Algae May Be to Blame for Manatee Deaths in Florida

July 15, 2016 | Erica Tennenhouse

Endangered Florida manatee (Trichechus manatus)
Photo credit: US Fish and Wildlife Headquarters/flickr (CC BY 2.0)

The Indian River Lagoon is suffocating.

166 manatees carcasses have been found in Florida’s Indian River Lagoon since 2012, including 8 recovered in recent weeks. The marine mammal deaths are linked to an algae bloom, Orlando Sentinal reports.

The Indian River Lagoon is the most biodiverse lagoon ecosystem in the northern hemisphere, home to more than 3,000 species of plants and animals including around 50 threatened and endangered species. West Indian manatees are classified as endangered, though the US Fish and Wildlife Service proposed downgrading their classification to “threatened” earlier this year.

DON'T MISS: Invasive Asian Carp Are Closing in on Lake Erie

This algae bloom believed to be killing the manatees is not the same as the massive toxic blue-green algae bloom that has recently taken over Lake Okeechobee in Florida. The bloom in Indian River Lagoon is a mix of several algae species predominated by a species called Aureoumbra lagunensis, also known as “brown tide.” It was showing up in lagoon samples back in 2005, but only low levels.

Harsh blooms did not occur until 2012, as a result of “decades of pollution from septic tanks, fertilizers, stormwater runoff and other sources, coupled with a ‘perfect storm’ of drought, followed by record cold in 2010,” according to Florida Today.

Since then, algae have been choking out the lagoon’s seagrass — a mainstay of the manatees’ diet. When their sea grass disappears, manatees turn to red seaweed, which researchers say contain “a suite of toxins.” Huffington Post reports that most of the manatees found dead since 2012 had guts filled with the seaweed.

Beyond the manatee deaths, the algae bloom has wreaked havoc on oysters, crabs, and fish in the Indian River Lagoon.

You might also like: Algae Slime Has Prompted a State of Emergency in Florida

Hot Topics

Facebook comments