Oceanologia No. 44 (4) / 02




Variability of coastal water hydrodynamics in the southern Baltic - hindcast modelling of an upwelling event along the Polish coast
Oceanologia 2002, 44(4), 395-418

Andrzej Jankowski
Institute of Oceanology, Polish Academy of Sciences, Powstańców Warszawy 55, PL-81-712 Sopot, Poland;

Keywords: Baltic Sea, coastal area, numerical modelling, upwelling

Manuscript received 15 October 2002, reviewed 14 November 2002, accepted 19 November 2002.
This paper presents the results of an attempt to reproduce, with the aid of a numerical circulation model, the hydrological conditions observed in the coastal area of the southern Baltic in September 1989. A large fall in surface layer seawater temperature was recorded in September 1989 at two coastal stations in the vicinity of Kolobrzeg and Wladyslawowo. This upwelling-like phenomenon was assumed to be related to the specific anemobaric situation in September 1989, however typical of this phenomenon to occur along the Polish Baltic coast (Malicki & Mietus 1994). A three-dimensional (3-D) sigma-coordinate baroclinic model of the Baltic Sea, with a horizontal resolution of ~5 km and 24 sigma-levels in the vertical, was applied to investigate water circulation and thermohaline variability. Hindcast numerical simulation showed that the model provided a good reproduction of the temporal history of the surface seawater temperature and the duration of the upwelling-like fall, but that the model results were underestimated. The maxima of this large fall in the surface layer temperature at both coastal stations are closely related to the phase of change of the upwelling-favourable wind direction to the opposite one. The results of simulation runs showed details of upwelling development due to wind field fluctuations in time and differences in shaping the temperature and current patterns in conjunction with the variations in topography and coastline features in some areas along the Polish coast. Two different hydrodynamic regimes of water movements along the coast resulting from topographical features (the Słupsk Bank) can be distinguished. From the model simulation the specific conditions for the occurrence and development of upwelling at the eastern end of the Polish coast (in the vicinity of Wladyslawowo) can be deduced.
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Pigment composition in relation to phytoplankton community structure and nutrient content in the Baltic Sea
Oceanologia 2002, 44(4), 419-437

Joanna Stoń, Alicja Kosakowska, Maria Łotocka
Institute of Oceanology, Polish Academy of Sciences, Powstańców Warszawy 55, PL-81-712 Sopot, Poland;

Elzbieta Łysiak-Pastuszak
Institute of Meteorology and Water Management, Maritime Branch, al. Waszyngtona 42, PL-81-342, Gdynia, Poland

Keywords: pigments, phytoplankton, HPLC, southern Baltic

Manuscript received 2 October 2002, reviewed 22 November 2002, accepted 3 December 2002.
The concentration of chlorophylls and carotenoids with respect to communities of characteristic phytoplankton species and hydrological parameters, such as temperature, salinity and nutrients were analysed. Samples from the southern Baltic were taken during three periods: spring 1999, autumn 1999 and 2000 during cruises of r/v 'Oceania' in this area. The seasonal differences between the phytoplankton species composition and pigmentation of samples (measured by HPLC) were noted. The total biomass of the spring phytoplankton population was 11-15 times greater than that of the autumn populations. However, the phytoplankton community was more diverse in the two autumns, whereas the spring population was almost mono-taxonomic: > 80% of the total biomass consisted of dinophytes. The total content of chlorophylls (a, b, c1 + c2) was about 20 times higher in spring. Moreover, in spring the concentrations of photosynthetic carotenoids (with dominant perdinin) were 2-4 times higher than those of the photoprotecting carotenoids (with dominant diadinoxanthin), whereas in the two autumns the situation was reversed: PPC concentrations (with dominant zeaxanthin and diadinoxanthin) exceeded those of PSC (with dominant fucoxanthin) by c. 3-10 times. Pigment markers have proved to be extremely useful biomarkers for elucidating the composition of phytoplankton populations in natural samples.
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Dependence of the photosynthesis quantum yield in oceans on environmental factors
Oceanologia 2002, 44(4), 439-459

