Bioeconomy is becoming a more interesting field for investments in the Republic of Croatia, especially in its small regions and local administrative units. Vukovar-Srijem county is one such unit in eastern Croatia with noticeable potential for development in a circular, carbon-neutral, and sustainable bioeconomy. Due to the nature potential represented by one of the largest forest reservoirs in Europe-Spačva basin, forestry is one of the most important county branches. Aiming to provide more inputs on the wood biomass management, the study on the biomass flow of Vukovar -Srijem c ounty was conducted in 2020 by collecting data from local stakeholders and official reports. The study results have shown that Vukovar-Srijem county has the potential to increase the efficiency level of biomass use, but specific actions on the value-chain strengthening, finalisation of wood products, and innovative ecosystem establishment are still needed. The results highlight the predominant use of sawdust for heating purposes in the VSC region, suggesting potential for optimizing its utilization towards a circular, carbon-neutral, and sustainable bioeconomy, thus offering novel insights for future research and initiatives aiming to maximize economic and environmental benefits from wood biomass residues.

Over the last 14 years, ichthyological and ecological parameters have been monitored in the Labudovo okno Ramsar site. This area is important for its biodiversity as it is home to many rare and endangered plants and animal species. A total of 3861 fish specimens were sampled and measured at six sampling sites four times during the sampling period. An analysis of biodiversity indexes, relative biomass (kg/ha), and relative annual production (kg/ha) was carried out to assess the effectiveness of existing conservation measures. The results obtained show a trend decline in biodiversity, relative biomass, and relative annual production. This indicates a biodiversity conservation problem that should be addressed through other mechanisms in addition to the principles of the Ramsar Convention.

Abstract The investigation of fish parasites in Bosnia and Herzegovina in recent years became significant, and therefore new records of parasitic trematodes and their hosts are important for better understanding of fish parasitology and pathology. In this study 41 parasitic specimens were collected and the basic taxonomical characters were measured (body length and width, diameter of oral and ventral sucker, length and width of pharynx, ovary length and width, testes length and width and eggs length and width). After the sampling of the parasites, they were collected and conserved in 70% ethanol. After that procedure the aforementioned characters were measured using Digimizer Image Analyzer Version 4.1. After all measurements, the trematode parasite Azygia robusta was confirmed for the first time on brown trout Salmo trutta. This first record was found in the Vrbas River near Banja Luka, Bosnia and Herzegovina (Sava River Basin). Former records of this parasite in Europe were observed on other salmonid fish species, as huchen Hucho hucho. This new record should be very important part of data of fish parasitology in Bosnia and Herzegovina.

The scientific investigation of aquatic ecosystems in Bosnia and Herzegovina has become increasingly intense in recent years. Due to a deficit in studies regarding parasitology and biological control of diseases, two important fish ectoparasites (Chilodonella cyprini and Ichthyophthirius multifiliis) were investigated in 22 fish species (400 individuals) during 2017 from the middle flow of the Sava River. The prevalence of infection and infection intensity were analyzed and signs of ichthyophthiriasis were also documented. The study gives recommendations for the development of aquatic ecosystem management. Keywords-ectoparasites, the Sava River, management, Bosnia and Herzegovina.

Condition factor of fish species is very important parameter for understanding fish biology and pathology. For that purpose, we sampled 120 fish individuals from the Sava River at four locations (Posavina region), where most of them belongs to the Cyprinidae family while the others belonging to the families: Percidae, Siluridae, Ameiuridae, Esocidae and Gobiidae. In total fish sample we found that 49 fish individuals were infected by different types of skin ectoparasitic protozoa species (Ichtyobodo necator, Chilodonella cyprini, Trichodina sp., Ichthyophthirius multifiliis and Apiosoma sp.). The values of condition factor were in interval of 0,520 to 1,834.

Istraživanjem ektoparazitskih trematoda na vrsti Scardinius erythrophthalmus donjeg toka rijeke Save ustanovljene su tri vrste trematoda koje parazitiraju na skrgama ili koži riba. Tokom istraživanog perioda uzrkovali smo 120 jedinki vrste Scardinius erythrophthalmus. Ukupno 85 jedinki ili vise od 70% pokazalo je prisustvo jedne tri ustanovljene ektoparazitske trematode. Determinacija trematoda provedena je do nivoa vrste za jednu trematodu (Posthodiplostomum cuticola) i do nivoa roda za dvije (Dactylogyrus i Gyrodactylus). Kljucne rijeci: rijeka Sava, donji tok Orasje, ektoparazitske trematode

Research on the skin ectoparasites of fish from the lower flow of the Sava River showed an extremely high level of biodiversity of the skin ectoparasitic protozoa. During the study period, we sampled 120 freshwater fish. We deteremined 15 fish species and most of them were classified in the family Cyprinidae. The others were classified in the fish families: Percidae, Siluridae, Ameiuridae, Esocidae and Gobiidae. In total, 49 individuals showed the presence of different types of the skin ectoparasites from the protozoa kingdom. Determination of the protozoa was done to the species level for three parasitic protozoa (Ichthyobodonecator, Chilodonellacyprini and Ichthyophthiriusmultifiliis), and for two of them to the genus level (Trichodina and Apiosoma). Key words: Sava River, Orasje Municipality, protozoa skin ectoparasites

In this study, the first aim was to find out the measures of lead (Pb) as the heavy metal pollution in Sarajevo, Bosnia and Herzegovina. The second aim was to test if chicory, Cichorium intybus L., can be used as a biomonitor of heavy metal pollution. Twenty-eight sites (urban, suburban and rural) in Sarajevo were investigated during the summer period in 2010. Concentrations of Pb were determined in leaves and roots of Cichorium intybus L. and also in soils collected from a wide range of sites with different degrees of metal pollution. As a result of measurements, the highest values of lead accumulations in plants have been observed in roots as expected. The highest values were detected as 30.10 mgkg-1 dry weight in roots and as 28.20 mgkg-1 dry weight in leaves in the PMF garden in Pofalici. On the other hand, the highest value of lead was detected as 450.05 mgkg-1 dry weight in soil in Museum Garden. Theoretically it is expected to observe highest accumulation in soils, roots and leaves, respectively. After getting results, it is observed the relationship of lead accumulation among soils, roots and leaves as expected. Cichorium intybus L. was found to be a useful biomonitor in the determination of lead pollution. Key words: Cichorium intybus L., lead pollution, biomonitoring, Sarajevo