Volume 37 (2008): Issue 3 (September 2008)

In order to assess changes in salt water inflow and potential flood risks due to sea level rise in a micro-tidal Beka brackish marsh on the Polish Baltic Coast GIS was used. Such wetlands are important elements of coastal zone natural environments. Creating a geodatabase within a GIS system makes it possible to carry out broad analyses of complex systems, such as coastal wetlands. The results indicate that a 40 cm sea-level rise would considerably increase the frequency of flooding in the investigated area, in part because of the small range of the annual sea level oscillations there. A map of the index of changes in saltwater inflow, created with the help of cost-weighted distance (functions), shows that changes which have occurred along the shore, consisting of filling in the drainage channel outlets, have likely had a significant impact on the vegetation of the area.

Diatom communities in alpine-zone streams of the Tatra National Park and the Swiss National Park were heterogeneous with respect to species richness, abundance, Shannon diversity index, and ecological preference. Two groups of diatoms were distinguished. Group 1, inhabited streams in the upper Gąsienicowa Valley (Tatra Mts) and Macun Lakes region (Alps), and had high species richness and Shannon diversities (especially in the Tatra Mts streams) but low abundances. The most abundant and common diatoms were Psammothidium helveticum, Diatoma mesodon, Aulacoseira alpigena, Achnanthidium minutissimum, Psammothidium subatomoides, Psammothidium marginulatum, and Gomphonema parvulum. Group 2 inhabited Tatra Mts streams in the Five Polish Lakes Valley and lower Gąsienicowa Valley. Diatoms were highly abundant but species richness and Shannon diversities were relatively low. The most abundant were Achnanthidium minutissimum, Diatoma mesodon, Fragilaria capucina gracilis group and Tabellaria flocculosa. There was no clear difference between the diatom communities of the outlet streams of upper lakes and the inlet streams of adjacent downstream lakes. The high abundance of diatoms in the streams of the Tatra Mts suggests recent ecosystem changes related to lake eutrophication and partly by weather anomalies resulting from climate change.

Anguillicola crassus Kuwahara, Niimi et Itagaki, 1974 is an Asian parasitic nematode that was introduced to Europe and inhabits the swim bladder of eels. In the 2002-2005 period, 237 eels, Anguilla anguilla (Linnaeus, 1758), from Lake Wdzydze were examined for the occurrence of the nematode. 79.3% of the fish were infected, at a mean intensity of 7.2 nematodes per fish. Morphological measurements of the observed A. crassus are presented. This is the first published report of A. crassus in eels from Lake Wdzydze.

The results of the application of chemometric methods, such as principal component analysis (PCA) and its generalization for N-way data, the Tucker3 model, for the analysis of an environmental data set are presented. The analyzed data consists of concentration values of chemical compounds of organic matter, and their transformed products, in a short-term study of a sea water column measured at the Gdańsk Deep (φ = 55°1'N, λ = 19°10'E).

The main goal of this paper is to present improved approaches for exploration of data sets with missing elements, based on the expectation-maximization (EM) algorithm. The most common methods for dealing with missing data, generally consisting of setting the missing elements to zero or to mean values of the measured data, are often unacceptable as they destroy data correlations or influence interpretation of relationships between objects and variables. The EM algorithm may be built into different computational procedures used for exploratory analysis (i.e. EM/PCA or EM/TUCKER3).

During a monitoring programme the diet composition of Asplanchna priodonta was studied. Samples were collected every month from the deepest part of the Dobczycki dam reservoir (Southern Poland). The diet of A. priodonta, which included colonial cyanobacteria, diatoms, dinoflagelates and protozoa, indicated that it is both a grazer and a predator. These results support the hypothesis that A. priodonta is an opportunistic feeder. Additionally these results include the first observations of the protozoan Tintinnopsis sp. as a food source of Asplanchna.

The studies concerned the ecosystem of the Solina-Myczkowce cascade of reservoirs. While the elemental C:N ratio was higher in the Solina Reservoir branches and in the Myczkowce Reservoir (>10), the values for stations located near the Solina Dam were low (<10). Markedly, the lowest values for δ¹³C were noted in the Myczkowce Reservoir (-28.5‰), and these contrasted with the higher values found in the Solina Reservoir (ca. -27‰). δ¹⁵N varied from 2‰ in the upper Solina to above 3.5-4‰ downstream. While the data obtained indicate the autochthonous origin of sedimentary matter, primary production influences the properties of the bottom sediments in the lower part of the Solina reservoirs.

Lead and cadmium levels were determined in the meat tissues of roach, bream, and carp netted in a lake and in fish ponds threatened by a pesticide tomb and in control basins in northeastern Poland. Concentrations in roach ranged from 20 to 124 μg kg^-1 of Pb and from 1 to 19 μg kg^-1 of Cd. In bream they were from 4 to 280 μg kg^-1 of Pb and 2 to 28 μg kg^-1 of Cd, while in carp they were from 9 to 82 μg kg^-1 of Pb and 2 to 260 μg kg^-1 of Cd. The metal concentrations were low; no result exceeded admissible residue levels set forth by Polish law, and no evident contamination of fish by leakage from the pesticide tomb was detected.

The aim of this study was to evaluate the total and soluble forms of Cr, Ni, Cu, and Co contents in bottom sediments of the Supraśl River and its tributaries. Studies were carried out in August 2005 and March 2006. The total contents of metals were determined, following the digestion of the sediments in nitric acid in a MARS 5 closed microwave system. Soluble forms of metals were extracted with 1 mol dm^-3 HC1 at the ambient temperature. The bottom sediments of the Supraśl and its tributaries are slightly contaminated with chromium. Copper, nickel, and cobalt occur mainly at a geochemical background level. A positive linear correlation between total forms of metal contents and their soluble forms was found.

Macrozoobenthos inhabiting six oxbow lakes in the basins of the Słupia, Łyna, and Vistula rivers was investigated during spring, summer, and fall 2002-2006. The researched reservoirs - re-opened, dredged, with a sluice, natural open, natural semi-open, and natural closed - differed in degree of succession and type of connection with the relevant river. In order to determine the dependency of macrozoobenthos structure on type of oxbow lake and season, multivariate regression and classification tree method (MR&CT), and indicator species analysis were applied.

The tree obtained revealed that the natural, semi-open oxbow lake differed distinctly from the others and was a favorable habitat for Diptera (mainly - Chironomidae larvae), Bivalvia, and Gastropoda. The latter taxon turned out to be an indicator for summer, while Insecta and Bivalvia dominated in spring and fall. Meliorated oxbow lakes (re-opened, dredged, with a sluice) were characterized by balanced density of all the macrozoobenthos organisms and the lack of indicator taxa. In turn, high trophy was indicated by Oligochaeta abundant in natural open and natural closed oxbow lakes, and in a reservoir with a sluice.

Establishing reference conditions is essential for performing ecological status assessments of surface waters according to the EU Water Framework Directive. Ecological status is described as the deviation from undisturbed (reference) conditions. This paper presents the process of establishing preliminary reference values for chlorophyll a, total phosphorus, and Secchi disc readings in different types of Polish lakes. This was done by selecting potential reference lakes and performing statistical analysis of the values of the main eutrophication parameters. The preliminary reference values for total phosphorus, chlorophyll, and Secchi disc depth were defined as 0.033 mgP dm^-3, 3.75 μg dm^-3, and 3.6 m for stratified lakes, and 0.048 mgP dm^-3, 5.80 μg dm^-3, and 2.5 m. for polymictic lakes, respectively.