Author: Hailey Shoptaugh

Publisher:

Published: 2022

Total Pages: 0

ISBN-13:

"Trophic cascades have frequently been observed in aquatic ecosystems. For example, the common snapping turtle (Chelydra serpentina), can reduce prey populations and trigger long-lasting phytoplankton blooms after short visits. This study aimed to disentangle both direct and indirect effects of common snapping turtles in experimental ponds. Each experimental pond contained food webs differing in predator presence with large and small apex predators (Chelydra serpentina), mesopredator presence (Notophthalmus viridescens), and herbivorous prey (Rana catesbeiana tadpoles). I predicted a direct effect of turtle predation on newts and tadpoles and that snapping turtle predation on newts would cause higher tadpole survival and growth, which indirectly would decrease algal biomass. Tadpoles had the largest masses in food webs with large turtles and newts. Tadpoles with newts and large turtles were further along developmentally than tadpoles in other food webs. Newt survival differed between food webs and appeared to be lowest in food webs with small turtles. There was no statistical difference in algal biomass among food webs at the conclusion of the experiment. Overall, these results highlight that a trophic cascade may occur in freshwater ponds following short term visits by common snapping turtles, but their role is complex and may be size dependent."--Abstract.