Advertisement
  1. Environment

New manatee population estimate hits 7,000 to 10,000 but more than 700 have died this year

DOUGLAS R. CLIFFORD A manatee swims near the entrance to Three Sisters Springs on on Kings Bay in Crystal River in Citrus County
Published Dec. 18, 2018

ST. PETERSBURG — More manatees than ever have been swimming around in Florida's waterways, scientists said Tuesday, although more than 700 have died this year, mostly from Red Tide and being hit by boats.

PREVIOUS COVERAGE: Red Tide taking a toll on manatees.

A new study by biologists with the Florida Fish and Wildlife Conservation Commission and the U.S. Geological Survey used data collected during aerial surveys in 2015 and 2016, combined with statistical estimation methods, to come up with a new estimate for the state's manatee population. It's between 7,520 and 10,280, the study found.

That's a considerable increase from the 5,680–8,110 manatees estimated by a previous study using data from 2011-2012. But in their study, the scientists warned against drawing any conclusions about manatees experiencing a population boom.

So much uncertainty is involved in making their estimates that "we're definitely not encouraging people to make any statements of a population increase," said lead author Jeff Hostetler, a research scientist at the Florida Fish and Wildlife Research Institute in St. Petersburg. Their findings are "not inconsistent with a population increase, but it's not certain," he explained.

But in a news release about the study's findings, state officials contended that the new estimate "contributes to the conclusion that conservation measures ... continue to create an environment that allows the manatee population to recover."

The study is the first new estimate of manatee abundance in five years. Hostetler said scientists may try to repeat the study in 2020 or 2021, but that's not guaranteed at this point.

Manatees were on the original endangered species list drawn up in 1967 because of the threats they faced from speeding boats, water pollution and loss of habitat. A lawsuit filed in 2000 by a coalition of environmental groups against state and federal wildlife agencies led to settlements requiring new boat speed zones and manatee sanctuaries. Biologists have credited those measures with spurring an increase in the population.

PREVIOUS COVERAGE: The Tea Party rails about manatee protection to the Daily Show.

The U.S. Fish and Wildlife Service knocked manatees down to "threatened" instead of "endangered" last year, although a record number of manatees were killed by boaters just the year before. For the first time ever, more than 100 manatees had died after being run over by boaters.

PREVIOUS COVERAGE: Manatees taken down a notch on endangered list.

So far this year, 117 manatees have been run over by speeding boaters — up from 102 in 2016 and 104 last year.

Meanwhile the lingering Red Tide algae bloom has been blamed for the deaths of 207 manatees this year. Of those 91 have been conclusively linked to the Red Tide toxins, and another 116 are still awaiting laboratory test results but show the symptoms of being poisoned by the algae.

Hostetler said scientists are now working on a method of estimating the impact to the population of such a large die-off of the species.

Contact Craig Pittman at craig@tampabay.com or . Follow @craigtimes.

ALSO IN THIS SECTION

  1. Previous competitions did not round up a lot of the invasive snakes
  2. Workers repair a broken pressurized sewer line along 62nd Avenue N. JAY CONNER  |  Tampa Bay Times
    Private sewer pipes have always been the responsibility of property owners. Now if city officials notice a problem, they can force a homeowner to make repairs.
  3. An aerial view of the Apalachicola River near the Florida Panhandle town of Wewahitchka. Although the state has spent millions of dollars trying to protect the river from pollution, it is now planning to issue permit allowing a company to drill for oil near the river. Photo is by Rick Zelznak for Apalachicola Riverkeeper. BY RICK ZELZNAK  |  Rick Zelznak for Apalachicola Riverkeeper
    State on the verge of allowing drilling in both the Everglades and Apalachicola basin.
  4. Hurricane Dorian left homes in ruin in the Bahamas. FERNANDO LLANO  |  AP
    The season’s strongest storm, Hurricane Dorian, had Florida in sight but turned north before making landfall. The storm decimated the Bahamas.
  5. Two rare reddish egrets on Florida's Gulf Coast. Jim Bennight
    This is one of North America’s rarest bird species.
  6. As if on a post card, palm trees are reflected in glass panels at the Dali Museum Friday in St. Petersburg. CHRIS URSO  |  Times
    Florida’s signature trees do little to mitigate against carbon and intensifying heat.
  7. This is a king tide at the Key Largo Kampground & Marina in Key Largo. (Photo by Nancy Snyder) NANCY SNYDER  |  Photo by Nancy Snyder
    Monroe County is asking for $150 million to raise roads, elevate homes and even move critical buildings to higher ground.
  8. A green iguana strolls around Eco Golf Club in Hollywood, Florida on Oct. 28. MATIAS J. OCNER  |  Miami Herald
    The state has no plan for how to deal with it.
  9. Pasco County is poised to increase water and sewer rates for its 120,000 customers to help finance the acquisition of three utility systems now owned by the Florida Governmental Utility Authority. Tampa Bay Times
    It’s only a matter of when county commissions will approve the 2 percent increase to subsidize buying the former Aqua Utilities properties.
  10. For the latest breaking news, check tampabay.com Tampa Bay Times
    The city said its reclaimed water has failed ‘disinfection criteria.’ It won’t be turned back on until it’s environmentally safe.
Advertisement
Advertisement
Advertisement