remedies and is becoming an increasingly popular object of research regarding its biological activities. The low concentrations of all heavy metals applied increased the germination of all variants of seeds – control, hydroprimed and those which were Pro and MeJA primed. Seed priming with Pro and MeJA promoted high germination percentage of seeds germinated on water agar with NaCl. PEG 6000 at its higher concentration (5%) slightly increased the seed germination of all variants. The growth of roots and hypocotyls was inhibited by HM and NaCl. However, PEG 6000 slightly influenced their growth.

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DOI: 10.3897/biorisk.17.77452

Authors: Dobrina Pecheva, Kalina Danova

Abstract: Artemisia alba Turra is an essential oil-bearing shrub, with a Euro-Mediterranean distribution widespread in the south-eastern parts of Europe. Phytochemical investigations have evidenced the presence of volatile mono- and sesquiterpene derivatives, as well as non-volatile sesquiterpenoids, flavonoids and phenolic acids contributing to the anti-inflammatory, antimicrobial, antioxidant and pro-apoptotic activity of different preparations, obtained from the plant. The current research aims at elucidation of the potential for biotechnological polyphenolic compounds productivity of non-differentiated cell lines of the plant. For this purpose, non-differentiated cell aggregates were initiated from either leaf or root explants of the sterile grown plant. They were cultivated either in the dark or at 16/8 h photoperiod in liquid media, supplemented with N6-benzyladenine (BA) as auxin. The cytokinin effects of indole-3-butyric acid (IBA) and 1-naphthalene acetic acid (NAA) were compared. It was established that NAA supplementation was superior to IBA and light treatment – to dark growth conditions in terms of polyphenolics productivity. In addition, NAA supplementation led to better expressed compaction and larger size of the cell aggregates as compared with IBA. The results of the present experiment indicate that secondary metabolites productivity in vitro is a dynamic process closely related to the plant’s growth and development and is in close relation to the interactions of the plant with its environmental conditions.

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DOI: 10.3897/biorisk.17.77327

Authors: Teodora Todorova, Krassimir Boyadzhiev, Aleksandar Shkondrov, Petya Parvanova, Maria Dimitrova, Iliana Ionkova, Ilina Krasteva, Ekaterina Kozuharova, Stephka Chankova

Abstract: The aim of the present study was to evaluate the potential genotoxic/antigenotoxic, mutagenic/antimutagenic, and carcinogenic/anticarcinogenic effect of Amorpha fruticosa (AF) fruit, Ailanthus altissima bark hexane (AAEH) and methanol (AAEM) extracts on a model system Saccharomyces cerevisiae. Plants were identified and extracted by Ekaterina Kozuharova. Three concentrations of each extract were tested – 10, 100 and 1000 µg/ml. In vitro pro-oxidant/antioxidant activities were evaluated by DPPH and DNA topology assay. The potential genotoxic/antigenotoxic, mutagenic/antimutagenic and carcinogenic/anticarcinogenic effects were revealed in vivo by: Zimmermman’s test on Saccharomyces cerevisiae diploid strain D7ts1, and Ty1 retrotransposition test on S. cerevisiae haploid strain 551. Zeocin was used as a positive control. Based on the in vitro antioxidant activity the extracts could be arranged as follows: AF>AAEM>AAEH. AAEH possessed moderate oxidative potential. No genotoxic and mutagenic capacity was obtained in vivo for extracts tested. The levels of total aberrants, convertants and revertants were comparable with the control ones. No Ty1 retrotransposition was induced by extracts treatment. Further, the extracts possessed well-expressed antigenotoxic, antimutagenic and anticarcinogenic activity. Significant reduction of the total aberrants, reverse point mutations and Ty1 retrotransposition was obtained. Only the AF extract was found to reduce the levels of zeocin-induced mitotic gene conversion. The three extracts did not possess any genotoxic, mutagenic and carcinogenic effect on Saccharomyces cerevisiae. Based on their protective activity, they can be arranged as follows: AF>AAEM>AAEH which corresponds well with their phytochemical composition. Further experiments could provide more detailed information concerning the mode of action of extracts, as well as their main constituents.

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DOI: 10.3897/biorisk.17.78169

Authors: Maria Dimitrova Todorova, Petya Nikolaeva Parvanova, Teodora Ivanova Todorova, Milena Tihomirova Nikolova, Strahil Hristov Berkov, Stephka Georgieva Chankova

Abstract: Aim: To compare the bioactivity of both polar and non-polar fraction of Origanum vulgare spp. hirtum methanolic extract on Chlamydomonas reinhardtii. Material and methods: The polar and non-polar fractions were derived from aerial parts of Origanum vulgare ssp. hirtum, collected during the flowering stage from the ex-situ collection of IBER-BAS. GC/MS analysis of both fractions was done following the standard protocol. The measured mass spectra were deconvoluted by the Automated Mass Spectral Deconvolution and Identification System (AMDIS), before comparison with the databases. Chlamydomonas reinhardtii 137C+ (WT) was used as a test system. Spot-test, cell survival fraction (SF), test of “visible mutations” and CFGE (for measurement of induced DNA double-strand breaks (DSBs)) were applied. Results: The polar fraction did not possess genotoxic, mutagenic as well as DNA-damaging effect. The situation with the non-polar fraction was quite different. Even at the lowest concentration of 250 ppm, cell survival was decreased by 60% (SF = 0.41 ± 0.08). Treatment with concentrations equal to/or greater than 500 ppm resulted in around 100% lethality. A mild mutagenic effect was obtained for the concentration of 250 ppm non-polar fraction (IM = 4.83 ± 0.004). Well-expressed and concentration-dependent induction of DSBs for even the strong DNA fragmentation was observed after the treatment with the non-polar fraction. Conclusions: The different bioactivity of the two fractions correlated well with their different chemical composition. The polar fraction, rich in sugars, organic acids and flavonoid glycosides, did not possess genotoxic and mutagenic potential. The strong genotoxic potential of the non-polar fraction might be related to carvacrol content (37.08%), which is not present in the composition of the polar fraction. To the best of our knowledge, this study provides the first information that the carvacrol-rich non-polar fraction of Origanum vulgare spp. hirtum methanolic extract possesses genotoxic, mutagenic and DNA damaging effect on some low eukaryotes, such as C. reinhardtii. Further experiments with carvacrol should be done in order to clarify the exact mechanism of action.

