Wyniki wyszukiwania - BazTech

1

Relationships between the Baltic Sea ice extent and ice parameters in the sheltered basins of the southern Baltic coast

Girjatowicz Józef P., Świątek Małgorzata

Oceanological and Hydrobiological Studies

|

2020

|

Vol. 49, No. 3

291--303

EN

In the study, archive data on the maximum annual ice extent in the Baltic Sea (MIB) for the period 1961–2018 were used. They were obtained from the FIMR database. Data on ice parameters for the four largest southern Baltic coastal lakes: Jamno, Bukowo, Gardno and Łebsko, and for Szczecin, Puck, and Vistula Lagoons, come from the Maritime Branch of Institute of Meteorology and Water Management – National Research Institute (in Polish: Instytut Meteorologii i Gospodarki Wodnej – Panstwowy Instytut Badawczy, IMGW-PIB) in Gdynia. The time series for the lakes cover the years from 1960 to 2018, and for the lagoons – from 1946 to 2018. Three ice parameters were selected for this study: the number of days with ice, the duration of the ice season and the maximum ice thickness for a given winter. Relationships between the selected ice parameters for the studied basins and the MIB were examined using correlation and regression methods. Correlations between the MIB and values of the ice parameters for the lakes and the southern Baltic coastal lagoons do not differ significantly. Considerable differences are observed amongst the correlation coefficients for individual ice parameters and the MIB. Larger differences are found in relationships between the values of individual ice parameters in the sheltered basins and the MIB. The strongest correlation with the MIB is observed for the maximum ice thickness and the number of days with ice.

2

The impact of Klaipėda Port entrance channel dredging on the dynamics of coastal zone, Lithuania

Žilinskas Gintautas, Janušaitė Rasa, Jarmalavičius Darius, Pupienis Donatas

Oceanologia

|

2020

|

No. 62 (4PA)

489--500

EN

Dredging entrance channels to ports on open littoral drift seashores often causes major morphological changes to the shoreline. This study aims to assess the impact of dredging the Port of Klaipėda's entrance channel and the construction of the jetties on the coastal zone. Based on an analysis of cartographic material collected between 1835 and 2017, and on field data (bathymetric surveys and cross-shore profile levelling), changes to the coastal zone in the area nearest to the port were evaluated. The dominant longshore sediment transport on the Lithuanian nearshore runs from south to north. Thus, based on established patterns, intensive accretion could have been expected to take place on the southern side of the port jetties and erosion on their northern side. However, in the case of the Port of Klaipėda, in the area nearest to the port on the updrift side of the port jetties, where accretion would have been expected to take place, the nearshore depth increased throughout the 20th century (when the length and configuration of the jetties did not change). The shoreline shifted landward instead of moving further out to sea. The present study shows that the intensive dredging of the entrance channel caused nearshore and shore erosion on the updrift side of the port jetties, even while a sufficient sediment load was being transported by the longshore drift.

3

Crangon crangon : can hydroxyproline be an indicator of changes in the species?

Kąkol Agnieszka, Szaniawska Anna

Oceanological and Hydrobiological Studies

|

2019

|

Vol. 48, No. 2

116--124

EN

The hydroxyproline content in Crangon crangon tissues from the Gulf of Gdansk (southern Baltic) was determined in males, non-ovigerous females and ovigerous females, depending on the individual body length, the study area (two profiles: Gdynia and Sopot) and the depth of occurrence. Individuals were collected and analyzed from April to August 2008. The research on the migratory species C. crangon indicates that the area and depth of its occurrence do not significantly affect the level of hydroxyproline in the tissues of this animal (p > 0.05). However, certain trends have been observed. Hydroxyproline participates in various life processes of C. crangon and its level in the tissues is significantly correlated with the sex of animals (p < 0.05). In males, hydroxyproline plays a major role in the body growth. Moreover, water temperature significantly affects the hydroxyproline content in males of different body sizes. Ovigerous females use hydroxyproline in the reproductive process. In non-ovigerous females, hydroxyproline participates both in the growth of organisms and in the reproductive period. Hydroxyproline can be an indicator of the collagen level, as well as an important factor in physiological processes.

4

Canthaxanthin in recent sediments as an indicator of heterocystous cyanobacteria in coastal waters

Krajewska Magdalena, Szymczak-Żyła Małgorzata, Kobos Justyna, Witak Małgorzata, Kowalewska Grażyna

Oceanologia

|

2019

|

No. 61 (1)

78--88

EN

The mean share of heterocystous cyanobacteria in total chlorophyll-a production in coastal waters, based on cyanobacterial marker carotenoid and chloropigments preserved in recent sediments (0-5 cm, ca 30 years), has been studied in the Gulf of Gdańsk (southern Baltic) and for comparison in the Oslofjord/Drammensfjord (southern Norway). First of all, Baltic cyanobacteria, both from laboratory cultures and field samples, were analysed to select marker heterocysteous cyanobacteria carotenoids for sediments. The pigment relation to diatom percentages of different salinity preferences has been tested, to confirm origin of cyanobacteria. The results indicate that canthaxanthin is the best marker of heterocystous cyanobacteria in the southern Baltic Sea. These filamentous cyanobacteria inflow to the Gulf of Gdańsk from the open sea and their abundance has increased in the last thirty years, in comparison with previous time. In that period they made up ca 4.6% of the total chlorophyll-a production in the Gulf of Gdańsk. The estimate for Oslofjord, at the same assumptions, suggests that heterocystous cyanobacteria occurred there also (up to 5.8% of the total chlorophyll-a production), were of marine origin, but their abundance has decreased during the last thirty years. Such an estimate may be used in environmental modelling and can be applied to other coastal areas, once the marker pigments of the main cyanobacteria species have been identified, and the percentage of total chlorophyll-a produced in a basin, preserved in sediments, has been determined for such area.