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Diatom record of progressive anthropopressure in the Gulf of Gdańsk and the Vistula Lagoon

Witak M., Pędziński J.

Oceanological and Hydrobiological Studies

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2018

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Vol. 47, No. 2

167--180

EN

This study describes the subfossil diatom flora in the surface sediments of the Polish coastal waters in relation to human impact. The material studied consists of the uppermost parts of seven sediment cores collected from the SW Gulf of Gdańsk and eight cores from the Vistula Lagoon. Our results show the present-day ecological state of both basins just before the planned construction of a navigable channel of the Vistula Spit, which will be the next factor affecting their hydrology. In different parts of the Gulf of Gdańsk, cultural eutrophication resulted in a distinct “anthropogenic assemblage” in the surface sediments. Its structure relates directly to the distance from the mouth of the Vistula River. In the surface assemblages of the Vistula Lagoon, the number of salt-tolerant diatoms increased with the salinity of the basin. Locally, a large number of pollution-resistant taxa was also observed.

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Diatom-based reconstruction of trophic status changes recorded in varved sediments of Lake Żabińskie (northeastern Poland), AD 1888-2010

Witak M., Hernández-Almeida I., Grosjean M., Tylmann W.

Oceanological and Hydrobiological Studies

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2017

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Vol. 46, No. 1

1--17

EN

We investigated diatom assemblages in surface sediments of 46 lakes in northern Poland and developed a diatom-based transfer function to infer epilimnetic total phosphorus (TP) concentrations. Multivariate ordination techniques (DCA, CCA) were used to identify major environmental gradients and to evaluate the effect of environmental parameters on the distribution of diatoms in the modern diatom dataset. The transfer function was developed using PLS, WA and WA-PLS models, and applied to a varved sediment core from Lake Żabińskie, AD 1888-2010. Annually-resolved quantitative reconstruction of TP concentrations shows that multidecadal changes in the TP level reflect the local settlement history, land-use changes and development of agriculture and tourism. The period of high trophic levels with maximum values of TP was documented until the late 1920s. In the 1930s-1970s period, TP generally decreased and eutraphentic flora was partly replaced by oligotraphentic and oligo-mesotraphentic diatom taxa. The reconstructed TP concentrations have started to increase from the 1970s. After the 1950s, strong short-term fluctuations of TP values were noted and explained by interactions between meteorological conditions, water column mixing and nutrient cycling in the lake.

3

Diatom biofacies in the SW Gulf of Gdańsk and the Vistula Lagoon (the southern Baltic Sea) as indicators of the basin evolution in the Middle and Late Holocene

Witak M.

Oceanological and Hydrobiological Studies

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2013

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Vol. 42, No. 1

70-88

EN

This article presents results of diatom analysis of seven sediment cores taken from various depths of the Gulf of Gdańsk between the Hel Peninsula and the coast of Gdańsk and Gdynia. Further eight cores were drilled in the northern, southern and central part of the Vistula Lagoon. The present investigations enabled the determination of: (i) differentiation of diatom assemblage zones, (ii) correlation of palaeoecological units with reference to the following stages: Mastogloia Sea, Littorina Sea, Post-Littorina Sea, including the latest environmental changes associated with an anthropogenic factor, (iii) description of the defined diatom biofacies based on statistical analysis, (iiii) reconstruction of spatial and temporal development of both basins with the emphasis on the role of inflows of sea and river waters.

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A review of the diatom research in the Gulf of Gdańsk and Vistula Lagoon (southern Baltic Sea)

Witak M.

Oceanological and Hydrobiological Studies

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2013

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Vol. 42, No. 3

336--346

EN

The paper presents the history of diatom studies carried out in the Gulf of Gdańsk and the Vistula Lagoon since the beginning of the 20th century. One aspect of the research focuses on describing the structure of planktonic and benthic communities living in different parts of the area or occurring in their surface sediments as taphocoenoses. Other investigations concentrate on the fossil diatom flora, which is widely used in the research on the Late Glacial and Holocene to resolve paleogeographic, sedimentological and paleoecological problems.

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Diatoms as indicators of eutrophication in the SW part of the Gulf of Gdańsk, the Baltic Sea

Leśniewska M., Witak M.

