Advertisement
  1. News

Scientists puzzled by manatee deaths on Florida's east coast

Lowry Park Zoo Manatee Hospital staff members take blood from Cheer, a manatee exposed to Red Tide. This year a record number have died from the algae bloom off southwest Florida, and now manatees are dying from an unknown cause on the east coast.
Published Mar. 19, 2013

Even as a Red Tide algae bloom is wiping out a record number of manatees in southwest Florida, a mysterious ailment is killing dozens more manatees on the state's east coast. So far, state biologists have been unable to pinpoint the cause.

Pat Rose, a former government manatee biologist who is now executive director of the Save the Manatee Club, said he could not recall another time when manatees were being killed in such numbers on both coasts at the same time.

Since last July, 55 manatees showing similar symptoms have died in the Indian River Lagoon area — 25 in just the past month, according to Kevin Baxter, a spokesman for the state's Fish and Wildlife Research Institute in St. Petersburg.

There is no Red Tide bloom on the east coast, and the winter has not been cold enough to kill manatees. So far, Baxter said, no sick manatees have been rescued, availing biologists with a live specimen to study for clues.

They suspect the manatee deaths may be connected to back-to-back blooms of a harmful algae, one that has stained the Indian River Lagoon a chocolate brown. Over the past two years the blooms wiped out some 31,000 acres of sea grass in the 156-mile-long lagoon that stretches along the state's Atlantic Coast. Manatees eat sea grass, but with the sea grass gone, they may have turned to less healthful sources of nutrition.

"A big part of it is that there's just not that much left for them to feed on," Rose said. "The system is way out of balance."

The manatees that have turned up dead on the east coast all appeared to have gone into shock and drowned after they "ingested large amounts of macroalgae," Baxter said. "Our researchers are thinking the deaths are related to some kind of dietary change."

This is not the only mystery that state biologists are trying to solve. Last week they announced that, since the start of 2013, more than 100 brown pelicans have been found dead in that same area of Brevard County. The pelicans were emaciated and full of parasites. So far biologists don't know what killed them or if there could be any connection with the dead manatees.

Rose blamed the Indian River Lagoon's toxic algae blooms on nutrient pollution from storm runoff. The runoff carries into the waterways excess fertilizer, sewage and animal waste that fuels the growth of some algae.

Although scientists suspect something similar fuels Red Tide blooms too, they lack the evidence to prove it. Red Tide, an algae bloom that turns the water the color of rust and releases toxins that can prove fatal for fish, dolphins and manatees, has killed more than 180 manatees so far this year in Lee County. That breaks the 1996 record of 151.

State biologists estimate the total Florida manatee population to be between 4,000 and 5,000. Manatees have been on the federal endangered species list since the list was created in 1967. They have been protected by state law since 1893.

Craig Pittman can be reached at craig@tampabay.com.

ALSO IN THIS SECTION

  1. Eboni Wiley, left, testifies at the trial of her ex-boyfriend Granville Ritchie who is accused of raping and killing 9-year-old Felecia Williams in 2014. Wiley led the girl to Ritchie, according to the state. Hillsborough Assistant State Attorney Jennifer Johnson, right, questions Wiley in a Hillsborough County Courtroom.Octavi OCTAVIO JONES  |  Octavio Jones
    Eboni Wiley was a friend of Felecia Williams’ family. She told jurors how she brought the girl to the man standing trial for raping and killing the 9-year-old.
  2. Students and community activists marched in Tampa last year after the Feb. 14, 2018 shooting at Marjory Stoneman Douglas High School in Parkland. The attack killed 17 people and gave rise to Florida’s school guardian law, which this year was changed to allow classroom teachers to be armed. Gov. Ron DeSantis signed the measure into law. [MONICA HERNDON   |   Times]
    Damien Kelly, the director of the Office of Safe Schools, told lawmakers that 11 districts have said they would like the option to arm instructional staff, but it wasn’t clear if all 11 had...
  3. This Jan. 31, 2017 photo shows the entrance to SeaWorld in Orlando, Fla. JOHN RAOUX  |  AP
    Gustavo “Gus” Antorcha cited a “difference of approach.”
  4. Check tampabay.com for the latest breaking news and updates. TMCCARTY  |  times staff
    The 15-year-old student was arrested Monday after shouting the threat out loud, according to St. Petersburg police.
  5. Clearwater Mayor George Cretekos, a Republican, has asked for a City Council vote on a resolution asking congress for gun control measures. DOUGLAS CLIFFORD  |  Tampa Bay Times
    However, the Republican’s symbolic resolution will almost certainly fail.
  6. A homeless Vietnam War veteran in Clearwater answers questions for a Pinellas County homeless survey. A shortage of affordable housing is considered a major cause of homelessness among vets in the Tampa Bay area. [Times files]
    Local agency leaders called on members of Congress to increase national affordable housing options as a solution to veteran homelessness
  7. Check tampabay.com for the latest breaking news and updates. TMCCARTY  |  times staff
    The Hillsborough County Sheriff’s Office said it is obtaining a search warrant to start looking for evidence inside the house.
  8. Josh Hensley was known for dressing as Jack Sparrow. Facebook
    Joshua Hensley, 43, was found dead Monday morning. He went missing after setting out on a paddle board Saturday.
  9. 6 hours ago• Pinellas
    Ele Fox, Kiwanis Club of Dunedin member, and Joe Mackin, president of the Dunedin Cares Food Pantry are pictured in front of the case of meals they received to be distributed to families in need in the Dunedin area. Photo Courtesy of Stephanie Bessette. Stephanie Bessette
    Local Kiwanis clubs supply food in service project
  10. Volunteers work to refurbish a home as part of the Fuller Center’s Greater Blessings Program in Pasco County in August. Fuller Center for Housing Nature Coast
    Comedy show and dinner will help raise money for ministry working in Hernando, Pasco and Citrus counties and beyond.
Advertisement
Advertisement
Advertisement