The Way We Eat Is Killing Manatees

Experts warn the Florida manatee is at risk of mass starvation as farm pollution continues to wipe out their primary food source.

manatee starvation caused by seagrass losses from water pollution

Reported Climate Wildlife

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Hundreds of manatees gather in the shadow of the power plant periodically poking their whiskered noses out of the water to breathe before sinking back down below the surface. From November to April every year, approximately 400,000 visitors enjoy this scene at Tampa Electric Company’s Manatee Viewing Center. 

Now experts are warning that manatees are at risk of mass starvation due to water pollution and dying seagrasses. 77,000 acres of seagrasses have already been lost — and one of the leading causes of pollution is food production. Florida is home to more than 47,000 farms that produce foods like citrus, sugar cane, dairy, chicken and beef. Fertilizer runoff from these operations, including manure, is a major contributor to water pollution that is killing seagrasses and, by extension, manatees. 

Manatees Are Facing An Unusual Mortality Event 

During the colder months of the year, manatees seek refuge in warmer waters, like those heated by the power plant.

But in the past few years, instead of finding a winter respite with ample seagrass, manatees have found many of their usual cold-weather haunts are now largely barren. Forced to choose between starvation and braving the frigid waters, many choose to starve. 

Since 2020, the Florida Fish and Wildlife Conservation Commission (FWC) has been tracking these losses in the manatee population, called an Unusual Mortality Event (UME) by researchers. 

According to researchers 1000 manatees died off Florida’s coasts and in the state’s springs in 2021, and manatee birth rates have also gone down, according to the agency’s tracking data. 

Last year, fewer animals died — 800 to be exact — but mortality numbers likely went down because so many manatees already died the year before, points out Patrick Rose, Executive Director of Save the Manatee Club. Warmer winter weather and fewer red algal blooms may have also offered some protection. 

Why Are Manatees Starving? 

Manatees depend upon seagrasses as their primary source of nutrients, consuming 4 to 9 percent of their body weight every single day. The average healthy, adult manatee weighs in at 1000 pounds and needs 40 to 90 pounds of seagrasses to stay healthy. 

Now seagrasses are under threat from water pollution. According to Rose, algal blooms started killing seagrasses en masse in 2011. Since then, 77 thousand acres of seagrass have been lost. 

Healthy seagrasses depend on healthy water. Florida’s waters face three major sources of contaminants: failing sewage systems, high rainfall leading to raw sewage being dumped into the water, and run off from fertilizers and agriculture, says Rose. 

In 2020, 9.7 million acres of land in Florida was dedicated to agricultural activity. Despite being a leading producer of oranges, sugarcane, fresh tomatoes and watermelon, more than half — 5.4 million acres — is dedicated to rangeland and pastureland for cattle. That’s equivalent to 15.6 percent of the state’s total land area. 

On top of the more than 1.5 million cattle, the state was also home to more than 63 million broiler chickens in 2022 — all of whom produce a staggering amount of manure. Each cow in Florida produces 12 tons of waste every year, whereas a single hen produces 130 pounds. 

Excess fertilizer and manure has to go somewhere — most often it ends up polluting waterways. For example, dairy farmers are known to dump what’s called a slurry, a mixture of animal waste and other byproducts. This slurry, and the manure that is often used as a fertilizer on farms, is high in phosphorus and nitrogen, the nutrients that are responsible for the formation of algal blooms. It’s these blooms that end up using all the available oxygen in the water, choking out other species like seagrasses. 

“Water quality needs to improve to the point that enough light makes it to the seagrasses”, says Rose, “efforts need to be made to prevent algal blooms, handle the nutrients already in the water, and plant seagrass nurseries”. 

In 2022, Florida’s Governor, Ron Desantis, announced just over $30 million in funding for manatee preservation, rescue and habitat restoration. While this funding has helped aid rescues, protect access to springs for manatees and plant seagrass nurseries, it’s nowhere near enough to fix the problem, says Rose. “We need hundreds of millions, not tens. The damage that has already been done is so great that it could be too little too late.” 

Lawsuit Alleges EPA Failed to Protect

Last year, a group of organizations — Save the Manatee Club, EarthJustice, Center for Biological Diversity and Defenders of Wildlife — launched a lawsuit against the EPA for failing to protect the water quality of the Indian River Lagoon under the Endangered Species Act and Clean Water Act, which is causing large-scale manatee die-offs. 

The Indian River Lagoon has historically been a seagrass-filled safe haven from predators and cold waters for manatees and other species. Now, due to water pollution, it faces collapse. In 2021, the brackish waters of the lagoon were where more than half of the manatees starved to death. 

Currently pending in a Florida district court, the lawsuit alleges that the EPA has a responsibility to reevaluate the total amount of each pollutant allowed to enter the water daily given recent manatee mortality numbers. 

There Is Hope But It’s Fading

Some seagrass regrowth has taken place in Mosquito Lagoon, where most of the manatees have been gathering. What’s more, in 2022 the amount of fresh produce thrown directly to the manatees in order to supplement their diets doubled. According to Rose, these efforts help, but they’re not enough. 

In 2017, manatees were downgraded from endangered to threatened under the Endangered Species Act. In order to save manatees, the recovery program needs to go back to what it was prior to that year, says Rose.

Their habits need to be prioritized with massive restoration efforts, he adds. The restoration efforts have only just begun and will likely take longer than a decade. 

“Florida has been growing unsustainably. We’ve been mortgaging our environmental future”, says Rose. “The value the Florida economy stands to lose from tourism, fishing, and property enjoyment, if water quality is not prioritized, is in the billions, well over what would be spent on restoration.”

Residents and visitors who see a manatee they suspect may be in distress can contact the FWC hotline at 888-404-3922. 

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