Wyniki wyszukiwania - Biblioteka Nauki

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Analysis of zooplankton assemblages from man-made ditches in relation to current velocity

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Czerniawski R. , Sługocki Ł.

Oceanological and Hydrobiological Studies

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2017

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tom Vol. 46, No. 2

199--211

EN

Because of the slow current velocity, man-made ditches may create distinct physical and ecological conditions that are suitable for the growth of zooplankton populations. However, the influence of drainage ditches on zooplankton communities has not been studied yet. This study aims to answer the following questions: i) Are man-made ditches a rich source of zooplankton? ii) What current velocity value leads to abundant zooplankton in man-made ditches? iii) Do zooplankton communities differ between man-made ditches and connected natural streams? In man-made drainage ditches with a water current lower than 0.1 m s-1, the abundance of zooplankton was greater than in the majority of streams. Sometimes this level of abundance was equivalent to the densities of zooplankton in lakes or dammed reservoirs. The presence of zooplankton in man-made ditches may be of great importance to the establishment of food webs, particularly during periods of high water levels or heavy rainfall, both of which may accelerate the water current, causing the dispersion of zooplankton along the ditches and into natural streams.

2

Canoeing and angling in Drawa river drainage as important issues in spatial planning: an ecosystem services approach

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Czerniawski R. , Sługocki Ł. , Dziewulska K. , Domagała J.

Ekonomia i Środowisko

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2017

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tom nr 1

246--256

EN

The analysis of ecosystem services in the Drawa River drainage with regard to canoeing and angling indicated that anglers found lake areas most attractive whereas canoeists preferred river sections. The use of the Drawa River only by the two branches (only the basic range) of economy and region development generates profi t of at least 1.5 million PLN within one year. The aforementioned analysis excludes indirect costs which may be equal to or exceed the value obtained directly from the sale of angling licenses and canoe rentals.

3

Zabieg krótkoterminowej biomanipulacji ekologicznej zastosowany w trzech śródleśnych płytkich jeziorach

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Czerniawski R. , Sługocki Ł. , Domagała J. , Pilecka-Rapacz M.

Rocznik Ochrona Środowiska

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2015

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tom Tom 17, cz. 2

1207--1223

EN

A crucial factor affecting the rate of eutrophication is the characteristics of the catchment area of lakes. The most visible result of excessive eutrophication is rapidly deteriorating transparency of waters in the summer which is caused by rapid development of planktonic algae. Another symptom of this process is gradual overgrowth of water reservoirs and watercourses by macrophytes. Hence, in order to improve the quality of water in these lakes the renovation treatment is applied. Lakes restoration can be made in many ways: physical, chemical and biological. The chemical and physical methods of lakes restoration are invasive and controversial. However, one of the relatively not invasive methods of lakes restoration is ecological biomanipulation. The goal of biomanipulation is to reduce the concentration of harmful phytoplankton, by the stocking of predatory fish triggers a trophic cascade with decreases in the biomass of smaller-bodied fish, e.g. cyprinids, increases in the biomass of herbivorous zooplankton, and decreases in the biomass of harmful phytoplankton. In some cases plankton-eating fish have been removed directly by lake managers. In addition, the removal of bottom-feeding fish from shallow lakes leads to increases in rooted vegetation and increased water clarity as the rooted plants stabilize the sediments. This transition involves a trophic cascade, as herbivorous zooplankton increase in biomass and consume phytoplankton, but also involves the direct effects of rooted vegetation on sediment stability and nutrient cycling. The most frequent cause of fast eutrophication is the runoff of untreated sewage directly into the waters of lakes and rivers or the excessive runoff of biogenic compounds from agricultural catchment areas. Forest lakes because of far distance from agglomeration and agricultural areas are in lesser extent exposed on the human pressure. Generally, one unfavorable variable affected these lakes is angling pressure. Thus, due to the lack of pollution and the relative stabilization of the mid-forest lakes they are a good place to conduct the ecological biomanipulation. The aim of the present study was to determine the short-term biomanipulation effectiveness in three shallow forest lakes. Biomanipulation was performed by stocking in 2012 to these lakes a summer fry of pike (200 ind. ha-1) and zander (150 ind. ha-1). Before the biomanipulation (in 2011) a control study of physic-chemical parameters, ichthyofauna and zooplankton composition were made. After the biomanipulation (in 2014) the same control study were conducted. Before and after the biomanipulation period significant changes in values of physic-chemical variables were not observed. Similarly, a slight changes in ichthyofauna composition between these two period occurred. The roach and bream were the biomass dominants. Only the zooplankton composition obtained pronounced changes, but statistically not significant. The most visible differences in zooplankton abundance concerned cladocerans – group that the most affect the phytoplankton decreasing. After the biomanipulation abundance of cladocerans increased from 31% to 67%. According to the results, it can be concluded that the biomanipulation time in study lakes was too short to make significant changes. To get a better effect of biomanipulation a successive stocking with summer or autumn fry of pike and zander should be conducted, even in 1000 ind. ha-1. Finally, we can assume that in the forest, shallow, highly eutrophic lakes a biomanipulation with predatory fish may be sufficient for their effective restoration.

4

Zooplankton of three suburban lakes in relation to select abiotic conditions

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Sługocki Ł. , Czerniawski R. , Domagała J. , Krepski T. , Pilecka-Rapacz M.

Rocznik Ochrona Środowiska

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2012

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tom Tom 14

146--160

PL

Badania prowadzono w trzech eutroficznych jeziorach położonych w północno-zachodniej Polsce: jeziorze Adamowo, Grażyna i Klasztorne. Z każdego stanowiska pobierano próbę zooplanktonu oraz próbę wody do określenia wybranych parametrów fizyko-chemicznych. W odniesieniu do uzyskanych wyników można uznać, że pomimo takiego samego statusu troficznego badane jeziora różniły się pod względem struktur jakościowych i ilościowych zooplanktonu, na co miały wpływ różne warunki środowiskowe badanych jezior. Podobieństwo jakościowe zooplanktonu pomiędzy jeziorami nie było zbyt wysokie. W najmniejszym jeziorze obserwowano największe liczebności zooplanktonu, szczególnie małych plankterów. Pozwala to wnioskować, że im mniejsza powierzchnia jeziora tym większa jest liczebność zasiedlającego je zooplanktonu. Biomasa zooplanktonu osiągała największe wartości w największym jeziorze Adamowo, co było spowodowane licznym występowaniem dojrzałych skorupiaków planktonowych. Biorąc pod uwagę zależność pomiędzy warunkami środowiskowymi jezior a zagęszczeniem zooplanktonu, stwierdzić można że największy wpływ na kształtowanie struktur zooplanktonu mają nieorganiczne związki biogenne.