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1

Characteristics of seasonal changes of the Baltic Sea extreme sea levels

Wolski Tomasz, Wiśniewski Bernard

Oceanologia

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2023

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Vol. 65 (1)

151--170

EN

This work analyses the monthly spatial distribution of extreme sea levels in the Baltic Sea as well as the relationship of these levels with the NAO and AO indicators. The research was based on hourly sea level data from the 45 tide gauge stations gathered in the years 1960 to 2020. The analysis shows that the duration of extreme sea levels tends to increase moving from along the line joining the open sea and the gulf end. This is associated with the narrowing of the gulf and the geomorphological and bathymetric configuration of the coastal zone. The duration of high and low sea levels in the Baltic Sea decreases from a maximum in January to a minimum in the months of May to August, then it increases again until the end of the year. This cycle corresponds well to the annual occurrence of storm surges, which are affected by the annual changes in atmospheric circulation. The impact of the variations of the circulation on extreme sea levels was confirmed by examining the relation between maximum, minimum and mean levels of the Baltic waters and the zone circulation indices NAO and AO for each month of the year and the seasons in the multiyear period 1960–2020. The results indicate that the strongest correlations exist between sea levels and NAO/AO in the winter months. There is a spatial differentiation of the correlation and its increase from the southwest to the northeast in Baltic Sea.

2

Determination and evaluation of seasonal changes of DBPs after chlorination in networks using underground water. Muş, Turkey case

Avşar Edip, Sönmez Mücahit, Kiliç Adile

Environment Protection Engineering

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2022

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Vol. 48, nr 4

5--19

EN

This study aimed to determine the seasonal change of the concentrations of trihalomethanes (THMs) and one of the newly emerging byproducts haloacetonitriles (HANs), the most abundant group of some disinfection by-products (DBPs) forming as a result of chlorination of drinking water supplied from 2 different reservoirs to the city centre of Muş for disinfection purposes and called chlorinated organic halogens. The quantitative determination of these compounds, some of which may have carcinogenic properties, and the evaluation of their possible effects on public health constitute the importance of the study. The results show that although there is not sufficient chlorination in both water networks and total organic carbon (TOC) values are low in underground water, the total THMs some-times exceed the 100 μg/dm3 value applied in Turkey and pose a risk. It was observed that the total HAN values remain below the 2 μg/dm3 concentration in both networks.

3

Seasonal Changes in Nitrogen, Phosphorus, BOD and COD Removal in Bystre Wastewater Treatment Plant

Skoczko I., Struk-Sokołowska J., Ofman P.

Journal of Ecological Engineering

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2017

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Vol. 18, nr 4

185--191

EN

The aim of this study was to determinate seasonal changes in industrial wastewater treatment effectiveness. Studies were carried out in mechanical-biological wastewater treatment plant in Bystre near Giżycko to which inflows mixture of domestic and dairy wastewater. Laboratory studies were carried out by Water and Wastewater Company in Giżycko. For statistical analysis results form years 2014 and 2015 were considered. The scope of statistical analysis includes basic statistical measures including arithmetic mean, median, minimum, maximum and standard deviation. Changes in seasonal treatment effectiveness were shown by Fisher-Snedecore LSD test. Seasonal changes were observed for BOD, COD and total nitrogen removal effectiveness. Total phosphorus was not subjected to that kind of changes.

4

Warunki meteorologiczne na Równinie Kaffiøyra (NW Spitsbergen) w sezonach letnich w okresie 2012-2014

Przybylak R., Ulandowska-Monarcha P., Araźny A.

