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Comparison of selected methods used in the assessment of contamination with heavy metals in littoral sediments of lakes

Dunalska J. A., Gusiatin Z. M., Zieliński R., Szymański D., Sieńska J.

Oceanological and Hydrobiological Studies

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2016

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Vol. 45, No. 4

493--504

EN

This study compared selected methods of assessing the pollution in the littoral sediments by heavy metals (Zn, Cu, Pb, Ni and Cd) in 13 lakes of the Borecka Forest. For this purpose, the ecotoxicological criteria (PEL TEL), the geoaccumulation index (Igeo), the contamination factor (CF) and the contamination degree (Cd) were applied. Characteristic values for both Poland (GBP) and the Earth’s crust (GBE) were assumed as the geochemical background. In addition, the organic (TOC) and inorganic (TIC) carbon were determined in the analyzed sediments. Regardless of the method or adopted background value, the highest pollution level was in the littoral sediments of Lake Szwałk Mały and Lake Kacze. This was primarily associated with increased concentrations of Cd (1.25 and 0.64 mg kg−1, respectively), which was considered as “likely to have toxic effects on organisms” (exceeding PEL). Several potential sources of this metal (fertilizers, herbicides, leaky septic tanks, bait fishing, drainage ditches, allochthonous organic matter) were identified. The content of heavy metals in the littoral sediments of other lakes was sufficiently low and they could be considered as basically uncontaminated.

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The use of biopreparations in lake restoration : experimental research

Dunalska J. A., Sieńska J., Szymański D.

Oceanological and Hydrobiological Studies

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2015

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Vol. 44, No. 4

500--507

EN

The experiment was established in a set of containers. Every container held a 10 cm thick layer of profundal sediments and water from a badly polluted lake. The following five preparations were tested (brand names): AQUAKALGON+, BIOGEN REMEDIANT, BIODENN K, ECOTABS 1(TABLETS), ECOTABS 2(POWDER). The biological preparations were applied twice: phase I lasted 56 days and phase II was continued for 21 days. The research results demonstrated that considerably higher values, compared to the control, were initially (day 3) obtained for TOC after the application of ECOTABS 1, for total nitrogen − after BIODENN K and ECOTABS 1, and for total phosphorus − after BIODENN K, ECOTABS 1 and BIOGEN REMEDIANT. Multiplying bacteria might have been an additional source of organic matter in water, which was subsequently deposited in the bottom sediments as implicated by a higher percentage (by 1 to 7% of d.w.) of organic matter in the sediments at the termination of the experiment. Our preliminary experiment did not provide any justification for using the tested preparations in lake restoration efforts. Subsequent studies should focus on the question whether mineral phosphorus released to the lake water or a drastic change in the environmental conditions would not lead towards the dominance of invasive and highly toxic cyanobacteria.

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Hourly and daily variability in nitrogen and phosphorus in a lake restored by the hypolimnetic with drawal method

Sieńska J., Dunalska J. A., Szymański D.

Oceanological and Hydrobiological Studies

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2015

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Vol. 44, No. 3

381--392

EN

An excess of nitrogen and phosphorus causes an increase in productivity, leading to degradation of a water reservoir. In order to reduce the eutrophication, protective and restoration methods are used. The objective of the paper was to determine the hourly and daily variability in nitrogen and phosphorus compounds in a lake restored by the hypolimnetic withdrawal method. In the epilimnion, the organic form dominates: 97% of Ptot and 75% of Ntot. Hourly variations in the concentration of the investigated compounds indicate that the highest values occurred at night and in the morning, whereas lower measurements were recorded at noon and in the evening. Such a distribution of the concentrations of nutrients during a day is strongly associated with photosynthesis. Along with depth, the proportion of this form decreased in favor of mineral forms. A high content of mineral phosphorus (70%) and ammonium ions (75%) in the hypolimnion results from their release from bottom sediments under anaerobic conditions. As a result of the generated thermocline, they are blocked and accumulated. At the experimental station, the concentration of mineral compounds was at a lower level than at the reference station since their amount was systematically reduced by the outflow of over-fertilized waters from the hypolimnion.

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Sezonowa zmienność produkcji pierwotnej i respiracji fitoplanktonu w litoralu jeziora eutroficznego

Szymański D., Dunalska J. A., Jaworska B., Bigaj I., Zieliński R., Nowosad E.

