Florence Briton, Université Pierre et Marie Curie, France, will present the Department of Biological Sciences seminar wtih a talk entitled, "Setting reference points for ecosystem indicators".  

The study investigates the possibility to determine ecosystem indicators’ reference points that could be used to support an Ecosystem Approach to Fisheries. In particular, we explored their variability when the ecosystem is exploited under a wide range of fishing strategies. The analysis was carried out using a simulation approach based on the ecosystem model OSMOSE in the Southern Benguela. We show that, for the 13 studied indicators, reference points associated with the Multi-species Maximum Sustainable Yield (MMSY) were highly dependent on fishing strategy. Without any assumption on the way an ecosystem is exploited, the reference points of those indicators were not very helpful in detecting whether the total catch taken was close to or far from reaching the MMSY. We used Principal Component Analysis (PCA) on model simulation results to explore the possibility of identifying particular reference points for seven typical exploitation strategies. The ranges of values covered by the reference points were generally reduced when typical strategies were considered independently. This allowed us to determine usable reference points under some typical fishing strategies. Usable reference points were also identified for the Southern Benguela when MMSY was reached under past fishing strategies from 2003-3012.