Phytoplankton composition and physicochemical properties in Lake Swarzędzkie (midwestern Poland) during restoration: Preliminary results
Anna Kozak, Katarzyna Kowalczewska-Madura, Ryszard Gołdyn, Anna Czart
ABSTRACT. This paper presents the preliminary results of a study of the phytoplankton structure and dynamics and physicochemical properties of Lake Swarzędzkie in 2011. The subject of the study is a shallow, elongated, post-glacial lake located in western Poland. The surface area is 93.7 ha with a maximum depth of 7.2 m. Its poor water quality led to the implementation of chemical and biological restoration procedures in an attempt to improve it. The highest concentration of total nitrogen was 13.07 mg l-1 N. Secchi depth (SD) was low in the summer with a minimum value of 0.5 m in September. The most abundant group of phytoplankton were cyanobacteria, and the maximum value of chlorophyll a concentration was 278.0 µg l-1. The dominant species were Pseudanabaena limnetica and Aphanizomenon gracile. Cyanobacteria were the most abundant phytoplankton until November. Maximum diatom, cryptophyte, and chrysophyte density was noted in the spring, and the most abundant were Nitzschia acicularis, Cryptomonas marssonii, Rhodomonas lacustris, Erkenia subaequiciliata, and Dinobryon sociale. One-hundred and thirty-six phytoplankton taxa belonging to nine taxonomic groups were identified in Lake Swarzędzkie. The highest number of taxa was noted among chlorophytes (57 taxa), cyanobacteria (19), diatoms (16), and chrysophytes (12), while other taxonomic groups were represented by smaller number of taxa.
Keywords: phytoplankton abundance, water physicochemistry, cyanobacteria blooms, lake restoration
CORRESPONDING AUTHOR:
A. Kozak [+], K. Kowalczewska-Madura, R. Gołdyn, A. Czart
Department of Water Protection
Faculty of Biology, Adam Mickiewicz University
Umultowska 89, 61-614 Poznań, Poland
tel. 061 829 58 78; e-mail: akozak@amu.edu.pl