Marine ecosystems and resources are often shared by neighboring states. Moreover, pollution, habitat degradation, and depleted resources in the world's oceans are problems that do not occur in isolation, but transcend national jurisdictions. In recognition of these problems and the plight of the marine environment, a need for the sustainable management of the ocean emerged in recent decades. Yet, due to the shared nature of this common resource, it became apparent that management must be coordinated among states. Regional ocean governance regimes were thus pursued as the appropriate unit for managing a shared ocean area - states neighboring a marine ecosystem or politically defined area began to coordinate their efforts toward mitigating regional ocean issues. The United Nations Environment Programme Regional Seas Programmes and the Large Marine Ecosystem projects, undertaken by countries bordering a Large Marine Ecosystem, and with initial funding provided by the Global Environment Facility, among others, are important regimes that have emerged to answer the call for regional governance. Today, however, in spite of a growing number of regional efforts and agreements, the global oceans community has become aware that we are falling short of meeting the goals of sustainable management and development. This study expands the knowledge base regarding the formation, dynamics, and effectiveness of regional ocean governance regimes in an effort to better understand when, how, and why these regimes work. Specifically, the research seeks to address the following: what are the "on the ground" effects of regional ocean governance regimes; to what extent do various regime features play a role in increasing or decreasing effectiveness; and which factors determine whether an existing regime becomes effective, and remains so over time? The literature review within the study investigates existing analyses of effectiveness in international environmental regimes and, further, those specific to ocean governance, to place the dissertation in the context of previous research and identify established factors in regime formation, regime attributes, and regime dynamics that play a key role in regime effectiveness. Based on the literature, definitions that guide the study are developed: (1) Regional Ocean Governance Regime - a regional ocean governance regime is a social institution composed of geographically proximate states that maintain agreed upon principles, norms, rules, procedures, and programs that govern the interactions of actors in their respective ocean area. (2) Effectiveness in Regional Ocean Governance Regimes - a regional ocean governance regime is effective when it changes the behavior of actors in a regional ocean area in such a manner that the problems and issues for which the regime was formed are solved or greatly reduced.