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1

Copepoda in the shallow hypersaline Bardawil coastal lake (Egypt ) : Are there long-term changes in composition and abundance?

Anufriieva E. V., El-Shabrawy G. M., Shadrin N. V.

Oceanological and Hydrobiological Studies

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2018

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Vol. 47, No. 3

219--229

EN

Coastal Lake Bardawil (Egypt) is one of the largest hypersaline lakes in the world. In 2009-2010, the authors studied composition, distribution and seasonal dynamics of copepods at 12 sites. A total of 10 species of copepods were recorded in zooplankton during the study period, including 5 Calanoida, 2 Cyclopoida and 3 Harpacticoida. Oithona nana was the most common and most abundant species. All copepods in the lake can be divided into three groups: 1) planktic species that form stable populations, 2) species of Mediterranean plankton incidentally entering the lake from the adjacent sea area, 3) benthic Cyclopoida and Harpacticoida that can be abundant in plankton. Two species - Acartia tonsa and A. danae were recorded here for the first time. The total abundance of copepods in the lake was significantly higher (90 times on average) compared to that observed in 2008-2009 in the waters of the Egyptian Mediterranean Sea. Since 1967, the complex of common and dominant copepod species in the lake has changed significantly. The total average annual copepod abundance varied: in 2002 - it was about 4000 ind. m-3, in 2004 - 152 000 ind. m-3, in 2005 - about 25 300 ind. m-3, and in 2009-2010 - about 56 000 ind. m-3.

2

Changes in hydrological, physical and chemical properties of water in closed/open coastal lakes due to hydrotechnical structures

Cieśliński R.

Oceanological and Hydrobiological Studies

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2018

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Vol. 47, No. 4

345--358

EN

The purpose of the study was to determine quantitative and qualitative changes in the waters of Lake Jamno in northern Poland due to the presence of new hydrotechnical structures in its drainage basin, with a special focus on the effects of a new storm barrier. The study consisted primarily of a review of measurement data, historical records and fieldwork prior to the construction (2002–2008) and following the construction of the storm barrier (2015). Fieldwork included hydrographic surveys and water sampling for laboratory analysis. The main and most easily discernible effect of the construction is the change in water quality in Lake Jamno. This is particularly true in the case of key indicators related to seawater, including conductivity, whose values changed from brackish to fresh water.

3

Comparison of Ichthyofauna composition in two estuarine lakes: Ptasi Raj and Mikoszewskie located in the Natura 2000 site “Ostoja w Ujściu Wisły

Kuczyński T., Pieckiel P.

Biuletyn Instytutu Morskiego w Gdańsku

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2018

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Vol. 33, No. 1

119--127

EN

The purpose of the following studies was to get knowledge about the composition of the ichthyofauna of two estuarine lakes: Mikoszewskie and Ptasi Raj in the Natura 2000 area “Ostoja w Ujściu Wisły” (PLH220044), located within the delta estuary created by two channels of the Vistula river: Wisła Śmiała and Przekop Wisły, reaching the Gulf of Gdańsk. Despite the research conducted on the existing flora and fauna in both nature reserves, the ichthyofauna of the lakes has not been studied so far. In order to determine as completely as possible the taxonomic composition and the quantitative structure of ichthyofauna, the different fishing gear was used: fyke nets, NORDIC multimash survey gillnets, minnow traps. In Mikoszewskie lake, there were caught a total of 774 fish representing 17 species. Higher fish number in catches, with a comparable effort applied, were recorded on the Ptasi Raj lake, where a total of 2032 fish representing 16 species were captured. Out of all 26 species found, only 9 of them were found in both water reservoirs. As it transpires from the above data, both lakes, despite seemingly similar location, due to different hydrological conditions, clearly differ in terms of the structure of inhabiting ichthyofauna. Based on the analysis of the results of conducted fish catches, it can be concluded that the ichthyofauna of the Mikoszewskie Lake is characteristic for freshwater habitats, whereas in the waters of the Ptasi Raj lake, fish populations depend on a permanent connection with the estuary waters of the Wisła Śmiała channel.