Przegląd Geofizyczny

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2016

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Z. 1-2

73--92

PL

W artykule przedstawiono charakterystykę warunków meteorologicznych w północnej części Kaffiøyry (NW Spitsbergen, rys. 1) w sezonach letnich (21 VII – 31 VIII) w okresie 2012-2014 (tab. 1, rys. 2-9). Pomiary i obserwacje meteorologiczne prowadzono w ogródku meteorologicznym zlokalizowanym w pobliżu stacji polarnej UMK na morenie czołowo-bocznej Lodowca Aavatsmarka (φ=78°4’N, λ=11°51’E, h=11,5 m n.p.m.). Wykonywano je 4 razy na dobę, w terminach 00, 06, 12, 18 UTC (01, 07, 13, 19 LMT). W artykule uzyskane wyniki porównano z wieloletnimi wartościami większości elementów meteorologicznych obliczonymi z kilkudziesięciu sezonów letnich, w których zorganizowano Toruńskie Wyprawy Polarne w okresie 1975-2014 (tab. 1). W sezonach letnich 2012-2014 stwierdzono większą prędkość wiatru (5,3 m·s-1 w stosunku do 4,6 m·s-1 w wieloleciu 1975-2014). Przyczyniła się do tego przede wszystkim zwiększona jego prędkość w sezonie letnim 2012 r. (6,1 m·s-1). Świadczy to o wzroście działalności cyklonalnej na obszarze Spitsbergenu. Oprócz wiatru znaczącym zmianom podległy także wszystkie parametry temperatury powietrza (tab. 1). W największym stopniu wzrosła temperatura maksymalna (o 0,8 oC), a w najmniejszym minimalna (tylko o 0.4 oC). Warto też odnotować znaczny wzrost średniej dobowej amplitudy temperatury powietrza, o 0,5 oC. Ociepleniu klimatu w rejonie Kaffiøyry towarzyszy także znaczny wzrost opadów, który w latach 2012-2014 wyniósł nieznacznie powyżej 150% ich wielkości z lat 1975-2014. (tab. 1). Pozostałe elementy wymawiane w artykule nie wykazały większych zmian w porównaniu do danych wieloletnich.

EN

This article provides the characteristics of meteorological conditions in the north of Kaffiøyra (NW Spitsbergen, Fig. 1) in the summer seasons (21 July – 31 August) of 2012-2014 (Table 1, Figs 2-9). The observations and measurements were carried out at a meteorological site located near the NCU Polar Station on the terminal-lateral moraine of the Aavatsmark Glacier (φ=78°4’N, λ=11°51’E, h=11.5 m a.s.l.). The measurements were taken four times per day at 00:00, 06:00, 12:00 and 18:00 UTC (01:00, 07:00, 13:00 and 19:00 LMT). In this article, the obtained results are compared with multi-annual values of most meteorological elements obtained from a few dozen summer seasons, during which Toruń Polar Expeditions were organised in the years 1975-2014 (Table 1). In the summer seasons of 2012-2014, the observed wind speed was greater than in the years 1975-2014 (5.3 m· s-1 vs. 4.6 m·s-1, respectively). This was mainly due to its increased speed in the summer of 2012 (6.1 m·s-1) and it is also an indication of intensified cyclonic activity in the area of Spitsbergen at the time. Besides the wind, all other parameters of air temperature were also subject to considerable changes (Table 1). The maximum temperature of air increased the most (by 0.8 oC), whereas the change in minimum temperature was the smallest (only by 0.4 oC). A substantial increase in the mean diurnal amplitude of air temperature by 0.5 oC is also noteworthy. The warming of the climate of Kaffiøyra is accompanied by greater precipitation, which in the years 2012-2014 slightly exceeded 150% of its respective amount for 1975-2014 (Table 1). The other meteorological elements analysed in this article do not show any major changes as compared with the long-term data.

5

Effect of Vegetation Period on the Quantitative Relations Between Nutritive Components in the Leaves of Anthurium (Anthurium cultorum Birdsey)

Kleiber T., Komosa A.

Ecological Chemistry and Engineering. A

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2011

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Vol. 18, nr 1

43-50

EN

The main objective of studies was the determination of the quantitadve relations between macro-and microelements in the leaves of amhurium (Anthurium cullonim Birdsey) cultivars: 'Baron', 'Choco', 'Midori', 'Pistache', 'President'. 'Tropical' (Anthura B.V., the Netherlands) in the spring-summer and autumn-winter periods. Plants were grown in expanded clay using drip fertigation with standard nutrient (in l dm'): < 14.0 mg NH4-N, 105.0 mg NO3-N, 31.0 mg P, 176.0 mg K, 60.0 mg Ca, 24.0 mg Mg, 48.0 mg SO4-S, 0.840 mg Fe, 0.160 mg Mn, 0.200 mg Zn, 0.220 mg B, 0.032 mg Cu and 0.048 mg Mo, with pH 5.5-5.7 and EC 1.5-1.8 mg o cm-1. Significant differences were found in the quantitative amounts between some nutritiye components in leaves, The leaves were fully developed, sampled from plants after freshly cut flowers. The mean N : K ratio from the last 3 years of studies in the spring-summer period was 1.0 : 2.7 and in the period of light deficit (autumn-winter period), it decreased to l.0 : 2.4. In the same period, the relation Fe : Mn equaled 1.0: 1.6 and with the improvement of light conditions (spring-summer period), it increased to 1.0 : 2.2. In the majority of the studied cultivars, there were significant changes in the Fe : Zn relation in autumn-winter and spring-summer periods. The awareness of changes in the qualitative relation between macro- and microelements is the basis for the modification of nutritive components in nutrients used for fertigation, depending on the vegetation period and protecting the environment against excessive quantities of used fertilizers.

