The greatest source of human-related mortality for endangered Florida manatees is collisions with watercraft. Regulation of boat speeds is the principal management tool to minimize this threat. Demands on law enforcement limit their ability to monitor boater behavior and managers seek alternative strategies to increase compliance. The purposes of this study were to: (1) explore the effectiveness of an on-site sign to enhance boater compliance in a boating speed zone, and (2)
Conservation Commission, unpublished data). Despite this effort, the leading identified human-related mortality factor continues to be collisions with watercraft (USFWS, 2001).Concern that boaters have not been adhering to manatee speed zone regulations led to a number of boating studies investigating compliance, and compliance studies are currently included as an objective in the current revision of the manatee recovery plan (USFWS, 2001). As defined by Ridgeway (2000), compliance is a change in behavior toward a group standard to avoid punishment or receive a reward. Because an individual can conform to a standard without personally believing in it, compliance does not necessarily denote an enduring behavioral change. From these boating studies, we can conclude that a myriad of variables both within and between study sites are related to compliance. However, there are two general trends: personal watercraft (e.g., jet skis) tend to be the least compliant vessels (Gorzelany, 1996(Gorzelany, , 1998(Gorzelany, , 2000Gorzelany, 2001;Shapiro, 2001;Tyson & Combs, 1999), and compliance tends to be positively correlated with vessel length (Gorzelany, 1998(Gorzelany, , 2001Shapiro, 2001; Tyson & Coombs, 1999; but see Tyson, 2001). Other identified relationships between compliance and observed variables (e.g., direction of travel) tend to vary among sites (Shapiro, 2001).Previous research on boating behavior in manatee speed zones indicates that the presence of law enforcement mediates compliance (Gorzelany, 1996(Gorzelany, , 1998(Gorzelany, , 2001Shapiro, 2001; Tyson& Coombs, 1999). This was further supported by a survey of Florida boaters in the Tampa Bay region that asked respondents about variables influencing compliance (Aipanjiguly et al., 2003). However, demands on wildlife officers at the local, state, and federal levels as well as the widely dispersed locations of manatee zones around the state, preclude the officers' ability to maintain a persistent presence in manatee zones. Thus, wildlife managers seek strategies to increase compliance without increasing the burden on law enforcement agencies.The purpose of this study was twofold: to investigate the effect of an alternative method of increasing compliance and to examine covariates that may help law enforcement understand and predict noncompliance. First, we examined the effectiveness of a supplemental on-site sign with messages providing two possible consequences of noncompliance (i.e., being sanctioned and colliding with a manatee) as well as the proper coping mechanism to avoid these ...