PL

Celem poniższej pracy było poznanie składu ichtiofauny dwóch jezior Mikoszewskiego i Ptasi Raj znajdujących si w obszarze Natura 2000 „Ostoja w Ujściu Wisły” (PLH220044), położonego w obrębie estuarium utworzonego przez ramiona Wisły, Śmiałej i Przekopu Wisły uchodzące do Zatoki Gdańskiej. Pomimo prowadzonych w tym obszarze badań flory i fauny, ichtiofauna znajdujących się w nich jezior nie była do tej pory poznana. W celu jak najbardziej pełnego określenia składu taksonomicznego oraz struktury ilościowej ichtiofauny zastosowano różne narzędzia połowowe: żaki, wielopanelowe sieci typu NORDIC oraz pułapki narybkowe. W jeziorze Mikoszewskim, odłowiono łącznie 774 ryb reprezentujących 17 gatunków. Wyższe liczebności ryb w połowach, przy porównywalnym nakładzie odnotowano na jeziorze Ptasi Raj, gdzie odłowiono łącznie 2032 ryb reprezentujących 16 gatunków. Ze wszystkich 26 stwierdzonych gatunków tylko 9 z nich występowało w obu zbiornikach. Oba jeziora, pomimo wydawałoby się podobnego położenia, na skutek odmiennych uwarunkowań hydrologicznych, wyraźnie się różnią pod względem struktury zamieszkującej je ichtiofauny. Na podstawie analizy wyników przeprowadzonych połowów można stwierdzić, że ichtiofauna jeziora Mikoszewskie jest charakterystyczna dla siedlisk słodkowodnych, natomiast w poddanym wpływowi wód słonawych jeziorze Ptasi Raj, populacje ryb są zależne od stałego połączenia z wodami estuarium Wisły Śmiałej.

4

Diatom assemblages as indicators of salinity gradients : a case study from a coastal lake

Rzodkiewicz M., Gąbka M., Szpikowska G., Woszczyk M.

Oceanological and Hydrobiological Studies

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2017

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Vol. 46, No. 3

325--339

EN

In order to understand the variability of diatoms in coastal lakes and its relationship to salinity, the authors have conducted a two-year study at Lake Resko Przymorskie (the Southern Baltic coast), which has a salinity between 1.9-4.8 PSU. Redundancy analysis (RDA) was used to describe the relationship between the species composition and selected variables. Four of the 10 measured variables of surface water chemistry (Cl- and PO43- concentrations, temperature, and pH) significantly explained 23% of the variation in the diatom species composition. We found 82 taxa of diatoms (mostly tychoplanktonic) and determined the optimum and tolerance levels of salinity for predominant taxa (49 species with minimum 2% abundance). The optimum chloride concentration for the predominant diatoms ranged from 1471 to 2961 mg Cl- l-1. The most abundant brackish water species was Pseudostaurosiropsis geocollegarum. Brackish-freshwater diatoms were represented by Cyclotella atomus, Cyclotella meneghiniana, Diatoma tenuis and Staurosira subsalina. The most abundant fresh-brackish water diatoms were Amphora pediculus, Fragilaria sopotensis, Hippodonta hungarica, Pseudostaurosira brevistriata and Staurosira construens. Freshwater taxa accounted for as little as 1% of the population. This study provides new data on the ecology of coastal lakes and the possibility of using diatom-based transfer functions in the reconstruction of past environmental changes.

5

The simplistic nitrogen input and output balance in Lake Łebsko : case study

Cieśliński R.

Oceanological and Hydrobiological Studies

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2016

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Vol. 45, No. 3

424--443

EN

The paper is based on the hypothesis that coastal lakes significantly affect changes in the quality of freshwater coming from catchments, which is best reflected in the reduction of biogenic loads. Some of the main reasons for this phenomenon include unique geographic locations of coastal lakes and physical and chemical properties of their waters as well as other hydrographic determinants that affect water circulation in catchments. The study area covered the direct drainage basin of Lake Łebsko, which is located in Słowiński National Park in northern Poland, on the coast of the southern Baltic Sea. The study was conducted from June 2008 to October 2010. Fieldwork was the main part of the research project and included hydrographic mapping, water sampling for laboratory analysis, and measurement of the discharge in all tributaries and outflows of the studied lake. Water chemistry data for Lake Łebsko indicate a significant accumulation of biogenic materials in the lake, which proves a strong effect exerted by the lake on the incoming water. This is true for both total chemical loads per year as well as concentrations of selected ions over short time intervals. This standard pattern may be interrupted by seawater intrusions that alter water chemistry in the whole lake.

