Manatee Status Gets Temporary Reprieve

by Becky A. Dayhuff

The Florida Fish and Wildlife Conservation Commission (FWC) has delayed voting on a proposal to down-list the status of the Florida manatee from endangered to threatened until November of 2004.

Originally scheduled to vote on the downlisting November 19th, 2003, the FWC announced it would delay the vote until its relisting criteria are revised.

The announcement, made at a FWC meeting in the Florida Keys, was met with enthusiasm by various environmental groups and Florida residents who have fought for decades to protect the dwindling population of manatees.

Wildlife Advocacy Project Executive Director Susannah Lindberg stated after the meeting, "They're waiting until they have all their ducks in a row. It's what we wanted to happen."

One of the criteria used by the FWC in the down-listing proposal was whether the Florida manatee is at risk of becoming extinct within the next 45 years. A computer generated model indicates that the manatee population will decrease by 50 percent within the 45 year time frame.

According to Gil McRae, director of the Florida Marine Research Institute, in order for the manatees to remain listed as a state endangered species, the computer model must show an 80 percent population loss.

Before becoming endangered by the impact of human activity, the gentle, giant Florida manatees existed for a million years in relative safety. Distant relatives of elephants (as evidenced by their wrinkled furrowed faces and remnant nails on their flippers), the slow-moving, air breathing manatees now face ever increasing threats to their survival.

The first manatee death from a boating strike did not occur until the 1940s, but as Florida's population influx began after WWII, manatee deaths from human related activity began to rise and continues to increase each year.

Over 350 manatees have died in Florida waters to date, which exceeds 10 percent of the approximate 3,300 total population counted statewide in January 2003. Mortality statistics prove more than 20 percent of the 350+ died from boating strikes.

Many of Florida's living manatees bear scars and disfigurements from both propeller cuts that leave a series of closely spaced deep slashing marks across their bodies, and 'skeg' cuts, the name given to long deep cuts inflicted by the V-shaped section of the keels immediately in front of the rudders.

Scars are so prevalent that researchers use scarring patterns to identify individual manatees. The Florida Marine Research Institute maintains a large catalog of manatees photos showing the individual scarring patterns.

Blunt trauma injuries from high speed strikes by boat hulls result in additional deaths occuring several days after the strikes although researchers are often handicapped in determining the exact cause due to decomposition.

In these cases, post-mortem exams demonstrate bone crushing injuries including skull fractures and broken ribs, leading scientists to assume death from brain damage and lung injuries.

This author has seen manatees unable to swim adequately due to completely amputated flippers and partial amputations of the large paddle shaped tails manatees use to propel themselves through the water.

During one winter's research this author was frequently accompanied by a female manatee who had a large compressed skull fracture and demonstrated obvious signs of brain trauma.

Manatees roam Florida's coastal waters during warmer months. As coastal water temperatures drop in the winter the cold-intolerant manatees must travel to inland springs and power plants where water temperatures remain a constant 72 degrees.

Manatees are highly susceptible to frost bite and resultant infections. Additionally, water colder than 72 degrees over an extended period of time causes the manatees' metabolism to slow precariously to the point they are unable to sustain life.

Given those factors, Florida's manatees must move inland when cold weather arrives.

Seeking the warmer waters of the springs, Florida's manatees traverse inland waterways and rivers where they encounter an ever increasing number of watercraft.

While speed zones and sanctuaries have been established, enforcing those zones is a continuing problem due to a lack of manpower and funding.

Many environmentalists, marine biologists, and veterinarians express grave concern that the manatees' rate of reproduction cannot keep pace with the annual death rate if current trends continue.

The FWC is required to accept public comment prior to down-listing any species. Interested parties may go to http://floridaconservation.org/emailus/feedback.asp and register opinions regarding the proposed down-listing.

Sources
News Press
www.news-press.com/news/local_state/
031111savemanatee.html
www.news-press.com/news/local_state/
031111manatee.html

© 2003 Animal News Center, Inc.