Impacts of hypoxia and planktivory on crustacean and rotifer diel vertical and horizontal migration behaviors
Résumé
Zooplankton perform daily migrations between pelagic surface waters, where they feed at night, and either deeper waters (diel vertical migration, DVM) or littoral areas (diel horizontal migration, DHM), where they avoid visual predators or damaging ultraviolet radiation during the day. Diel migration patterns can change based on environmental stressors and food web perturbations, and these behavioral changes have implications for ecological processes in lakes. We hypothesized that crustacean DVM decreases and DHM increases in ponds with hypoxic bottom waters and that DVM and DHM are more extensive with higher planktivory by fish. To address our hypotheses, we assessed crustacean and rotifer community composition and daily migration behavior across pelagic and littoral zones of 16 shallow experimental ponds with differing dissolved oxygen concentrations and planktivorous fish densities in August 2019. Community metrics were driven by habitat, with littoral samples containing a higher taxa richness and diversity of crustaceans and rotifers compared to pelagic samples. DVM and DHM behaviors varied widely based on taxonomic groups. Hypoxia and planktivory had minor effects on zooplankton community metrics and migration behaviors. Our findings contribute to the body of knowledge regarding interactive impacts of hypoxia and planktivory on zooplankton communities and behavioral dynamics in shallow ponds.
Auteurs, date et publication :
Auteurs Anna G. Schmidt , Isabel M. Anderson , Rosalie Bruel , Rosaura J. Chapina , Jonathan P. Doubek , Sarah Fiorini , Sadye K. Goldfarb , Gérard Lacroix , Heather L. Wander , Savannah Zigic , Jason D. Stockwell
Publication : Hydrobiologia
Date : 2024