Wigry Lake: The Cradle of Polish Hydrobiology - a Century of Limnological Exploration

Wigry Lake, located in North-Eastern (NE) Poland, has a century-old history of limnological exploration and is an excellent place to assess the impact of catchment changes caused by urbanization on the functioning of a large, polymictic, and flow-through lake. The history of prewar limnological research, the course of hydrochemical effects of urbanization in the river flowing into the lake since the 1970s, and long-term changes in the functioning of Wigry Lake are presented. The collected archival and current results indicate that the hydrochemical type of the lake’s waters remained the same, and the inflow of river waters from the urban catchment strongly transformed the lake bay receiving the load. In the remaining part of the lake, the eutrophication load caused smaller changes because of a gradual reduction in the inflow of nutrients. Consequently, there was an increase in vertical differentiation of oxygen, algal biomass, and their structure. A significant share of supplying the lake with groundwater and the natural in-lake system of biotic and chemical regulations significantly reduced the effects of the eutrophication process. The existing lake biodiversity has been maintained, constituting a valuable element of the European NATURA 2000 system

Development of crustacean plankton in a shallow, polyhumic reservoir in the first 20 years after impoundment (northeast Poland)

Multiannual changes of structure and biomass of crustacean zooplankton were studied in the shallow, lowland, polyhumic Siemianówka Reservoir on the upper Narew River in northeast Poland. High ammonium and soluble reactive phosphorus ion availability for phytoplankton, low water transparency, and high dissolved oxygen concentration resulted in humoeutrophication and caused an intensive development of summer cyanobacteria. We compiled and analyzed long-term (1993–2011) crustacean zooplankton community data and chlorophyll a concentrations. Zooplankton biomass and structure in the summer were related to the intensity of the cyanoprokaryota blooms. As chlorophyll a concentration increased, crustacean zooplankton biomass decreased and smaller crustacean species dominated the zooplankton structure. Large species of crustaceans (Daphnia longispina, D. magna, and Eudiaptomus graciloides) disappeared from the reservoir after filamentous cyanobacteria dominated the phytoplankton. Long-term studies suggest that phytoplankton with strong dominance of filamentous cyanobacteria shape the crustacean community but are probably an insignificant food source for the crustacean zooplankton in the Siemianówka Reservoir

Biomass, abundance and sensitivity to antibiotics and antimycotics of the fungi in the Vistula River with its main tributaries

Mycoplankton of Vistula River and its main tributaries biomass as well as the number and morphotype diversity was studied in summer and autumn 2011. Summer mycoplankton biomass was within the range of 0.2 – 0.5 μg/l, while in the autumn it was two times wider range (0.1 – 1.3μg/l). The number of fungi in river water most often did not exceed 1000 – 2000 CFU/ml. Fungi colonies isolated from rivers water were sensitive to the commonly used amphotericine B (10 μg) and gentamicin (10 μg). It seems to be plausible that aquatic fungi can acquire immunity to drugs as a result of horizontal transfer of a gene responsible for drug resistance or as an effect of antibiotics and antimycotics getting into the aquatic ecosystems from wastewaters

History of meteorological observations and measurements in Białystok

Przedstawiono historię pomiarów i obserwacji meteorologicznych w Białymstoku prowadzonych od 1808 roku. Lokalizacja miejsc pomiarowych stacji meteorologicznej z profesjonalnym oprzyrządowaniem zmieniała się pięciokrotnie na terenie miasta. W XIX wieku szczególne zasługi w tym względzie mieli nauczyciele Szkoły Realnej w Białymstoku - Jan Wolski i Karol Czechowicz. Przerwy w ponad 210 letniej serii obserwacyjnej były skutkiem zmian obserwatorów oraz światowych wojen. Zebrane pomiary stanu pogody w Białymstoku są najdłuższą serią pomiarową w północno-wschodniej Polsce i mają duże znaczenie w ocenie wieloletnich zmian klimatu najchłodniejszego regionu kraju, o silnie zaznaczających się cechach kontynentalizmu termicznego.The history of meteorological measurements and observations in Białystok since 1808 is presented. The location of measuring points of a meteorological station with professional instrumentation changed five times in the city. In the nineteenth century, the teachers of the Real School in Białystok - Jan Wolski and Karol Czechowicz - had special merits in this regard. The breaks in the more than 210-year-long observation series were the result of changes in observers and world wars. The collected weather condition measurements in Białystok are the longest series of measurements in north-eastern Poland and are of great importance in the assessment of long-term climate changes in the coldest region of the country, with strong features of thermal continentalism

Effect of Humic Acid on the Growth and Metabolism of Candida albicans Isolated from Surface Waters in North-Eastern Poland

The aim of this study was to determine the effect of humic acid on the growth and metabolism of Candida albicans, a common waterborne pathogenic yeast. At 10–20 mg/L, humic acid caused the greatest increase in biomass and compactness of proteins and monosaccharides, both in cells and in extracellular secretion of the yeast. At higher humic acid concentrations (40–80 mg/L), C. albicans cells still had higher protein levels compared to control, but showed reduced levels of metabolites and inhibited growth, and a significant increase in the activity of antioxidant enzymes, indicating a toxic effect of the humic acid. The increase in protein content in the cells of C. albicans combined with an increase in the activity of antioxidant enzymes may indicate that the studied yeast excels in conditions of high water enrichment with low availability of organic matter. This indicates that Candida albicans is capable of breaking down organic matter that other microorganisms cannot cope with, and for this reason, this yeast uses carbon sources that are not available to other microorganisms. This indicates that this fungus plays an important role in the organic carbon sphere to higher trophic levels, and is common in water polluted with organic matter