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Preliminary PhD workplan Magnus Aune Wiedmann. Myself. Magnus Aune Wiedmann 27 years old, married to Ingrid, no children Master in Marine Ecology, University of Tromsø, spring 2010. Supervisors: Ole Petter Pedersen & Kurt Tande Worked as research assistant at UiT autumn 2010
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Preliminary PhD workplan Magnus Aune Wiedmann
Myself • Magnus Aune Wiedmann • 27 years old, married to Ingrid, no children • Master in Marine Ecology, University of Tromsø, spring 2010. Supervisors: Ole Petter Pedersen & Kurt Tande • Worked as research assistant at UiT autumn 2010 • Spare time interests: diving and ocean sailing
Status Paper 1 • Title: Capelin larvae in the Barents Sea: multiple enemies or mainly threatened by herring? • Focus: Spatio-temporally modelled survival of capelin larvae preyed upon by young herring. • Conclusion: - Herring is important, but - Capelin larvae are also threatened by numerous other factors. • Status: Submitted to the Canadian Journal of Fisheries and Aquatic Sciences • Relates to BarEcoRe: - Feeding relationship - Ecosystem fluctuations
Paper 2 • Title: Vulnerable species in the Barents Sea • Background: - Increased temperatures decreased organism size (Daufresne et al. 2009) - fisheries modifies age compositions and increase fish abundance variability (Hsieh et al. 2006) • Approach: - Study fish length distributions through time. - Study the number of species vs. the number of individuals at specific areas through time. • Goal: - Any changes in length structure? - Establish a ”vulnerable species list” - Are we ”fishing down the foodweb” in the Barents Sea? • Submission: Autumn 2011?
Paper 3 • Title: Functional redundancy in the Barents Sea fish community • Background: Species interacting with many other species might be destabilizing for the ecosystem network (Wilmers 2007), and can be unrobust (Wilmers et al. 2002). • Approach:- Study the degree of ecological /trophic overlap. - Will use cluster and multivariate analyses. - Based on information that soon will be available from a fish life trait matrix. • Aim: - Identify the food web structure of the Barents Sea by means of ecological overlap between species. - This will be connected to their redundancy. • Submission: Late spring 2012?
Paper 4 • Title: BS fish communities: resilience and early warning signals • Approach: - Identify possibly reduced BS ecosystem resilience - Identify possibly approaching critical transitions (Scheffer et al. 2009). - Study early warning signals by means of potential changes in fish abundance variance and autocorrelation • Aim: - Assess how the results from the latter two papers (Paper 2+3) in combination can explain changes in fish abundance. - Estimate engineering resilience • Submission: Spring 2013
Other possible papers • Barents Sea food web compartmentalization • ?
Deliverables - BarEcoRe • Paper 1: Feeding relationship, ecosystem fluctuations • Paper 2: Vulnerable species list • Paper 3: Functional redundancy/diversity • Paper 4: Resilience, early warning signals
Progression • Literature study • Started on a fish life history table • This spring: much focus on university courses
References Daufresne, M., Lengfellner, K. and Sommer, U. 2009. Global warming benefits the small in aquatic ecosystems. Proc. Nat. Ac. Sci. 106: 12788-12793. Hsieh, C., Reiss, C.S., Hunter, J.R., Beddington, J.R., May, R.M. and Sugihara, G. 2006. Fishing elevates variability in the abundance of exploited species. Nature 443: 859-862. Levin, S.A. and Lubchenco, J. 2008. Resilience, robustness and marine ecosystem-based management. Bioscience 58: 27-32. Scheffer, M. et al. 2009. Early-warning signals for critical transitions. Nature 461: 53-59. Wilmers, C.C. 2007. Understanding ecosystem robustness. TREE 22: 504-506. Wilmers, C.C., Sinha, S. and Brede, M. 2002. Examining the effects of species richness on community stability: an assembly model approach. OIKOS 99: 363-367.