Florida’s Treasure Coast has turned toxic this summer, as a foul-smelling algae bloom that resembles guacamole has made some of the Sunshine State’s beaches untouchable.
One cause is the controlled release of water from an over-full Lake Okeechobee into local rivers that flow east to the Atlantic and west to the Gulf of Mexico. Heavy precipitation makes these controlled releases necessary because Lake Okeechobee’s aging dike system can’t retain the large amount of water. Even if the lake’s infrastructure was up to snuff, the water in Lake Okeechobee is in bad shape.
The lake’s poor water quality starts with its surrounding watershed, or drainage area. This agricultural area is planted with citrus and sugarcane and also has hundreds of thousands of acres of pasture, with only a small percentage of urbanized land. Rains can carry fertilizers and manure into the lake, and ultimately to the coast. Fertilizer, manure and sewage are loaded with nutrients, nitrogen and phosphorus, which can build up in water in a process known as eutrophication, or over-enrichment. And just as fertilizer feeds plant growth on land, it feeds algal growth in water. It can cause the kind of harmful algal blooms now occurring in Florida.
Besides disrupting tourism, harmful algal blooms can cause health problems—such as nausea, respiratory issues, and skin irritations—for humans who come in contact with the water. The algae can also choke out marine life by blocking sunlight and consuming oxygen that fish and other aquatic species need to survive. When oxygen levels become dangerously low, or hypoxic, “dead zones” may occur and result in massive fish kills.
Florida Is Not Alone
This problem is not unique to this summer. Periodic hypoxia has been documented in this area since the 1980s. It’s also not unique to Florida. In 2014, a toxic algal bloom in Lake Erie forced the city of Toledo to shut down its drinking water system, leaving more than 400,000 people without access to water. Just before the 2008 Summer Olympics in Beijing, there were images of algae overtaking the Yellow Sea. This year, Brazil is also grappling with poor water quality conditions as it prepares to host the 2016 Summer Olympics. And on South America’s west coast, Chile’s salmon farming industry lost $800 million a few months ago when massive algal blooms killed millions of fish.
Source: WRI, 2011
WRI’s interactive map of coastal eutrophication and hypoxia identifies the St. Lucie River, one of Lake Okeechobee’s outlets, as having experienced periodic hypoxia since the 1980s.
All over the world, we’re seeing increased nutrient pollution and its harmful effects. In the past century, nutrient pollution in waterways nearly doubled globally, driven by growth in agriculture, industry and population. Eutrophication has become one of the main causes of poor water quality. The situation is expected to get worse, particularly for developing countries. A recent study projected that even under optimistic conditions, we will see more people at high risk of water pollution in 2050 – as many as one in three (it’s now about one in five).
Stopping the Trend
In order to stop this trend, urgent action is needed from policy makers, corporations, farmers and citizens to better manage nutrients from farms, urban and suburban areas, and industries. For example, cover crops and riverside forest buffers can filter excess nutrients before they leave farm fields and end up polluting local streams. Septic systems and sewage treatment plants may be able to better treat wastewater to reduce the amount of nutrients they discharge into rivers. And cities can be designed with green infrastructure that naturally filters pollutants out of stormwater.
To inform decision makers on possible solutions to these water quality challenges, WRI—together with the Global Environment and Technology Foundation, the Energy Research Centre of the Netherlands, and the wider Global Partnership on Nutrient Management (GPNM)—developed a Global Nutrient Management Toolbox. The Toolbox provides a plethora of online resources to support management actions and policy decisions related to the sustainable management of nutrients and includes hundreds of examples of best management practices and policies from across the globe.
From the Eastern to the Western hemisphere, we can learn from each other and take action now before nutrient pollution and algal blooms wreak irreversible havoc on our ecosystems, economy and health.