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DOI: 10.3897/biorisk.17.77313

Authors: Maria D. Todorova, Petya N. Parvanova, Teodora I. Todorova, Georgi D. Dronchev, Milena T. Nikolova, Strahil H. Berkov, Stephka G. Chankova

Abstract: Aim: To reveal whether methanolic extract and essential oil from Origanum vulgare subsp. hirtum in doses causing even low levels of mortality in aphids, would have harmful effects on plants-genotoxic, mutagenic and/or DNA damaging. Materials and methods: Aerial parts of Origanum vulgare ssp. hirtum from the ex-situ collection of IBER, BAS during flowering were collected. Extraction and isolation procedures, as well as GC/MS analysis of essential oil and methanolic extract were performed by standard protocols. The components were identified by comparing their relative retention times to the retention times of authentic standards, and with mass spectra with the NIST. Test system: Chlamydomonas reinhardtii strain 137 C+ (WT). Endpoints: “clonal” assay, the test of “visible mutations”, constant field gel electrophoresis. Statistics: GraphPad Prism version 6.04 (San Diego, USA) and One-way Analysis of Variance ANOVA with multiple comparisons using the Tukey method. Results: A good correlation was observed between chemical composition of essential oil and methanolic extract, and their mode of action. Our genotoxic and double strand breaks results demonstrated mild genotoxic and statistically non-significant DNA damaging potential of methanolic extract and concentration-dependent well - expressed genotoxic and DNA damaging potential of essential oil. A good relationship between increased double strand breaks levels and decreased survival might be related to one of the main constituents of essential oil, suspected to be carvacrol. No mutagenic effect for ME and EO was found. Conclusion: Well-expressed toxic/genotoxic capacity of essential oil, as well as its capacity to damage DNA inducing double strand breaks, but the absence of mutagenic potential, could be considered as a good reason to recommend Origanum vulgare subsp. hirtum essential oil as a promising candidate for purposes of “green” technologies.

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DOI: 10.3897/biorisk.17.77384

Authors: Almira Georgieva, Elina Tsvetanova, Nesho Chipev, Albena Alexandrova

Abstract: Pollution and climate change can induce oxidative stress (OS) in aquatic organisms. Reduced activity or incoordination between antioxidant enzymes in marine bivalves may cause cellular impairment with effects on higher levels of ecological organization. The present study aims to assess the condition factor and the activity of antioxidant enzymes catalase (CAT), superoxide dismutase (SOD), glutathione peroxidase (GPx), glutathione-S-transferase (GST), and glutathione concentration (GSH) in soft tissues of Donax trunculus (Linnaeus, 1758) as indicators of the state of marine ecosystems along the Bulgarian Black Sea coast. The wedge clams were sampled manually from different localities in June and in September. The activity of antioxidant enzymes and GSH concentrations varied both seasonally and among localities. Higher values of GSH, SOD and GPx were registered in wedge clams collected in autumn compared to those collected in summer. In wedge clams higher activity of the major phase II detoxification enzyme GST was observed in summer at localities with intensive tourism, suggesting an activation of the cell detoxification processes, presumably in response to increased environmental pressure. In conclusion, the observed presence of elevated enzyme activities suggested activation of the antioxidant protection system of the wedge clams in response to environmental pressure, indicating their ability to cope with induced OS and adapt to local conditions, and thus maintain ecosystem health.

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DOI: 10.3897/biorisk.17.77463

Authors: Mihaela Belouhova, Dobromira Yaneva, Yana Topalova

Abstract: To stimulate plant development in phytoremediation or in the cultivation of non-food crops in potentially contaminated soils, a biotechnologically created product could be applied. The aim of this study was to explore the possibility of creation of biofertiliser, based on activated sludge combined with bacterial strain with detoxifying and plant growth promoting properties. The presented study is focused on the effect of phenol in the following concentrations: 5 mg/l, 100 mg/l, 250 mg/l, 500 mg/l and 1000 mg/l on the metabolic activity of Brevibacillus laterosporus BT271. The gradual increased concentration of phenol was used to study the metabolic activity of mineralised activated sludge and B. laterosporus BT271. The CTC/DAPI staining showed high activity of the bacteria even at the highest concentration. The greatest amount of biomass was accumulated at 5 mg/l phenol (4.44 × 107 cells/ml). At this toxicant concentration, a total dehydrogenase activity of 5.72 × 10-4 μg H+/ml*min was found. Studies of the metabolic activity of microorganisms in experiments involving a combination of mineralised activated sludge, B. laterosporus BT271 and phenol at three concentrations (5 mg/l, 250 mg/l and 1000 mg/l) showed the highest value for dehydrogenase activity in the variant with average phenolic concentration (up to 6.39 × 10-6 μg H+/ml*min. The results proved the detoxification potential of B. laterosporus BT271 when different concentrations of phenol were present. The combination of a mineralised activated sludge and selected highly active biodegrading B. laterosporus BT271 showed valuable properties of detoxification and metabolic activity and keep these potentials up to 1000mg/l phenol.

