Tough Year for Sea Cows

The underwater grazing sea cows of Florida are not having a good year. So far over 770 of the slow moving gentle marine mammals known as the West Indian or Florida manatee have perished.  This breaks the previous record of 722 deaths in 2010 that occurred when a record-breaking cold snap decimated the already endangered population.

Many of 2013 deaths have been caused by toxic red algae, according to Save The Manatee Club, co-founded by Jimmy Buffet to protect the species. An average of two manatees died each day for the first ten months of 2013.

Of that number, 126 were calves. The high mortality count skyrocketed with a sudden bloom of toxic oxygen depleting red algae that killed 276 manatees near Fort Myers.  Another 111 manatees died along with 47,000 acres of sea grass near Indian River under mysterious causes earlier this year.

Patrick Rose, Executive Director of Save the Manatee Club said that in 2010 the Florida Fish and Wildlife commission counted a record 5,077 manatees before the cold related deaths that occurred later that year.   He added that the 2013 toll is nearly double the 392 deaths that occurred in 2012. 

The Fish and Wildlife Commission reported another 453 manatee deaths in 2011.

Considered endangered, the West Indian manatees are protected in the U.S.  Under federal law by the Marine Mammal Protection Act of 1972 and the Endangered Species Act of 1973 which makes it illegal to harass, hunt, capture or kill any marine mammal.  The Florida Manatee Sanctuary Act of 1978 also protects the West Indian manatee.

Long before the conquistadors, explorers and European settlers made their way to the shores of what would become known as the Americas, the West Indian manatee made its home along the tropical and subtropical waters.  To the indigenous populations along the shores and inland rivers the large and slow moving marine mammal was a familiar sight.

Sailing in and around the Caribbean Christopher Columbus wrote about manatees. He is attributed to seeing three “mermaids” that are not as beautiful as they are painted while on a trip to discover a western trade route to Asia in the late 15^th century.

Adult manatees can reach 10 t0 12 feet long and weigh 800 to 1,200 pounds.   The aquatic mammals have human like round faces and paddle shaped tails.  Gray in color, manatees often sport a symbiotic dark tan algae growing on their skin.

On close inspection one can see that the skin is sparsely covered with tactile hairs that the manatee uses to detect slight changes in the water movement.  They have a whiskery snout that helps in locating underwater vegetation for grazing.

A small group of manatee barrel rolled and glided in around the dinghies tied to a dock in Marathon Florida recently.  The awkward looking creatures gracefully moved through the slightly murky aquamarine water without creating a ripple. A mother and baby stayed close followed by another adult manatee and a juvenile.   It wasn’t long before the word spread.  Dinghies streamed from boats in the mooring field to catch a real life manatee documentary in progress.

Manatees love and are drawn to fresh water and were probably looking for it near where the cruisers fill their water jugs. The manatees disappeared under a dinghy and reappear with a slow flip of a large paddle like tail used for propulsion. 

One might, with a little imagination, see why sailors mistook the manatee for a mermaid.  My son, Ian, while kayaking in Florida during a stint in the U.S. Navy described his first close encounter with a manatee.  “I was enjoying the morning and suddenly I saw this grayish body ahead.  I though it was a bloated dead body.” 

According to National Geographic the manatee skeleton consists of heavy, dense, pachyosteosclerotic bones that help serve as ballast.  Manatees have teeth is that are continually replaced as they are worn down by grazing.

Florida manatees migrate seasonally.  In the winter, many move to the warmer and southern parts of the state.   These giant and gentle marine mammals have low metabolic rates and a low capacity for retaining body heat.

Manatees are often called sea cows because of their normally slow pace and bulk.   They can however move quickly, gliding along at five miles an hour and swimming up to 15 miles an hour in short burst powered by their strong tail.

Often manatees are seen alone or in small groups for periods of time near feeding areas, freshwater areas or near warm water sources.   During extreme cold spells groups of 300 or more have been observed in the warm water outflows of Florida power plants.

In darker waters usually the only thing visible from the surface is the animals nostrils and snout as it comes up for air.  A resting manatee can remain below water for up to 15 minutes, but while swimming it must surface every three to four minutes.

Female Florida manatees can become sexually mature as young as three years old, although most first give birth at age four to five. Mothers must help calves to the surface for their first breath after birth.  The manatee calves drink their mother’s milk from a nipple found under her flipper.   Adult manatees are voracious grazers.  They can eat a tenth of its weight in a 24-hour period.  A calve may nurse up to two years.

This docile species can live up to 60 years.  While the manatee has no natural predators, it faces extinction at the hands of man and nature.  Some die as they are caught in locks, accidently hit by motorboats in the crowded Florida waters.   Manatees also succumb to unusually cold winters, poisoning by a red tide organism, and sometimes hurricanes.

Increased human population has also resulted in habitat loss.  Using former coastal zones and lowlands for agricultural and industrial purposes have led to pollution and run-off that add to threat of extinction for this migratory marine mammal.  

While concentrated in Florida, manatees can be seen as far west as Texas and as far north as Massachusetts.  It is more common to see the grazing sea cow along Alabama, Georgia and South Carolina when the weather is warm.