Manatee deaths soar in Florida, but drop in Volusia

Widespread red tide algae blooms proved devastating for Florida's manatees in 2018, helping boost the total number of manatee deaths statewide to the second highest on record.

A preliminary analysis from the Florida Fish and Wildlife Conservation Commission puts the total manatee deaths at 823, just seven shy of the record set in 2013 — 830.

At least 211 of those deaths have been attributed to red-tide algae blooms that plagued the Southwest Florida coast for a year. Similar algae bloom events occurred in 2013, not only on the Southwest coast, but also in the Indian River Lagoon system, where manatees died in both Volusia and Brevard counties.

The total deaths in 2018 were more than a 50 percent increase over the deaths in 2017. But, in one glimmer of good news in an otherwise grim situation, manatee deaths dropped slightly last year in Volusia County.

State biologists are still investigating and finalizing their annual manatee mortality report and awaiting necropsy results for manatees thought to have been killed by the red tide blooms, said Martine de Wit, a manatee veterinarian for the FWC.

So many manatees died on the southwest coast that the state couldn't recover or necropsy them all, de Wit said. "There were a large number that were verified but not recovered. A large portion, if not the majority of those, were red tide-related."

The agency is examining the correlation between where dead manatees were found and areas where manatee deaths were confirmed to be red tide. The number of red tide deaths "will change in the coming months," she said. When the investigation and analysis is done, she thinks the number will be "close to the 2013 record (277) if not slightly above it."

Local manatee deaths

In Volusia County, manatee deaths dropped from 39 in 2017 to 36 in 2018, with a reduction in the number of watercraft-related incidents from 14 in 2017 to 11 in 2018.

"Hopefully, that means people are following the speed zone signs" said Debbie Wingfield, Volusia County's manatee program manager. She hopes it means more people understand why speed limit signs are posted on waterways and why they're important.

No red tide-related deaths were reported in Volusia or Flagler counties. "We lucked out on that aspect," Wingfield said.

Flagler County remains significantly below the six manatee deaths reported in the county in 2014 and 2015. However, one watercraft-related incident gave the county a total of two deaths. In 2017, only one manatee death — an infant — was reported.

Honing in on algae blooms

Environmental groups are alarmed by the large increase in manatee deaths statewide. 

"Even if the mortality figures for red tide aren't the record, they'll be the second highest," said Katie Tripp, director of science and conservation for the Save the Manatee Club. "In terms of the extent of this red tide — the scope, the geography — it's been going on for a year."

Red tide covered the entire west coast and even killed manatees as far north as Brevard County on the east coast, Tripp said. "It's the worst red tide that's ever been documented. It has implications that reach far beyond manatees. That's one of the things we continue to shine a light on, these long-term water quality issues that are ravaging the coasts."

Earlier in December, three other non-profit groups announced they would sue three federal agencies to try to force improvements in water quality to curb the algae blooms such as red tide and the super blooms that have killed manatees in the Indian River Lagoon system, including in Volusia County.

The groups — the Center for Biological Diversity, the Calusa Waterkeeper and Waterkeeper Alliance — are challenging the U.S. Army Corps of Engineers’ plan to extend deadly discharges from Lake Okeechobee into the Caloosahatchee and St. Lucie rivers.

“It breaks my heart that we’ve lost so many of these gentle giants this year,” said Jaclyn Lopez, Florida director for the Center for Biological Diversity. “The worst part is that it’s so preventable. We’ve got to do more to curb deaths from boat strikes and red tide."

Whenever a red tide bloom reaches the extent of the bloom in 2018, "it's a concern," said de Wit. The red tide bloom killed healthy, reproductive females that are important to keep the manatee population growing.

"Even if the population is growing, I think with a trend like that, a growing population cannot expect to win, especially if the other categories (of mortality) are increasing as well," she said. "That to me is the red flag for last year."

Tracking manatee numbers

Tracking the number of manatee deaths and the overall manatee population is still far from an exact science.

The FWC can only count manatee carcasses that are reported to the agency.

"We don't know exactly how many animals are dying," said de Wit. For that reason, state biologists have always discouraged people from comparing the manatee mortality numbers to abundance estimates and aerial flyover survey counts.

In mid-December, the agency, in conjunction with the U.S. Geological Survey, released an updated manatee abundance survey, based on analysis done in 2015 and 2016.

That analysis estimated the state's manatee population at 8,810, compared with 6,350 in a previous assessment four years earlier.

It was "a good report,"  said the Save the Manatee Club's Tripp. However, she contends the agencies need to delve more into the work that remains to be done to protect manatees and their ability to thrive, such as preventing or reducing algae blooms and restoring waterways. For example, she said, "What's being done to restore the Ocklawaha River so a thousand manatees can winter there?" Restoration of the Ocklawaha would provide additional habitat for manatees that live in the St. Johns River.

The club also remains concerned about watercraft-related incidents. That number has continued to climb, growing to 121 in 2018, from 111 i n 2017. The controversial boat speed zones were established locally and in other Florida counties about 30 years ago to try to reduce the number of potentially deadly boat strikes.

De Wit said there are many explanations for watercraft-related deaths. One could be the growing population, but it could be there are more manatees and boats in the same locations.

Without the algae blooms last year, the experts said there could have been even more watercraft-related deaths. Tripp and de Wit said they've been told algae blooms all along the Indian River Lagoon and on the southwest coast kept people from boating.

"It just wasn't a great summer to be on the water," said Tripp. "But we still had record watercraft mortality. I haven't been able to wrap my head around that."

To Tripp, it's also frustrating that boaters aren't more willing to report it when they've hit a manatee. "I don't know why we can't get people to understand what leads to those strikes," she said.  "It just seems like one of those causes of death that's largely preventable."

"FWC has this amnesty program, where if you're following the law and you hit a manatee you're not going to get in trouble," she said. "When you hit something, you put it in neutral and you go back and check your prop and look around to see what you've hit.

 "It continues to be frustrating that we don't have more than a handful of reported strikes," she said. "The data that boaters could provide about where they were traveling and how fast they were traveling is important. We know that manatees can have these strikes and potentially suffer with them before they succumb to their injuries. If people know there's been a strike, they can intervene and get the animal help."

To report a sick, injured or dead manatee or other marine mammal, call 888-404-3922.