Issues

Morphological analysis of specimens of the wood mouse (Apodemus sylvaticus) from agricultural region in Northeastern Bulgaria was carried out. The degree of sexual dimorphism of the studied craniometrical measurements was revealed through: (a) variation flow, (b) assessment of degree of comparative variation and (c) morphological profiles. The obtained results extend the knowledge about population characteristics of the zoo-monitor A. sylvaticus in regard to the assessment of phenotype population variation of the two sexes under agricultural conditions. The established characteristics represented substantial morphological basis for further eco-physiological investigations of this zoo-monitor species in agricultural ecosystems in Bulgaria.

The subject of the current article is the ichthyofauna and the ichtyocenosis of Ivailovgrad dam. Eleven species of fish have been identified, one of which has been registered for the first time for this dam. Two species of asp fish and eel can be considered extinct since they haven't been caught for the last 30 years. On the basis of the coenosis results the contemporary state of the fishing stocks in Borislavtsi Bay has been established. The rates of growing and predominance have been found, leading to the conclusion that the ecological balance has been seriously disturbed as a result of the illegal catch. The predominant species in the region such as Roach and Dark Vimba are of little value. The commercially important European catfish, Carp and Pikperch have a very irregular size and age structure and make up a small percentage of the total catch. The structure of Vardar Nase has also been disturbed, probably due to changes in the spawn areas. The results of our research lead to the conclusion that a stricter control over the catch must be imposed especially during the spawn season. Dramatic changes have occurred as a result of the cascade of the three dams. They constitute an insurmountable barrier to fish populations and cause for genetic isolation. Lack of fish passages along the river have led to complete disappearance of the asp. and eal. And in a significant reduction of typical reofil species as maritza barbel vardar nase, dark vimba. With the construction of the dam has significantly increased opportunities for the cultivation of valuable species for industrial and sports fishing. These are carp, pikperch, catfish from the natural species and grass carp and silver carp from intoduction.

Ceroplastes japonicus (Green) is a new insect species in Bulgaria. It identification was for the first time in 2006, from plant material, collected in greenhouses (Sofia). During monitoring in the period 2007-2009 this species was found outdoors only along the Black sea coast, (Sozopol, Burgas and Sunny beach), but nowhere else. We noticed mass outbreaks of C. japonicus mainly on Ilex aquifolium, and also on Laurus nobilis and Citrus sp.

The following conclusions were made based on the three year long studies:

- The plants examined in the studies are an important source tor the introduction of Ceroplastes japonicus in Bulgaria.

- During the course of the studies the species has adapted to the conditions of both the region around Sozopol and more barren areas around Burgas and is able to develop sucessfully there.

In the framework of project "Investigation on leaf-mining insects (Lepidoptera) in Bulgaria", the published information about leafminers of Bulgaria was analized. On the base of new collected insect material the species composition of 10 lepidopteran families was studied.

The establishment of 466 leaf mining species belonging to 29 families from 14 superfamilies of order Lepidopterain Bulgariawas confirmed by our survey. A list of alien leaf-miner moths, review of their spreading pattern and actual population status is presented. The possible threat leafminers to biodiversity and economy of Bulgariais discussed.  

In the framework of the ATARTIB project, the level of knowledge about alien insects and their environmental impact in Bulgaria was assessed. The literature survey, showed that the published information was dispersed among many publications, most of them very old or difficult to be found in the libraries.

The published data about negative environmental impact of alien insects on biodiversity of Bulgaria was not found but the following gaps in our knowledge were detected: (1) for most of the species reported, only faunistic datawere found; (2) for some species only a single report was found with no information on their population status;(3) some species are present in Bulgaria according to Fauna Europea database, but the references ware not available for us, since they most probably ware reported by not local entomologists;(4) the inclusion of such species in the preliminary analysis made, is questionable, since it is not clear whether the species are established or have been intercepted only;(5) only alien species of economic concern and under phytosanitary control are studied (6) the analysis concerns published information about species considered to be of exotic origin and introduced in Bulgaria by means of human activity only.

We propose following investigations to be carried on, in order to be created the general monitoring and management system of alien arthropods of Bulgaria: (1) accurate inventory of alien arthropods filling the gaps in knowledge concerning alien arthropods in Bulgaria detected in framework of conducted projects; (2) study the ecological impact of selected alien species and the mechanisms underlying this impact; (3) assessing the role of natural enemies in the invasion success of alien species; (4) assessing the role of alien arthropods on mammals and birds as vectors of diseases.

The initial effect of the insecticide bensultap on the structure of the syrphid community was assessed in the field experiment.The species composition, the population density of each species, the total average density, the dominant structure, and the species structure indices of the syrphid community were studied.The used indices show a deterioration of the ecological situation for the syrphid community in the field immediately after insecticide treatment.

The report examines the importance of nature parks to protect the natural heritage and in terms of regional development through investment in local economies on specific projects for development of tourism. In analyzing the survey the role of parks directorates for the establishment of new tourist destinations through the formation of preconditions for the development of ecotourism and ecotourism specific products, interaction with local authorities, local and regional business contribution to the conservation and development of local crafts, traditions, culture and environmental education.

Results are presentedof the activities from the ecotourism development in the biggest Bulgarian National Park - Rila.

Duringan eight-year period investigation in Rila National Park and the region as a whole the priority ecotourism activity and projects have been identified and presented.

Results have been shown from the visitor monitoring management process of the National Park territory and presented developing of ecotourism infrastructure as specialized paths and eco-trails and created new ecotourism product.

The conducting of the ecotourism development in the Rila National park is part of the integrated information database for implementation of efficient policies related with the sustainable forms of tourism development in the protected areas.

Landscape assessment scale for winter recreation was made. By analyzing some of the characteristics of the relief, as the most sustainable landscape component, soil and plants characteristics a landscape map for winter recreation was created. Appropriate areas for active and passive recreation were determined.

On the basis of two years monitoring on astream of tourists on the territory of Rila-Monastery Natural Parksome dataabout characteristic of visitors are collected as: number of visitors;nationality, age and occupation;motives of visit etc. The twenty-four hours and season dynamics are find out and presented on different point of view;the intensity of astream of automobiles, different forms of tourism and recreation and natural resources use etc.

Some recommendations on Rila-Monastery Natural Parkmanagement are formulated and pointed out as:

- some main consequences on the environment are find out;accelerate the workin more influenced areas for a "model" of sustainable natural resources management implementation on the territory;

- to make an optimal conditions to meet the needs of tourists and automobiles, without number limitation, with the opportunities of the park territory, to orientate the stream of tourists and automobiles to well laid out for recreation and relaxation areas of natural park;

- supporting the rural tourism development by tourist orientation to the near villages and towns for hosting, accommodation and entertainment in aspirit of Bulgarian traditions.