This weekend, Defenders of Wildlife sent a petition with 40,750 signatures to the U.S. Fish and Wildlife Service (FWS), urging swift and meaningful action to prevent more manatee deaths in Florida. 946 manatees have been reported dead in 2021, representing over 10% of the estimated total population. The mass mortality event has shattered the previous record of 830 deaths, set in 2013.
“Our waterways are inundated with chemicals, human waste and other pollutants that are harming manatees, other marine species, and humans alike,” said Elizabeth Fleming, senior Florida representative at Defenders of Wildlife. “This lethal cocktail is destroying manatee habitat at a record pace, starving the species in the process. Without immediate action, we can expect this year’s catastrophic die-off to become the norm going forward.”
The petition, sent to FWS Principal Deputy Director Martha Williams and FWS Assistant Director for Endangered Species Gary Frazer, urges the Service to “prioritize safeguarding and securing manatee habitat to prevent further unprecedented loss of manatees.” Manatees need healthy food sources near warm water areas to survive during cold weather.
During the winter, manatees can suffer from cold stress—a sometimes fatal condition they experience in water below 68 degrees Fahrenheit—forcing them to take refuge in warm water areas around the state. Over the past five decades, and due to habitat loss, more than 60% of the manatee population has learned to depend on warm-water outfalls at electric power plants to survive cold winter days — an unsustainable situation.
With more than 21.5 million residents and growing, Florida is the third most populous state in the country. In recent years, a combination of agricultural, residential, and industrial runoff—exacerbated by lax enforcement of water quality laws and waning oversight of land development—has fueled algal blooms that have killed tens of thousands of acres of seagrass. This seagrass loss has led to hundreds of manatees starving to death as they seek shelter during the winter months. Even when water temperatures rise with spring’s arrival, many emaciated manatees continue to suffer from—and succumb to—malnutrition.
While the species has rebounded since its inclusion on the Endangered Species List in the 1970s, manatees remain vulnerable to various threats, including habitat destruction, watercraft strikes, climate change and water pollution. Warming water temperatures favor the growth of harmful algae throughout much of the year. At the same time, extreme cold weather events intensified by climate change can also have chilling effects on the water, causing the manatees to develop cold stress and die.