Ecopath with Ecosim (EwE) is an ecological modeling software suite for personal computers that has built and extended on for almost twenty years (see https://ecopath.org). EwE has three main components: Ecopath – a static, mass-balanced snapshot of the system; Ecosim – a time dynamic simulation module for policy exploration; and Ecospace – a spatial and temporal dynamic module primarily designed for exploring impact and placement of protected areas. The Ecopath software package can be used to address a wide variety of ecological research and management questions.
EwE is the first ecosystem level simulation model to be widely and freely accessible. As of January 2018, EwE has an estimated 8000 users in over 170 different countries and well over 800 publications, making EwE an important modelling approach to explore ecosystem related questions in marine science.
Dr. Kim de Mutsert has used EwE to develop spatially and temporally explicit community models of living resources in Louisiana and the Mississippi River delta. The Louisiana model is designed to help the state develop and implement the most effective restoration and protection projects for all stakeholders in Louisiana. In contrast, Mississippi River Delta model is designed to determine how sediment and freshwater diversions in the lower Mississippi River Deltaic Plain affect the distribution and biomass of fish.
In addition, NOAA’s Chesapeake Bay Office has developed a Chesapeake Bay implementation of EwE (Chesapeake Bay Fisheries Ecosystem management Model or CBFEM). In this implementation, Ecopath uses the biomass estimations of 45 trophic groups representing the fisheries species of the Bay and their prey and predators to create a mass-balanced snapshot of the organisms and trophic linkages in the Bay as it may have been in 1950 (Townsend, 2014). The snapshot provides the base model for time-dependent Ecosim simulations. The CBFEM Ecosim module provides a 53-year (1950–2002) simulation that attempts to estimate the current status and dynamics of the Bay’s fish species (Townsend, 2014).
Reference:
Townsend, H. 2014. ‘Comparing and coupling a water quality and a fisheries ecosystem model of the Chesapeake Bay for the exploratory assessment of resource management strategies’, ICES Journal of Marine Science, 71: 703-12.