Szikesvizek mezo- és makrofauna együttesei, populációméretek és táplálkozási kapcsolatok a vízimadarak felé = Aquatic invertebrate assemblages in sodic waters, population sizes and feeding connection to the aquatic birds

2002-ben, 2003-ban a HNP, a KNP és FHNP szikes vizeiben végeztünk zooplankton és gerinctelen makrofauna vizsgálatokat azzal a céllal, hogy felmérjük a parkok Európa szerte méltán híres vízimadár populációk számára rendelkezésre álló táplálékkínálatot. Összesen 15 kisrákfaj (9 Cladocera és 6 Copepoda) került elő a 85um-es hálóval való szürés során. A rákok denzitása 4-2728 ind/l között, szélsőségesen változott. Ezek a fajok a különféle uszórécék, különösen a kanalas, tőkés és a csörgőrécék számára nyújtanak jó táplálékforrást. A bentonikus állatok közül a hemimetabol szervezeteket csak szórványosan találtuk a bentoszban. A fehér szikesek fenékfaunája az újabb felméréseink szerint is rendkívül szegényesnek adódott. Az iszapban csak gyűjtésenként egy-két árva és törpeszúnyogot valamint gyűrűsférget találtunk. A fertői elárasztott tavak szélirányos részénél (koncentrált táplálkozóhely) a hullámzáshoz kapcsolódó ökológiai tényezők hatnak kiemelkedően. | The sodic ponds are the world famous remnants of ancient wetland in the Carpathian Basin. The aim of this study is to estimate the population sizes of waterfowl in the small sodic ponds, and to complete our knowledge about the feeding parameters of water birds or their regulation effects for the material cycle in the continental sodic waters. In the water, the biomass and the production of the algae are relatively low. The species number and density of the zooplankton are very variable in time and space and the characteristic. In white, sodic waters, only a few Oligochaeta, Chironomida and Ceratopogonida can be found. Parallel with the potential and the real food supply examinations, the guild groups of aquatic birds also studied. We divided them into three guild groups the aquatic bird species. These were the transporters, the accelerators and bioturbation accelerates. From the territories, 115 aquatic bird species were found. 15 species of material transporters, mainly the grazer geese (41 ind/ha density). The dabbling ducks and the Coot's max. individual number was 50601 (density 68 ind/ha). In the white sodic ponds, analysis of alimentary canals of birds and feeding experiments showed that the regulations of organic material and energy cycle in these waters instead of the 'bottom-up' regulation, the important. In these waters, the roles of the fishes missing replace by the nourishment, defecations and mechanical effects of the aquatic bird guilds

Distribution and conservation status of fairy shrimps (Crustacea: Anostraca) in the astatic soda pans of the Carpathian basin: the role of local and spatial factors

The distribution of Branchinecta orientalis, B. ferox and Chirocephalus carnuntanus was assessed in the natural and semi-natural astatic soda pans of the Carpathian basin. In Europe, these habitats are exclusively restricted to Hungary (Great Hungarian Plain), Austria (Seewinkel) and Serbia (Vojvodina). The present research is the first comprehensive large-scale study – covering an area of approximately 125,000 km2 – on these three fairy shrimp species in the region, and it is important especially in the case of Branchinecta spp., due to former taxonomical uncertainties. The local, land use and spatial effects on the species distribution were also analysed. The three anostracans were found to adopt different strategies, mainly according to the salinity of the pans. The apparently halophilous B. orientalis tolerated higher salinities than the other species, which can be regarded as habitat-generalist halotolerants, showing a high preference for soda waters in Central Europe. The density of the species was significantly affected only by local factors, while their occurrence was influenced also by pan isolation. Land use did not explain a significant amount of variation in either case. In conclusion, soda pans with a wide range of different salinities constitute a suitable habitat for all the three species. Also, protected areas with high number of pans – as Seewinkel (in Austria) or Kiskunság (in Hungary) – can play an essential role in the long-term conservation of these anostracans. Finally, we suggest that these species should be legally protected, primarily because the number of their habitats in the basin is seriously declining

Where the Little Ones Play the Main Role-Picophytoplankton Predominance in the Soda and Hypersaline Lakes of the Carpathian Basin

The extreme environmental conditions of the diverse saline inland waters (soda lakes and pans, hypersaline lakes and ponds) of the Carpathian Basin are an advantage for picophytoplankton. The abundance of picophytoplankton in these waters can be up to several orders of magnitude higher than that in freshwater shallow lakes, but differences are also found within different saline water types: higher picophytoplankton abundances were observed in hypersaline lakes compared to humic soda lakes, and their highest numbers were detected in turbid soda lakes. Moreover, their contribution to phytoplankton biomass is higher than that in shallow freshwater lakes with similar trophic states. Based on long-term data, their ratio within the phytoplankton increased with turbidity in the case of turbid soda lakes, while, in hypersaline lakes, their proportion increased with salinity. Picocyanobacteria were only detected with high abundance (>10(6)-10(7) cells/mL) in turbid soda lakes, while picoeukaryotes occurred in high numbers in both turbid and hypersaline lakes. Despite the extreme conditions of the lakes, the diversity of picophytoplankton is remarkable, with the dominance of non-marine Synechococcus/Cyanobium, Choricystis, Chloroparva and uncultured trebouxiophycean green algae in the soda lakes, and marine Synechococcus and Picochlorum in the hypersaline lakes

Anion-type modulates the effect of salt stress on saline lake bacteria

Beside sodium chloride, inland saline aquatic systems often contain other anions than chloride such as hydrogen carbonate and sulfate. Our understanding of the biological effects of salt composition diversity is limited; therefore, the aim of this study was to examine the effect of different anions on the growth of halophilic bacteria. Accordingly, the salt composition and concentration preference of 172 strains isolated from saline and soda lakes that differed in ionic composition was tested using media containing either carbonate, chloride or sulfate as anion in concentration values ranging from 0 to 0.40 mol/L. Differences in salt-type preference among bacterial strains were observed in relationship to the salt composition of the natural habitat they were isolated from indicating specific salt-type adaptation. Sodium carbonate represented the strongest selective force, while majority of strains was well-adapted to growth even at high concentrations of sodium sulfate. Salt preference was to some extent associated with taxonomy, although variations even within the same bacterial species were also identified. Our results suggest that the extent of the effect of dissolved salts in saline lakes is not limited to their concentration but the type of anion also substantially impacts the growth and survival of individual microorganisms