Rocznik Ochrona Środowiska

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2013

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Tom 15, cz. 3

2573--2590

EN

Littoral zone is the first zone of the lake, which directly borders the land and is a barrier to substances flowing from the catchment. It can play an important role in the productivity of the entire ecosystem, with both production and degradation of organic carbon. The aim of this study was to determine the role of phytoplankton in primary production and respiration in the littoral zone, depending on the development of the basin. The research was conducted in the spring, summer and autumn at eight sites of littoral zone with a different level of the direct catchment area development: two sites (1, 2) in the western part of the lake, which is dominated by forests, three sites (3, 4, 5) in the northern part of the basin, dominated by wasteland and private recreational areas, two sites (6, 7) in the eastern, the most transformed by man and one site (8) located in the southern part of the lake near the outflow. The production volume of the primary and respiration were determined by the change of the oxygen concentration in water using the method of "light and dark bottles" exposed for 24 hours in the surface layer of water. The lake primary production was significantly lower in the littoral parts shaded by forest than in sites exposed to the sun, occurring in the northern part of the lake. The highest primary production with simultaneously high phytoplankton biomass was found at the site in the north. The additional factor intensifying the primary production was the nutrient inflow from the recreationally used land. The highest rate of respiration was recorded in not forested sites, located in the northeastern part of the lake, where the autochthonic and allochtonic organic matter was reduced to CO2. The results indicate a dual role of littoral in the metabolism of Lake Kortowskie. On the one hand, the littoral zone supplies the basin in autochthonic organic matter, on the other hand reduces the organic matter which was produced in the water column and was supplied from the catchment. One suspects that the actual primary production in the littoral zone of Lake Kortowskiego was higher because a significant cover the bottom of the macrophytes limited primary production of phytoplankton.

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Indicators of changes in the phytoplankton metabolism in the littoral and pelagial zones of a eutrophic lake

Dunalska J. A., Zieliński R. A., Bigaj I., Szymański D.

Rocznik Ochrona Środowiska

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2013

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Tom 15, cz. 1

621--636

PL

Badania przeprowadzono na eutroficznym Jeziorze Kortowskim położonym w granicach administracyjnych miasta Olsztyn (Pojezierze Mazurskie). Próbki wody do analiz pobierano codziennie w okresie od 31 lipca do 12 sierpnia 2010 roku w strefie litoralu (w pasie roślin wynurzonych) oraz w strefie pelagialu (w najgłębszej części jeziora). Badania obejmowały wielkość produkcji pierwotnej oraz respirację metodą jasnych i ciemnych butelek. Dodatkowo analizowano parametry fizyko-chemiczne wody oraz dane meteorologiczne. Wyraźna dobowa zmienność tempa produkcji pierwotnej fitoplanktonu i respiracji w obu badanych strefach świadczyła o dużej dynamice procesów metabolicznych zachodzących w całym jeziorze. Nieco wyższą produkcję pierwotną fitoplanktonu stwierdzono w pelagialu, tutaj też procesy respiracji były bardziej dynamiczne. Przy dużej dostępności substancji biogennych w pelagialu Jeziora Kortowskiego o dynamice produkcji pierwotnej w większym stopniu decydowała ilość uwolnionej łatwo przyswajalnej materii organicznej, pochodzącej z produkcji pierwotnej, aniżeli dostępność azotu (r = 0,20, n = 13, p < 0,05) czy fosforu (r = -0.47, n = 13, p < 0,05). Brak istotnych statystycznie zależności pomiędzy GPP a wskaźnikami chemicznymi wody czy danymi meteorologicznymi świadczył, że w jeziorze nie było czynników ograniczających rozwój fitoplanktonu. Produkcja pierwotna fitoplanktonu dominowała w całym okresie badawczym. Czynniki zewnętrzne miały natomiast większy wpływ na wielkość i tempo respiracji. W litoralu istotne znaczenie miała pulsacyjna dostawa labilnego węgla organicznego, w pelagialu zaś temperatura powietrza oraz wielkość opadów atmosferycznych. Interesujący jest fakt, że w Jeziorze Kortowskim z dnia na dzień tempo produkcji pierwotnej i respiracji zmieniało się nawet o ponad 40%, natomiast zawartość TOC utrzymywała się na dość stałym, wyrównanym poziomie. Zależność ta może być wykorzystana w monitoringu jakości wód. Pomiary produkcji pierwotnej fitoplanktonu metodą jasnych i ciemnych butelek w danym dniu nie odzwierciedlają rzeczywistych procesów metabolicznych w całym jeziorze. Jest to wynik adekwatny do danej chwili i miejsca poboru próbek wody. Zatem lepszym i bardziej stabilnym wskaźnikiem nawet dobowej zmianności metabolizmu fitoplanktonu może być TOC. Każda istotna zmiana stężeń TOC w pelagialu w powiązaniu z danymi meteorologicznymi powinna być sygnałem do szerszych badań w celu uchwycenia zmian odpowiedzialnych za gwałtowny rozwój fitoplanktonu, a szczególnie uciążliwych zakwitów sinicowych. Przeprowadzenie tego typu badań porównawczych w regionach różniących się ilością substancji biogennych oraz w różnych strefach klimatycznych, umożliwiłoby opracowanie modelu dobowej równowagi metabolicznej fitoplanktonu, który mógłby być wykorzystany w programach ochrony wód.

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Total organic carbon as a new index for monitoring trophic states in lakes [commun.]

Dunalska J.A.

Oceanological and Hydrobiological Studies

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2011

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Vol. 40, No.2

112-115

EN

Total organic carbon (TOC) can be one of the parameters used to determine trophic state in lakes, as shown by the statistically significant correlation between TOC and chlorophyll, total phosphorus and Secchi disk transparency. Calculation of the TSI index based on TOC according to the formula TSI(TOC) = 20.59 + 15.71 ln(TOC) and its introduction as an additional index to the classification by Carlson may optimize the comparative analysis of lakes and allow a measurable assessment of lakes with respect to the trophic gradient.