Science 304: 1463-1466 4June2004

•There is no single, fully integrated model that can simulate all possible ocean ecosystem states •The key steps in representing extended food webs in complex marine systems are (i) to concentrate the biological resolution, or detail of representation, in the main target species and (ii) make increasing simplifications, or decrease in resolution, with distance both up and down the trophic scale from the target species (the “rhomboid” or “middle out” approach).