The Florida manatee (Trichechus manatus latirostris) is a unique element of the U.S. fauna. It is a distinct subspecies of the West Indian manatee (Domning and Hayek 1986) and one of the largest inshore mammals of the continent, reaching weights to 1,650 kg (Rathbun et al. 1990). Annual migratory circuits of some individuals through the intracoastal waterways of the Atlantic Coast are 1,700 km round trips at seasonal travel rates as high as 50km/day (*3 Reid and O'Shea 1989; Reid et al. 1991), resulting in one of the longest remaining intact mammalian migrations in the eastern United States.