Biodiversity Change in Marine Food Webs – The Consequences of Species Loss for Food Web Structure and Ecosystem Functioning

Biodiversity Change in Marine Food Webs

Biodiversity Change in Marine Food Webs – The Consequences of Species Loss for Food Web Structure and Ecosystem Functioning

Researcher:  Marion Twomey

Email:  marion.twomey@mars.ucc.ie
Telephone:  021 4901944

Project Description

Funding Body: IRCSET
Programme: IRCSET
Project type: PhD.
Period: October 2007 - 2009


To date, food web studies have largely focused on small-scale manipulative experiments, which examine the direct impact of a disturbance on single trophic levels.  Yet food webs are complex structures with highly connected species.  Understanding the consequences of indirect effects of biodiversity change across multiple trophic levels remains a significant challenge, one which we address in this project.  We will construct a comprehensive data set, documenting existing food web structure and community composition, including abundance, body size and feeding links of species across multiple trophic levels.

The food web will then be perturbed in-situ by reducing and enhancing the densities of two species, the highly connected herbivore, Paracentrotus lividus, and a highly connected intermediate predator, Marthasterias glacialis.  The resultant effects of each manipulation on food web structure and ecosystem functioning (decomposition, primary productivity) will then be determined over a 12 month period, as these press perturbations are applied.  This large scale in-situ manipulation of a natural food web will allow us to explore species loss at larger scales and across many trophic levels.  It will also provide an experimental framework against which to test model predictions of the responses of different species to perturbations.

Environmental Research Institute

University College Cork, Lee Road, Cork

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