PL

Głównym celem badań było określenie relacji ilościowych między makro- i mikroelementami w liściach anturium (Anthurium cultonim Birdsey) odmian: 'Baron'. 'Choco', 'Midori', 'Pistache', 'President', 'Tropical' (Anthura B.Y., The Netherlands) w okresie wiosenno-letnim i jesienno-zimowym. Rośliny uprawiano w keramzycie z zastosowaniem fertygacji kroplowej pożywka standardowa, zawierającą f w 1 dm3): < 14,0 mg N-NH4, 105,0 mg N-N03, 31,0 mg P, 176,0 mg K, 60,0 mg Ca, 24,0 mg Mg, 48,0 mg S-SO4, 0,840 mg Fe, 0,160 mg Mn, 0,200 mg Zn, 0,220 mg B, 0,032 mg Cu oraz 0,048 mg Mo, o pH 5,5-5,7 i EC 1,5-1,8 mS o cm-1. Stwierdzono istotne zmiany w relacjach ilościowych między niektórymi składnikami pokarmowymi w organa wskaźnikowych, którymi były w pełni wyrośnięte liście, pobrane z roślin po świeżo ściętym kwiecie. Średni z 3 lat badań stosunek N : K w okresie wiosenno-letnim wynosił 1,0 : 2,7, a w okresie deficytu światła (okres jesienno-zimowy) malał do 1.0 : 2.4. W tym samym okresie stosunek Fe : Mn wynosił 1,0 : 1,6. a wraz z poprawą warunków świetlnych (okres wiosenno-letni) wzrastał do 1,0 : 2,2. W większości badanych odmian zaznaczyły się istotne zmiany stosunku Fe : Zn w okresie jesienno-zimowym i wiosenno-letnim. Znajomość zmian stosunków ilościowych między makro- i mikroelementami stanowi podstawę do modyfikacji zawartości składników pokarmowych w pożywkach stosowanych do fertygacji w zależności od okresu wegetacji, chroniąc środowisko przed nadmiernym stosowaniem nawozów.

6

Wstępna analiza wyników polowych badań zróżnicowania obszarowego i sezonowych zmian zawartości azotanów w pierwszym poziomie wodonośnym

Czebreszuk J., Ćwiertniewska Z., Nidental M.

Biuletyn Państwowego Instytutu Geologicznego

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2011

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nr 445 Hydrogeologia z. 12/1

59--66

PL

Od 2006 r. w Państwowym Instytucie Geologicznym – Państwowym Instytucie Badawczym prowadzone są prace dotyczące opracowania warstw informacyjnych bazy danych GIS MhP 1:50 000 „pierwszy poziom wodonośny – wrażliwość na zanieczyszczenie i jakość wód” (PPW-WJ). Analiza wyników badań terenowych wskazała na problematykę obszarowej i sezonowej interpretacji zawartości azotanów w wodach PPW. Zaprezentowano wstępną ocenę wyników badań polowych I i II transzy PPW-WJ, w celu przedstawienia ogólnego stanu zanieczyszczenia wód oraz możliwości ich obszarowej interpretacji. Badania wód przeprowadzono w punktach dokumentacyjnych ujmujących pierwszy poziom wodonośny. Zestawienie wyników pozwoliło na wstępne wskazanie rejonów o wysokiej zawartości w wodach PPW i widocznej sezonowej zmienności. W celu potwierdzenia uzyskanych wyników należałoby przeprowadzić bardziej ukierunkowane badania przez znacznie dłuższy okres czasu.

