Atlantic and Caribbean areas, it discusses the construction of quantitative (Ecopath-Ecosim-Ecospace and Centrality of Node Sets) and semi- quantitative (Loop Analysis) multispecies trophic-network models to describe and assess the impacts of natural and human interventions like pelagic and benthic fishing as well as natural events such as El Niño, and La Niña. The book also features steady state (and/or near moving equilibrium) and dynamical models to support the management of exploited organisms, and applies and quantifies macroscopic indices, based on Ascendency (Ulanowicz) and Local Stability (Levins¿ Loop Analysis). Further, it discusses the determination of the Keystone Species Complex Index, which is a holistic extension of the classical concept of Keystone Species (Paine), offering novel strategies for conservation monitoring and management.