Abstract

1. The present study compares the propagation of effects observed as a response to changes in the abundance of a top predator (top-down cascading effect) in a benthic community within the south-east Pacific upwelling ecosystem of northern Chile, with predictions derived from quantitative and qualitative multispecific models. 2. Results with Loop Analysis achieved 71.4% of predictive certainty; indicating that this technique is useful for assessment of the effects of human intervention related to the mud-bottom ecosystem tested. On the other hand, Ecosim using bottom-up flow control mechanism achieved only 14.3% certainty. In an intermediate range, predictions obtained using the Mixed Trophic Impacts and Ecosim models using top-down, mixed and flow control mechanisms estimated by the program, achieved 57.1% certainty. 3. The results obtained have important implications for the management of communities and ecosystems since human interventions can be studied using holistic models with an end result of evaluating the eventual changes that they propagate. Copyright © 2007 John Wiley & Sons, Ltd.