Original paper

Interrelations between Dreissena polymorpha colonization and autotrophic periphyton development – a field study in a temperate floodplain lake

Stević, Filip; Čerba, Dubravka; Čakalić, Ivana Turković; Pfeiffer, Tanja Žuna; Vidaković, Jasna; Mihaljević, Melita


Temporal changes in autotrophic periphyton (algae and cyanobacteria) in relation to the colonization of Dreissena polymorpha, an invasive species, were investigated in situ using artificial substrata (glass slides) from April to August of 2008 in a Danubian floodplain. The colonization of cyanobacteria and planktonic diatoms firmly attached to the substrata followed by the development of apical pad forming diatoms and stalk forming diatoms, resulted in the rapid formation of a three-dimensional structure of periphyton. Increasing water temperatures, together with the well developed autotrophic periphyton, supported the colonization of Dreissena. A total of 16 size classes of Dreissena were found during the gradual mussel community development. The community most likely formed from the initially settled larvae which dominated the first period of aggregation, while adult individuals dominated the later phase, contributing to the increase in habitat complexity. High competition for space and nutri - ents on small-size substrata limited the autotrophic periphyton to achieve the “climax community” characterized by filamentous green algae. Consequently, algal abundance decreased and diatoms firmly attached to the substrata prevailed. The decrease in mussel abundance at the end of the colonization experiment enabled a gradual increase in diatom abundance and redevelopment of a three-dimensional autotrophic periphyton structure. Altogether, our re - sults showed that dense coverage of hard surfaces by mussels may have negatively influenced the algal community causing a significant decrease in algal abundance and a shift to the dominance of species resistant to the disturbance.


algaefloodplaininvasive speciesperiphytonzebra mussel