Oceanological and Hydrobiological Studies

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2011

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Vol. 40, No.1

68-81

EN

The aim of this study was to reconstruct paleoenvironmental changes of the SW part of the Gulf of Gdańsk. Three subbottom sedimentary cores were analyzed with respect to diatom flora. Post-Littorina Sea assemblages were noticed in the lower parts of the cores, whilst the present-day eutrophication of the gulf was evidenced in their superficial sediments, with high abundance of so-called "anthropogenic assemblage" taxa. Shifts in the species composition might have been caused by intensified nutrient load, increasing organic matter concentrations and possible silica limitation.

6

Chaetoceros resting spores as indicators of Holocene paleoenvironmental changes in the Gulf of Gdańsk, southern Baltic Sea

Witak M., Dunder J., Leśniewska M.

Oceanological and Hydrobiological Studies

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2011

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Vol. 40, No.4

21-29

EN

The aim of this study was to analyze resting spores of Chaetoceros spp. preserved in Middle and Late Holocene sediments of the three parts of the Gulf of Gdańsk, southern Baltic Sea. The material studied consists of ten cores retrieved from Kuźnica Deep (Puck Lagoon), as well as the shallower and deeper parts of the Outer Puck Bay region. Our results indicate that the abundance of Chaetoceros resting spores in diatom taphocoenoses corresponded to regional and local paleoecological changes registered in Mastogloia, Littorina and Post-Littorina sediments, and that they also reflect human impact in the last hundred years.

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Holocene diatom biostratigraphy of the SW Gulf of Gdańsk, Southern Baltic Sea (part III)

Leśniewska M., Witak M.

Oceanological and Hydrobiological Studies

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2008

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Vol. 37, No.4

35-52

EN

The palaeoenvironmental changes of the south-western part of the Gulf of Gdańsk during the last 8,000 years, with reference to the stages of the Baltic Sea, were reconstructed. Diatom analyses of two cores taken from the shallower and deeper parts of the basin enabled the conclusion to be drawn that the microflora studied developed in the three Baltic phases: Mastogloia, Littorina and Post-Littorina. Moreover, the so-called anthropogenic assemblage was observed in subbottom sediments of the study area.

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Holocene diatom biostratigraphy of the SW Gulf of Gdańsk, Southern Baltic Sea (part II)

Witak M., Dunder J.

Oceanological and Hydrobiological Studies

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2007

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Vol. 36, No.3

3-20

EN

The diatom records of two sediment cores taken in the SW part of the Gulf of Gdańsk indicate paleoenvironmental variability in the last three stages of formation of the Baltic Sea: the Mastogloia, the Littorina and the Post-Littorina. Diatom community compositions of the cores show the influence of several factors on past environmental conditions of the study area: (1) regional salinity changes, (2) changes of the Vistula River inflow, and (3) sedimentary processes connected with the Hel Peninsula development.

9

Holocene diatom biostratigraphy of the southwestern Gulf of Gdańsk, southern Baltic Sea (Part I)

Witak M., Jankowska D., Piekarek-Jankowska H.

Oceanological and Hydrobiological Studies

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2006

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Vol. 35, No.4

307-329

EN

The aim of the study was to analyze the diatom taphocoenoses preserved in the Holocene sediments of the southwestern Gulf of Gdańsk (southern Baltic Sea). Three sediment cores collected at sites located between the tip of the Hel Peninsula and Gdynia were used to reconstruct environmental changes that have occurred over the last 9 ka. The floristic spectrum and the distribution of ecological groups indicate that the diatom flora developed during four Baltic Sea paleoecological stages; thus, the Ancylus Lake, Mastogloia Sea, Littorina Sea, and Post-Littorina Sea stages are discussed. The anthropogenic assemblage in the superficial sediments of the study area is also described.

10

Paleoecological changes of the Vistula Lagoon in the last 7,000 YBP based on diatom flora

Jankowska D., Witak M., Huszczo D.

