Ana Petrović

Spatio-temporal pattern of the Chironomidae community: toward the use of non-biting midges in bioassessment programs

We employed the self-organizing map (SOM) method to investigate the spatio-temporal pattern of the Chironomidae community in the Southern Morava River basin (Serbia) and to examine to what extent the Chironomidae community is affected by environmental factors. Additionally, this study explores the problems of utilizing chironomids in bioassessment programs. The SOM analysis of the chironomid community data produced 3 groups of sites. The indicator species analysis presented indicator taxa for two groups. Twenty taxa (at species, species group and genus level), according to the Kruskal–Wallis test, showed the most pronounced differences among the temporal units. Out of 15 measured environmental parameters, one-way ANOVA pointed out that 10 significantly differ between the groups. Elevation had the most important influence on the chironomid community, also affecting other environmental parameters. According to our findings, the winter season and the periods with high water level are the main sources of natural variability. To avoid such variability and to successfully incorporate Chironomidae in bioassessment programs, we suggest exclusion of the arguable months from monitoring programs.

Different aggregation approaches in the chironomid community and the threshold of acceptable information loss

Due to the problem of identification, Chironomidae larvae, although very abundant, are often avoided or not properly used in bioassessment programs. The aim of this work was to test how different aggregation processes—taxonomic resolution and the random aggregation approach (best practicable aggregation of species—BestAgg) affect the analysis of chironomid communities regarding any information loss. The self-organizing map method, together with classification strength analysis and Spearman’s rank correlation, revealed that the genus-level and BestAgg-abundance matrix most accurately approximated the species-level community pattern. The subfamily-level dataset was ineffective at presenting the chironomid community structure, with a substantially lower concordance with the species-level dataset. The biologic environmental gradients analyses presented the same set of important environmental variables for the species-level, genus-level, and BestAgg-abundance matrix. The indicator values analysis showed that indicator genera provide information very close to that gained from species indicators. According to our results, the numeric relationship between species and higher taxa influences taxonomic scaling, limiting Chironomidae family aggregation, with acceptable information loss only up to genus level. In addition, the BestAgg approach, with the maximum level of aggregation, properly assesses the community structure and consequently describes environmental conditions.

The Alburnus benthopelagic fish species of the Western Balkan Peninsula: An assessment of their sustainable use.

In this study, we aimed to assess the population status of bleak (Alburnus spp.) over the Western Balkan Peninsula in terms of its sustainable use. A second objective was to determine key factors important for fishery management planning. Two different basins, continental (the Danube Basin and the Sava River sub-basin) and marine (the Adriatic and the Aegean Sea Basins) were examined. A sustainability assessment and factor analysis were conducted using the adjusted ESHIPPOfishing model, extended with additional socio-economic sub-elements, and the categorical principal components analysis (CATPCA), respectively. The results of the assessment revealed the bleak populations in the Danube Basin and the Sava River sub-basin to be highly sustainable. The population characteristics with abiotic and biotic factors were responsible for this status, while the influence of socio-economic factors was insignificant. The sustainability status of the bleak populations of the Mediterranean basin varied, with the populations from Ohrid and Skadar Lakes showing a high and those from Prespa and Dojran Lakes a medium status. Socio-economic factors with traditional fishing were the most important for the Mediterranean bleak populations.

Indicative Status Assessment, Biodiversity Conservation, and Protected Areas Within the Sava River Basin

