Wyniki wyszukiwania - BazTech

1

Phytoplankton dynamics in relation to physicochemical conditions in large, stratified Lake Charzykowskie (Northern Poland)

Wiśniewska M., Dembowska E. A.

Oceanological and Hydrobiological Studies

|

2017

|

Vol. 46, No. 3

260--270

EN

The comparison of the latest and previous data on the structure of phytoplankton and chlorophyll a concentration in Lake Charzykowskie indicated long-term changes and fluctuations. The main objective of this study was to assess the phytoplankton communities in the lake with reference to hydrochemical conditions. Detailed hydrobiological studies were carried out in 2014-2015 to explain the improvement in the trophic status of the lake observed in 2008-2009. The research has shown that the phytoplankton community structure does not change significantly during the limnological cycle. The spring/ autumn season is characterized by the highest contribution of diatoms and cryptophytes. Massive development of dinoflagellates was observed during the summer. Relative abundance of cyanobacteria (Aphanizomenon, Dolichospermum and Microcystis) was significantly lower compared to the previous years. In August 2014, cyanobacteria accounted for 100% of the total phytoplankton at site 2. In the following year, cyanobacteria represented only 13% in the summer phytoplankton. The current research has confirmed the favorable trophic changes in the phytoplankton of the lake. Unfortunately, very poor oxygen conditions will continue to affect the trophic status of the lake through mobilization of the internal nutrient supply. The current conditions of the lake require further monitoring of changes in the ecosystem.

2

Long-term changes in the dynamics and structure of cyanobacteria in Koronowo Reservoir

Wiśniewska M., Paczuska B.

Oceanological and Hydrobiological Studies

|

2015

|

Vol. 44, No. 1

127--138

EN

The Koronowo Reservoir (16.6 km2) is located in the lower reaches of the Brda River, in the Kujawy-Pomerania Province, 20 km from Bydgoszcz near the town of Koronowo, hence the name of the reservoir. The reservoir was built in the 1960s and started from damming the waters of the Brda River by a ca. 20 m high earth dam in the village of Pieczyska. This reservoir is used mainly for water retention and production of electric energy in the hydroelectric power station; in addition, it plays a significant recreational function. In terms of the latter function, the spread of cyanobacteria is a serious problem. The aim of the study was to assess longterm changes in the structure of cyanobacteria in waters of the Koronowo Reservoir. The results from 1996, 2008, 2011 and 2013 were compared. As evidenced by the analysis of the phytoplankton composition in the Koronowo Reservoir in terms of functional groups, especially the occurrence of dominant and subdominant species from the groups P, H1, S1, LM, J, G and W2, the waters of the reservoir can be classified as eutrophic, potentially evolving towards the hypertrophic conditions. The HPLC analysis of cyanobacterial toxins revealed the presence of microcystins at two sites of the water body. The species structure, the distribution and the dominance of specific species of cyanobacteria is recurrent over the 17 years; the following species form algal blooms: Aphanizomenon flos-aquae (L.) Ralfs et Bornet et Flahault and Microcystis aeruginosa (Kütz.) Kützing.

3

Long-term changes in the phytoplankton of Lake Charzykowskie

Wiśniewska M., Luścińska M

Oceanological and Hydrobiological Studies

|

2012

|

Vol. 41, No. 3

90-98

EN

The research on phytoplankton communities in Lake Charzykowskie was carried out at intervals since the 1940s till the beginning of the 21 century. Long-term observations, initially of the species composition and in the following years also of the biomass and the concentration of chlorophyll-a in relation to habitat conditions, allowed to assess the impact of the catchment area on changes in the trophic status of the lake for over 50 years. And thus, based on the results of physicochemical analysis and studies on the phytoplankton structure in the 1940s, the lake was classified as ß-mesotrophic (Cabejszek 1950), between the 1960s and the1990s as eutrophic (Szulkowska-Wojaczek 1968, 1976; Wiśniewska 1994, 2000), in 2004 as hypertrophic (Wiśniewska 2005), and in 2008 and 2009 as meso-eutrophic.

4

The trophic state of the Vistula Lagoon: an assessment based on selected biotic and abiotic parameters according to the Water Framework Directive

Nawrocka L., Kobos J.

Oceanologia

|

2011

|

No. 53 (3)

881-894

EN

The aim of the study was to determine the trophic state of the Vistula Lagoon in 2007-2009. The analysis of various trophic state indices, abiotic parameters and different water classifications indicated the eutrophy and even advanced hypereutrophy of the lagoon waters. The composition, abundance and biomass of phytoplankton likewise reflect the eutrophic nature of this water body. For this lagoon, Reynold's functional groups of phytoplankton wereused as an indicator of eutrophication for the first time. The dominant phytoplankton organisms in the surface waters belong to 8 functional groups: S1, X1, F, J, K, H1, LO, M. Some key concepts of the EU Water Framework Directive were implemented in this study.