Interest in applying ecosystem-based management (EBM) to marine ecosystems has grown in recent years, but factors that affect its implementation have not been studied extensively. This dissertation focused on three implementation needs: (1) expanding scientific information about the ecosystem, (2) understanding diverse stakeholders’ perceptions and priorities, and (3) incorporating scientific information into management. One study investigated ecosystem change in the Gulf of Maine based on forty years of fish community data. Substantial compositional changes, shifts in biomass and abundance, and marked reductions in organism size were noted across multiple levels of organization, from individual species to the aggregate community. Many of these changes were concentrated in the mid-1980s and early 1990s, suggesting a rapid biological shift in the ecosystem. Another study documented the perceptions of six stakeholder groups regarding EBM. Across the groups, stakeholders viewed EBM as building on a foundation of good resource management that is guided by both scientific information and stakeholder input. However, they also expected EBM to account for complexity in the ecosystem and address cross-jurisdictional issues. Despite some common perceptions and goals, key distinctions between groups were also noted, which may affect their ability to work together to implement EBM. A final study evaluated the effectiveness of ecosystem indicators and state-ofthe-environment (SOE) reports for providing stakeholders and decision-makers with scientific information needed to support EBM. Results show that current indicator and reporting programs do not convey fundamental ecosystem concepts, and improvements are necessary to ensure that they build scientific understandings that are relevant to EBM. Together these three studies highlight the utility of interdisciplinary perspectives and the need for strategic advancement of scientific knowledge to meet the goals of marine EBM.