Vertical distribution of expansive, bloom-forming algaeGonyostomum semenvs.plankton community and water chemistry in four small humic lakes

Abstract

One of the features of Gonyostomum semen, a bloom-forming and expansive flagellate, is uneven distribution in the vertical water column often observed in humic lakes. In this paper, we analysed vertical distribution of the algae in four small (0.9–2.5 ha) and humic (DOC: 7.4–16.5 mg dm−3) lakes with similar morphometric features with the aim to test the hypothesis that vertical distribution of G. semen may be shaped by zooplankton structure and abundance. In addition, we wanted to check whether high biomass of this flagellate has any influence on the chemical composition as well as on planktonic bacteria abundance of the water column. The results of the study showed that vertical distribution of the algae during the day varied among all studied lakes. Our most important finding was that (a) the abundance and structure of zooplankton community (especially in case of large bodied daphnids Daphnia pulicaria, D. longispina and copepod Eudiaptomus graciloides) may shape G. semen vertical distribution in studied lakes; (b) high G. semen biomass may decrease the content of ammonium ions in the water column by intense uptake, but has low effect on other water chemical parameters. The results of the study contribute to the understanding of the factors influencing this expansive algae behaviour as well as it shows interesting aspects of G. semen influence on some components of the lake ecosystem.

Zooplankton Community Responses to Oxygen Stress

“…However, larger cladocerans experienced difficulty feeding in the presence of cyanobacteria because they do not feed selectively, and longer algae filaments clog their filtering apparatuses [56][57][58][59]. The mass development of inedible algae Gonyostomum semen is a common phenomenon in humic lakes in NE Poland [15,60,61], and the lakes from G4 were eutrophic and dominated by cyanobacteria. Therefore, inedible algae or cyanobacteria could be the main factor that favors small zooplankton species in these lakes because they are better competitors than large herbivorous filterfeeders in the presence of large inedible algae [62].…”

Humic lakes with inefficient and efficient transfer of matter in planktonic food webs

“…This species could be considered a valuable food source due to its high concentration of polyunsaturated fatty acids (especially EPA and C18 PUFAs), but it is too large for most zooplankton to ingest 33 . However, some species such as Asplanchna priodonta , Eudiaptomus gracilis and Holopedium gibberum can feed on G. semen at high rates 17 , 34 . The results of our study suggest that A. priodonta could have an advantage over other zooplankton species during the domination of G. semen in phytoplankton, while E. gracilis and H. gibberum were negatively related to G. semen biomass.…”

Transfer efficiency of carbon, nutrients, and polyunsaturated fatty acids in planktonic food webs under different environmental conditions

“…The well‐oxygenated hypolimnion in oligotrophic lakes creates favorable habitat for large cold‐water species and increases zooplankton species richness, which further promotes the effective transfer of matter (Karpowicz, Ejsmont‐Karabin, et al., 2020). Decreases in TTE can also be attributed to an increase in inedible algae in the eutrophic lakes, which were dominated by filamentous cyanobacteria, while in dystrophic lakes there was commonly mass development of the large raphidophyte Gonyostomum semen (Pęczuła et al., 2018). Therefore, our study indicated that different disturbances like eutrophication and dystrophication similarly decrease the TTE of matter between phytoplankton and zooplankton.…”