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DOI: 10.3897/biorisk.17.77435

Authors: Michaela Beltcheva, Peter Ostoich, Iliana Aleksieva, Roumiana Metcheva

Abstract: The present investigation analyzes the literature about the toxicity of Cd and Pb in small rodents’ organisms and the role of natural zeolites as modifiers of the biological effects. An array of ecotoxicological, morpho-physiological, hematological, genetic and biochemical methods as most representative are under discussion as a basic point for further exploration of biological effects in laboratory mice. The review of existing results demonstrated that there is abundant data on the sorption of lead and cadmium by modified natural zeolites in water and soils. Nevertheless, there is insufficient data on the ion exchange capacity and biological effects of this sorbent in living organisms, especially regarding Cd detoxification. On the basis of the current review, it is possible to conclude that future investigations in this field will elucidate the potential of the use of zeolites as successful detoxifiers against heavy metals and other toxic elements in living organisms.

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DOI: 10.3897/biorisk.17.77306

Authors: Lubov Sharapova, Nadezhda Yurina

Abstract: Proteins similar to Hli (high light inducible) proteins of cyanobacteria are present in all photosynthetic eukaryotes and are necessary for survival in various stressful conditions, although their exact function is not fully understood. In current study, the recombinant stress-induced protein HliA of cyanobacterium Synechocystis was isolated and characterised for the first time. The synthetic gene of HliA protein was created and cloned into plasmid for expression of recombinant protein with Hisx6-tag at the C-terminus in bacteria. Recombinant HliA protein of Synechocystis was isolated by metal-affinity chromatography. The HliA protein was reconstituted with chlorophyll a and carotenoids. Using circular dichroism spectroscopy, it was shown that chlorophyll a and carotenoids interact in vitro with the HliA protein. The binding of pigments to the HliA protein favours the protective function of this protein. Apparently, Hli proteins are involved in the coordinated delivery of pigments for the biogenesis of photosynthetic complexes, thereby reducing the risk of accumulation of phototoxic free chlorophyll molecules. Current results are important for understanding the processes of photoprotection in either cyanobacteria or algae and higher plants.

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DOI: 10.3897/biorisk.17.77320

Authors: Polya Galinova Marinovska, Teodora Ivanova Todorova, Krassimir Plamenov Boyadzhiev, Emiliya Ivanova Pisareva, Anna Atanasova Tomova, Petya Nikolaeva Parvanova, Maria Dimitrova, Stephka Georgieva Chankova, Ventsislava Yankova Petrova

Abstract: The aim of the present study was to compare cellular susceptibility and oxidative stress response of S. cerevisiae logarithmic (log), quiescent (Q), and non-quiescent (NQ) cell populations to menadione – a well-known inducer of oxidative stress. Three main approaches were used: microbiological – cell survival, molecular – constant field gel electrophoresis for detection of DNA double-strand breaks (DSB), and biochemical – measurement of reactive oxygen species (ROS) levels, oxidized proteins, lipid peroxidation, glutathione, superoxide dismutase (SOD) and catalase on S. cerevisiae haploid strain BY4741. The doses causing 20% (LD20) and 50% (LD50) lethality were calculated. The effect of menadione as a well-known oxidative stress inducer is compared in the log, Q, and NQ cells. Survival data reveal that Q cells are the most susceptible to menadione with LD50 corresponding to 9 µM menadione. On the other hand, dose-dependent DSB induction is found only in Q cells confirming the results shown above. No effect on DSBs levels is observed in log and NQ cells. Further, the oxidative stress response of the cell populations is clarified. Results show significantly higher levels of SOD and ROS in Q cells than in log cells after the treatment with 100 µM menadione. On the other side, higher induction of oxidized proteins, malondialdehyde, and glutathione is observed after menadione treatment of log cells. Our study provides evidence that Saccharomyces cerevisiae quiescent cells are the most susceptible to the menadione action. It might be suggested that the DNA damaging and genotoxic action of menadione in Saccharomyces cerevisiae quiescent cells could be related to ROS production.

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DOI: 10.3897/biorisk.17.77300

Authors: Albena Alexandrova, Yordan Raev, Dimitar Dimitrov, Nesho Chipev, Elina Tsvetanova, Almira Georgieva, Violin Raykov

Abstract: The aim of the present study was to perform a pilot assessment and analysis of the oxidative stress (OS) level in four commercially important fish species (round goby, red mullet, sprat and horse mackerel) from different localities of the Bulgarian Black Sea coast. The fish were sampled during trawl selectivity experiments. The OS level in the fish was assessed by measuring lipid peroxidation (LPO), glutathione concentration (GSH), activities of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx) and glutathione-S-transferase (GST), as well as acetylcholine esterase (AChE) in gills and liver. Round goby and red mullet caught in the Nessebar Bay showed clear signs of OS with the highest levels of LPO and GST activities, accompanied by the lowest AChE activities in both liver and gills. On the contrary, round goby caught near Maslen Nos (a region with good ecological conditions) were least affected by OS with low LPO and high GSH concentrations and SOD activity. There were no significant differences in the OS bioindicators of horse mackerel from the different localities. Sprat caught in Nessebar Bay, compared to those caught from the other localities, showed presence of OS indicated by lower GSH levels and relatively higher CAT, GPx and GST activities, accompanied by low AChE activity in gills. It can be concluded that round goby and red mullet were more vulnerable to OS induced by marine environmental factors than the horse mackerel and sprat. However, their antioxidant defense system allows them to tolerate and adapt to the environment of their habitats. Further studies are needed for the assessment of OS in important fish species in the Bulgarian part of the Black Sea.