6

Reconstruction of palaeoecological changes in Lake Łebsko on the basis diatom analysis (the southern Baltic coast, Poland)

Staszak-Piekarska A., Rzodkiewicz M.

Landform Analysis

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2015

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Vol. 29

81--90

EN

This study focuses on diatom assemblages occurring in core Łeb1 of Late-glacial and Holocene deposits from Lake Łebsko, off the southern coast of the Baltic Sea. Diatom-inferred environmental characteristics, e.g., water level, water salinity (conductivity), trophic status and pH, from the Holocene are presented. In the sediments from the early Boreal/early Atlantic period, an increase in the participation of brackish-freshwater species is observed, as well as increased numbers of Chaetoceros spores in the samples. The Atlantic sediments of Lake Łebsko mirror conditions typical of the Littorina Sea phase during the development of the Baltic Sea (from c. 7,500 BP to c. 5,000 BP). However, communities of that period dominated by fresh-brackish water species suggest the relatively low salinity of the waters. The presence of isolated frustules of Terpsinoë americana and other typically marine species, e.g., Mastogloia smithii, and the occurrence of silts with Cardium shell detritus point to the Littorina transgression and the functioning of a lagoon within the area of present-day Lake Łebsko. During Subboreal occurrence, a higher number of brackish-freshwater diatoms corresponds to an increase in the water level of the Baltic Sea (approximately 3,000 14C BP). Changes in diatom community structure imply a close relationship with the climate controlled eustatic rise of ocean level and the consequent Littorina transgression, as with other southern Baltic Sea localities.

7

Present-day evolution of coastal lakes based on the example of Jamno and Bukowo (the Southern Baltic coast)

Choiński A., Ptak M., Strzelczak A.

Oceanological and Hydrobiological Studies

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2014

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Vol. 43, No. 2

178--184

EN

This study presents the directions and the rate of changes occurring in the coastal lakes Jamno and Bukowo, located in northern Poland. Based on the cartographic materials and aerial photographs of those water bodies, it was established that in 1909–2012, the area of the lakes decreased by 183.6 ha (7.7%) and 250.7 ha (13.6%) for Jamno and Bukowo, respectively. Another component of lake disappearance - shallowing of lake basins - was analyzed using bathymetric plans. It turned out that water supplies of Jamno during more than 100 years decreased by 2.4 million m3 (5.9%), while in the case of Bukowo, it was 5.9 million (17.5%). Unfavorable location (inflow of pollutants from the basin) and morphometry of both lakes should be considered as the main causes of such major changes. The lakes are polymictic with a considerable area of the shallowest zone (1 m depth). This favors the vegetation succession and, consequently, shallowing of the lake basins. Moreover, direct connection with the Baltic Sea contributes to the fact that the materials of marine origin deposited in the form of a reverse delta also contribute to a decrease in the open water surface area.

8

Differences in the abiotic parameters of water in coastal lakes in the light of the EU water framework directive: an example of the Polish southern baltic coast

Cieśliński R., Major M.

Acta Geophysica

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2012

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Vol. 60, no. 4

1159-1179

EN

Coastal lakes have a specific hydrological regime determined by the influence of sea and inland water and the local hydrographic conditions. There are several problems concerning the protection and assessment of water quality of these bodies. The most important features differentiating coastal lakes from other lakes are: high salinity, a wide range of seasonal and short-term water quality changes, and specific aquatic ecosystems adapted to these conditions. These matters have not been sufficiently taken into account in the existing classifications and typologies of lakes in Poland. The problem has not been solved by the establishment of the adequate reference conditions and new guidelines for the classification of water status (which are being prepared according to the Common Strategy for the Implementation of the Water Framework Directive) regarding inland surface waters (rivers and lakes) and marine waters (coastal and transitional). An important issue is to define criteria which would help to distinguish all those hydrographic objects and to establish water quality standards for them.

9

Ewolucja jezior przybrzeżnych Niziny Gardzieńsko - Łebskiej na tle rozwoju środkowego wybrzeża Bałtyku w świetle badań malakologicznych

Wojciechowski A.

