Different effects of planktonic invertebrate predators and fish on the plankton community in experimental mesocosms

Mgr. Michal ŠORF

Rigorózní práce

Abstract:

The impact of fish and cyclopoid copepod predation on zooplankton communities was evaluated using large-volume mesocosms (depth 9.5 m; volume 13 m3) in the Římov reservoir (Czech Republic). Two yearling roach and perch individuals introduced into mesocosms represented the fish treatment, which was compared to cyclopoid copepods (initial abundance of 2 ind.L-1) and a control with no initial addition of predators. Our results clearly support the hypothesis that planktivorous fish feeding leads to the suppression of large-bodied cladocerans. In the presence of fish, the cladoceran community changed from a dominance of large-bodied Daphnia spp. at the beginning to dominance by the smaller Bosmina longirostris at the end of the experiment. The overall strong effect of fish over cyclopoid predation suggests the main role of fish predation in the forming of zooplankton communities and in turn impacting phytoplankton biomass in mesocosms.

Jazyk práce: angličtina

Datum vytvoření / odevzdání či podání práce: 15. 1. 2014

Zveřejnit od: 15. 1. 2014

Obhajoba závěrečné práce

• Obhajoba proběhla 18. 2. 2014

JIHOČESKÁ UNIVERZITA V ČESKÝCH BUDĚJOVICÍCH

Přírodovědecká fakulta

Rigorózní řízení / obor:
Biologie / Biologie ekosystémů