Effects of environmental stressors and their interactions on zooplankton biomass and abundance in a large eutrophic lake
Laen...
Kuupäev
2021
Kättesaadav alates
Ajakirja pealkiri
Ajakirja ISSN
Köite pealkiri
Kirjastaja
Springer
Abstrakt
We assessed long-term impacts of multi-
ple stressors and their interaction on the zooplankton
community of the large, eutrophic, cyanobacteria-
dominated Lake Peipsi (Estonia, Russia). Stressor
dataset consisted in time series (1997–2018) of
temperature, nutrients, pH, water transparency, phy-
toplankton biomass and taxonomic richness. The best
predictors were selected with random forests machine-
learning algorithms and the subsequent models were
constructed with generalized linear modeling. We also
aimed to identify graphical thresholds representing
non-linear, marked responses of abundance or bio-
mass to stressors. Temperature was the dominant
stressor for explaining zooplankton abundance and
biomass, followed by cyanobacteria biomass, total
nitrogen concentration and water transparency. The
effect of water temperature was positive, whereas the
effect of cyanobacteria became negative after their
biomass exceeded a threshold of * 2 mg l-1 . How-
ever, the two stressors together had antagonistic
effects on zooplankton, causing a decrease in biomass
and abundance. For zooplankton, critical thresholds of total nitrogen (* 700 lg l-1 ), total phosphorus
(* 70 lg l-1 ), and water transparency (* 1.4 m)
after which zooplankton metrics changed drastically,
were determined. These findings show that although
lake warming alone could be positive for zooplankton,
the necessity of reducing interacting stressors that
influence harmful cyanobacteria growth and biomass,
especially nitrogen loads, must be considered.
Funding was provided by Estonian Research Council PSG32.
Funding was provided by Estonian Research Council PSG32.
Kirjeldus
Märksõnad
zooplankton, large lake, random forests, cyanobacteria, eutrophication, stressor interaction, articles