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DOI: 10.3897/biorisk.17.77227

Authors: Polya Marinovska, Teodora Todorova, Anna Tomova, Emiliya Pisareva, Krassimir Boyadzhiev, Martin Dimitrov, Petya Parvanova, Maria Dimitrova, Stephka Chankova, Ventsislava Petrova

Abstract: Having unique genetic machinery and a high degree of conservation with higher eukaryotes, the yeast Saccharomyces cerevisiae is recognised as a smart experimental system for studying the modes of chemical toxicity. The present study was undertaken to elucidate the changes in the intracellular redox homeostasis and key macromolecule structure following exposure to Zeocin. Cell populations of logarithmic, quiescent (Q) and non-quiescent (NQ) cells of Saccharomyces cerevisiae BY4741 were used as a model to examine the cytotoxic effect of this radiomimetic. The levels of endogenous ROS, oxidized lipids, carbonylated proteins, and glutathione were analysed after treatment with Zeocin (IC50). An increase in ROS production and respectively increased oxidative stress was detected in all three types of cell populations, with the highest degree being observed in proliferating S. cerevisiae BY4741 cells. The stress response of both proliferating and stationary phase (Q and NQ) cells to Zeocin included an overexpression of glutathione. The quiescent cells also showed very low DNA susceptibility to high Zeocin concentration (100–300 µg/ml), presented as no induced double-strand breaks (DSBs) in the macromolecule. Based on our research it could be concluded that the cellular physiological state is a critical factor determining the resistance to environmental stress with Q cells being the most robust.

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DOI: 10.3897/biorisk.17.77343

Authors: Stanislava K. Georgieva, Mona D. Stancheva, Zlatina V. Peteva, Tsveteslava I. Ivanova, Albena V. Alexandrova

Abstract: Anthropogenic pollution of marine ecosystems is one of the main sources of polycyclic aromatic hydrocarbons (PAHs). Marine bivalves are often used as bioindicators of environmental pollution due to their wide distribution and capability of xenobiotic bioaccumulation. The aim of the present study was to assess the presence of PAHs in soft tissues of wedge clams Donax trunculus (Linnaeus, 1758), collected from sublittoral sandy habitats at different locations off the Bulgarian Black Sea coast. Wedge clams from the different locations showed variations in the content of accumulated PAHs’ compounds. The concentrations of PAHs were measured by gas chromatography system with mass spectrometry detection. The total PAHs content (sum of 13 PAHs’ compounds) measured was in the range from 5.59 to 50.50 ng/g wet weight and was comparable with other European studies. The compounds phenanthrene and fluorene were most abundant in all analyzed samples. The results showed that low molecular weight (LMW) PAHs (2 and 3 aromatic rings) were predominant, accounting for 91% of the total PAHs levels, while high molecular weight (HMW) PAHs (4–5- and 6- rings) presence was 8.9% on average. The ratio LMW/HMW PAHs was higher than one, suggesting predominant pollution of petrogenic origin. The concentrations of benzo (a)pyrene did not exceed the limit set in EC Regulation although it was detected in 20% of the analyzed samples. In conclusion, maximum overall PAHs content was found in clams from Arkutino, while minimum PAHs content was present in samples from Elenite. The Sum PAH4 (sum of four polycyclic aromatic hydrocarbons: benzo[a]pyrene, chrisene, benzo[a]anthracene, and benzo[b]fluoranthene) in the wedge clams for all localities studied was below legislation limits. Data from the present research can be used for assessing pollution levels in the marine environment and also risk of human exposure to PAHs using D. trunculus as bioindicator species.

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DOI: 10.3897/biorisk.17.77483

Authors: Zornitsa Karcheva, Zhaneta Georgieva, Alexander Tomov, Detelina Petrova, Miroslava Zhiponova, Ivanina Vasileva, Ganka Chaneva

Abstract: The present study compared the stress response of two microalgal strains – Arthronema africanum (Cyanoprokaryota) and Coelastrella sp. BGV (Chlorophyta), after heavy metals’ treatment. Changes of algal growth, pigment and protein content were analyzed after adding Cu, Cd and Pb (50 µM and 100 µM) to the nutrition medium. It was found that Cd and Pb significantly inhibited growth and protein biosynthesis of microalgae, but the effect of Cu remained less pronounced. In both strains, a decrease of chlorophyll content was observed, while carotenoid content markedly increased, especially in Coelastrella sp. BGV biomass. The addition of 100 µM Cd and 100 µM Pb to the medium caused a strong enhancement of malondialdehyde in both microalgal strains, which corresponded to the significant increase of superoxide dismutase and catalase activity. The antioxidant enzymes appeared to be differently altered by heavy metals’ exposure. The activity of SOD in the Arthronema africanum cells was most strongly affected by Cd, in contrast to Coelastrella sp. BGV that was highly increased by 100 µM Pb. The application of 100 µM Cd and 100 µM Pb increased in a similar manner catalase activity in both microalgae. The strains that were studied showed a high absorption capacity for metal ions, especially for Pb, which was absorbed largely than Cd and Cu. For that reason, we assumed that both microalga and, in particular, Coelastrella sp. BGV, could be successfully used for treatment of contaminated water bodies.