Landform Analysis

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2008

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Vol. 7

154--171

PL

Wartykule przedstawiono syntezę dotychczasowego stanu wiedzy o rozwoju jezior przybrzeżnych Niziny Gardzieńsko- Łebskiej i środkowego wybrzeża Bałtyku, bazującą na wynikach badań malakologicznych. Analizy zespołów mięczaków z osadów limnicznych i morskich pozwoliły na wyróżnienie czterech faz rozwojowych jezior: wczesnoholoceńskiej fazy limniczno-bagiennej (trwającej od późnego glacjału do około 7500 lat 14C BP), fazy lagunowej (około 7500–6600 lat 14C BP), fazy przejściowej, słonawowodno-limnicznej (6600–4000 lat 14C BP) oraz fazy jeziornej (młodszej od 4000 lat 14C BP).W artykule wykazano, iż sukcesja malakofauny jest odzwierciedleniem regionalnych przemian środowiska, zarejestrowanych podobnymi zmianami zespołów fauny na całym wybrzeżu południowego Bałtyku.

EN

The papers presents the synthesis of the current understanding of the evolution of coastal lakes in the Gardno-Łeba Lowland. Particular emphasis has been placed upon the influence of pre-Holocene surface topography on lake basin evolution and water level changes caused by the transgression of southern Baltic. Malacological analysis reveals four phases in lake environmental history: limnic-swampy phase, lagoon phase, transitional brackish-limnic phase, and limnic phase. The oldest, early Holocene limnic-swampy phase in the Gardno-Łeba Lowland area is represented by Preboreal and Boreal assemblages with freshwater fauna, described as Planorbis phase. It is characterized by rich assemblages, in terms of both number of individuals and species, composed of members of Planorbis, accompanied by Bithynia tentaculata, Valvata piscinalis and Pisidium. The lagoon-marine phase, described as Scrobicularia phase (7500–6000 BP), is defined by a homogeneous assemblage of malacofauna, consisting entirely of brackish and marine species, such as Hydrobia ulvae, H. ventrosa, Cerastoderma glaucum, Macoma baltica, Mytilus edulis and indicative Lusitanian and Lower Boreal species for the Mesoholocene of the southern Baltic, including Scrobicularia plana, Rissoa membranaea, R. inconspicua, Parvicardium exiguum and Mysella bidentata. The transitional brackish-limnic phase Cardium (6600–4000 BP) is correlated with late Littorina transgressive phases. It is dominated by Cardium glaucum, with minor percentage of Hydrobia ventrosa, Mytilus edulis, and sporadic freshwater species. The limnic Lymnaea phase corresponds with the post-Littorina period (4000 BP–1900 AD). The onset of this phase is marked by an assemblage with dominating Theodoxus fluviatilis, the optimum – by Lymnea peregra assemblages, whereas frequent Bithynia tentaculata indicate the end of the phase. The youngest Potamopyrgus phase includes recent lake sediments from the last 100 years and is marked by the first appearance of a new mollusc species in the coastal zone of the Baltic – Potamopyrgus antipodarium. The malacofauna succession identified in the coastal lakes in the Gardno-Łeba Lowland reflects regional environmental change, recorded by similar faunal assemblages throughout the southern coast of the Baltic.

10

Miesięczne i sezonowe charakterystyki poziomów wody wybranych polskich jezior przybrzeżnych

Girjatowicz J.P.

Inżynieria Morska i Geotechnika

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2008

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nr 1

27-32

PL

Średnie i miesięczne, sezonowe i roczne poziomy wody dla jezior Jamno, Gardno i Łebsko. Analiza rocznego przebiegu poziomów wody, ich wzajemnych relacji i powiązań z poziomami morza.

EN

Mean monthly, seasonal and annual water levels in Jamno, Gardno and Łebsko lakes. Analysis of annual fluctuations of water levels, its mutual relations with seawater level.

11

Miesięczne i sezonowe charakterystyki i temperatury wody wybranych polskich jezior przybrzeżnych

Girjatowicz J.P.

Inżynieria Morska i Geotechnika

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2006

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nr 3

150-154

PL

Podstawowe dane statystyczne średniej miesięcznej i sezonowej temperatury wody na jeziorach Jamno, Gardno i Łebsko w okresie 1961-2000. Związki temperatur między poszczególnymi jeziorami. Wnioski.

EN

Basic statistics of mean monthly and seasonal water temperature in Jamno, Gardno and Łebsko lakes in the period 1961-2000. Relation of temperatures between particular lakes. Conclusion.