EN

Since 2006 the Polish Geological Institute – National Research Institute has been conducting works on GIS HMP 1:50 000 information layers of “first aquifer – vulnerability and quality” (FA–VQ). The analysis of the field data indicated the problems of areal and seasonal interpretations of the concentration of nitrates in the FA. This article present the preliminary analysis of from stages I and II of the FA–VQ and associated tasks, which was aimed at the assessment of water pollution with and the possibility of its spatial interpretations. The water investigation was conducted in the First Aquifer’s documentation points. The summary of results allowed for a preliminary indication of the regions with high contents of in the FA and apparent seasonal changes. In order to confirm the results, it is necessary to carry out a more targeted research for a much longer period of time.

7

Heavy Metals in Surface Microlayer in Water of Lake Gardno

Trojanowski J., Antonowicz J.

Archives of Environmental Protection

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2011

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Vol. 37, no. 1

75-88

EN

In the present paper we show results of our research on the contents of selected heavy metals in the surface and subsurface water layers of the estuarine lake Gardno. Obtained results show that there are substantial differences between concentrations of lead, copper and zinc in surface microlayer and subsurface waters. We observed that the surface microlayer is capable of accumulating much higher amounts of these metals than the subsurface waters. Analysis of seasonal changes in heavy metal concentrations in surface microlayers and subsurface waters shows some periodicity of these changes.

PL

W prezentowanej pracy są przedstawione wyniki analizy stężenia metali ciężkich w powierzchniowej i podpowierzchniowej warstwie wody estuariowego jeziora Gardno. Uzyskane wyniki wskazują, że są znaczące różnice między stężeniem ołowiu, miedzi i cynku w mikrowarstwie powierzchniowej wody a ich stężeniem w warstwie wody podpowierzchniowej. Zaobserwowano, że mikrowarstwa powierzchniowa ma zdolność do akumulowania znacznie wyższych ilości tych metali niż woda podpowierzchniowa. Analiza zmian sezonowych fluktuacji koncentracji metali ciężkich w mikrowarstwie powierzchniowej i podpowierzchniowej wody wskazuje na periodyczny charakter tych zmian.

8

Influence of year season and room type on indoor 222Rn activity

Dołhańczuk-Śródka A., Ziembik Z., Majcherczyk T., Wacławek M.

Proceedings of ECOpole

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2010

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Vol. 4, No. 2

249--252

EN

In this work the monitoring of 222Rn was carried out in selected houses, located in the district of Krapkowice (it lies to the south of Opole, PL). The passive detectors LR-115 type II films (Kodak, Pathe) have been used in this survey. The measurements were carried out in single-storied residential houses in two time periods: from the end of June to the end of September and from the beginning of November to the beginning of February. The detectors were placed in kitchens, bathrooms and cellars. Our results showed that in all of the rooms examined the Rn activity did not exceed 149 kBq/m3. This value is lower than the European Commission recommendations for existing buildings (Commission recommendation 2001/928/Euratom). Considering all of room types investigated, no statistically significant differences between 222Rn activities in summer and in winter were asserted. But in cellars higher than in other rooms 222Rn activities were confirmed, independently on the season of year. In most of the houses activities of 222Rn were similar, though in two of them they were significantly higher than in the others.

PL

Przedstawiono wyniki badań aktywności 222Rn przeprowadzonych w wybranych budynkach znajdujących się na terenie powiatu krapkowickiego (na południe od Opola, PL). W badaniach wykorzystano pasywne detektory typu LR-115 (Kodak, Pathe). Pomiary przeprowadzono w jednorodzinnych domach mieszkalnych w dwóch okresach: od końca czerwca do końca września i od początku listopada do początku lutego. Detektory zostały umieszczone w kuchniach, łazienkach i piwnicach. Otrzymane wyniki wskazują, że w żadnym z pomieszczeń aktywność 222Rn nie przekroczyła 149 kBq/m3. Wartość ta jest niższa od zalecanej przez Komisję Europejską dla budynków istniejących (zalecenie Komisji 2001/928/Euratom). Biorąc pod uwagę wszystkie rodzaje badanych pomieszczeń, nie stwierdzono statystycznie istotnych różnic między aktywnością 222Rn w okresie letnim i zimowym. W piwnicach stwierdzono wyższą niż w innych pomieszczeniach aktywność 222Rn, niezależnie od pory roku. W większości domów aktywności 222Rn były podobne, choć w dwóch z nich były one znacząco większe niż w pozostałych.

9

Surface microlayer in eutrophic lake : variablity in heavy metals contents

Antonowicz J., Trojanowski J.

