Manatees were dying in record-breaking numbers. But that trend may be slowing down

Record-breaking numbers of manatees have died in Florida the past few years. But data from a recently released report may indicate that that trend is slowing down this year—at least so far.

According to a Florida Fish and Wildlife Conservation Commission, 431 manatees died across Florida from Jan. 1 to Aug. 25. In 2022, that figure was 669 manatees, and in 2021, it was 928 manatees. The five-year average of manatee deaths is 597.

The previous unprecedented manatee mortality was linked to starvation during the colder months when manatees migrated to and through the Indian River Lagoon, where the majority of seagrass had been dying off. This started affecting the Indian River Lagoon, a habitat central to Florida’s manatee migration, in 2020.

This year, far fewer deaths have been attributed to starvation, said Martine DeWit, a research scientist with the FWC’s Fish and Wildlife Research Institute, in an email to the Miami Herald. According to graphs on the FWC website, manatee deaths linked to starvation have been in decline since early 2022.

“One of the main reasons for this is some recovery of seagrass in parts of the Indian River Lagoon, a trend that started last summer,” DeWit said.

This spring, a leading cause of death was the red tide bloom, which was first documented in November 2022. During a red tide, fast-growing algae produce toxins that can kill fish and other marine creatures. The red tide bloom killed 85 manatees in southwest Florida this March, according to the FWC.

However, there’s a human-related activity that continues to claim the lives of Florida’s manatees—boating. Seventy-two manatee deaths so far in 2023 were linked to watercraft.

“What the data show is that watercraft collisions remain the most significant cause of death statewide over the years, whether the number goes up or down from year to year,” DeWit said. “…This is consistent with population models that identify watercraft-related mortality as one of the main threats to the population long-term.”

Where did most of Florida’s manatees die?

• Lee County: 98
• Pinellas County: 42
• Brevard County: 36
• Volusia County: 26
• Hillsborough County: 24
• Charlotte County: 23
• Citrus County: 22
• Manatee County: 19
• Sarasota County: 19
• Collier County: 16
• Duval County: 14
• Monroe County: 13
• Broward County: 10
• Miami-Dade County: 9

2023 Miami Herald.
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