Manatee Ecology 

Why do wild manatees come to Moore's Creek?

The manatee, a marine mammal, needs warmth when surrounding water temperatures drop below 68°f. At one time, Fort Pierce Utilities Authority operated the Henry D. King power plant that was located just across the street from the Center. The plant used water from the Indian River Lagoon to help cool the pipes in the plant. As the water left the plant and was discharged into Moore's Creek, it was 7 degrees warmer than the surrounding water, so manatees stayed close to the Center to enjoy the warmer water. As the weather warmed, manatees travel in and out of Moore's Creek, and visited the creek the rest of the year because of the fresh water in the creek. As a result, Moore's Creek is on the manatee's migration pattern. Although the Henry D. King power plant has been removed and there is no more warm water source, manatees still visit the creek as it is a secluded resting spot and contains fresher water than the lagoon. Manatee Center volunteers spot approximately 400 manatees visiting Moore's Creek per year, and that is just during the hours that we are open!

Learn more about the endangered manatee:

• Common name: Florida manatee
• Scientific name Trichechus manatus latirostris
• Population status: Endangered
• Estimated population: A minimum of 3,200 individuals as of early 2002
• Range: Rivers, springs, and shallow coastal waters of Florida and adjacent states

Manatees in Florida (Trichechus manatus latirostris), are subspecies of the West Indian manatee (Trichechus manatus). The Florida manatee lives in brackish, salt and freshwater coastal areas around Florida. The manatee is a plant-eating mammal (herbivore) that must come to the surface to breathe air every three to five minutes. The adult manatee weighs around 1,000 pounds and is about 10 feet long. Manatees reach sexual maturity at 4–7 years, and the female reproductive rate is an average of one birth every two to three years. The gestation period is 13 months, and usually one calf is produced, although twin births are known to occur. Calves remain with their mothers for up to 2 1/2 years. At birth, calves weigh about 60-80 pounds. Like all mammals, it has hair on its body, nurses its young, and is warm-blooded. Manatees can live to be about 50 to 60 years old.

Threats to Manatees

The manatee’s low reproductive rate, combined with loss of habitat and high rates of mortality, often from human-related causes, threaten the animal’s survival. Manatees and humans interact with one another on a regular basis. Our activities in and around manatee habitats have increased in recent years. The manatee is endangered due to:

1. Extensive development of coastal lands for housing, agricultural, and commercial purposes which has affected important manatee feeding sites
2. Irresponsible recreational and commercial boating practices
3. Poor water quality from civic, commercial, industrial, or agricultural affluent
4. Alteration of wetlands for dredge and fill operations; channelization of rivers, streams, and other changes to fresh-water flow

These human impacts have diminished the extent and environmental quality of much of the manatee's once pristine habitat and continue to do so at an alarming rate.

Do manatees impact their own habitats?

Manatees may impact habitats that they feed in, especially sea grass beds. Studies done by Lefebvre and Provancha found that manatees normally feed on the edges of sparse seagrass beds, and that they returned to formerly-grazed areas to feed from year to year. It is thought that manatees return to these grazed beds because seagrasses that have been "mowed" have more nutritional value and protein. Repeated cropping of seagrasses by manatees, although not substantiated in any study to date, may cause damage to seagrass meadows if large numbers of manatees converge on a site where seagrass is the primary food source.

What can I do to help manatees?

Be aware of your actions, especially near water.

• Don't litter; fishing line, rope, trash, etc. can entangle and kill manatees and other animals.
• If you own a home or business near the water, reduce the amount of fertilizer used. Fertilizer causes increased algae growth on sea grasses. Also, be aware of any other pollutants that might enter the water; even dirt can cloud the water, reducing sunlight that results in reduced seagrass growth.
• Be a responsible boater. Wear polarized sunglasses to aid in spotting manatees and seagrass beds. Please slow down in areas that manatees frequent.

Become an active citizen.

• If issues that affect manatees are important to you, then tell your friends and government that you are concerned.
• Buy a manatee license tag as those funds are designated for manatee research and education.
• Join an organization that supports manatee education and preservation.

What can I do if I see an injured manatee?

Call the Florida Fish & Wildlife Conservation Commission at 1-888-404-3922 and be prepared to answer the following questions:

• What is the exact location of the manatee?
• Is the manatee alive or dead?
• How long have you been observing the manatee?
• What is the approximate size of the manatee?
• What is the location of the closest public boat ramp to the manatee?
• Can you provide a contact number where you can be reached for further information?

The above information is the most important you can provide. However, all additional information you can give will be helpful.