Polish Journal of Ecology

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2010

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Vol. 58, nr 4

671-680

EN

The surface microlayer is a thin layer found at the contact zone of two environments forming an ecotone at the atmosphere-hydrosphere interface. It is the boundary layer of extreme importance for both environments. In the years 2000-2004 surface water microlayer of an eutrophic, deep lake (577 ha, max. depth 32.2 m, Lake Jasień in Northern Poland) was analyzed (in four seasons each year) in terms of their capacity to accumulate lead, cadmium and manganese. The following surface water layers were collected using the different devices (plate method, net method) and compared: a microlayer of approx. 100 [mu]m in thickness (SM), a microlayer of approx. 240 [mu]m in thickness (PM) and subsurface water (about 20 cm below surface) (SSW). The highest concentrations of analyzed metals were observed in the microlayer of 100 [mu]m, characterized by enrichment factor (EF-ratio of surface to subsurface values) of 2.61 for cadmium, 2.55 for manganese and 1.57 for lead, respectively. Enrichment factors for these metals are much higher than in respective microlayers of brackish lake situated close and studied before. Seasonal changes in concentrations of analyzed elements were correlated with changes in their concentrations in subsurface water. Statistical analysis of results showed that during a year variation in Cd and Mn accumulation in analyzed layers was significant. In contrast, variation in Pb accumulation was statistically non-significant. It means that in the surface microlayer of lake water a seasonal cycle is observed for changes in heavy metal concentrations and this variability in concentrations of analyzed substances is not accidental, but definitely periodical in character. The accumulation of analyzed heavy metals in the surface microlayers of the studied deep eutrophic lake seems to be a regular phenomenon.

10

Accumulation capacity of cadmium and manganese in surface water microlayer of esutarine lake

Antonowicz J., Trojanowski J.

Ecological Chemistry and Engineering. S

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2010

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Vol. 17, nr 4

497-503

EN

In order to investigate the effect of salinity level on the concentration of cadmium and manganese in the surface microlayer, several samples were collected from an estuarine lake Gardno in a quarterly cycle over the period of four years. Three testing stations were established in locations typical of this lake. In the estuarine lake Gardno, one can distinguish three areas with various levels of salinity, with a sampling site for each of these areas. The volume of water taken as samples varied, depending on the techniques used. During the experiment, surface microlayer samples of ca 0.1 and 0.25 mm were obtained. The subsurface water was obtained at the depth of 15 cm. The collected samples were analysed with an atomic absorption spectrometer in order to determine the concentration of cadmium and manganese. Cadmium accumulation in microlayers of surface waters in Lake Gardno was dependent on the concentration of this metal in the deep waters and varied with water salinity. In turn, counts of heterotrophic bacteria had a significant effect on the concentration of manganese. Concentrations of both metals in analyzed surface water microlayers were higher than in the subsurface layer.

PL

Badając wpływ zasolenia na koncentrację kadmu i manganu w mikrowarstwie powierzchniowej wody, próbki tej mikrowarstwy pobierano z estuariowego jeziora Gardno w cyklu kwartalnym przez okres 4 lat. Na jeziorze usytuowano trzy stanowiska badawcze w jego reprezentatywnych punktach. Jezioro Gardno jest zbiornikiem estuariowym i można w nim wyróżnić trzy zasadnicze strefy o różnym zasoleniu. W zależności od stosowanej techniki pobierania próbek wody zbierano mikrowarstwę powierzchniową wody o grubości około 0,1 mm i około 0,25 mm. Wodę podpowierzchniową pobierano na głębokości 15 cm od lustra wody. W pozyskanych próbkach wyznaczono stężenie kadmu i manganu metodami spektrometrii atomowej. Kumulacja kadmu w mikowarstwach powierzchniowej wody jeziora Gardno była zależna od stężenia tego metalu w toni wodnej i zmieniała się wraz z zasoleniem wody. Natomiast na koncentrację manganu duży wpływ miała liczebność bakterii heterotroficznych. Stężenia obydwu metali w badanych mikrowarstwach powierzchniowych wody były większe niż w warstwie podpowierzchniowej.

11

Psammon ciliates : diversity and abundance in hygroarenal of eutrophic lake

Kalinowska K.

