Evaluation of interventions focused on reducing propeller scarring by recreational boaters in Florida, USA

Abstract Propeller scarring by recreational vessels is a known threat to seagrass meadows in Florida. Despite decades of awareness about the problem, there has been little meaningful progress in addressing this largely preventable stressor. We consider it preventable because it rests on human behaviors, which can be changed by education, technology, social norms, and policy. However, past attempts to address seagrass scarring have rarely been evaluated for effectiveness. Thus, very little guidance exists for natural resource managers, educators, and policy makers responsible for allocating limited resources toward effective interventions. Using a social marketing approach, we deployed two separate interventions, one education-based and the other cue-based (navigational aids) in Florida, USA. We measured boater behavior and attitudes before and after the interventions to assess the relative effectiveness of each. Navigational aids elicited a clear behavioral improvement across a broad cross-section of boaters, while minimal effects were observed for the educational intervention. However, analyses suggest the recreational boating audience can be segmented by factors such as experience level to better target educational messages in future seagrass protection efforts. These results will assist seagrass managers, educators, advocates, policy makers, and boating industry stakeholders in deploying an efficient combination of approaches to better address propeller scarring in Florida's seagrass meadows.