Wyniki wyszukiwania - BazTech

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Comparison of bacterial production in the water column between two Arctic fjords, Hornsund and Kongsfjorden (West Spitsbergen)

Ameryk A., Jankowska K. M., Kalinowska A., Węsławski J. M.

Oceanologia

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2017

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No. 59 (4)

496--507

EN

Bacterial production and the accompanying environmental factors were measured in the water columns of two Arctic fjords during the cruise in July and August 2013. Water samples were collected at six stations located in the central part of Hornsund and Kongsfjorden. In Hornsund, where average water temperatures were 1.25-fold lower than in Kongsfjorden, the bacterial production was twice as high (0.116 ± 0.102 vs 0.05 ± 0.03 mg C m−3 h−1). Statistical analysis indicated that chlorophyll a concentration itself was not a significant factor that affected bacterial production, in contrast to its decomposition product, pheophytin, originating from senescent algal cells or herbivorous activity of zooplankton. Single and multiple regression analysis revealed that water temperature, dissolved organic carbon (DOC), and pheophytin concentration were the main factors affecting bacterial production in both fjords.

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Bacterial community structure influenced by Coscinodiscus sp. in the Vistula river plume

Ameryk A., Hahnke R. L., Gromisz S., Kownacka J., Zalewski M., Szymanek L., Całkiewicz J., Dunalska J., Harder J.

Oceanologia

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2014

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No. 56 (4)

825--856

EN

The Gulf of Gdańsk is influenced by freshwater inflow from the River Vistula and by a wind-driven current along the coast. Bacterial communities from five stations along a salinity gradient were sampled during one day and analysed by terminal restriction fragment length polymorphism (T-RFLP), catalysed reporter deposition-fluorescence in situ hybridisation (CARD-FISH) and 16S rRNA gene libraries. On the day of sampling, we observed a probable current-driven seawater influx into the inner part of the gulf that separated the gulf into distinct water bodies. Members of the diatom Coscinodiscus sp. dominated one of these water bodies and influenced the bacterial community. The coexistence of typically freshwater and marine bacterioplankton populations in the Vistula river plume suggested an integration of some freshwater populations into the Baltic Sea bacterioplankton.

3

Impact of the inflow of Vistula river waters on the pelagic zone in the Gulf of Gdańsk

Wielgat-Rychert M., Ameryk A., Jarosiewicz A., Kownacka J., Rychert K., Szymanek L., Zalewski M., Agatova A., Lapina N., Torgunova N.

Oceanologia

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2013

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No. 55 (4)

859--886

EN

The biomass, production, composition of autotrophic phytoplankton and hetero-trophic bacteria were studied along with environmental and biological parameters. Samples were taken from Vistula river water (at Kiezmark) and from the river plume to the outer stations in the Gulf of Gdańsk (Baltic Sea) in June 2005. The phytoplankton biomass gradient appeared to be simply the result of dilution of the river water in the sea water, whereas the bacterial abundance and biomass dropped between the river station and the first sea water stations, a decrease that cannot be explained by the dilution effect. The Vistula water stimulated the production mainly of bacterioplankton but also of phytoplankton in the river plume as compared to rates measured in Vistula waters and at the open sea stations. However, this stimulation did not result in a measurable increase in biomasses, probably because of the short retention time of water in the river plume. Phytoplankton production was correlated with phytoplankton biomass (Chl a), while bacterial production was correlated with phytoplankton production and phytoplankton biomass (Chl a).

4

The dependence between bacterial production and environmental conditions in the Gulf of Gdańsk

Ameryk A., Podgórska B., Witek Z.

Oceanologia

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2005

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No. 47 (1)

27-45

EN

Bacterial production, primary production and a number of other environmental factors were measured during six cruises in the Gulf of Gdańsk conducted in various seasons from 1995 to 2001. Bacterial production (BP) in the epipelagic layer ranged from 1.5% (April) to 80% (July) of the gross primary production (PP). Significant differences were observed between the BP/PP ratios in estuarine and open-water areas. The highest values were recorded in the coastal area and near the mouth of the river Vistula. It suggests that allochthonous organic matter has a great influence on BP. The correlations between particular parameters and regression analyses indicated that BP in the Gulf of Gdańsk depended on temperature, organic nitrogen concentration, PP, chlorophyll a concentration, organic phosphorus concentration, salinity and biochemical oxygen demand. Of all the independent variables, the temperature had the greatest impact on BP (R2 = 0.62). There was an inverse parabolic relationship between bacterial production and temperature. It appears that above a temperature of 12°C bacterial production depended on substrates to a higher degree than on temperature. The negative correlation between BP and concentrations of mineral nitrogen and phosphorus in the annual cycle were probably due to an indirect dependence. A multiple regression equation, which included temperature and organic phosphorus concentrations, explained 78% of the variation in BP.

5

The occurrence and activity of sulphate-reducing bacteria in the bottom - sediments of the Gulf of Gdańsk

Mudryk Z. J., Podgórska B., Ameryk A., Bolałek J.

Oceanologia

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2000

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No. 42 (1)

105-117

EN

The paper presents the results of investigations concerning the number, distribution and physiological activity of sulphate-reducing bacteria (SRB) inhabiting the bottom sediments of the Gulf of Gdansk. The numbers of this group of bacteria range between 0.76 x 103 and 1.27 x 104 cells per g wet sediment. The bacterial sulphate reduction rate in bottom sediments of this area of the Baltic Sea varies from 1.89 to 31.6 nM SO42– g-1 24 h-1. The numbers of SRB and their physiological activity were subject to considerable seasonal fluctuations, maximum values being noted in summer (June) and minima in spring (April). A direct relationship has been found between the number of SRB and hydrogen sulphide concentrations; there is, however, no such relationship with reference to sulphate concentrations. The numbers and distributions of SRB demonstrated considerable variation in a depth profile of bottom sediments. SRB inhabiting the bottom sediments of the Gulf of Gdansk were able to use three different organic substrates (lactate, acetate, propionate) as electron donors and as carbon and energy sources.

6

The abundance, biomass and production of bacterioplankton in the Pomeranian Bay

Ameryk A., Mudryk Z., Podgórska B.

Oceanologia

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1999

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No. 41 (3)

389-401

EN

A microbiological investigation was carried out in the Pomeranian Bay in 1996-1997 to determine the spatial and seasonal changes in the numbers, biomass and productivity of bacterioplankton. Substantial differences in the spatial distribution of bacterioplankton populations were found. At the stations in the coastal zone of the Pomeranian Bay numbers, biomass and production of bacteria were high, with maximum values noted at the mouth of the river Swina. This is indicative of the significant impact of riverine waters on the bacterioplankton in the Pomeranian Bay. Seasonal fluctuations and bacterial microflora activity were recorded. The dynamics of the changes showed that most of the bacteriological parameters examined reached their maximum in summer while minimum values were noted in winter.