Understanding public perceptions, values, and preferences can be fundamental to effective conservation governance, management, and outreach. This is particularly true in socially and ecologically complex marine and coastal spaces, where many relevant questions remain. The social-ecological system of Biscayne Bay and Miami-Dade are on the frontier of problems that will soon engulf many coastal-urban systems. Despite the economic, ecological, and cultural importance of Biscayne Bay, research into the social components of this social-ecological system is distinctly lacking. In order to effectively address urgent coastal management issues, practitioners and policy-makers need a clear understanding of public perceptions, values, and priorities. In this paper I present the results of a large online survey (n = 1146) exploring public attitudes toward Biscayne Bay as a case study of management and opportunity in a complex coastal social-ecological system. Results describe a public that interacts with and utilizes Biscayne Bay in a variety of ways, from leisure and recreation, to subsistence. This public believes the Bay to be moderately healthy, though somewhat in decline, and has experienced a range of local environmental threats, about which they feel considerable concern. These interactions and concerns are in turn reflected in overwhelming endorsement of value statements regarding the ecological, material, cultural and economic importance of the ecosystem to the city, as well as high levels of support for policy actions to protect and restore that ecosystem. Together these findings indicate that additional policy steps to preserve and restore Biscayne Bay would enjoy support from the local public and demonstrate the power of public perceptions research to identify gaps and opportunities for management and outreach.