Bogdan Woźniak1, 2, Jerzy Dera1, Dariusz Ficek2, Mirosława Ostrowska1, Roman Majchrowski2
1 Institute of Oceanology, Polish Academy of Sciences, Powstańców Warszawy 55, PL-81-712 Sopot, Poland;
2 Pomeranian Pedagogical University, Arciszewskiego 22b, PL-76-200 Słupsk, Poland

Keywords: quantum yield of photosynthesis, bio-optical modelling, primary production, environmental factors

Manuscript received 19 September 2002, reviewed 21 October 2002, accepted 30 October 2002.
Statistical relationships between the quantum yield of photosynthesis and selected environmental factors in the ocean have been studied. The underwater irradiance, nutrient content, water temperature and water trophicity (i.e. the surface concentration of chlorophyll Ca(0)) have been considered, utilizing a large empirical data base. On the basis of these relationships, a mathematical model of the quantum yield was worked out in which the quantum yield Phi is expressed as a product of the theoretical maximum quantum yield PhiMAX = 0.125 atom C quanta -1 and six dimensionless factors. Each of these factors fi appears to be, to a sufficiently good approximation, dependent on one or two environmental factors and optical depth at most. The model makes it possible to determine the quantum yield from known values of these environmental factors. Empirical verification of the model yielded a positive result - the statistical error of the approximate values of the quantum yield Phi is 42%.
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Adenosine triphosphate in the marine boundary layer in the southern Baltic Sea
Oceanologia 2002, 44(4), 461-473

Dorota Pryputniewicz, Lucyna Falkowska, Dorota Burska
Institute of Oceanology, Polish Academy of Sciences, Powstańców Warszawy 55, PL-81-712 Sopot, Poland;

Keywords: ATP, microlayer, vertical distribution, spring

Manuscript received 30 July 2002, reviewed 4 October 2002, accepted 16 October 2002.
Changes in adenosine triphosphate (ATP) concentration were measured in the offshore and coastal waters of the Gdańsk Basin in spring. As regards the vertical distribution, it was found that high ATP concentrations occurred mainly in the euphotic layer (above the thermocline) and near the bottom (below the halocline). The high concentrations of ATP in the euphotic layer resulted from primary and secondary production, while the other maximum was due to the presence of bacteria actively degrading organic matter. Changes in ATP concentration in the euphotic layer were closely correlated with the phase of the day. An increase in ATP concentrations in the surface microlayer was observed in the evening and at night, probably as a result of heterotroph proliferation. During daylight, ATP production was inhibited by increasing radiation, hence its concentrations in the sea surface microlayer were considerably lower. Strong winds exerted a significant influence on ATP concentrations in the surface microlayer and in the subsurface water. Windstress depressed ATP concentrations. The biomass of living microorganisms in the microlayer was comparable with the microbiomass beneath the halocline.
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Reproductive cycle and the related spatial and temporal distribution of the ninespine stickleback (Pungitius pungitius L.) in Puck Bay
Oceanologia 2002, 44(4), 475-490

Ewa Sokołowska
Institute of Oceanology, Polish Academy of Sciences, Powstańców Warszawy 55, PL-81-712 Sopot, Poland;

Krzysztof E. Skóra
Marine Station, Institute of Oceanography, University of Gdańsk, Morska 2, PL-84-150 Hel, Poland; oceks@univ.gda.pl

Keywords: ninespine stickleback, breeding period, spawning, stages of maturity, Puck Bay

Manuscript received 3 July 2002, reviewed 23 October 2002, accepted 28 October 2002.
The cycle of gonad development and related changes in the length structure and spatial-temporal distribution of ninespine sticklebacks (Pungitius pungitius L.) in Puck Bay were studied. Observations were carried out in the shallow shore zones, as well as in the deeper epipelagic zone of the Bay. Ninespine sticklebacks reproduce in the brackish environment of Puck Bay, breeding in its warmer, inshore zones. Reproduction takes place in the spring and summer months, from April to July. One female spawns several clutches of eggs during one breeding season. The average length of ninespine sticklebacks in Puck Bay was about 40 mm, and the sex ratio in the population was close to 1:1. However, both length structure and sex ratio were subject to local and periodic variations, resulting from possible breeding-related territorial divisions. Higher gonadosomatic indices in females in early spring represented the transition of fish to the advanced vitelligenous phase. The lowest GSI of males during the breeding season indicated the termination of spermatogenesis. The completion of spawning in August started a new process of gonad restoration to prepare the fish for the next breeding season.
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Spatio-temporal decay 'hot spots' of stranded wrack in a Baltic sandy coastal system. Part I. Comparative study of the pattern: 1 type of wrack vs 3 beach sites
Oceanologia 2002, 44(4), 491-512

