1. School of Mathematics and Statistics; University of Canterbury; Christchurch 8140 New Zealand
2. Te Pūnaha Matatini; a New Zealand Centre of Research Excellence; Auckland New Zealand
3. Department of Biology; High Technology Center; University of Bergen; PO Box 7800 Bergen N-5020 Norway
4. Hjort Centre for Marine Ecosystem Dynamics; Bergen 5817 Norway
5. York Centre for Complex Systems Analysis; University of York; York YO10 5GE UK
6. Marine Institute; Rinville Oranmore Co Galway Ireland