Quantcast

Manatees Dying in Record Numbers from Toxic Algal Bloom

Defenders of Wildlife

By Elizabeth Fleming

2013 is shaping up to be a particularly deadly year for the endangered Florida manatee, whose population is estimated at around 5,000 animals. More than 460 dead manatees have been documented in the first three months of this year—an alarmingly high number. It has already topped the number of manatees that died all of last year. What’s going on here?

More than 460 dead manatees have been documented in the first three months of this year.

Well, among other threats, these aquatic mammals are experiencing injury and death in record numbers from exposure to a toxic algal bloom known as red tide in southwest Florida. Lee County has been particularly hard hit, followed by Charlotte County, Sarasota County and Collier County. Red tide is a naturally occurring event, but this outbreak has persisted since September 2012 and has killed as many as 240 manatees, a new record for red tide deaths in southwest Florida. Manatees are affected by red tide neurotoxins when they breathe, and even more so when they eat seagrass coated by the algae. The toxins cause seizures that can result in drowning when the animals cannot lift their snouts above the water to breathe.

According to the New York Times, experts are uncertain why this year’s algae bloom was so lengthy and toxic. Phosphorus runoff from fertilized farms and lawns may have contributed, because algae thrive on a phosphorus diet. The Caloosahatchee River, which runs through rural Florida farmland, empties into the ocean at Fort Myers.

Red tide algal bloom. Photo: ©NOAA

Some manatees have been found alive but very ill, and have been transported to facilities where they receive around-the-clock care. This is the worst red tide outbreak since 1996, when 151 animals were killed by the algal bloom in the southwest part of the state. Even though the bloom is subsiding, manatees will continue to be affected for some time because toxins from the red tide have settled onto seagrass beds.

On the east coast of Florida, yet another threat is claiming manatee lives in the Indian River Lagoon in Brevard County. Nearly 100 manatees have died of an unknown cause, possibly from a different toxin, since July 2012. With most of Brevard’s seagrass eliminated due to a combination of factors (such as cold and drought that resulted in higher salinity) algal blooms known as “brown tide” have developed in the lagoon and impacted water clarity and seagrass growth. In some areas 99 percent of the seagrass has been lost. Without their staple food supply, manatees may be consuming macroalgae or other food sources that are making them ill and killing them.

The U.S. Fish and Wildlife Service is currently considering a proposal to downlist the manatee from “endangered” to “threatened.” Considering that the existing risks to manatees have not been alleviated and that little is known about emerging new threats, Defenders of Wildlife urges the Service to carefully incorporate these significant losses into their review and assessment of the status of the manatee population.

These large manatee die-offs are the latest struggle in a long history of challenges for the Florida manatee, which was one of the first species protected by the Endangered Species Act when it was enacted in 1973. The leading human-caused threat to manatees is collisions with watercraft. So far this year, 15 manatees have been killed by boats. We expect this number to rise substantially before the year is over, and especially during the summer months. Scientists believe that unless this cause of death is controlled, the manatee population will not recover.

To address this threat, Defenders of Wildlife has been instrumental in the creation of new manatee protection speed zones, sanctuaries and refuge areas. We supported the establishment of manatee speed zones in Tampa Bay and Flagler County, and the creation of the Kings Bay Manatee Refuge that made all but a small portion of the bay a slow-speed area. We advocate for improved enforcement of speed zones and comment on management plans for federal and state parks and refuges to ensure that they adequately address manatee protections.

An even greater, long-term threat is the loss of warm water habitat that manatees need to survive in winter. The deadliest year on record, 2010, saw 766 manatees killed, nearly 300 of them by an extended period of very cold weather. Because residential development has greatly reduced the natural warm water springs manatees need to stay warm, many of the animals aggregate in the warm-water outfalls at electric power plants on cold winter days. A large percentage of the manatee population could be lost in the future if aging plants are shut down.

