Lidia Sakelarieva

Very large specimens of T. graeca ibera were found in Bulgaria, but mostly in the 20th century. Presently, such tortoises are almost absent in the country. Here we summarise data about the largest spur-thighed tortoises registered in Bulgaria and provide information about five new large-sized individuals. We also draw attention to the fact that large specimens can hardly be found in the country today and discuss some possible negative effects of the extinction of these specimens on the existing populations. The maximum straight carapace length of the largest T. graeca ibera ever found in Bulgaria was ≈ 389 mm, but the maximum straight carapace length of the newly measured tortoises was 298 mm. Considering the rarity of such tortoises in the country today, the genes that determine the potential to reach larger sizes may gradually disappear. Thus, the institutions responsible for the conservation of nature should pay attention to areas where the presence of large-sized individuals has been established. This might help preserve the natural genome of T. graeca ibera in the country and therefore the existence of large individuals.

The aim of this paper is to compare the taxonomic composition and species diversity of the macrozoobenthos in Maritsa River (Bulgaria) and Han River (South Korea). Samples were collected at 15 selected sites in each river, including some of their main tributaries in 2020 and 2021. The number of the taxa recorded in Maritsa River was more than twice as great as in Han River: 192 taxa belonging to 19 systematic groups compared to 88 taxa belonging to 18 groups respectively. The order Ephemeroptera had the highest species richness: 31 taxa in the Bulgarian rivers and 26 taxa in the South Korean ones. The macrozoobenthic communities responded and adapted to the various conditions and impacts in the water environment with changes in the species composition and structure. The analysis of the similarity in the taxonomic composition showed low resemblance between all study sites but displayed distinct separations between the rivers and the two years. In general, the species structure of the macrozoobenthic communities in Maritsa River and its studied tributaries was better than in Han River. In both years, high species diversity was recorded at the reference sites in the rivers, characterized by conditions closely resembling natural environments. The species richness and the evenness of macrozoobenthos were very low at sites downstream subjected to considerable anthropogenic pressure. Some of the communities in Han River were almost destroyed completely.

Lizards in Bulgaria hibernate in winter. Yet, individuals of many species were found active in this period. Cases of winter activity of Podarcis muralis and P. erhardii in the country have been published, but this behavior has not been studied in detail. The purpose of this research was to observe and analyze the winter activity of these two species in the city of Blagoevgrad. The observations took place at two sites in days with high solar radiation in December, January, and February 2015–2017. One of the sites was a typical urban territory, inhabited only by P. muralis. The other site was a suburban area, inhabited by P. erhardii. The number of the active individuals of the Common Wall Lizard recorded was about 8.5 times higher than that of the Erhard's Wall Lizard. The lowest air temperature at which P. muralis was observed was -4°C and for P. erhardii it was +0.5°C. Individuals of both species were registered only at positive substrate temperatures. Representatives of all age groups of P. muralis were recorded often with dorsoventrally flattened bodies while basking. On the other hand, few juveniles of P. erhardii were found active and they flattened their bodies very rarely.

A survey of the macrozoobenthos communities in the Maritsa River (South Bulgaria) was carried out in the summer of 2021. Benthic samples were collected and physicochemical parameters (water temperature, pH, conductivity, dissolved oxygen and nutrients) were measured at 15 sites located on the main river and its tributary system. The studied sites belonged to different river types and characterised the diversity of the ecological conditions—from unaffected to anthropogenically influenced river stretches. In addition, data from a study conducted in the summer of 2020 were used to analyse species–factor interactions in the river ecosystems and to assess the bio-indicative potential of the aquatic invertebrates. The dynamics of the taxonomic composition and abundance of the macrozoobenthos were analysed in relation to environmental factors. The physicochemical conditions of the water environment changed during the period of high water, which led to a reduction in the composition of the macrozoobenthos. Plecoptera and Trichoptera decreased in richness and abundance downstream and under human impacts. Ephemeroptera and Chironomidae were permanently present along the whole river. Oligochaeta increased in the lower river reaches and at sites with a greater amount of organic matter. The ecological status determined by the macrozoobenthos varied from high (site 1) to good, moderate and bad (site 13) at the studied sites.

