Florida Manatees Are Dying Of Hunger At An Alarmingly Excessive Charge : NPR

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More than 10% of Florida’s total manatee population has died so far this year

Manatees are large marine mammals native to Florida that spend their time grazing on seaweed in shallow coastal areas. Since January, manatee deaths have been nearly three times as high in each of the past five years as in the same period. Eva Marie Uzcategui / Getty Images hide caption

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Eva Marie Uzcategui / Getty Images

Manatees are large marine mammals native to Florida that spend their time grazing on seaweed in shallow coastal areas. Since January, manatee deaths have been nearly three times as high in each of the past five years as in the same period.

Eva Marie Uzcategui / Getty Images

In Florida, wildlife managers and environmental groups are stunned by a record number of manatee deaths. More than 750 manatees have died since the beginning of the year, the highest number of deaths ever recorded in a five-month period. Most of the deaths occur in Florida’s Indian River Lagoon, where a major seagrass dieback has left manatees without enough to eat.

The Indian River Lagoon is actually not a river. It is a large estuary bounded by barrier islands on the Atlantic coast of Florida and stretching for more than 150 miles from Cape Canaveral to Stuart. For years there have been concerns about declining water quality in the lagoon caused by a number of factors including development, sewage treatment plants, rainwater runoff and warming from climate change.

The turning point of the lagoon

These problems peaked in 2011 when an algae super bloom covered more than 130,000 acres of the lagoon’s water, blocking sunlight and causing massive seaweed death. “In hindsight,” says Ryan Brushwood, a local biologist, “it was probably the turning point.”

The lagoon saw algal blooms in early January this year. Reisig, who works for a company that grows seaweed in the estuary, says, “When these flowers were really bad, you couldn’t see your hand beneath the surface. Not much light got to the plants.”

Manatees love the Indian River Lagoon, and for years it has provided them with lush seaweed. This is not the case now. Chuck Jacoby, an environmental scientist for the regional waterfront, has observed the decline in seaweed. Over a 10 year period, he says, “There has been about 46,000 acres of decline.” That’s a 58% decrease in total hectares over the decade.

The Indian River Lagoon is a special and fragile place. It is one of the most biodiverse estuaries in the northern hemisphere and is home to 35 endangered or threatened species. Nearly a third of Florida’s manatees spend some time in the lagoon each year, but the great death of seaweed has left them without food.

A SeaWorld rescue team finds a sick manatee in need of rehabilitation. Bethany Bagley / courtesy SeaWorld Hide caption

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Bethany Bagley / Courtesy SeaWorld

A SeaWorld rescue team finds a sick manatee in need of rehabilitation.

Bethany Bagley / Courtesy SeaWorld

Jon Peterson leads rescue operations at SeaWorld in Orlando. Since December, its employees have been busy responding to the large numbers of sick and dying manatees.

“It’s really a feast for the eyes when you see what’s happening,” he says. “There are animals that soar as high as you would think a pierced lung from a boat attack would in a normal year.

An “unusual mortality event” that may not be over yet

The high number of manatee deaths that year prompted the US Fish and Wildlife Service to classify it as an “unusual mortality event” and to open an investigation. The total population of Florida manatees is estimated to be no more than 6,800.

“When you talk [about] a population like this and you have a loss of 700 in the first quarter of the year, “says Peterson,” that looks very scary right now. “

SeaWorld is one of four Florida facilities that rehabilitate sick and injured manatees. 28 of them are looked after by his employees. Ten are so weak that they are fed through feeding tubes. Because the manatees have lost so much weight, rehabilitation takes longer than usual.

“You’re talking about an animal lying on the ground … 400, 500 pounds,” says Peterson. “It’ll take us three to five months to get that weight back up, to get her to a point where we can release her.”

A SeaWorld team in Orlando, Florida is nursing malnourished manatees. Bethany Bagley / courtesy SeaWorld Hide caption

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Bethany Bagley / Courtesy SeaWorld

Manatees do not do well in cold water, which is why they congregate in the Indian River Lagoon and other warm coastal areas during the winter months. Now that it’s warming, scientists say manatees are starting to disperse to other areas along the Gulf and Atlantic coasts where they may find seaweed in abundance. But in late autumn they return to familiar waters in large numbers, including the lagoon.

Michael Walsh, an associate professor at the University of Florida who specializes in aquatic animal health, fears this death event may not be over for a long time. “We have a compromised system that the animals use and have to stay in,” he says, “but the feed is no longer available in the same amount as it used to be.”

Manatees need large-scale restoration efforts

Walsh and other scientists say the key to helping manatees is getting the Indian River Lagoon back to health. It will take years, maybe decades, but there are signs of progress. Florida has just allocated half a billion dollars to begin eliminating wastewater treatment plants, which are a major contributor to nutrient pollution in the area.

In the lagoon, Brushwood’s Sea and Shoreline company has had success in restoring seaweed. As part of a grant from the National Estuary Program, Sea and Shoreline planted two acres of a hardy species of seagrass last June. A year later it flourishes. Similar replanting efforts helped bring back healthy seagrass meadows in Crystal River, another Florida manatee habitat.

Brushwood believes that a large-scale effort, with enough time and money, could bring the seaweed back to the Indian River Lagoon and bring things back in favor of the manatees.