Photo-Identification

Documenting individual manatees over long periods of time allows researchers to compile life histories of these distinctive individuals, which can then be used to calculate reproductive rates, adult survival rates, site fidelity and seasonal movement patterns. Federal and state managers are using these data in their decisions regarding population assessment, recovery and management strategies of this endangered marine mammal.

Many Florida manatees bear scars and markings, primarily from collisions with boats, but also from entanglement in fishing gear and from fungal infections. These scars and markings usually form distinctive patterns and shapes that researchers use to identify individual manatees. Photo-identification studies document sightings of individual manatees by photographing their distinctive scars and markings. Data collected during sightings include when and where the manatee was observed and its size class (calf, sub adult, or juvenile, or adult). Data are collected throughout the range of the Florida manatee and compiled into a statewide database that was initiated by USGS Sirenia Project in the late 1970s. This statewide database is currently maintained through a partnership of USGS Sirenia Project, Florida Fish and Wildlife Conservation Commission and Mote Marine Laboratory.

Mote Marine Lab began photo-identification efforts in Southwest Florida in 1993. Initial focus was on specific sites within and near Sarasota Bay that were identified as "manatee hot spots" by the long-term aerial survey project. In subsequent years, our efforts also migrated further south to include Charlotte Harbor, Fort Myers, Estero Bay and occasionally the Ten Thousand Islands. Some sites where manatees are frequently found, such as Crystal River and Homosassa Springs, allow for underwater photography.  Unfortunately, much of Southwest Florida consists of turbid and/or tannin-stained water, making it difficult to impossible to photograph underwater. We therefore photograph distinctive individuals from research vessels, shorelines, docks or bridges. 

Return to Manatee Research Program Home Page.

Publications:

Koelsch, J.K. 2001. Reproduction in female manatees observed in
Sarasota Bay, Florida. Marine Mammal Science 17(2): 331-342.

Langtimm, C., C. Beck, H. Edwards, K. Fick-Child, B. Ackerman, S. Barton, and W. Hartley. 2004. Survival estimates for Florida manatees from the photo-identification of individuals. Marine Mammal Science 20(3): 438-463.

Note: Numerous Technical Reports may be found in the Mote's Arthur Vining Davis Library