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DOI: 10.3897/biorisk.17.77290

Authors: Darina Bachvarova, Mona Stancheva, Tsveteslava Ignatova-Ivanova, Sevginar Ibryamova, Nesho Chipev, Albena Alexandrova

Abstract: The aim of the present study was to carry out an initial screening of trace metals bioaccumulation in soft tissues of the wedge clam (Donax trunculus Linnaeus, 1758) from different localities of the Bulgarian Black Sea coastal area and to evaluate the bioindicator potential of this species. Wedge clams were collected in June and September 2020 from sublittoral sandy habitats at different localities of the Bulgarian Black Sea coast. Soft tissues of individual clams were digested with nitric acid followed by ICP-OES analytical determination. The content of trace metals in the wedge clams differed significantly amongst localities. Higher metal content was present in wedge clams from Sveti Vlas, Shkorpilovtsi, Slanchev Bryag, Ahtopol and Kranevo. The highest values of lead (Pb) (2.51 mg/kg) and cadmium (Cd) (0.32 mg/kg) were found in samples from Sveti Vlas and the highest concentration of copper (Cu) (34.12 mg/kg), iron (Fe) (269.52 mg/kg) and nickel (Ni) (0.32 mg/kg) were detected in wedge clams from Shkorpilovtzi. Maximum content of chromium (Cr) (0.58 mg/kg) was present in samples from Slanchev Bryag, together with high values of Fe. The highest concentration of zinc (Zn) (18.04 mg/kg) together with high values of Cr and Fe were measured in wedge clams from Irakli. In conclusion, the wedge clams from the localities known to have higher coastal inflows and touristic pressures, i.e. Varna, Shkorpilovtzi, Sveti Vlas, Slanchev Bryag and Ahtopol accumulated significantly higher metal elements in their tissues. Only few significant seasonal differences in the concentration of metal elements in wedge clams were present and the observed seasonal variations were probably connected to the hydrological parameters of the ecosystems. The wedge clam D. trunculus is a suitable bioindicator for assessment and monitoring of metal pollution in the Bulgarian Black Sea environment.

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DOI: 10.3897/biorisk.17.77381

Authors: Veronika Yordanova, Yovana Todorova, Mihaela Belouhova, Lyubomir Kenderov, Valentina Lyubomirova, Yana Topalova

Abstract: The upper Iskar sub-catchment is one of Bulgaria’s most important economic and socially significant water sources because of its role in supplying Sofia with drinking water. Among the critical factors that carry potential high-risk levels for water quality in this hydrosystem are the discharge from the Samokov Wastewater Treatment Plant (WWTP), diffuse pollution from agriculture, and the percolation of untreated sewage from the small villages. In this study, we assessed the effect of treated wastewater effluent on water quality, and on the ecological state and microbial communities in the river sector of Samokov’s WWTP discharge area. The assessment was based on the complex use of chemical and microbiological indicators and biological quality elements. The concentrations of organics, nutrients and microcomponents were determined with results confirming the expected increase for parameters associated with the discharge of urban wastewater. The ecological state, according to macrozoobenthos indicators, was “good” throughout the river sector but local deterioration was registered in a proximal location downstream of the WWTP outfall. The analysis of stream water and bed sediment microbial communities by a fluorescent technique showed the high metabolic activity and intensive transformation processes in addition to high abundance registered with standard cultivation methods. The importance of the studied sub-catchment for the functioning of the urban water cycle, and for the quality of Sofia’s drinking water, underlines the need to extend an existing monitoring program with a more detailed assessment of the environmental impact of wastewater discharge.

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DOI: 10.3897/biorisk.17.77432

Authors: Milena Hristozova, Radoslava Lazarova

Abstract: Local values of natural radiation background in soils from unexplored regions in the Eastern Rhodopes were established. The impact of anthropogenic activity as a potential risk for increase in radiation background was assessed. Soil samples from areas near the liquidated lead-zinc mines – Madzharovo, gold mine – Ada Tepe, Krumovgrad, lead-zinc complex – Kardzhali, Neochim – Dimitrovgrad, deposits for extraction of gneiss, marble quarries, etc. were analyzed to study possible contamination. Specific activity of natural radionuclides 210Pb, 238U, 226Ra, 235U, 232Th, 40K and technogenic 137Cs in the studied samples was determined by gamma spectrometric analysis with Multichannel analyzer DSA 1000, production of CANBERRA and HPGe-detector.

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DOI: 10.3897/biorisk.17.76939

Authors: Michaella Petkova, Anelia Kenarova, Silvena Boteva, Stela Georgieva, Christo Chanev, Galina Radeva

Abstract: The non-target effect of the fungicide QuadrisR on the bacterial community from grassland loamy sand (LS) and cropland clay loam (CL) soils with unknown history of fungicide usage was investigated. QuadrisR was applied to soil mesocosms at 0.0 mg kg-1 (Az0), 2.90 mg kg-1 (Az1), 14.65 mg kg-1 (Az2) and 35.0 mg kg-1 (Az3) calculated towards the active ingredient azoxystrobin (Az). Response of bacterial communities to QuadrisR was investigated during a 120-day incubation experiment, evaluating the shifts in bacterial catabolic profiles by the community-level physiological profiling (CLPP) technique and Biolog EcoPlatesTM method. QuadrisR decreased the overall catabolic activity (AWCD) of soil bacterial communities and the rate of decrease was independent of soil type and fungicide concentration. Fungicide affected negatively the utilisation of amines and positively that of amino acids in both soil types, whereas the effects on other carbon guilds (carbohydrates, carboxylic acids and polymers) corresponded closely to the respective soil type and fungicide concentration. Results indicated the presence of non-target effects of QuadrisR on bacterial functioning; hence, it is important to address the fungicide side-effects on soil health.