The aim of this chapter is to provide the overview of the water status, state of the biological diversity, and protected areas along the Sava River as well as to underline the necessity of identification and implementation of effective conservation measures. The chapter is based on historical data on environment and recent investigation on macroinvertebrate communities (2011–2012). Ecological status of water bodies within the Sava River basin ranges from high to poor, while the ecological status of the majority of water bodies is assessed as moderate, which indicates the necessity of design and implementation of relevant mitigation measures. The assessment of water quality and ecological status of the river Sava based on the macroinvertebrates community, alongside with the use of several standard biological methods and regional biotic index BNBI indicates a high correlation of the obtained results. BNBI has proven to be a method reliable enough for both the assessment of water quality and the assessment of ecological status of large rivers. Based on the results of water status assessment, the Sava River could be divided into three zones. The best water quality was recorded within the Slovenian stretch of the river, being within the limits of betamesosaprobic zone, while the ecological status was assessed as a good one. The middle part of the Sava River, stretching mainly through Croatia and Bosnia and Herzegovina, has a somewhat worse water quality, approaching the limit of betamesosaprobic zone, while the ecological status in this part of the flow was also determined as a “good” one. The lower parts of the Sava River flow through Serbia are by all indicators more heavily polluted; the water quality is on the border between beta- and alfamesosaprobic zones, while the ecological status is between “good” and “moderate.” The biodiversity of the Sava River may be considered significant, when compared to similar watercourses of Central Europe and Balkan Peninsula. The work contains a more detailed analysis of the biodiversity of aquatic macroinvertebrates and fish of the main flow of the Sava River. Based on the condition of biodiversity of these groups, the river’s ecosystem is divided into three “macrohabitats.” The first macrohabitat includes the upper rhithron parts of the river through Slovenia, with a significant diversity of stenovalent groups of macroinvertebrates (larvae EPT) and salmonid species of fish (brown trout, grayling, and huchen trout). The second macrohabitat includes the parts of the flow through Croatia and Bosnia and Herzegovina with significant diversity of invertebrates from the groups Odonata, Mollusca, Hirudinea, and Chironomidae and fish from the families of Cyprinidae, Percidae, and Gobiidae. The highest number of protected species of fish has been registered in this section. The third “macrohabitat” includes the lower part of the potamon of the Sava River and mostly flows through Serbia wherein this part of the flow represents the most important habitat of the globally endangered and fishing-wise important sturgeon species of sterlet (Acipenser ruthenus) in this river. It is characterized by a decreased biodiversity of macroinvertebrates in the main flow of the river and a significant diversity in the flood zones. In the biodiversity of fish, the highest number of allochthonous species appears. In this section, the diversity of fish in flood zones especially as the habitat of endangered species such as Umbra krameri, Misgurnus fossilis, and Carassius carassius is also important. Research has shown that in order to perform a successful conservation of large river biodiversity, the ecosystem must be observed as a complex consisting of the main flow of the river, flood zone, and its tributaries.

A NEW RECORDS OF EPEORUS YOUGOSLAVICUS (ŠAMAL, 1935) (EPHEMEROPTERA) IN SERBIA AND MONTENEGRO

ABSTRACT During hydrobiological investigations of diversity of rivers and brooks of Serbia and Montenegro, new records of Ephemeroptera species, Epeorus yougoslavicus (12) was ascertained, in period from 2000 to 2005 years. The find of this species, except that it enriches diversity of Ephemeroptera fauna of Serbia and Montenegro, is also important for knowledge of distributions of this species. New biotopes of this species in Gobeljska River on Kopaonik Mountain represents the most northward border of its areal, known until now. On all bitopes where it was found in Serbia and Montenegro, the species occurs in very rare populations, that is a case and with its other until now known finds on Balkan and Apennine peninsula. Small populations and mutually isolated bitope can be taken as parameters on which this species can be consider as endangered for territory of Serbia and Montenegro.

The best data design for applying the taxonomic distinctness index in lotic systems: A case study of the Southern Morava River basin

The taxonomic distinctness (Δ+) index has been recognized as a robust measure to assess human impacts on marine biodiversity. However, its applicability in freshwater ecosystems has still not been confirmed. We aimed to propose the most suitable data design for calculating the Δ+ index for application in assessing anthropogenically caused degradation in lotic environments. We calculated the values of Δ+ based on different taxa groups and taxa resolutions, in order to examine its utility as a potential metric in bioassessment programs. We found that the exclusion of non-insect taxa and selected insect orders significantly increased the index sensitivity. Thus, we believe that an appropriate data design for Δ+ calculation based on macroinvertebrate assemblages is the main prerequisite for the effective estimation of degradation in lotic environments. In addition, we argue that a decrease in taxonomic resolution up to genus level is completely acceptable, as it results in only minor information loss. Bearing this in mind would significantly facilitate its application in rapid bioassessment programs. Despite the observed correlation, the utility of Δ+ as a potential bioassessment metric is rather limited, since its fails to detect fine differences in environmental stress, and instead only roughly distinguishes between two basic classes of degradation level, unimpacted and impacted.