Mass Balance of Atlantic Oceanic Systems

M. Vasconcellos, R. Watson, (2004). “Mass Balance of Atlantic Oceanic Systems,” Fisheries Centre Research Reports No. 12 (Fisheries Centre, University of British Columbia, Vancouver, Canada

This report describes the methods and data sources used to estimate ecological parameters and to construct mass-balance models of oceanic ecosystem of the Atlantic using the Ecopath with Ecosim (EwE) software. Six models were constructed representing oceanic ecosystems of the North, Central and South Atlantic for the 1950s and the late 1990s (1997-1998). The first section of this report characterizes some of the fundamental characteristics of oceanic ecosystems which were captured in a model template for oceanic areas. The subsequent sections are devoted to individual functional groups, composed of species or group of species that share similar ecological functions, habitats and demographic characteristics, or represent important fisheries resources, such as tunas and swordfish. The last sections describe the approach used to balance the models in EwE and the adjustments made to the late 1990s model so that it could represent the ecosystem state in 1950.