The contemporary communication context includes heightened risk, increasing the need for dialogic or relational risk communication with key stakeholders. Scholars have identified social media's potential to improve dialogic communication, yet governments may face challenges when using social media, particularly in a risk communication context. This study explored social media use in "the complex communication context of risk communication" (Sellnow et al., 2009, p. 53) within the under-studied U.S. public sector and applied a complexity and relational theoretical framework to explore the intersection of government public relations, risk communication, and social media. Questions focused on how government communicators in high-risk environments perceived the public sector context influences their risk communication and social media communication; how they viewed social media's role in risk communication; the extent to which they engaged in social-mediated relational risk communication; and, how they planned and executed social media communication. An ethnographic case study of the U.S. Coast Guard's social media program was conducted, including analysis of 205.25 participant observation hours at the headquarters social media office, 10 interviews, and 49 documents.

Findings suggest that organizations with risk-related missions or responsibilities may have a "risk communication mindset" that spurs and constrains social media communication and integrates social-mediated risk communication into ongoing public affairs. Intersecting, overlapping influences within public sector contexts also influenced social media strategies and tactics. Data suggest a continuum exists between organizations participating in and hosting social media engagement. Findings suggest moving toward a multivocal conversational relational communication model that encompasses the distributed public relations model (Kelleher, 2009). The dissertation adds depth to the human conversational voice construct (e.g., Bruning, et al., 2004; Kelleher, 2009; Sweetser & Metzgar, 2007) and online relational maintenance strategies by offering a behind-the-scenes understanding of why and how government organizations can be engaging and conversational hosts via social media by inviting audiences to engage without organizations having to maintain conversations. The study offers practical recommendations such as reducing blog content to increase efforts using more engaging platforms like Facebook; increasing use of visually-rich and engaging content; cultivating internal relationships to improve personnel compliance and participation; and, improving strategic integration and evaluation.