Oceanological and Hydrobiological Studies

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2005

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Vol. 34, No.4

109--129

EN

Fossil and subfossil diatom flora were analyzed in four sediment cores (ZW 1, ZW 4, ZW 11, ZW 15) taken from the Vistula Lagoon. The aim of the study was to reconstruct environmental changes in the Holocene with an emphasis on the relationship with paleoecological stages of the Baltic Sea. Results of the diatom study supported by lithological analyses indicate that the development of the Vistula Lagoon took place under changing environmental conditions. The basin was formed in the Late Atlantic chronozone and was indirectly connected with the Littorina Sea transgression. The basin became shallower and its waters fresh in the Subboreal period. Due to the last marine transgression linked with the Post-Littorina Sea in the Subatlantic chronozone, slightly higher salinity was observed in the diatom record. Moreover, the effects of eutrophication are recorded in the subfossil diatom flora preserved in sediments from the southwestern part of the lagoon. Additionally, the results of the discontinuation of the Nogat River inflow in 1915 are noted in the superficial sediments.

11

Holocene environmental changes recorded by diatom stratigraphy in the Vistula Lagoon

Witak M., Boryń K., Mayer A.

Oceanological and Hydrobiological Studies

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2005

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Vol. 34, No.2

111--133

EN

Four 6 m long sediment cores from the Vistula Lagoon were analyzed with respect to their content of diatoms. The aim was to detect changes of the composition of the diatom flora and to link these changes to Holocene climatic fluctuations and paleoecological stages of the Baltic Sea. The location of cores creates a good opportunity for reconstruction environmental changes both in the northern and southern part of the lagoon. Based on species composition of the diatom flora, distribution of salinity and habitat groups and stratigraphical information supported by 14C data and lithological analyses four diatom assemblage zones were distinguished in each core. The study shows that the area originally had a terrestrial environment, whereas its later evolution is linked with the marine stages of the Baltic Sea. The northern part of the lagoon originated due to input of marine waters through the Vistula Spit, which is indirectly connected with two Littorina transgressions. Next, probably in Late Atlantic-Early Subboreal period, the basin expanded southwards caused by intensification of marine water inflow during maximum Littorina transgressions. As a result the shallow, eutrophic, brackish water basin originated. In Subboreal period the basin became shallower and slightly brackish water. However, intensive Bauda river inflow caused locally decreasing of salinity. Moreover, symptoms of Post-Littorina transgression in Subatlantic chronozone were observed in the diatom record. Finally, the effects of eutrophication are recorded in subfossil diatom flora. Moreover, as a consequence of closing the Nogat river inflow, the stronger influence of marine waters from the Baltic Sea are observed in the lagoon.

12

Diatom record of northeast Atlantic circulation changes in marine isotope stages 1 and 5

Witak M., Kuijpers A.

Oceanological Studies

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2001

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Vol. 30, No. 1-2

21--36

EN

Fossil and subfossil diatom floras were analysed in a sediment core taken near the outlet of the Faroe Bank Channel, NE Atlantic. Diatom preservation horizons were found at various levels in the core. The correlation with the oxygen isotope stratigraphy of the core indicates that these horizons correspond to the Marine Oxygen Isotope Sub-Stages 5e (Eemian), 5a and Stage 1 (Holocene). Results of the study show that environmental conditions for the development of diatoms were more favourable in Stage 5 than in the Holocene. At the very beginning of the Sub-Stages 5e and 5a distinct changes in the diatom concentration are indicative of circulation changes probably associated with a marked intensification of the North Atlantic Current. The highest surface water temperature is indicated by the diatom flora from early Sub-Stage 5e.

13

A diatom record of late Holocene environmental changes in the Gulf of Gdańsk

Witak M.

Oceanological Studies

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2000

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Vol. 29, No. 2

57-74

EN

The aim of this study was to analyse fossil and subfossil diatom floras preserved in a sediment core taken from the Gulf of Gdansk, near the eastern end of the Hel Peninsula. The diatom record, supported by lithology and radiocarbon data, indicates environmental changes during the later stages of development of the Baltic Sea. In the Litorina Sea stage the diatom flora developed under marine conditions, whereas during the Post-Litorina stage there was a decrease in salinity. During the Subatlantic period the sublittoral diatom flora was replaced by shallow water diatoms originating from the coastal zone, and were redeposited in the deeper part of the basin. In the surface sediments the change to a presumably anthropogenically-influenced diatom flora can be attributed to the eutrophication of the Gulf of Gdańsk.