Toxic algae collects at a dam on a river in Florida.
An algae bloom at a dam on the Caloosahatchee River in Alva, Florida, July 12, 2018. Lynne Sladky/AP

The algae blooms pose risks to humans and marine animals—and to Florida’s tourism-dependent economy.

Toxic blue-green algae has bloomed again in Lake Okeechobee, Florida’s largest lake, an outbreak so severe that Governor Rick Scott has declared a state of emergency in seven counties. While the term “algae bloom” might not sound dangerous, it is an outbreak of cyanobacteria that presents a significant risk to public health.

In early July, the bloom was reported to cover more than 90 percent of Lake Okeechobee’s surface. The green sludge has crept outward from the lake and filled waterways with a putrid sludge that locals say smells like mold. News reports are warning residents to keep children and animals away from contaminated water. According to the CDC, ingesting it—including through consumption of marine animals like oysters—is the most dangerous type of exposure. Effects can include skin, nose, eye, and throat irritation, nausea, vomiting, diarrhea, and abdominal pain.

What’s causing the bloom?

Pollution and warm water fuel the algae’s growth. Research from the U.S. EPA suggests that fertilizer runoff is introducing phosphorous and nitrogen to waterways, essentially fertilizing the algae.

Another factor is water flow. The Everglades, a wetland ecosystem, naturally flows from Lake Okeechobee south to Florida Bay. But since 1910, a series of more and more robust dikes have been built to contain that flow. The current dike system, called the Herbert Hoover Dike, is made up of about 143 miles of levees. Additional canals divert the flow to the east and west coasts.

With the natural flow of the Everglades staunched, water builds up when it rains. Then the algae blooms again, and like clockwork, the U.S. Army Corps of Engineers tries to relieve Lake Okeechobee’s water levels by discharging more water along the canals. This increases the concentration of fresh water in the estuary, giving the cyanobacteria even more opportunity to thrive.

Lake Okeechobee in 2016. (Wilfredo Lee/AP)

The Army Corps has been releasing a lot of water from Lake Okeechobee, and, in combination with the rain runoff from the basin, it’s compressed the estuary so that it’s mostly fresh [water] now—which is what cyanobacteria like,” said John Cassani of Calusa Waterkeeper, a nonprofit that’s part of the Waterkeeper Alliance. “So cutting back on those fresh-water inflows would increase the salinity of the estuary, and hopefully discourage continued growth of this cyanobacteria.

When the Army Corps discharges water from Lake Okeechobee, it increases the concentration of fresh water in the Caloosahatchee and St. Lucie estuaries, giving the cyanobacteria even more opportunity to thrive there—while interrupting the Everglades’ natural southward flow.

Others point to the role of agriculture, especially Florida’s massive sugar industry. Peter Girard, a spokesperson from the environmental group Bull Sugar, said, “Sugarcane needs water when Florida is dry, and it needs drainage when Florida is wet. The industry has secured policy and practice from both state and federal authorities to give them that at the expense of everyone else in Florida.”

For years, Florida environmentalists have complained that agricultural runoff from and water mismanagement by “Big Sugar” cause damage to Lake Okeechobee and the Everglades. Grassroots pushes for the state to buy back land from sugar companies go back two decades. Many contracts and pieces of legislation have been signed and then nixed.

Buying back land could help

Still, organizations including the Everglades Trust and the Sierra Club have joined with a long list of companies, such as Yeti and Costa, to champion SB10, the latest iteration of the state’s land buyback scheme (also known as the Now or Neverglades Declaration).

SB10 was introduced into the Florida State Senate in January 2017 and approved by Governor Scott by that May. The bill calls for the creation of a reservoir south of Lake Okeechobee, in the region called the Everglades Agricultural Area. If the construction of the reservoir is executed as planned, freshwater will be able to flow southward rather than in forced discharges to the St. Lucie and Caloosahatchee estuaries. The new southward flow would alleviate the toxic algae blooms and help save the state’s fragile ecosystems. Last week, the White House’s Office of Management and Budget approved the reservoir project.

Legislators have suggested other ways to solve the algae-bloom problem, like increasing salinity in areas plagued with blooms. But Chris Wittman, co-founder and program director of the nonprofit Captains for Clear Water, said these measures would amount to treating the symptoms of a disease instead of its root cause.

“The reason we’re in this [mess] this year is manmade manipulation of a natural system,” Wittman said. “So the idea is not to manipulate it farther. The idea is to get that system back to functioning with delivery and timing as close to the natural cycle as possible.”

Meanwhile, another type of algae bloom, red tide, has been killing fish in the Gulf of Mexico. The two blooms are sending tremors through businesses in a state that is known for its natural beauty and depends on tourism. In 2013, a year that was plagued by algae blooms and the deaths of hundreds of manatees, more than 90 percent of hotels in Fort Myers Beach reported cancellations related to water conditions.

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