Marcin F. Jędrzejczak*
Department of Environmental Chemistry and Ecotoxicology, Faculty of Chemistry, University of Gdańsk, Jana III Sobieskiego 18/19, PL-80-952 Gdańsk, Poland;
*current address: Dipartimento di Biologia Animale e Genetica 'Leo Pardi', Universita degli Studi di Firenze, Via Romana 17, I-50125 Firenze, Italia

Keywords: sandy beach, decomposition, Zostera marina, hot spots, spatio-temporal variations

Manuscript received 1 July 2002, reviewed 4 September 2002, accepted 1 October 2002.
The significance of distance along the beach-dune transect and different moisture conditions as regards the decay of Zostera marina leaf litter was investigated in simple field experiments in three temperate, medium- to fine-quartz-sediment, sandy beaches of the Gulf of Gdańsk in Poland. 1800 replicate litterbags of freshly stranded Zostera marina leaves were placed in beach sediments at different strata and levels on each of the beaches. The litterbags were sampled after 5, 10, 50, 100 and 150 days in the field and the remaining material was then dried and weighed. Under similar conditions of sediment composition, salinity and wave inundation, ANOVA tests revealed significant differences in breakdown through time and site. Thus there were some differences in the decay process between the low and high beach. In the former, degradation proceeded rapidly in the initial stages and then stabilised, while in the latter it remained linear throughout the study period. Matter loss in each stratum was also seasonally dependent. This may, however, be more closely linked to successional changes in the chemistry and/or microflora of the beach wrack than to its physical breakdown. Differences between organic matter degradation in the high and low beaches may be explained by differences in the moisture regime and nutrient status, and not by differences in the decay processes themselves. Therefore, two decay centres were found in the beach-dune system: the low beach together with the strandline (wrack consumption 12-21% day-1 in the warm season, and 4-10% day-1 in the cold season) and the dune (active consumption 2-6% day-1 in the warm season only).
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The contribution of the fine sediment fraction to the Fluffy Layer Suspended Matter (FLSM)
Oceanologia 2002, 44(4), 513-527

Janusz Pempkowiak1, Jacek Bełdowski1, Ksenia Pazdro1, Andrzej Staniszewski1, Thomas Leipe2, Kay-Christian Emeis2
1Institute of Oceanology, Polish Academy of Sciences, Powstańców Warszawy 55, PL-81-712 Sopot, Poland;
2Baltic Sea Research Institute, Seestrasse 15, 18119 Rostock-Warnemunde, Germany

Keywords: Lead 210, Polonium 210, isotopic disequilibria, Pomeranian Bay, Baltic Sea

Manuscript received 10 October 2002, reviewed 13 November 2002, accepted 18 November 2002.
Fluffy Layer Suspended Matter (FLSM) is a layer of fairly concentrated suspended matter resting on the sea floor. Its passage to the depositional basins in the Pomeranian Bay - Arkona Deep System of the Baltic Sea is estimated to take around six months. In the course of this migration, the properties of FLSM change as a result of ageing and the influx of fresh particles from the water column, and possibly also because of mass exchange with the uppermost sediment layers. Measurements of radioisotopes (210Po, 210Pb, 137Cs) have demonstrated that in shallow water this topmost layer of sediments, from 8 cm to 3 cm in thickness, is subject to mixing. This creates redox profiles favourable to biota and bioturbation.
Basing on 210Pb/210Po disequilibria and the 210Po excess, it was estimated that under steady state conditions from 1.5 to 2.2% of fine fraction (FSF) in the mixed layer of sediments is freshly imported from FLSM. This implies replacement of FSF from the sediments and its incorporation into FLSM. On the assumption that the surface density of FLSM is 10 mg cm-2, FSF freshly exported from sediments actually comprises up to 15% of FLSM. Therefore, the properties of FLSM are strongly influenced by the processes taking place in the sediments, although FLSM by definition is independent of sediments.
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