Polish Journal of Ecology

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2008

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Vol. 56, nr 2

259-271

EN

Taxonomic composition, spatial distribution and seasonal changes in abundance of ciliates were investigated in hygroarenal (the zone of the beach adjacent to lake littoral and affected by wave action) of the eutrophic Lake Mikołajskie (area 498 ha, max. depth 26 m, Masurian Lake District, Poland). The choosen beach amounted 10.8 x 1.5 m in size and 30 sampling points were distributed according to regular network 60 x 30 cm. Three sampling points were located in each of 10 sampling stations parallel to water line and at an increasing 0, 30, 60 cm distance from it). The small-scale distribution of ciliates was recognized from the set of 30 samples taken once in June 2003 from all stations and sampling points. The seasonal changes of ciliate density were analysed on the set of 41 samples taken from March to November 2004 from the middle sampling points (about 30 cm from water line) in 3 sampling stations. Ciliate community was characterised by relatively high taxonomic richness (56 ciliate taxa) and numbers (up to 2750 ind. cm[^-3] of sand). The numbers of ciliates varied seasonally from 4.6 to 1630 ind. per 1 cm[^3] of sand, showed three distinct peaks (maximum in summer) and were markedly differentiated among the sampling stations distributed along the 10 m of homogenous beach. Significant correlations between ciliates and the share of largest grain size fraction suggest that grain size of sand may be responsible for the observed spatial heterogeneity of ciliates. Hymenostomes, particularly the omnivorous Pleuronema coronatum Kent, dominated the ciliate assemblages. The statistical analysis showed a significant correlation between ciliate numbers and total phosphorus and total nitrogen concentrations in interstitial water, but there was no correlation with chlorophyll a.

12

Seasonal changeability of indoor radon concentrations in one-family house

Karpińska M., Mnich Z., Kapała J., Antonowicz K.

Nukleonika

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2004

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Vol. 49, nr 1

33--36

EN

Indoor radon concentration undergoes 24-hour and seasonal changes. The paper presents first in Poland results of radon concentration changeability in one building during the whole year. We performed 103 measurements of indoor radon concentrations. The following parameters of radon concentration distribution were obtained: arithmetic mean - 224.1 Bq m 3, geometric mean - 194.5 Bq m 3, median - 207 Bq m 3, and geometric standard deviation - 1.84. The minimum observed value was 22 Bq m 3 and the maximum - 748 Bq m 3. We determined the monthly and annual values of radon concentrations. The values for particular months are in the range of 0.5 to 1.6 of the annual mean. We observed a correlation between the mean radon concentrations in the examined buildings and the differences in the mean values of indoor (R = 0.91, p < 0.05) and outdoor temperatures (R = 0.91, p < 0.05). There was also a connection between the radon concentration inside the buildings and the changes in atmospheric pressure.

13

Upper Vistula River : response of aquatic communities to pollution and impoundment. 10, Oligochaete taxocens

Dumnicka E.

Polish Journal of Ecology

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2002

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Vol. 50, nr 2

237-247

EN

The studies were carried out on 9 sites situated between 10 and 337 km of the river course to asses which parameters are the most important for the composition and density of oligochaete taxocens. 42 species and 4 genera of oligochaetes were found. Considering number of species (24) and number of specimens Naididae were the most numerous, Tubificidae were less frequent (12 species), other families were represented by a few taxa. In the studied sector of the Vistula the natural taxocens of oligochaetes did not exist. Various reasons were responsible for these modifications: eutrophication (sites 2, 3), strong pollution (from site 5 downstream) and hydrotechnical structures (sites 1, 4, 6). The natural changes of oligochaetes density connected with their life cycles were modified by the effects of flood and water pollution.

14

Seasonal and daily distribution of commercial and non-commercial fish in shallow inshore waters of the Gulf of Gdańsk

Lizińska A.

Oceanological Studies

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2002

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Vol. 31, No. 1-2

31-42

EN

Seasonal and daily changes in the fish community and variations between commercial and non-commercial fish abundance were monitored in the inshore waters of the western part of the Gulf of Gdask (the Sopot territory). Samples were collected from December 1998 to December 1999, though monthly samplings, and supplemented by 24-hour investigations taken every three months, using a two-meter wide trawl. Among the 16 species collected, 5 were commercial and 11 were non-commercial. Juvenile forms of herring and flounder dominated the commercial fish; the highest catches were in March (89 ind. 100 m-2). Among the non-commercial fish, two species of Gobiidae (sand and common goby), and three-spine stickleback were most frequently caught. During the 24hour observations, commercial fish were noticed mostly at night. The investigated area is an important zone for both juvenile commercial fish and some ecologically important uncomercial species.

