The Florida manatee, Trichechus manatus latirostris, lives in near-shore marine, estuarine and fresh waters that are shallow, warm and calm. As herbivores, they eat sea grasses and other submerged or floating vegetation.
Because the waters throughout the Rookery Bay National Estuarine Research Reserve provide this essential habitat and food supply, manatees are commonly seen in these waters especially in winter when their population concentrates in the warmest waters available.
Despite protection under the Endangered Species and Marine Mammal Protection Acts, the manatee population in Florida is at risk. This is partly because human activity in manatee habitat directly correlates with manatee mortality. With one of the largest boating populations in the state, Collier County generally ranks within the top five counties statewide for manatee mortality resulting from collisions with boats.
The reserve works in many ways to provide federal, state and county officials with science-based information on which to base their conservation efforts. In cooperation with the U.S. Fish and Wildlife Service and other partners, the reserve has participated in a long-term monitoring program to identify areas of heavy use by both manatees and boats through aerial surveys. The reserve also provides workshops for coastal law enforcement and natural resource managers through the Coastal Training Program. These efforts have begun to interagency coordination of manatee strandings.
As a member of the Florida-Southwest Region Marine Mammal Stranding Network, the reserve provides trained staff and logistic support to the Florida Fish and Wildlife Research Institute (FWRI), the agency responsible for rescuing stranded, injured or sick manatees around the state. Because they have so much coastline to cover, reserve biologists often serve as first responders who verify the location and status of injured manatees (and other marine mammals), keeping tabs on their whereabouts until more help arrives from FWRI headquarters in Port Charlotte.
On Jan. 7, reserve biologists assisted in the recovery of an injured manatee and her calf from the Faka-Union Canal near Port of the Islands in eastern Collier County. Reserve staff transported the manatees to the Miami Sea Aquarium for treatment and rehabilitation until they can be released back into reserve waters in the future.
When Gulf water temperatures drop below 68 degrees, manatees can become cold-stressed and must seek warmer waters. The Faka-Union Canal and Henderson Creek are examples of waterways that provide a freshwater source that is warmer than the Gulf, which is why these locations frequently serve as manatee aggregation areas. It is extremely important for boaters to recognize that inland waterways like these see a significant increase in use by manatees during the winter months and extra caution is necessary when navigating these locations at this time of year. A spring-fed basin at the headwaters of Henderson Creek is the only “No Motor Zone” in Collier County because of its consistent use by manatees as a cold-weather refuge.
Rookery Bay National Estuarine Research Reserve serves as an outdoor classroom and laboratory for students and scientists from around the world. With 110,000 acres of coastal lands and waters, Rookery Bay is one of three reserves in the state managed by the Florida Department of Environmental Protection’s Office of Coastal and Aquatic Managed Areas in cooperation with the National Oceanic and Atmospheric Administration. For more information visit www.rookerybay.org.
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Renee Wilson is the research translator for the Rookery Bay National Estuarine Research Reserve.