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DOI: 10.3897/biorisk.17.77458

Authors: Radina Nikolova, Michaella Petkova, Nikolai Dinev, Anelia Kenarova, Silvena Boteva, Dimitar Berov, Galina Radeva

Abstract: In the present study, the correlation between bacterial abundance and soil physicochemical properties along the heavy metal contamination gradient in the area of non-ferrous metal processing plant was assessed. Our results showed that bacterial abundance (number of heterotrophic bacteria and number of 16S rRNA gene copies) decreased with 45–56% (CFU) and 54–87% (16S rRNA gene) along the Zn, Pb and Cd contamination gradient. The total bacterial abundance (16S rRNA gene) increased exponentially in contrast to the abundance of heterotrophic bacteria. The reduction of bacterial abundance in heavily contaminated soil indicated that the soil properties (soil pH, total organic carbon, inorganic ions, soil texture) could modify the effects of heavy metals and the response of microorganisms to that stress in long-term contaminated soils.

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DOI: 10.3897/biorisk.17.77438

Authors: Roumiana Metcheva, Peter Ostoich, Michaela Beltcheva

Abstract: The problem of environmental pollution is becoming increasingly important on a global scale. Man has oversaturated the environment of his habitat with harmful and most often toxic waste. It is difficult to describe all the toxic substances, as a separate book can be written for each group. The term “ecocide” has been introduced, which reflects large-scale destruction of the natural environment. We will focus only on three classes of pollutants that are of particular concern, creating environmental conflicts. These are: • Pesticides are extremely toxic and create large amounts of non-degradable waste. It accumulates in tissues and organs of target organisms, becoming toxic and causing serious pathological changes in the body, mainly at the cellular and subcellular levels, causing various diseases and as a result, serious changes in the structure and functions of the populations and the whole ecosystem are increasingly observed. • Waste from the nuclear industry and radioactive fallout from nuclear explosions. It is especially dangerous that radioactive elements can be concentrated in certain organs. • Petroleum products - often large quantities end up in the seas and oceans, along with industrial waste of various kinds, impossible to compensate for by nature and they pose a serious threat to ecosystems, many of which have already been destroyed. At the submolecular level, chemical and physical effects can lead to genetic rearrangements (mutations); destructive ionization in the tissues of every living being, sometimes with completely unexpected consequences for humans.

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DOI: 10.3897/biorisk.17.84978

Authors: Stephka Chankova

Abstract: none

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DOI: 10.3897/biorisk.16.61099

Authors: Matthias Seidel, Maren Lüttke, Christian Cocquempot, Katy Potts, Wil J. Heeney, Martin Husemann

Abstract: The Asian bamboo borer Chlorophorus annularis is a beetle species that has been introduced in many countries globally. Originating in Southeast Asia, it can now be found in the Americas, South Africa, the Middle East, Australasia and Europe. The literature record of the species in Europe consists of findings of single individuals usually associated with imported bamboo products. A general European effort in surveying C. annularis was never undertaken, since the overall scientific consensus was that the species cannot establish here. Yet, recent records in Genk, Torhout (Belgium) and in Hamburg (Germany) do not seem directly associated with a recently imported product and hence may indicate otherwise. Such a shortfall in recording commonly imported, potentially invasive species may be counteracted through citizen science initiatives, allowing for continuous, high density monitoring. In this paper we present thirteen new records of the species from five European countries, including two new country records, mostly going back to interested citizen scientists.

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DOI: 10.3897/biorisk.15.59823

Authors: Andreas Lang, Matthias Dolek, Marina S. Lee, Anja Freese-Hager, Mathias Otto

Abstract: Bt maize targeting Lepidopteran pests poses potential risks for non-target (NT) butterflies and moths which are addressed in the environmental risk assessment of genetically modified crop plants. For this purpose, eco-toxicological tests are often conducted with specific NT species in the laboratory in order to assess possible adverse effects. As only a limited number of surrogate species can be addressed, the choice of focal species to be tested is an important decision. However, practical and standardised selection procedures have hardly been developed and applied for NT Lepidoptera, so far. Here, we present a transparent and systematic selection process of suitable test species for Germany, involving selection criteria such as exposure to Bt maize, habitat range and laboratory maintenance of the species. As a result, we compiled a list of 15 lepidopteran species particularly appropriate for testing the adverse effects of Bt maize in the laboratory. In addition, we collected and reviewed published reports for breeding methods of Lepidoptera, which provides essential information on maintaining lab stocks of NT Lepidoptera. The presented selection procedure allows focusing on the relevant test species in a transparent and reproducible way, and supplies the breeding knowledge required to breed and maintain them, which will be of great utility for the future assessment on possible risks of Bt maize cultivation to non-target Lepidoptera.

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DOI: 10.3897/biorisk.15.58455

Authors: Jessica Borbolla-Vazquez, Paul Ugalde-Silva, José León-Borges, Job Alí Díaz-Hernández

Abstract: The large increase in population in Cancun, Mexico has increased domestic, agricultural and industrial activities, resulting in inadequate solid and liquid waste management that can affect underground aquifers. One of the factors which affects water quality is coliform bacteria. The present study focused on determining the presence of total and faecal coliforms in ten urban cenotes in Cancun. Sampling was carried out in the dry and rainy seasons of 2018. The Most Probable Number (MPN) technique was used to determine the concentration of coliform bacteria. The results from the analyses indicate that the ten cenotes are contaminated with total and faecal coliforms. Additionally, the concentration of coliforms increases during the rainy season. We conclude that all the cenotes are contaminated with faecal coliforms and suggest that more studies are necessary to determine the origin of this contamination and the impact on the ecosystem.

