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EN
Due to the limited water exchange, lagoons are particularly prone to eutrophication. The consumption of oxygen in this process, coupled with simultaneous enrichment of bottom sediments with organic matter, reinforces the occurrence of anaerobic conditions and methanogenic growth. Methanogenic archaea activities cause depolymerization of organic compounds accumulated in sediments. As a result of such ecosystem transformation, methane might be produced and emitted from this basin. Chemical studies conducted in 2010 were focused on methane content in the surface bottom sediments in the Polish part of the Vistula Lagoon. The results showed that the highest methane concentration occurs in the southwestern part of this basin (6.45 mmol dm-3), while the lowest one in the southeastern part (7.1 × 10-3 mmol dm-3). Molecular studies were focused on specific methanogenic archaea gene identification. The comparison of nucleotide sequences of “mcrA gene” clones obtained from genomic DNA isolated from the Vistula Lagoon sediments indicates a similarity to the yet uncultivated archaea, but also to archaea from the Methanosarcinales and Methanomicrobiales orders.
2
Content available remote Residue of chlorinated pesticides in fish caught in the Southern Baltic
EN
The aim of this study was to estimate the residue of chlorinated pesticides in the edible fish caught in the Gulf of Gdańsk and in the Vistula Lagoon. The highest mean concentrations of total DDT were found in the muscles of salmon (331.45 ng g−1 lw.) and sabre carp (306.29 ng g−1 lw.) caught in the Vistula Lagoon, and in the muscles of cod (309.88 ng g−1 lw.) and herring (304.86 ng g−1 lw.) from the Gulf of Gdańsk. Moreover, it was discovered that the following were present in the muscles of fish: DDT metabolites (pp’-DDE and pp’-DDD isomers) as well as hexachlorobenzene and its metabolites and endrin, dieldrin, α-endosulfan isomers and methoxychlor. Pesticides concentrations were higher in the livers of fish than in the muscles, which proves that the removal of toxins from the fish systems dominates over their accumulation. Because no concentration limits for pesticides have been defined, consumer safety assessment of fish caught in the Southern Baltic and in the Vistula Lagoon is not possible. The authors, having observed an increase in heksachlorobenzen in fish tissues suggested the existence of contemporary sources of pesticides which introduce them into the coastal zone.
EN
The aim of this project was to study the fate of chemically persistent organochlorine xenobiotics in the marine link of the food web, between penguins and herrings (Clupea harengus), which are the only food for Spheniscus demersus from the Gdańsk Zoo. Concentrations of hexachlorobenzene (HCBz), pentachlorobenzene (PCBz), trichlorobenzene (TCBz) and the .- HCH isomer were determined in Baltic herrings, in muscles, fat and liver of penguins, unhatched eggs, contour feathers and guano. The highest concentrations of fungicides were observed for HCBz. Fungicides were not detected in the liver of penguins and herrings. The bioaccumulation factor (BAF) for fungicides reached the highest values in the penguin brain. The highest biomagnification factor (BMF) for PCBz was determined in the muscle tissue and for lindane – in liver. It was confirmed that detoxification of penguins occurred through deposition of fungicides and lindane in guano and through epithelial tissue and eggs.
EN
In this work, data on methanogenic Archaea communities in sediment from the coastal area of Puck Bay were investigated. Sediments were collected along the Hel Peninsula from areas characterized by the occurrence of gas bubbles. Based on the analysis of molecular markers, the presence of a specific methanogenic Archaea gene was detected at all stations. Further research involved the cloning and sequencing of methanogenic DNA. Based on the comparison of obtained genetic sequences with existing genetic databases, it was confirmed that all of the nucleotide sequences belonged to the domain Archaea. Furthermore, in the investigated sediment certain sequences had certain similarities to the sequences of organisms from the families Methanosarcinaceae, Methanospirillaceae and Methanocorpusculaceae.
EN
This work presents the results of the study on methane emission from the sea bottom in the coastal zone of Puck Bay. The investigations were conducted from June through September 2010 at seven sampling sites located along the Hel Peninsula. The research results indicate that the methane flux rates vary periodically. Methane emission from seabed into near-bottom water in the coastal zone of Puck Bay along the Hel Peninsula ranged from 0.91 mmol m-2 d-1 to 49.15 mmol m-2 d-1.
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