Ecopath with Ecosim (EwE) is a free and
open sourceecosystem modellingsoftware 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.
Components
EwE has three main components:
Ecopath – a static, mass-balanced snapshot of the system[2]
Ecosim – a time dynamic simulation module for policy exploration[3]
Ecospace – a spatial and temporal dynamic module designed for exploring the combined impacts of fishing, the placement of protected areas,[4] and changing environmental conditions.
facilitate end-to-end ecosystem model construction[14]
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.
Funding
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.
^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
^Walters, C.J. and Martell, S.J.D., 2004. Fisheries Ecology and Management.
Princeton University Press, Princeton, 399 p.
^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
^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.
ISSN0265-931X.
PMID29145014.
^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.
ISSN0706-652X.
^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.
ISSN1432-9840.
S2CID3896465.
^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.
ISSN0304-3800.
^Christensen, V. and Lai, S., 2007. Ecopath with Ecosim 6: the sequel. The
Sea Around Us Project Newsletter, 43:1-4 (September–October).
^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.