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DOI: 10.3897/biorisk.15.49297

Authors: Marion Dolezel, Christoph Lüthi, Helmut Gaugitsch

Abstract: Gene drive organisms (GDOs) have been suggested as approaches to combat some of the most pressing environmental and public health issues. No such organisms have so far been released into the environment, but it remains unclear whether the relevant regulatory provisions will be fit for purpose to cover their potential environmental, human and animal health risks if environmental releases of GDOs are envisaged. We evaluate the novel features of GDOs and outline the resulting challenges for the environmental risk assessment. These are related to the definition of the receiving environment, the use of the comparative approach, the definition of potential harm, the stepwise testing approach, the assessment of long-term and large-scale risks at population and ecosystem level and the post-release monitoring of adverse effects. Fundamental adaptations as well as the development of adequate risk assessment methodologies are needed in order to enable an operational risk assessment for globally spreading GDOs before these organisms are released into environments in the EU.

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DOI: 10.3897/biorisk.14.35953

Authors: Pablo Medrano-Vizcaíno

Abstract: Aspects about the feeding behavior of the Laughing falcon (Herpetotheres cachinnans)article remain poorly investigated with scarce reports of identified species ingested by this bird. Worse still, information describing how this bird ingests poisonous snakes is not known. Although this falcon eats snakes, there are no reports of feeding on Bothrops atrox. In this work, I describe this predation event and analyze how roads seem to be a potential hunting strategy that H. cachinnans exploit to prey on snakes.

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DOI: 10.3897/biorisk.14.32682

Authors: Roberto Moreno, Claudia Jimena Guerrero-Jimenez

Abstract: Natural ecosystems are increasingly being affected by climate change and fragmentation, which have a strong impact on biodiversity thus affecting habitats and species diversity of flora and fauna at all levels. As a response to this situation the idea of biological corridors was developed. This review relates the problems associated with the main concepts and definitions of the biological corridors, seeking to highlight the advantages of this tool and describing its potential applicability, and showing the importance of the biological corridors as a solution to improve the conservation of species and so as to support sustainable development in areas of high biodiversity. Examples of biological corridors in several countries are cited and its application guidelines and conservation benefits are described. In conclusion, the need to improve information on habitat and its association with wild species is highlighted through adaptive forestry that is part of a comprehensive management of forest ecosystems. In addition, it is important to monitor the effects of corridors implemented in a feedback process that allows a greater analysis and evaluation of the overall positive effects of their implementation. Finally, some management actions are proposed to improve the conservation of ecosystems.

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DOI: 10.3897/biorisk.14.30319

Authors: Maissour Abdellah, Benamar Saad

Abstract: One of the important tools to evaluate the ecological quality of surface water is the Macrophytes indices based on the bioindication capacity of aquatic plants. In Mediterranean rivers (France, Spain, and Portugal), the development of some macrophytes indices like l’Indice Biologique Macrophytes Rivières (IBMR), the biological metric score (BMS), as well as the Fluvial Macrophyte Index (IMF) are founded on the determination of the indicator values of the floristic reference lists. The aim of this study was to test the impact of the eco-Mediterranean differences (from one country to another) on the indicator taxa by comparing the indicator values of the Euro‐ Mediterranean macrophyte indices. With this in mind, we explore the possibility of the introduction of the Euro‐Mediterranean macrophytes-based indices in Morocco (i.e. the hydrological basin of Sebou (HBS)) as a part of a preliminary attempt to develop the first Afro-Mediterranean macrophyte index. We confirm that the ecological amplitude and species optima vary between Mediterranean ecoregions, and indicator taxa differ between countries: There are medium to small correlations between Mediterranean indices: IBMR/BMS (p = 0.000, R2 = 0.57), IMF/BMS (p = 0.000, R2 = 0.34), and IBMR/IMF (p = 0.000, R2 = 0.30). Five species exhibit major differences in indicator values: Zannichellia palustris and Potamogeton pectinatus have more eutrophic indicator values in France (IBMR) than in Spain (IMF). Potamogeton nodosus, Amblystegium riparium and Lycopus europaeus have broader ecological amplitudes in Portugal (BMS) than in France (IBMR) and in Spain (IMF), where it is restricted to eutrophic conditions. Furthermore, the three indicator systems include different indicator-taxon numbers. The comparison of the HBS elaborated list with the Euro‐Mediterranean indices revealed the low level of common taxa approximately 6.76% of all indicator species used in the French index (IBMR), 10.48% in the Portuguese index (IMF) and 12.38% in the Spanish index (BMS). These results show the inadequacy of the trophic indices approach with the HBS conditions and thus the need for the development of an index based on biotic indices approach.

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DOI: 10.3897/biorisk.13.23514

Authors: Shigenori Karasawa, Kensuke Nakata

Abstract: Evaluating potential distribution areas and limiting factors for the distribution of exotic species in invasive regions are essential to identify risks and protect the native ecosystem. However, less research has been conducted on the underground ecosystem than for above-ground. Factors, limiting the distributions of exotic terrestrial isopods, have been identified and their invasive stages and potential distribution areas in Japan evaluated. A database of distribution data has been developed for 17,412 terrestrial isopod specimens in Japan and two ecological niche models constructed using 19 bioclimatic variables; the regional model was calculated using data from Japan (invasive region) only, whereas a combination of data from Japan and North America (invasive regions) and Europe (native region) was used to construct the global model. The global model predicted that annual mean temperature and mean diurnal-temperature range were the important limiting factors for most exotic isopods. It was found that Armadillidium nasatum Budde-Lund, 1833, A. vulgare Latreille, 1804, Haplophthalmus danicus Budde-Lund, 1880, Porcellio laevis Latreille, 1804, P. scaber Latreille, 1804 and Porcellionides pruinosus (Brandt, 1833) were composed of stabilising and colonising populations, which enabled prediction of the future spread of distribution areas for these species in Japan. Porcellio dilatatus Brandt, 1833 was introduced in unstable environments and thus was found in fewer locations.

