A New Sighting Network Adds to 20 Years of Historical Data on Fringe West Indian Manatee (Trichechus manatus) Populations in Alabama Waters
Recent findings suggest increased use of fringe habitats by the endangered West Indian manatee. To begin collecting fundamental data on population dynamics and ecology of fringe manatees in the northern Gulf of Mexico, we established the Mobile Manatees Sighting Network (MMSN), the first formal network to receive and track manatee sightings in Alabama waters. Comparison of MMSN data with compiled historical data indicated that West Indian manatees are regular seasonal visitors to Alabama waters. Historical (1985–2006) and newly collected data shared consistent distributions, seasonal patterns of abundance in sighting number, and group size frequencies. These data indicate that MMSN was as effective at capturing data as two decades of historical sighting reports and suggest consistent long-term patterns in habitat preference and seasonal movements of manatees in Alabama waters. A nearly fourfold increase in number of manatee sightings, with inception of the MMSN, made evident the success of community outreach efforts but also betrayed the potential influence of observers on data quality. The MMSN maintains a 24-hr toll-free phone line, website with interactive online sighting form, and E-mail address to receive citizen sighting reports and provide supporting educational materials. Our data demonstrate that this type of monitoring for manatees in fringe habitat is feasible, effective, and essential to guide local management and recovery efforts of this endangered species.