The aim of this study is to conclude the experiences of the maintenance practice of an artificial thermal lake. The first years (2015-2017) of the development of the lake were analysed and evaluated along the following questions: a) What kind of design processes and maintenance interventions are related to the process of fitting the lake into the landscape? b) How have the ecological conditions of the lake evolved in the past period (zonation, succession, plantation and colonization)? c) Which general experiences could be gained from the operation of this artificial thermal lake this far? The authors of the present study were already engaged in the planning process, participating in the preparation of four different design documentations. The planting design and the maintenance instructions were based on a physico-chemical monitoring, phytoplankton, zooplankton and macroinvertebrate sampling, and machrophyte assessment. The significant processes during the three years of the lake are presented by functional groups of biota, separately assessing the characteristics of the changes of macrophytes. In 2017 an individual macroinvertebrate assessment was done, moreover a fish die-off occurred in August 2017, which are mentioned separately as well. The data in total suggested that the water of the lake is highly hypertrophic, further machrophyte introduction can prevent the plant nutriments to be absorbed by algae. Partly the algal growth but also the unlucky coincidence of other factors (e.g. high water temperature, cold weather front, maintenance problems) led to the die-off of the spontaneously overpopulated fish stock in 2017.
REFERENCES A dey W., L uckett C., J ensen K., 1993: Phosphorus Removal from Natural Waters Using Controlled Algal Production. – Restoration Ecology, 29–39. B ergström L., A htiainen H., A vellan L., E stlander S., H aapaniemi J., H aldin J., H oikkala L., R uiz M., R owe O., L i Z weifel U., 2017: State of the Baltic Sea. Second HELCOM holistic assessment 2011–2016 S. Baltic Sea Environment Proceedings, 155. B ingham M., S inha S.K., L upi F., 2015: Economic benefits of reducing harmful algalblooms in Lake Erie. – Environmental Consulting
Cyanobacterial blooms in shallow lakes of the Iławskie Lake District
The dominance of blue-green algae observed in many lakes is related to a high trophic level. Shallow eutrophic lakes are particularly often abundant in blue-green algae. The research on phytoplankton, the results of which are presented in this paper, was carried out between 2002 and 2005 in six lakes. These lakes differed considerably in their size and management methods applied in the catchment (drainage) area. A few types of water blooms were distinguished, which is related to the catchment area management, the intensity of mixing and the trophic level. Algal blooms of the Planktothrix type appeared in lakes situated in an open area of agricultural catchment basins. Algal blooms of the Limnothrix type were characteristic of lakes with a forest-agricultural catchment area but surrounded by high shores, which reduced the wind influence on the mixing. Sporadic mixed algal blooms were typical of lakes situated in forest catchment areas.
The SatBałtyk (Satellite Monitoring of the Baltic Sea Environment) project is being realized in Poland by the SatBałtyk Scientific Consortium, specifically appointed for this purpose, which associates four scientific institutions: the Institute of Oceanology PAN in Sopot - coordinator of the project, the University of Gdańsk (Institute of Oceanography), the Pomeranian Academy in Słupsk (Institute of Physics) and the University of Szczecin (Institute of Marine Sciences). The project is aiming to prepare a technical infrastructure and set in motion operational procedures for the satellite monitoring of the Baltic Sea ecosystem. The main sources of input data for this system will be the results of systematic observations by metrological and environmental satellites such as TIROS N/NOAA, MSG (currently Meteosat 10), EOS/AQUA and Sentinel -1, 2, 3 (in the future). The system will deliver on a routine basis the variety of structural and functional properties of this sea, based on data provided by relevant satellites and supported by hydro-biological models. Among them: the solar radiation influx to the sea’s waters in various spectral intervals, energy balances of the short- and long-wave radiation at the Baltic Sea surface and in the upper layers of the atmosphere over the Baltic, sea surface temperature distribution, dynamic states of the water surface, concentrations of chlorophyll a and other phytoplankton pigments in the Baltic waters, spatial distributions of algal blooms, the occurrence of coastal upwelling events, and the characteristics of primary production of organic matter and photosynthetically released oxygen in the water and many others. The structure of the system and preliminary results will be presented.
: 60-63. Gikuma-Njuru P., Hecky R.E., 2005: Nutrient concentrations in Nyanza Gulf, Lake Victoria, Kenya: light limits algal demand and abundance. - Hydrobiologia, 534: 131-140. Havens K.E., 2008: Cyanobacteria blooms: effects on aquatic ecosystems. - In: Hudnell H.K. (ed.), Cyanobacterial Harmful AlgalBlooms: State of the Science and Research Needs: 733-747. Houghton J.T., Ding Y., Griggs D.J., Noguer M., Van der Lin-den P.J., Dai X., Maskell K., John son C.A., 2001: Climate Change 2001: The Scientific Basis. 881. - Cambridge. Huisman J., Hulot F., 2005: Population
’s Marine Resources, 1996, 8, 16-17. 8. Gessner B.D., Bell P., Doucette G.J., Moczydlowski E., Poli M.A., Van Dolah F., Hall S.: Hypertension and identification of toxin in human urine and serum following a cluster of mussel- associated paralytic shellfish poisoning outbreaks. Toxicon 1997, 35, 711-722. 9. Gomaal M.N., Soliman K.M., Embaby M.A., Ayesh A.M.: Simultaneous occurrence of saxitoxins and biogenic amines in mackerel fish. Afr J Microbiol Res 2011, 5, 5178-5187. 10. Hallegraeff G.M.: Harmful algalblooms: a global overview. In: Manual on Harmful Marine
whole-lake nitrogen fertilization for controlling blue-green algalblooms in a hypereutrophic lake, Can. J. Fish. Aquat. Sci. 45: 2061-1075. Lin C., 1972, Phytoplankton succession in eutrophic lake with special reference to blue-green algalblooms, Hydrobiologia 39(3): 321-334. Mientki C., Dunalska J., 2001, Phosphorus balance at various water flow in a lake restored by hypolimnetic withdrawal, Ecohydrol. Hydrobiol. 1(4): 417-422. Mientki C., Teodorowicz M., 1996, Assessment of the effects of hypolimnion water removal from the Kortowskie Lake, Chem. Prot. Environ. 2