The article is an attempt to review some basic ethical concepts in their historical and substantive development, within the context of the environment and environmental knowledge. It also tries to answer the question whether there is a difference between traditional and environmental ethics. The comparative-historical method is used, which considers some classical ethical concepts and their interpretations related to the environment. The concepts of classical and modern scientists are also analyzed. The authors consider whether these concepts should be supplemented with new content in this area or should be reformulated in terms of moral relevance not only for the human community, but also for all non-human inhabitants of the environment. The article explores issues about the origin of morality, as well as some ideas about the moral status of attitudes among primates. More important conclusions are that ethics and environmental knowledge must be developed in cooperation in order to explain and form moral consciousness, a new type of ethos that does not allow indifference to the environment in human interaction with it, and that moral considerations should contain not only prescriptions for due human behavior in human society, but also obligations to non-human inhabitants of nature or to the environment.

Although there are still some large and stable populations of the European Ground Squirrel, there has been a serious decline in the number and density of most of the species populations throughout its range, including in Bulgaria. The aim of the study is to supplement the scientific data about the population of the European Ground Squirrel and its habitat in Rila National Park, Southwestern Bulgaria. The research was carried out in 2017-2019 in two study areas, each divided into 20 (21) transects (every 100 m long and 5 m wide). The results have shown that the relative population density based on the number of holes tends to decrease in the period of study. The most likely reason for this, and the most significant identified threat to the population of the species in the research area in general, is the observed deterioration of the habitat status.

The article is devoted to the ideas of the Club of Rome and their modern reading. The Club of Rome, founded in 1968, is an international society of politicians, business leaders, and scientists, who appeal for mutual tolerance, understanding, and solidarity in relation to the real problems of the world, and the environmental problems in the first place. The members of the Club prescribe the setting of limits to human expansion over nature, which is explained with superfluous “anthropocentric confidence”, after the words of the foundation member Aurelio Peccei. Recently, these ideas of the Club of Rome have been criticized by economists, philosophers, and politicians, being described as “environmental alarmism”, i.e. as groundless alarm relevant to incorrect notions about the inevitability of ecological crisis and its devastating consequences for humanity. However the global environmental crisis is already an undeniable fact and requires a thorough study of the ethical standards of the human behaviour, which are often rooted in moral phenomena such as consumerism, irresponsibility, insensitivity or even selfishness. Nature cannot be only considered as a source of natural resources or benefits to people. The moral motive of nature conservation, despite the power of modern science, is one of the main ideas of the founders and followers of the case of the Club of Rome. It concerns the future where the respect for the value of nature is a new moral principle.

The city of Blagoevgrad and its surroundings (about 16.4 km2) were researched in order to establish the diversity, distribution and level of synanthropy of the amphibian and reptile species. Data about the herpetofauna were obtained in the period 1988–2012. Totally 25 species were registered – 10 amphibians and 15 reptiles. The number of species, discovered around the city, was 23, and 6 of them were not found within the administrative boundaries of the city. The different urban zones are inhabited by 19 species. They represent 37% of the amphibians and 31% of the reptiles, found in Bulgaria, and 64% of the amphibians and 60% of the reptiles, distributed in the Blagoevgrad municipality, which is very high species richness. The herpetofauna has found quite favourable conditions in the territory of the city as a whole, and especially in the sparsely populated and built up areas and city periphery. The presence of great variety of urban habitats and the pattern of situation of the city residential districts are very important for the successful adaptation of herpetofauna for inhabiting in urban environment. The high species richness could be explained also by the fact, that comparatively great number of amphibians and reptiles are hemerodiaphoric species, which easily exist in landscapes, transformed by man. The results from the case study of the herpetofauna in Blagoevgrad show that the urban areas could provide good conditions for the wild animals and could be places of substantial biological diversity

Benthic macroinvertebrate communities in the Blagoevgradska Bistritsa River were examined as a part of a complex study of the river and its basin. Monthly in 2002 and seasonal in 2003 handnet samples were taken from seven stations along the river length. The similarity of the benthic communities at different stations—along the river continuum and at each station—in different months was determined in order to study the taxonomic (species) composition dynamics and to identify the main factors affecting it. Generally the species composition along the river continuum was changed slightly, which confirms the results about the dominant structure of benthic macroinvertebrate communities and the conclusion that the whole river possesses characteristics typical of upper river courses. Both in 2002 and 2003 the similarity in species composition between sampling stations from 1 to 6 was high (above 50% almost in all cases) but comparatively low (from 21.6 to 41.1%) between the first six stations and the last one where the saprobic pollution was quite high. The seasonal changes in composition between the stations and at each station were determined mainly by the river flow alterations. In periods with prolonged high flow (2002) the species composition similarity along the river continuum increased while in low flow period (summer-autumn 2003) the tendency was the opposite. During the summer-autumn low flow period in 2003 the composition of macrozoobenthos in the lower river course was strongly influenced by the altered characteristics of the basic hydrological parameters (velocity, temperature etc.) and was considerably changed.