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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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Neustonic versus planktonic bacteria in eutrophic lake

Kalwasińska A., Donderski W.

Polish Journal of Ecology

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2005

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Vol. 53, nr 4

571-577

EN

This paper presents the results of research on the number, the rate of secondary production and physiological properties of neustonic (surface microlayer SM ≈ 250 μm) and planktonic (subsurface water SSW ≈ 10-15cm) bacteria of the eutrophic lake (TP 30-99 μg l-1; TN 0.94-1.76 mg l-1; chlorophyll a 26.4-56.9 mg l-1; water transparency 1.2-1.9 m). It was found that the total number of neustonic bacteria (TNB) varied from 1.28 × 106 to 1.98 × 106 cells ml-1 and was from 1.4 to 2.0 times higher than the number of planktonic bacteria (P <0.001). TNB range for planktonic bacteria oscillated between 0.75 × 106 and 1.45 × 106 cells ml-1. The number of heterotrophic neustonic (SM) bacteria (CFU 22°C) was also higher by 2.0 to 13.3 times (P <0.001) being between 1.48 and 12.5 × 103 cells ml-1 while the CFU of bacteria in the SSW oscillated between 0.35 to 0.94 × 103 cells ml-1. Both the values of TNB and CFU displayed a distinct seasonal variation (P <0.001). However, the rate of secondary production of planktonic bacteria was higher (from 1.1 to 6.0 times) than the rate of production of neustonic bacteria (P <0.05) and displayed seasonal variability (P <0.001). The rate of secondary production in subsurface water ranged from 0.676 to 1.265 μgC l-1 h-1 while in surface microlayer from 0.118 to 0.597 μgC l-1 h-1. In neuston the bacteria decomposing fat and DNA were more common than in plankton (P <0.05).

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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.