Defenders of Wildlife is hard at work to protect manatee habitat. We petitioned the U.S. Fish and Wildlife Service to revise critical habitat for the Florida manatee, supported the acquisition of Three Sisters Spring for Crystal River National Wildlife Refuge, increased protections for manatees overwintering in Kings Bay and strengthened seagrass protections in Everglades National Park. We advocate for increased protection for natural springs, agency efforts to increase manatee access to springs and adoption by agencies and power companies of a warm-water contingency plan to help manatees transition from artificial to natural sites.

If you’re in Florida and you see a manatee in distress that may be suffering from red tide exposure or any other injury, call 1-888-404-3922 immediately. Be sure that your actions are not putting manatees at risk: refrain from pursuing, touching, feeding or watering manatees, and practice safe boating for the manatees’ sake and yours.

Visit EcoWatch’s BIODIVERSITY page for more related news on this topic.

 

EcoWatch Daily Newsletter

Natural Resources Defense Council

By Emily Deanne

Shower shoes? Check. Extra-long sheets? Yep. Energy efficiency checklist? No worries — we've got you covered there. If you're one of the nation's 12.1 million full-time undergraduate college students, you no doubt have a lot to keep in mind as you head off to school. If you're reading this, climate change is probably one of them, and with one-third of students choosing to live on campus, dorm life can have a big impact on the health of our planet. In fact, the annual energy use of one typical dormitory room can generate as much greenhouse gas pollution as the tailpipe emissions of a car driven more than 156,000 miles.

Read More Show Less
Kokia drynarioides, commonly known as Hawaiian tree cotton, is a critically endangered species of flowering plant that is endemic to the Big Island of Hawaii. David Eickhoff / Wikipedia

By Lorraine Chow

Kokia drynarioides is a small but significant flowering tree endemic to Hawaii's dry forests. Native Hawaiians used its large, scarlet flowers to make lei. Its sap was used as dye for ropes and nets. Its bark was used medicinally to treat thrush.

Read More Show Less
Sponsored
Frederick Bass / Getty Images

States that invest heavily in renewable energy will generate billions of dollars in health benefits in the next decade instead of spending billions to take care of people getting sick from air pollution caused by burning fossil fuels, according to a new study from MIT and reported on by The Verge.

Read More Show Less
Aerial view of lava flows from the eruption of volcano Kilauea on Hawaii, May 2018. Frizi / iStock / Getty Images

Hawaii's Kilauea volcano could be gearing up for an eruption after a pond of water was discovered inside its summit crater for the first time in recorded history, according to the AP.

Read More Show Less
A couple works in their organic garden. kupicoo / E+ / Getty Images

By Kristin Ohlson

From where I stand inside the South Dakota cornfield I was visiting with entomologist and former USDA scientist Jonathan Lundgren, all the human-inflicted traumas to Earth seem far away. It isn't just that the corn is as high as an elephant's eye — are people singing that song again? — but that the field burgeons and buzzes and chirps with all sorts of other life, too.

Read More Show Less
Sponsored
A competitor in action during the Drambuie World Ice Golf Championships in Uummannaq, Greenland on April 9, 2001. Michael Steele / Allsport / Getty Images

Greenland is open for business, but it's not for sale, Greenland's foreign minister Ane Lone Bagger told Reuters after hearing that President Donald Trump asked his advisers about the feasibility of buying the world's largest island.

Read More Show Less
AFP / Getty Images / S. Platt

Humanity faced its hottest month in at least 140 years in July, the US National Oceanic and Atmospheric Administration (NOAA) said on Thursday. The finding confirms similar analysis provided by its EU counterparts.

Read More Show Less
Newly established oil palm plantation in Central Kalimantan, Indonesia. Rhett A. Butler / Mongabay

By Hans Nicholas Jong

Indonesia's president has made permanent a temporary moratorium on forest-clearing permits for plantations and logging.

It's a policy the government says has proven effective in curtailing deforestation, but whose apparent gains have been criticized by environmental activists as mere "propaganda."

Read More Show Less