Ecopath with Ecosim
Developer(s)Ecopath Research and Development Consortium
Initial release1992
Stable release
6.6.8 / 04 November 2022
Preview release
6.7 alpha (on request) / 04 November 2022
Written inVisual Basic.NET, C#
Operating systemWindows Vista (non-supported), 7, 8*, 10, 11 (EwE desktop version), Unix and Linux (EwE core via Mono)
Platform.NET Framework 4.8
Available inEnglish
TypeEcosystem model
LicenseGPL v2

Ecopath with Ecosim (EwE) is a free and open source ecosystem modelling software suite, initially started at NOAA by Jeffrey Polovina, but has since primarily been developed at the formerly UBC 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".[1] Behind this lie more than three decades of development work in association with a thriving network of fisheries scientists such as Villy Christensen, Carl Walters and Daniel Pauly, and software engineers around the world. EwE is funded through projects, user contributions, user support, training courses and co-development collaborations. Per November 2021 there are an estimated 8000+ users across academia, non-government organizations, industry and governments in 150+ countries.


EwE has three main components:


The Ecopath software package can be used to:

Development Ecopath version 6.0[15] received support from the Lenfest Ocean Program and the Pew Charitable trusts. In 2011 the Ecopath Research and Development Consortium was founded to share the responsibility of maintaining and further developing the approach with institutions around the world. EwE exclusively relies on user involvement for continued software development and releases of new versions.

The desktop version of Ecopath with Ecosim runs only on Windows and requires Microsoft Access database drivers version 2007 or newer. The computational core of Ecopath with Ecosim can be executed on other operating systems such as Unix or Linux using the Mono common language runtime.[16] Spin-off versions in R, Matlab and Fortran are developed independently of the main desktop version of EwE, and are not supported by the Ecopath Research and Development Consortium.


In 2013, development efforts were centralized under Ecopath International Initiative, Spain, which coincided with a switch to a community-driven development model overseen by the Ecopath Research and Development Consortium.[17] As the approach does not receive any core funding, the Ecopath with Ecosim approach now relies entirely on user-contributed project funding for continued development and releases.


  1. ^ NOAA, 2007. ECOPATH Modeling: Precursor to an Ecosystem Approach to Fisheries Management [WWW Document]. URL (accessed 8.26.12).
  2. ^ 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.
  3. ^ 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
  4. ^ 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.
  5. ^ Sinnickson, Dylan; Chagaris, David; Allen, Micheal (10 June 2021). "Exploring Impacts of River Discharge on Forage Fish and Predators Using Ecopath With Ecosim". Frontiers in Marine Science. 8. doi:10.3389/fmars.2021.689950. ProQuest 2539744082.
  6. ^ Christensen, V. and Pauly, D. (Editors), 1993. Trophic Models of Aquatic Ecosystems. ICLARM Conference Proceedings 26, Manila, 390 p.
  7. ^ 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.
  8. ^ Christensen, V. and Walters, C.J., 2004. Trade-offs in ecosystem-scale optimization of fisheries management policies. Bull Mar Sci, 74:549-562
  9. ^ Walters, C.J. and Martell, S.J.D., 2004. Fisheries Ecology and Management. Princeton University Press, Princeton, 399 p.
  10. ^ 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. UBC Fisheries Centre Research Reports 14(3). Fisheries Centre, University of British Columbia [ISSN 1198-6727], Vancouver
  11. ^ Walters, William J.; Christensen, Villy (2018). "Ecotracer: analyzing concentration of contaminants and radioisotopes in an aquatic spatial-dynamic food web model". Journal of Environmental Radioactivity. 181: 118–127. doi:10.1016/j.jenvrad.2017.11.008. ISSN 0265-931X. PMID 29145014.
  12. ^ Guénette, Sylvie; Heymans, Sheila JJ; Christensen, Villy; Trites, Andrew W (2006). "Ecosystem models show combined effects of fishing, predation, competition, and ocean productivity on Steller sea lions (Eumetopias jubatus) in Alaska". Canadian Journal of Fisheries and Aquatic Sciences. 63 (11): 2495–2517. doi:10.1139/f06-136. ISSN 0706-652X.
  13. ^ Christensen, Villy; Coll, Marta; Steenbeek, Jeroen; Buszowski, Joe; Chagaris, Dave; Walters, Carl J. (2014). "Representing Variable Habitat Quality in a Spatial Food Web Model". Ecosystems. 17 (8): 1397–1412. doi:10.1007/s10021-014-9803-3. ISSN 1432-9840. S2CID 3896465.
  14. ^ Steenbeek, Jeroen; Coll, Marta; Gurney, Leigh; Mélin, Frédéric; Hoepffner, Nicolas; Buszowski, Joe; Christensen, Villy (2013). "Bridging the gap between ecosystem modeling tools and geographic information systems: Driving a food web model with external spatial–temporal data". Ecological Modelling. 263: 139–151. doi:10.1016/j.ecolmodel.2013.04.027. ISSN 0304-3800.
  15. ^ Christensen, V. and Lai, S., 2007. Ecopath with Ecosim 6: the sequel. The Sea Around Us Project Newsletter, 43:1-4 (September–October).
  16. ^ Steenbeek, Jeroen; Buszowski, Joe; Christensen, Villy; Akoglu, Ekin; Aydin, Kerim; Ellis, Nick; Felinto, Dalai; Guitton, Jerome; Lucey, Sean; Kearney, Kelly; Mackinson, Steven; Pan, Mike; Platts, Mark; Walters, Carl (January 2016). "Ecopath with Ecosim as a model-building toolbox: Source code capabilities, extensions, and variations". Ecological Modelling. 319: 178–189. doi:10.1016/j.ecolmodel.2015.06.031.
  17. ^ Heymans, J.J.; Coll, Marta; Link, J.S.; Mackinson, Steve; Steenbeek, Jeroen; Christensen, Villy (2016). "Best practice in Ecopath with Ecosim food-web models for ecosystem-based management". Ecological Modelling. 331: 173–184. doi:10.1016/j.ecolmodel.2015.12.007.