Ecopath with Ecosim (EwE) is a free ecosystem modelling software suite, initially started at NOAA by Jeffrey Polovina, but has since primarily been developed at the Fisheries Centre of the University of British Columbia. In 2007, it was named as one of the ten biggest scientific breakthroughs in NOAA’s 200-year history. The NOAA citation states that Ecopath “revolutionized scientists’ ability worldwide to understand complex marine ecosystems”.[full citation needed] Behind this lies two decades of development work in association with Villy Christensen, Carl Walters, Daniel Pauly, and other fisheries scientists, followed with the provision of user support, training and co-development collaborations. Per January 2012 there are 6000+ registered users in 150+ countries.
^Christensen, V. and Pauly, D., 1992. Ecopath II - a software for balancing steady-state ecosystem models and calculating network characteristics. Ecological Modelling, 61:169-185.
^Walters, C., Christensen, V. and Pauly, D., 1997. Structuring dynamic models of exploited ecosystems from trophic mass-balance assessments. Rev Fish Biol Fish, 7:139-172
^Walters, C., Pauly, D. and Christensen, V., 1999. Ecospace: Prediction of mesoscale spatial patterns in trophic relationships of exploited ecosystems, with emphasis on the impacts of marine protected areas. Ecosystems, 2:539-554.
^Christensen, V. and Pauly, D. (Editors), 1993. Trophic Models of Aquatic Ecosystems. ICLARM Conference Proceedings 26, Manila, 390 p.
^Walters, C.J., Christensen, V., Martell, S.J. and Kitchell, J.F., 2005. Possible ecosystem impacts of applying MSY policies from single-species assessment. ICES J Mar Sci, 62:558-568.
^Christensen, V. and Walters, C.J., 2004. Trade-offs in ecosystem-scale optimization of fisheries management policies. Bull Mar Sci, 74:549-562
^Christensen, V. and Booth, S., 2006. Ecosystem modeling of dioxin distribution patterns in the marine environment. Chapter 6. In: J. Alder and D. Pauly (Editor), On the multiple uses of small pelagic fishes: from ecosystems to markets. Fisheries Centre Research Reports 14(3). Fisheries Centre, University of British Columbia [ISSN 1198-6727], Vancouver
^Guénette, S., Heymans, J.J., Christensen, V. and Trites, A.W., 2006. Ecosystem models show combined effects of fishing, predation, competition, and ocean productivity on Steller sea lions (Eumetopias jubatus) in Alaska. Can J Fish Aquat Sci, 63:2495-2517.
^Ecopath with Ecosim Website Downloads Retrieved 4 May 2012.
^Christensen, V. and Lai, S., 2007. Ecopath with Ecosim 6: the sequel. The Sea Around Us Project Newsletter, 43:1-4 (September–October).