The 631 manatee deaths in Florida through mid-July this year already stands as the fourth deadliest annual count since records began nearly a half-century ago.
Though a blistering pace, the 2022 toll so far is behind the last year’s count of 864 for the same period. For 2021, a record 1,101 manatees died primarily from starvation along Central Florida’s coast in the Indian River system.
“I do not know where we will end up at the end of this year because statewide so much can happen,” said Martine de Wit, a state veterinarian and scientist, joining a briefing Wednesday by wildlife authorities on the status of a rapid die-off of manatees.
The veterinarian said that hundreds of the animals remain in the Indian River Lagoon system, which has been stricken by pollution and an ecosystem collapse that has eradicated their diet of seagrass.
“Whether the numbers are going to be a record, I don’t think that really matters because this is something that is going to be long lasting,” de Wit said. “It’s going to have chronic health effects and reproductive effects and it’s going to be years before you can measure the real extent of what’s happening.”
Based at the Florida Fish and Wildlife Research Institute, de Wit presented comparisons between the spike in manatee deaths during the past two winters.
The winter of 2020-21 came on more quickly and continued with cold snaps, triggering a surge in deaths starting in December and contributing to 582 dead manatees for all causes for the winter. In one week in February 2021, the toll was more than 80.
By comparison, the toll was 457 during this past winter, which started later and was relatively warmer than the previous one, de Wit said.
She also presented figures, conveying that the vast majority of deaths in January, February and March of the past two winters involved starvation. Already weakened by starvation, cold weather finished them off, de Wit said.
She compared manatees that died of cold stress, which shut their bodies down with the effect of relatively rapid starvation, while animals that died primarily of starvation suffered for a prolonged period.
“This was not something that happened within a month,” de Wit said. “This is something that accumulated over time — more than a few months.”
Also a factor last year was a surge in deaths of manatees from red tide toxins along the state’s southwest coast.
State and federal authorities expect to conduct an emergency feeding of manatees this winter in Brevard County’s share of the Indian River, repeating last year’s emergency response that went through 200,000 pounds of lettuce.
Prospects for significant recovery of seagrass in the Indian River are uncertain but expected to take many years.
