|Abundance and composition of plankton in the Gulf of Gdansk near the Gdansk-Wschód sewage treatment plant discharge|
Zmijewska, M.I.; Niemkiewicz, E.; Bielecka, L. (2000). Abundance and composition of plankton in the Gulf of Gdansk near the Gdansk-Wschód sewage treatment plant discharge. Oceanologia 42(3): 335-357
In: Oceanologia. Polish Academy of Sciences, Institute of Oceanology: Wroclaw; Gdansk. ISSN 0078-3234, more
|Authors|| || Top |
- Zmijewska, M.I., more
- Niemkiewicz, E.
- Bielecka, L., more
The aim of this paper is to determine the current biological state of life in the pelagiczone of the Gulf of Gdańsk in relation to the planned start-up of an underwateroutfall which will discharge sewage from the Gdańsk-Wschód (Gdańsk-East)sewage treatment plant. The plankton material was collected during two researchcruises in July and October 1998. The samples were taken at 15 stations in fourprofiles located near Wyspa Sobieszewska (Sobieszewo Island), perpendicular tothe coastline. Both the taxonomic and numerical structure of phytoplankton andzooplankton were typical of the coastal area of the Gulf of Gdańsk. The speciesdiversity depends on hydrological conditions, mainly input from the River Wisła(Vistula). The abundance and biomass of phytoplankton in 1998 were several timeslower than in 1994 and 1995 in the area off Górki Wschodnie, the profile locatedclosest to the planned construction site. This could have been caused by generallylower temperatures in 1998 in comparison to previous years. In the investigatedarea only traces of algal eutrophication indicator species were noted. However,potentially toxic species were confirmed and were most abundant near the Wisłamouth. The highest concentrations of pelagic fauna occur in the shallowest areaclosest to the shoreline. Long-term observations of the dynamics of the variationsin abundance and species composition indicate the increasing significance of oneparticular species - Acartia bifilosa.