PhD position: Modelling stability and thresholds in Lake Victoria's food web subject to eutrophication and fishery

Co-supervised by (Wageningen University, Aquatic Ecology and Waterquality Group, NIOO Center for Limnology)

The position is part of an integrated research project on " Exploitation or eutrophication as threats for fisheries? Disentangling social and ecological drivers of ecosystem changes in Lake Victoria, Tanzania (SEDEC)" awarded by NWO.

Background:
Lake Victoria is the second largest freshwater lake and supports the largest freshwater commercial fishery in the world. Eutrophication and fisheries drive Lake Victoria's changing ecosystem with far-reaching consequences for exploitation patterns, livelihoods and trade. The changes in Lake Victoria's food web are driven both by top-down (e.g. fishing influenced by trade and management) and by bottom-up processes (e.g. eutrophication). Both processes structure the food web and thus the resource base of the fishery, yet no attempt has been made to link them to understand feedbacks in food webs, resource use patterns and trade. Our main objective is to unravel the social and ecological drivers of ecosystem change and to develop long-term strategies to deal with the combined risks of these ecosystem changes. The responses of the fishery to changes caused by increased eutrophication as well as the responses of Nile perch stocks to the combined impacts of size selective fishing and eutrophication will be researched in four inter-related projects. A detailed project outline can be found here <http://www.afi.wur.nl:90/NR/rdonlyres/6A7FBFEB-50EA-4B31-B338-0492DE2A1 CCB/51182/Victoriafullproposal_wobudget.pdf> .

The PhD project we are now seeking candidates for is will be a modelling study to unravel interactions and feedbacks resulting from eutrophication or fishery as most likely factors driving changes in Lake Victoria's food web. Dominant interactions will be further explored to assess the risk of potential future regime shifts, using models of different levels of complexity.

We are searching for: Highly motivated individuals with a keen interest in ecology and mathematical modelling, and the ability to work both independently and in a multi/interdisciplinary team.

Qualifications: Master degree ; Knowledge of mathematical modelling techniques and basic dynamical systems theory ; Excellent analytical capacity ; fluency in written and spoken English. We offer: A full-time PhD position for an initial period of one year, with the intent of extension to four years after an assessment of proven abilities, that should lead to a dissertation and PhD degree. Conditions are based on the Collective Employment Agreement of the Dutch Universities and are supplemented with a holiday allowance of 8 % per year. Start date: from 1 March 2008 on Information and application:

Prof. Dr. Marten Scheffer (tel. +31- (0)317- 484039 marten.scheffer at wur.nl

Dr. Egbert van Nes (tel. +31- (0)317- 482733 Egbert.vanNes at wur.nl

Dr. Wolf Mooij (tel. +31- (0)294 239 352 w.mooij at nioo.knaw.nl

How to apply: Applications, including a curriculum vitae, a letter motivating your application and a statement of your research interests, the names and addresses of 2 referees, and must be sent, before 21-3-2008 to: (preferably by email: Marijke.Kuipers at wur.nl or alternatively by mail to Marijke Kuipers, AEW, PO Box 47, 6700 AA Wageningen, The Netherlands)