Covering more than 60% of the lake surface, macrophytes determined the taxonomic composition of phytoplankton. We have found numerous indications of ecological deterioration and an increased trophic level year to year: an increased total number of taxa; a significantly increased number of species of Chlorophyta, Bacillariophyceae and Cyanoprokaryota; a decreased number of Chrysophyceae; increased Nygaard index, and high diversity and variability of phytoplankton functional groups. Within 2 years (2002 and 2003) algal biomass doubled: from 3.616 to 7.968 mg l⁻¹. An increased contribution of Chlorococcales and Cyanoprokaryota indicates progressive eutrophication of the lake. The average size of planktonic algae increased, particularly Cyanoprokaryota, where small-celled decreased dramatically and were replaced by large colonies. Cyanoprokaryota remained the dominant group of phytoplankton after 10 years, and the ecosystem of the lake remained in the turbid state. This group of algae had the average biomass 9.734 mg l⁻¹, which constituted almost 92% of the total biomass.

This study was aimed at determining whether the origin, morphometry, and hydrology of post-mining lakes affect their hydrochemical and hydrobiological parameters (i.e. water quality). The investigated post-mining lakes were very young compared to glacial lakes and represent early stages of ecosystem succession. Despite their different ages and morphometries, they are all mesotrophic and have good water quality. They have not been supplied with phosphorus and nitrogen, which can cause excessive development of pelagic phytoplankton; as a result, they share low chlorophyll a (Chl a) content, low phytoplankton biomass, and relatively high water transparency. Low abundance and species richness of zooplankton indicate low trophic levels in all of the lakes. Chl a in Lakes Przykona and Bogdałów were within the range typical of mesotrophic lakes, while Lake Janiszew had very low Chl a, typical of an oligotrophic water body. The low N:P ratios (4–6), especially in summer, indicates nitrogen limitation of primary production. There is a risk that such a proportion of the major biogenic elements could lead to harmful cyanobacterial blooms. The lake basins were formed using quaternary deposits (sand, clay) at their bottoms; as a result, the lakes had a slightly alkaline pH (>8), which favors the development of aquatic organisms. Optimum depth helps establish lake stratification and ensures ecological stability. This applies to post-mining lakes as well; an optimum depth should be determined to ensure the development of thermal stratification, which affects lake processes. Diese Studie sollte ermitteln, ob der Ursprung, die Morphologie und Hydrologie von Bergbauseen Auswirkungen auf hydrochemische und hydrobiologische Parameter (z.B. Wasserqualität) haben. Im Vergleich zu glazialen Seen sind die Bergbauseen sehr jung und haben frühe Stadien der Ökosystemfolge. Trotz unterschiedlicher Alter und Morphologie sind sie alle mesotroph und haben gute Wasserqualität. Phosphor und Stickstoff wurden nicht zugeführt, welche exzessive Vermehrung von pelagischem Phytoplankton bewirken können; daraus resultiert ein niedriger Chlorophyll a-Gehalt (Chl a), eine geringe Phytoplanktonbiomasse und eine relativ hohe Transparenz des Wassers. Eine geringe Menge und Artenarmut von Zooplankton indizieren in allen Seen geringe Nährstoffgehalte. Chl a in den Przykona und Bogdałów Seen war in der gewöhnlichen Bandbreite mesotropher Seen, während der Janiszewsee sehr wenig Chl a enthielt, typisch für ein oligotrophes Gewässer. Niedrige N:P Verhältnisse (4–6), besonders im Sommer, zeigen an, daß die primäre Produktion N-limitiert ist. Dieses Verhältnis der wichtigsten biogenen Elemente bedeutet ein Risiko der Entstehung schädlicher Blüten von Cyanobakterien. Die Böden der Seebecken wurden aus quartärem Material (Sand, Ton) hergestellt; deshalb haben die Seen leicht alkalischen pH (>8), was die Entwicklung aquatischer Organismen fördert. Eine optimale Tiefe fördert eine Stratifikation der Wasserkörper und garantiert ökologische Stabilität. Das gilt auch für Bergbauseen; die optimale Tiefe sollte erkundet werden, um die Entwicklung einer thermalen Stratifikation zu sichern, welche limnische Prozesse steuert. Este estudio fue realizado para determinar si el origen, morfometría e hidrología de los lagos postminería afectan sus parámetros hidroquímicos e hidrobiológicos (i.e. calidad del agua). Los lagos postminería investigados fueron muy recientes comparados con lagos glaciales y representan estados tempranos del desarrollo sucesivo dentro del ecosistema. Independientemente de sus diferentes edades y morfometrías, ambos tipos de lagos son mesotróficos y tienen una buena calidad de agua. En general, no poseen fósforo y nitrógeno que podría causar un excesivo desarrollo de fitoplancton pelágico; debido a eso, comparten bajo contenido de clorofila a (Chl a), baja biomasa de fitoplancton y relativamente alta transparencia del agua. La baja abundancia y riqueza de especies de zooplancton indican bajos niveles tróficos en todos los lagos. La Chl a en los lagos Przykona y Bogdałów estuvieron dentro del rango típico de los lagos mesotróficos mientras que el lago Janiszew tenía muy baja cantidad de Chl a, típico de un cuerpo de agua oligotrófico. La baja relación N:P (4-6), especialmente en verano, indica limitación de nitrógeno para la producción primaria. Hay cierto riesgo de que tal proporción de los principales elementos biogénicos pudieran generar floraciones de cianobacterias nocivas. Las cuencas del lago fueron formadas con depósitos cuaternarios (arena, arcilla) en el fondo; como un resultado de ello, los lagos tenían un pH ligeramente alcalino (> 8), lo que favorece el desarrollo de organismos acuáticos. La profundidad óptima ayuda el establecimiento de la estratificación del lago y asegura la estabilidad ecológica. Esto aplica también a lagos formados luego de la actividad minera; una profundidad óptima debería ser determinada para asegurar el desarrollo de la estratificación termal que afecta los procesos en el lago. Open image in new window

