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EN
The experiments testing the toxicity of glyphosate Roundup® formulation were conducted on the natural microphytobenthic communities collected from the Gulf of Gdansk. The toxic effect of glyphosate was assessed by changes in the biomass of microphytobenthos cells [mm3 ∙ ml-1], chlorophyll a concentration and reduction of efficiency of photosystem II. Negative impact of glyphosate on microphytobenthic communities, both at the cellular and population scale, was determined. Hence it can be concluded that certain concentrations of the herbicide Roundup (glyphosate – active substance), in the marine environment may adversely impact natural microphytobenthic communities, and in consequence also other elements of the ecosystem.
EN
This aim of this study was to test the applicability of diatom indices developed in Europe for monitoring coastal stream waters in northern Poland. Water, sediment, and diatom samples were taken from streams in the resort town of Sopot that discharge into the Gulf of Gdańsk. The physical and chemical measurements taken during the sampling period indicated that the purity of the stream waters had improved, and recently they were classified as I class water purity. This is contrasted by the studied waters’ diatom communities, which were dominated by eutraphentic taxa. High abundances of ß-mesosaprobic and α-mesosaprobic taxa were recorded at most of the sites. Diatom indices developed for water quality surveillance were calculated with the Omnidia 3 database software. Redundancy analyses (RDA), an ordination technique, was used to determine the indices that best correspond to water pollution in coastal streams.
EN
The subject of the study was microphytobenthos in the sediments of the coastal zone of the Sopot sea-resort (the Gulf of Gdask). Sediment samples were taken from 12 sites situated in the mouths of the streams and creeks and from the beach close to the sea, once a month from January to December 1998. The indicative groups of diatoms were the basis of the estimation of water quality, taking into consideration its salinity, trophic state and saprobity. The quality of water was classified according to Lange-Bertalot (1979). The results of the diatom studies indicate that the dominating groups were the oligo-halobous and mesohalobous taxa, chatacteristic of highly eutrophic waters. The most abundant groups were the resistant (poly-saprobic and '-mesosaprobic) and tolerant ($-mesosaprobic) diatoms, which are indicators of water quality class III in the coastal zone of the Sopot sea-resort.
EN
The aim of the study was to investigate Holocene history as recorded in a single sediment core taken from the Słupsk Furrow, southern Baltic Sea, with the use of diatom analysis. Diatom stratigraphy and abundance of cysts of Chrysophyceae Pascher enabled the changes in salinity and depth of the Baltic during the last 7500 years or so to be followed. Four developmental stages of the Baltic Sea were distinguished on this basis: the decline of the Ancylus Lake (or the Ancylus/Mastogloia transition), the Mastogloia Sea, the Litorina Sea and the Postlitorina Sea.
EN
The material studied originated from the marine Holocene sediments of the Gulf of Gdańsk and from Kiel Bay. During the diatom analysis, the interest was focused on the dominance of Chaetoceros resting spores. An abundant occurrence of such resting spores was interpreted in terms of changes of environmental conditions in the study areas. In the fossil sediments, it indicated the inflow of the oceanic waters which caused the salinity increase and the natural rise in the nutrient content, whereas in the subfossil sediments, it marked the increasing human impact.
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