Florida Manatee: Gentle Giants Need Support
Healthy waterways are critical for manatees.
The manatee is a Florida icon, but it faces several serious challenges, especially the need for healthy, connected habitats. Sometimes called sea cows, manatees are marine mammals averaging 10 feet in length and weighing about 1,000 pounds. Found in coastal areas, springs and rivers, manatees can live more than 65 years. They graze on aquatic vegetation.
In the Gulf of Mexico, manatees are typically found from Florida through coastal Louisiana. In warmer months, they may travel up the Atlantic coast into Georgia and the Carolinas. Despite their size, they have relatively little body fat, so in cooler months, they migrate to warm waters, often in a large group called an aggregation. Calves stay with their mothers up to two years. Manatees have recently been downlisted from endangered to threatened by the U.S. Department of Interior, but they are not out of danger.
Challenges to Manatees and TNC Solutions
Challenge: Access to warm water is critical. Many manatees gather in Florida’s springs during cooler months, attracted by the consistent water temperatures in the 70s. “Cold stress is a serious issue. Florida manatees cannot tolerate temperatures below 68° for extended periods of time,” said Anne Birch, marine program manager.
- TNC solution: We have teamed up with the Warm Mineral Springs Working Group to provide a safe, warm-water refuge in Sarasota County, free from boats that can be dangerous for manatees.
Challenge: Healthy and plentiful springs. Manatees are sustained by high water quality and appropriate flow in our springs.
- TNC solution: We’re protecting areas that allow rainwater to recharge our spring systems, and we support legislation that protects water quality and assures appropriate water volumes in our springs. In the Big Bend area, we helped restore seagrass beds, a primary food source for manatees.
Challenge: Unrestricted, connected waterways. Obstructions or restrictions like sediment buildup create a life-threatening issue for manatees. “To help manatees survive for future generations and increase their population, it’s essential that their freshwater and marine habitats be reconnected, and remain connected,” Birch said.
- TNC solution: In the Chassahowitza National Wildlife Refuge, we have funded a project to remove boulders blocking the only remaining safe path for manatees to access Three Sisters Springs—providing safe haven for at least 200 manatees who spend winters there. Across the state, Conservancy projects also have reduced the impact of dams, weirs and other manmade obstructions. At Fanning Springs, we dredged the Suwannee River and rebuilt a dock that had obstructed safe passage.
Good news, but challenges remain
In addition to the need for access to consistently warm spring waters in the winter, manatees face habitat destruction, canal locks, flood gates and dams. Boat strikes continue to harm manatees, and they are threatened by entanglement in fishing gear and traps. The Conservancy’s focus on freshwater springs and coastal protection and restoration will help to support the manatee’s survival.