15

Temporal variations in phosphorus species in the surface layer of bottom sediments from the Gulf of Gdańsk - preliminary research

Graca B., Bolałek J.

Oceanological Studies

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2000

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Vol. 29, No. 4

55-66

EN

Temporal variations in phosphorus species [total phosphorus (Ptot), organic phosphorus (Porg), total inorganic phosphorus (Pmin), phosphorus bound to calcium (PCa), aluminium (PAl) and iron (PFe)] were studied in the surface layer of bottom sediments from the Gulf of Gdańsk. These changes were caused mainly by variability in Porg, PAl and PFe concentrations and were closely related to the growth cycle in the basin. The phosphorus concentration was higher in the spring and summer (April - September) that in the autumn and winter (November-March). For much of the year concentrations of Pmin were higher than those of organic phosphorus. The prevalent form of inorganic phosphorus was PCa, whose concentrations exceeded those of iron- and aluminium-bound phosphorus.

16

Macrozoobenthos of the sandy littoral zone in the military area between Hel and Jurata

Kotwicki L., Włodarska-Kowalczuk M., Wieczorek P.

Oceanological Studies

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1999

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Vol. 28, No. 3-4

97-107

EN

The aim of the study was to determine the distribution, composition and seasonal variability of macrozoobenthos in the sandy littoral zone of the military area between Hel and Jurata. The results of qualitative and quantitative investigations of the benthic fauna are presented. The material was collected monthly from November 1991 till November 1992 at 10 stations situated in the sandy littoral zone (0.5-1 m depth) on the Puck Bay shore of the Hel Peninsula. A total of 17 macrofaunal taxa were identified. At each station 2 or 3 subsamples were collected with a 225 cm2 Petersen grab. The average abundance and wet weight of particular taxa were calculated. Bathyporeia pilosa, Hediste diversicolor and Oligochaeta were most frequent taxa in the study area. Polychaeta and Bivalvia constituted up to 93% of the bottom fauna biomass, Hediste diversicolor was the dominant species.

17

Seasonal changes in selected optical parameters in the Pomeranian Bay in 1996-1997

Kowalczuk P., Sagan S., Olszewski J., Darecki M., Hapter R.

Oceanologia

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1999

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No. 41 (3)

309-334

EN

The main task of the Joint Polish-German Pomeranian Bay Project was to achieve a better understanding of the impact of freshwater discharge on this environment. The freshwater from the River Odra enters the Pomeranian Bay through four outlets. The most important of these is the River Swina, as it carries the largest volume of water exchange between the bay and the Szczecin Lagoon. This freshwater carries a large load of optically active substances: dissolved organic materials, mineral and organic sediments, as well as nutrients, which boost phytoplankton growth. The effect of riverine discharge can be traced with the use of optical methods. The elevated level of optically active components can significantly reduce the light required for photosynthesis. The Institute of Oceanology carried out a survey of selected inherent and apparent optical properties in the Pomeranian Bay in three seasons in 1996 and 1997. The results are presented and discussed, as are the relations between the various optical parameters and salinity.

18

Endopsammic algal communities from shallow littoral sediments of Lobelia lake (the Pomeranian Lakeland, Northern Poland)

Picińska-Fałtynowicz J.

Oceanological Studies

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1998

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Vol. 27, No. 2

51-67

EN

Endopsammic algal communities from shallow littoral sediments in a subeutrophic Lobelia lake are presented. The flora in the studied lake consisted of 492 taxa. During the two years of study, the density of algae fluctuated between 0.65x103 and 23.24x103 individuals in 1 cm3 of sand and resulted mainly from growth of cyanobacteria, green algae and diatoms. The poorest communities occurred in spring, the most abundant in summer and autumn. In 1985, cyanophytes dominated (up to 92%) and Aphanotece microscopica in particular; the latter species grew in masses, particularly in summer and constituted more than 50% to 64% of the total quantity. In the next year, greater abundance of green algae, diatoms and desmids was noted, probably owing to the higher concentration of nutrients in interstitial water. The most suitable conditions for algal growth created sediments of flat bottom stabilized by isoetids. Mass development of certain cyanobacteria species resulted from medium trophy of the lake.