West Indian Manatee
By Austin Soto

Dog of the Sea?

Sometimes referred to as the “Dog of the Sea,” the West Indian Manatee sure looks like it could just nuzzle up to you like any fun loving dog would on dry land! But there’s much more to this amazing, tender creature than you could imagine that you will soon find out! This informative blog is dedicated to all those manatees out there and to the efforts to conserve this threatened species for generations to come.

*Throughout this blog, the West Indian Manatee will be abbreviated as WIM*

The West Indian Manatee Family

The West Indian Manatee (Trichechus manatus latirostris) is a member of the aquatic animal order Sirenia, which consist of herbivorous aquatic mammals that live in swamps, lakes, rivers, estuaries, and coastal waters. The WIM is one of only four species of Sirenia, with its family members consisting of the West African Manatee, the Amazonian Manatee, and the Dugong. A fifth member, the Steller’s Sea Cow, was hunted to extinction in the mid-1700s. The WIM itself has two subspecies, the Florida Manatee and the Antillean Manatee.

What exactly is the West Indian Manatee?

Fun Fact: Did you know that sailors sometimes mistook the WIM for mermaids back in the day before they knew what the WIM was? Maybe because from afar, the shape and characteristics of the WIM do appear somewhat like the image of a mermaid (convince yourself it does)!

The WIM has a large, grayish, round body with a large, rounded tail to help it propel through the water. It also has a pair forelimbs, called flippers, located on both sides of the sides of the body to help it steer and move around. The head of the manatee has a wrinkled look, with a squashed nose that has whiskers protruding from it. The average adult WIM grows to about 10 feet or so, and weighs between 800 and 1,200 pounds. The baby calves themselves are also large, averaging around 3 feet at birth and weighing around 50 pounds.

Where does the West Indian Manatee call home?

The WIM is found primarily in the shallow, calm waters of rivers, bays, estuaries, swamps, and coastal shores of Florida, the Gulf of Mexico, and surrounding Caribbean waters down extending to South America. The coastal areas outlined in orange on the map provide a visual guide to where the WIM lives. However, they have been found as far north as Rhode Island and as far west as Texas, although this is rare. The WIM prefers freshwater environments, but can survive in saltwater as well. And speaking of the kind of water they like, the WIM cannot tolerate water that dips below 68 degrees Fahrenheit, as their digestive tracts begin to shut down due to their slow metabolism and little insulating body fat, and can possibly result in death. This is why they prefer the ideal warm waters of Florida and the Caribbean.

What is the West Indian Manatee diet like?

What does the WIM eat for its daily diet? It mainly feeds on aquatic plants such as turtle grass, shoal grass, and algae. They prefer to eat submerged vegetation, followed by vegetation that is floating on the surface of the water. However, they have been known to eat some small fish as well. The WIM consumes from around 4% to 9% of its body weight each day through its meals. All that eating must be quite nutritious to the WIM, helping it survive to an estimated 60 years of age. No other animal has the WIM in its diet, therefore it has no natural predators or documented predations from other animals!

What are the reproduction and breeding habits of the West Indian Manatee?

The WIM has a naturally low reproduction rate, producing an average of one baby manatee every two to five years, and though it is rare, sometimes twins are produced. The gestation period for the female manatee is about one year, and once born, the calf stays close to and depends on its mother for survival for about a year or two before becoming more independent. Female manatees become sexually mature anywhere from three to ten years of age, and usually attract several bull (male) manatees for mating purposes, often leading to competition between the bull manatees to see who gets to mate with the female first.

How does the West Indian Manatee behave?

The WIM is not going to attack you anytime soon. It is naturally a very passive, non-aggressive, slow-moving fellow, only swimming around 3-5 miles per hour on average. They spend most of their time underwater, just under the surface of the water. However, they do surface to breathe, and they can hold their breath for an average of 4 to 5 minutes underwater. The WIM spends most of its time feeding, resting, and traveling. They do, however, like to socialize with other manatees, nuzzling up to each other or playing follow the leader! Most of the time, manatees casually join other manatees and disburse from them as they wish. They temporarily just “hang out.” There is no given number to the size, age, or sex or manatees that could congregate at any given point. However, the basic social unit of the WIM is just simply the mother and the calf.

How long do West Indian Manatees live, and what are the threats to it?

The average lifespan of the WIM is a healthy 50-60 years of age. However, there are many factors, mainly natural and human, that cause the deaths of these creatures. Natural causes may be due to coldness of the water as mentioned previously, disease, and of old age. Human causes include poaching, entanglement in fishing nets, boating collisions, pollution, habitat destruction, and crushing from flood gates. However, boat-related accidents and the loss of their warm water habitat are the top overall causes of manatee deaths, with 25% of manatee deaths directly attributable to the incidents involving boats. The wounds from boat propellers and boat collisions leave the manatees severely injured, and they may die from the blunt trauma afterwards. The loss of their habitat, in the form of clearing the marshes, swamps, and low-lying areas of water, leave the manatees to flee to inhospitable waters that they cannot tolerate, and they may die as a result. Many of the sea grasses the manatees feed on are also lost through boating activities and dredging, leaving the manatees with less food and it may lead to starvation.

Recovery Plan of West Indian Manatees

Oh no - the West Indian Manatee is endangered! It was first listed in 1967, but thankfully, there is a recovery plan for the Florida Manatee(essentially the West Indian Manatee that lives around the coastal areas of Florida and the Caribbean and encompasses a large proportion of the habitat of the West Indian Manatee). The main goal of the plan is to make sure that the long term survival of the Florida manatee in the wild is sustained, and that one day it can be downlisted to threatened and eventually de-listed altogether. By reducing threats, both natural and human caused, and also achieving population benchmarks in the regions where the manatees live, where the average rate of survival of manatees is to be 90% or higher, we can ensure the long-term survival of the manatee. Some examples of reducing threats include protecting warm water habitats of the manatee, reduce the unauthorized human “take” of manatees, building manatee-safe dams and canal locks, and allowing less boats in the areas where manatees live. The current Florida manatee population is at 1,865 individuals, and hopefully many more will be out in the wild in the long run with the help of the recovery plan.

Personal Action Plan

One of the most effective actions you can take to save the manatees is to spread the word about manatees and their conservation status, and get people to notice and support actions that save the manatees. You can donate to programs such as Save the Manatee Club and the National Wildlife Federation that help protect the habitat of manatees and ensure their survival in the wild. You can even adopt a manatee at http://www.savethemanatee.org/ and be a partial owner of a manatee, with proceeds going to helping conserve manatees! If you ever find yourself in a manatee habitat, remember to respect them and the surrounding wildlife by not littering and looking after yourself. Hopefully one day, with your help, the West Indian Manatee will be self-sustaining, thriving population that future generations will be able to enjoy for years to come.

 

Works Cited

Deutsch, C.J., Self-Sullivan, C. & Mignucci-Giannoni, A. 2008. Trichechus manatus.

The IUCN Red List of Threatened Species 2008. Web. 28 November 2015.

"Florida Manatee Recovery Plan." U.S. Fish and Wildlife Service (2001): n. pag.

Environmental Conservation FWS. U.S. Fish and Wildlife Service, 30 Oct. 2001. Web. 29 Nov. 2015.

"Manatee Information." Manatee Information. Save the Manatee Club, n.d. Web. 23 Nov. 2015.

"West Indian Manatee." National Wildlife Federation, n.d. Web. 22 Nov. 2015.

"West Indian Manatee: Species Profile." Everglades National Park. National Park Service, n.d. Web. 23 Nov. 2015.