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DOI: 10.3897/biorisk.13.20688

Authors: Dolezel Marion, Bartel Andreas, Heissenberger Andreas

Abstract: In the environmental risk assessment (ERA) of genetically modified plants (GMP), the consideration of the different environments where genetically modified plants (GMP) will be commercially grown (the receiving environments) plays a crucial role. In addition, relevant protection goals which may be adversely affected by the GMP have to be considered during the ERA. Using a literature- and GIS-based approach, distribution data of protected lepidopteran species listed in Council Directive 92/43/EEC and of maize cultivation was used in order to evaluate potential spatial overlaps between GM maize and protected non-target Lepidoptera in different biogeographical regions (BGR) of the EU. Each BGR has its peculiarity regarding maize cultivation and the distribution of protected butterflies. The lepidopteran fauna of the Pannonian BGR is particularly sensitive due to large maize cultivation shares and wide distribution of protected butterflies within this BGR. For the BGRs evaluated potential, spatial exposures of protected butterflies to GM maize cannot be excluded. This study shows that the suggested approach is a useful tool for the consideration of EU-wide protected species in different receiving environments during the problem formulation of the ERA of GMPs.

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DOI: 10.3897/biorisk.13.22316

Authors: Philipp Andreas Unterweger, Jorinde Klammer, Manuela Unger, Oliver Betz

Abstract: Insect conservation is challenging on various ecological scales. One largely neglected aspect is the quality of undisturbed hibernation sites. This study aims to fill a lack of knowledge concerning insect hibernation on uncut meadows persisting in urban green spaces during the winter season in a middle-sized town in south Germany. During two years of sampling, 13,511 insect specimens of the orders Heteroptera, Hymenoptera, Coleoptera and Diptera were caught from their winter stands. The specimens were assigned to 120 families and 140 taxonomic species were determined from the orders Heteroptera, Coleoptera and Diptera and 324 morphotypes from the orders Hymenoptera, Coleoptera and Diptera. The data indicate the importance of winter fallows for insect hibernation. Unmown meadows offer additional plant structures in winter (flower heads, stems, tufts and leaves) that are absent from mown ones. This increased structural diversity results in both higher species diversity and numbers of insect individuals during spring emergence. The results of this study thus emphasise the value of unmown structures for insect conservation and suggest a mosaic-like cutting maintenance of meadows, way- and river-sides and other green infrastructure in both the urban area and the open landscape.

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DOI: 10.3897/biorisk.12.14061

Authors: Shawn Cheng, Kar-Men Chan, Shah-Fadir Ishak, V. Khoo, M.Y. Chew

Abstract: The aggregative, synchronously flashing firefly, Pteroptyx tener congregates on a nightly basis on Berembang trees (Sonneratia caseolaris) growing along the lower reaches of the Selangor River (West Malaysia). Every night, the males and females of this species engage one another in a pre-mating ritual of flash communication. Little is known of the dietary requirements of the adults of P. tener apart from suggestions that these beetles feed on the nectar and sap of mangrove trees. The drastic reduction in their numbers in recent years has sparked an urgency to understand their dietary needs. Here, we report on a series of probing experiments where we sequenced and analysed DNA fragments obtained from the gut contents of adult P. tener specimens. We detected coding and non-coding chloroplast DNA (cpDNA) gene sequences in the gut DNA extracts of P. tener. One DNA sequence was in reasonably good condition to allow us to match it to the cpDNA sequence of a Malvacean, that is, Heritiera littoralis, a common inhabitant of estuarine habitats. We also detected the DNA sequences of plants (cultivated and natural) that may have come from hamlets or isolated freshwater swamps located further inland. The findings reported here provide early indication that P. tener may be able to travel further inland to search for their hosts. Future research should focus on visually confirming if P. tener feeds on H. littoralis and obtaining a more complete reference DNA database of plants in the firefly habitat.

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DOI: 10.3897/biorisk.12.12156

Authors: Sreenivas Reddy Bathula, A. Rakhimol

Abstract: This report recapitulates the diverse aspects of biological safety. Biological laboratory is a space that facilitates the handling and storage of microorganisms, their components or their derivatives. Laboratories that handle dangerous pathogens have to act in a responsible manner to manage the safety and security threats posed by these pathogens. This necessity was foreground in the December 2008 World at risk report, which specifically demanded bioscience laboratories that handle dangerous pathogens to implement a unified laboratory biorisk management framework to enhance their safety and security. The report also discusses the guidelines of biosafety regulations provided by World Health Organization (WHO) that are necessary to adequately and sustainably manage these biorisks and helps in better understanding of risk governance approaches for laboratories that handle dangerous pathogens to achieve the ultimate goal of minimizing or preventing the occurrence and consequences of human error within the laboratory environment: the biorisk management approach, composed of biosafety, laboratory biosecurity and ethical responsibility. It preferably provides an agreement between authorities, the public, and the scientific community establishing trust and societal safety and security, while enabling the continued progress of science. Biorisk management approach demonstrates that biorisks in all their potential forms are appropriately addressed, managed and minimized. Thus, biorisk management has become an important aspect of the development and sustainability of biological activities.

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