So far this year, nearly 100 manatees are suspected of dying from red tide poisoning in Southwest Florida, which puts the endangered species mortality rate on track to break a record, according to the Florida Fish and Wildlife Conservation Commission.
"The number is really high. We’re already almost at our second highest in historical records,” said FWC veterinarian Martine de Wit. “Records may be broken but you never know what happens and it depends on a lot of factors.”
The worst outbreak of red tide is suspected of killing 151 manatees in 1996, the first year records were kept. The second worst year was in 2003, when 100 manatees died.
The red tide bloom that's suspected of killing 96 manatees since Jan. 1 is primarily located in the waters off Lee County and Collier County.
"The bloom boundaries go a little more north and south,” de Wit said. “Manatees are exposed to red tide by eating sea grass that has the toxin on it. Once they eat it, once it’s in their system, they die from a toxic shock."
The FWC Marine Mammal Pathobiology Laboratory in St. Petersburg, along with the Lowry Park Zoo in Tampa, play critical roles in saving the lives of rescued red tide manatees.
"We are red tide central," said Virginia Edmonds, the animal care manager of mammals at the Lowry Park Zoo. "We are usually the facility that gets red tide manatees.
FWC biologists have rescued six red tide manatees this year, all from Lee County. The FWC transports those manatees to the Lowry Park Zoo to recover.
"We get manatees in with red tide in all different stages," Edmonds said. "So sometimes they’ll come in and they have a little mobility. A lot of times they’ll come in and they’ll have no mobility.”
The FWC veterinarian said red tide affects the manatee's nervous system which causes the air breathing mammal to become paralyzed and drown. Zookeepers have come up with a simple solution to keep the manatee's head above water while it's in this condition.
“We’ll put a life jacket and a noodle under their chin,” said Edmonds. “It’s a funny little look but it works great. Someone who previously worked at the zoo came up with it.”
The mammal care manager said while red tide poisoning can be deadly for manatees, once the sea cows are removed from the toxic environment they recover quickly.
“They’ll be under observation for 24 to 48-hours until they come out of the red tide,” said Edmonds. “It’s a lot like food poisoning. You’ve got to wait for it to pass through your system... the same thing happens with manatees and the red tide.”
Even though the rescued manatees recover in a day or two, they typically end up staying at the zoo for months as biologists wait for the red tide to go away.
“Because their release sites are in red tide areas we can’t send them back out," said Edmonds. "We always send everyone back to the area they’re found and that’s because of that warm water migration they need to do in the winter.”
The FWC veterinarian said typically the worst months for red tide blooms are March and April.
“We’re only at the start of the spring," de Wit said. "So we’re not sure where this will be going."
Zookeepers said they've already saved more manatees this year than during the worst outbreak on record.
“In 1996, when we had the first really big die off of manatees. We only got five red tide manatees in," Edmonds said. "But they were the only five that survived of the red tides that were rescued.”
The FWC wants anyone who spots a manatee in distress or a carcass to call the wildlife alert hotline at 1-888-404-3922.
FWC manatee red tide mortality records
- 2013 - 96
- 2012 - 33
- 2011 - 23
- 2010 - 0
- 2009 - 10
- 2008 - 3
- 2007 - 52
- 2006 - 64
- 2005 - 93
- 2004 - 5
- 2003 - 100
- 2002 - 37
- 2001 - 16
- 2000 - 15
- 1999 - 12
- 1998 - 0
- 1997 - 15
- 1996 - 151