#MapMonday: Florida Manatees

Hey there everybody and thanks for joining us for another Map Monday!

Today I have the pleasure of sharing with you some of the ways we coexist with our beloved “sea cows” here at Defenders. These “sea cows,” otherwise known as Florida manatees, are a threatened subspecies of the West Indian manatee native to the southeastern United States.

The current population is estimated to be anywhere between 7,500 to just over 10,000 manatees. They are found primarily in saltwater, freshwater, and brackish habitats, which are a mix of saltwater and freshwater. They are herbivores, which means they graze on grasses and other aquatic vegetation in shallow waters.

The Florida manatee serves an important ecological role by preventing vegetation overgrowth and maintaining a healthy, balanced ecosystem by fertilizing the very seagrass they consume. They even eat some invasive aquatic plant species, which just about bumps them up to ecological superhero status if you ask me.

Florida manatee critical habitat was designated along some key Florida coastline and waterways back in 1976, which you can see in red on this map. Though this designation is currently out of date, he U.S. Fish and Wildlife Service has yet to revise this critical habitat area for manatees in the 21st century. Critical habitat for a threatened or endangered species is designated by the Fish and Wildlife Service and includes the “specific geographic areas that contain features essential to the conservation of an endangered or threatened species and that may require special management and protection.”

Florida manatees can also be found in areas beyond this critical habitat, as you can see here in a yellow gradient showing the density of manatee sightings throughout Florida. Manatees utilize a variety of areas throughout Florida when traveling, feeding, breeding and resting.

Florida manatees have faced a myriad of threats beginning over a century ago. Hunting of manatees caused their initial decline, which led to the prohibition of manatee hunting in Florida in 1893. Over time, new threats have risen to the surface, the most prevalent being collisions with watercraft.

This map here shows where dead manatees have been found in Florida, many of which have been the result of such collisions. Propellers and boat hulls inflict serious or mortal wounds, and most manatees have scars on their backs or tails after surviving such collisions. To address this threat, the Florida Fish and Wildlife Conservation Commission nd the U.S. Fish and Wildlife Service created and enforces Manatee Protection Zones with designated speed limits for watercraft. These are in locations that have been particularly dangerous to manatees.

Additionally, Florida manatees face loss and fragmentation of habitat from coastal development, mortality and entrapment in water control structures such as gates, locks, and dams, entanglement in fishing lines and other debris, human disturbance and harassment, and harmful algal blooms.

The biggest long-term threat to manatees is lack of warm water habitat that manatees need to survive during cold weather.

Our field staff work tirelessly on the ground to address many of these threats, including Elizabeth Fleming, our Senior Florida Representative, and Liz Neville, our Manatee Advocate.

Let’s first take it over to Elizabeth to learn more!

Thanks Mae!

The Florida manatee has been protected under the Endangered Species Act since 1973. And while decades of conservation efforts have helped the population grow the manatee’s future is far from secure.

Defenders of Wildlife is working to ensure the manatee’s long-term survival. The leading threat to manatees is watercraft collisions and we advocate for the designation and enforcement of boating speed zones to make waters safer. Residential and commercial development continue to degrade manatee habitat. We support land acquisition, restoration and management, and the establishment of protected areas.

We promote responsible stewardship of public lands that support manatees such as Crystal River National Wildlife Refuge and Blue Springs State Park. We are also working to address the greatest long-term threat to manatees, which is lack of warm water winter habitat. More than 60% of Florida’s manatees shelter in artificial, impermanent sources of warm water, and a significant number could be lost without access to springs and other warm water habitat.

Defenders’ Manatee Advocate Liz is going to talk about a restoration project that addresses this dire threat. Over to you Liz.

Thanks Elizabeth.

Restoring Florida’s Ocklawaha River would indeed provide essential warm water winter habitat for hundreds of manatees. The Ocklawaha has been dammed for over 50 years as part of the failed Cross Florida Barge Canal project. This obstructed river migration pathways and submerged 20 freshwater springs.

While about 100 manatees have been identified in the system in recent years the dam, it’s locks, and related issues inhibit more manatees from using this river. Restoring the Ocklawaha by breaching the dam would provide manatees with access to some of the river’s 20 freshwater springs, and improved ability to access Silver Springs through the connected Silver River. Scientists estimate that these springs could serve as essential warm water winter habitat for hundreds of manatees including for as many as 500 at Silver Springs.

Defenders advocates for restored Ocklawaha through policy, outreach, and as a member of the Free the Ocklawaha Coalition. This work has included providing input to government agencies, speaking at events, and engaging with TV and print media.

Back to you Mae.

Thanks Liz and Elizabeth. If you want to learn more about Defenders’ efforts to coexist with Florida manatees, check out our story map. For more information on the many ways you can help protect manatees and their habitat, check out our website and Facebook pages. And finally, if you’re a boater in Florida, please be sure to take these steps on the water and in the marina to ensure safe encounters with manatees. Thanks for watching and happy mapping!