A toxic algae bloom has continued expanding throughout Florida’s lake Okeechobee since May and has also spread through the St. Lucie River estuary all the way to the Atlantic Ocean. The bloom has gotten so large that it is now visible from space.

The algae bloom has made the water unsafe for consumption and agricultural use, and has caused Florida’s governor Rick Scott to declare an environmental state of emergency in two south Florida counties. Scientists and politicians continue to dispute exactly what is causing this toxic spread of algae.

Florida Toxic Algae Bloom
Image Credit: NASA Earth Observatory images by Joshua Stevens, using Landsat data from the U.S. Geological Survey

Algae bloom large enough to see from space

Satellite photos taken on July 2 by NASA’s Operational Land Imager revealed a growing section of cyanobacteria, a single-celled organism. This type of algae is colloquially known as blue-green algae, though technically, it is really a type of bacteria. The bloom in question covers a large area of Lake Okeechobee, which is the second largest lake completely within the United States, at 720 square miles. Lake Michigan is the largest.

Between early May and July 2, when the satellite imagery was taken, the bloom had grown from 33 square miles to an estimated 239 square miles, representing a 500 percent increase in area over the last two months.

The blue-green algal bloom has continued into July, and has since caused issues for tourism and local commerce during what was normally a busy Fourth of July season. In response to the bloom, the United States Army Corps of Engineers mobilized to aid in reducing the flow of water from Lake Okeechobee in hopes of stopping the algae from spreading downstream and continuing into the Atlantic Ocean.

“Human activities have dramatically increased nitrogen and phosphorus inputs into many rivers and lakes, casing algal blooms that threaten economic and recreational uses of those waters,” says Hans Paerl, a professor of marine and environmental sciences at the University of North Carolina Chapel Hill Institute of Marine Sciences.

Consequences of poor water management

Algal blooms are the result of a buildup of nitrogen and phosphorus in waterways, mostly from the water runoff having picked up various nutrients while passing through heavily fertilized land, such as farms or golf courses. This excess in nutrients allows for the algae to thrive and prosper. However, with increased levels of algae, the amount of oxygen in the water drops dramatically, which in turn kills off other aquatic life, such as fish and plants. These toxins can also poison humans, as contact with the water can cause nausea, vomiting, and in extreme cases, liver failure.

Many scientists analyzing the situation have stated that this bloom can be attributed to Florida’s wet winter, as it not only caused an increase in water runoff, but also created a spreading of algae and toxins, especially when state water managers decided to discharge water through the St. Lucie Canal out to the Atlantic Ocean near Stuart, Florida.

Drastic action necessary

“These types of blooms are going to be more prevalent as the climate warms,” warns Rob Moore, a senior policy analyst for the Natural Resources Defense Council’s (NRDC) water program. “That’s yet another motivating factor for the U.S. and for governments around the world to take rapid action to decrease emissions that are causing climate change.”

Considering both the rising temperatures and heavy rains, Moore says that “it will take less nutrients to produce the same types of blooms in the future. The nutrients causing the current blue-green algae bloom in Florida are the result of decades of pollution.”

Unless action is taken reducing water pollution and mitigating the effects of climate change, the toxic algae will keep coming back.