TEMPERATURE AND SESTON STOICHIOMETRY DRIVE SEASONAL SHIFTS IN ZOOPLANKTON ELEMENTAL COMPOSITION AND BIOMASS

Seston elemental composition and temperature interact to shape the elemental composition, population dynamics, and biomass of zooplankton communities. However, the nature of these interactions are poorly understood in natural environments, particularly during early spring and with multiple zooplankton taxa. Here, we investigate seasonal shifts in seston and zooplankton elemental composition and biomass. Beginning in March, we conducted weekly sampling in a eutrophic, dimictic, small lake in southeast Michigan, USA. Seston samples were collected from the photic zone to measure elemental composition and chlorophyll a concentration.  Additionally, we assessed zooplankton biomass and analyzed elemental composition and abundance of two zooplankton taxa: Daphnia and copepods. Our findings reveal that Daphnia exhibited higher phosphorus (P) content than copepods, consistent with the growth rate hypothesis. However, both Daphnia and copepods had a rapid decline in their %P and carbon (C) body composition during early spring as temperatures increased. Cyclopoid copepods dominated early spring biomass but by May, the biomass of Daphnia and cyclopoid copepods biomass began to converge. These results highlight the temperature-dependency of zooplankton elemental composition among taxa and the role of seston stoichiometry in shaping elemental dynamics within zooplankton communities.

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Primary Presenter: Hailee Mersino, Oakland University (hmersino@oakland.edu)

Authors:

Hailee Mersino, Oakland University  (hmersino@oakland.edu)

Olivia Sowa, Oakland University  (oliviasowa@oakland.edu)

Clay Prater, University of Arkansas  (praterc@uark.edu)

Nicole Wagner, Oakland University  (nicolewagner@oakland.edu)