In the modern world, healthy habits and physical and mental fitness are more important than ever. A growing number of people participate in sports to improve their overall health. However, the conditions in which people exercise are seldom examined. It is obvious that the air in buildings, including sports facilities, can be contaminated with pathogenic microorganisms, causing infections and allergies. Our study was aimed at assessing microbial air quality inside several sports facilities (fitness room, martial arts room, swimming pool, sports hall, gym) and at a sports field. Another objective was to evaluate the antibiotic resistance of isolated Staphylococcus strains. Air samples were collected with MAS-100 sampler, using selective substrates. Antibiotic resistance of mannitol-positive staphylococci was assessed using a disk diffusion method in accordance with EUCAST recommendations. The results indicated large fluctuations in average concentrations of heterotrophic bacteria, ranging from 38 CFU m⁻³ (swimming pool) to 1036 CFU m⁻³ (sports hall). Generally, bacteria were more abundant inside the buildings, while fungi in the sports field (658 CFU m⁻³ on average). In all facilities, airborne fungal communities were dominated by the genus Cladosporium, followed by Penicillium, Fusarium and Acremonium. Alternaria and Aureobasidium constituted only a small percentage of isolated molds. We recorded only low concentrations of mannitol-positive staphylococci (on average ranging from 1 CFU m⁻³ at the swimming pool and sports field to 9 CFU m⁻³ in the martial arts room). Of all isolated Staphylococcus strains, 73% were resistant to benzopenicillin, while more than 90% were sensitive to gentamycin, levofloxacin and rifampicin.

Phytoplankton studies were carried out in the lower course of Poland’s largest river, the Vistula. This section of the Vistula has changed much since the 19th century due to regulation of the bed and limitation of its flood banks. In the years 1994–2020, hydrobiological studies of physical and chemical parameters and phytoplankton were carried out. On the basis of these studies, this research investigated the water quality of the river. Since 2000, a gradual improvement in water quality in the river has been observed, as manifested by decreasing phytoplankton biomass (from over 15 mg/L in 1994 and 2003 to less than 10 mg/L in the 2000s) and lower chlorophyll a concentrations (from 48 µg/L in 1998 to 12.5 µg/L in 2020). The river’s ecological potential index, calculated on the basis of indicator species of phytoplankton and chlorophyll a concentration, also indicates a progressive improvement. In the 1990s, the ecological potential was poor; at the turn of the century, it was moderate; and in the following years, the phytoplankton studies showed an ecological potential that was good or moderate (slightly below the lower threshold of good potential).