A Comparative Analysis Approach to Reducing Vessel Strikes on the Florida Manatee

Abstract

The Florida manatee (Trichecheus manatus latirostris) is an endangered species, having been listed in the first U.S. federal endangered species legislation in 1967. However, forty years later, they have not been removed from endangered status. Watercraft collisions with manatees have been estimated to have the greatest impact on their population sustainability. These accidents account for about a quarter of manatee deaths every year. The Florida registered boater population has now reached almost one million registered boaters, and the manatee population is growing as well. Consequently, the frequency of manatee-vessel collisions is likely to become even more frequent. A comparison of terrestrial wildlife collision management measures, primarily of ungulates, to the mitigation management schemes for the Florida manatee was undertaken. A unique approach to viewing the problem after decades of management may provide new insights and approaches to reduce occurrence of manatee-boat collisions. Based on the findings from this research, the application of many terrestrial wildlife collision mitigation measures are inappropriate to reduce manatee-boat strikes. However, some of the terrestrial strategies may be appropriate if the manatee population becomes more imperiled. Aggressive management techniques such as marine fencing, seagrass management, and measures to encourage or force boaters to reduce speed may become necessary. Lessons from effective signage from the terrestrial environment can be successfully applied to signage in the marine environment indicating that further work in this area should be a priority for marine wildlife managers.