Florida’s Red Tide Fueled By Sewage

Wastewater Treatment Plants Dumping Sewage On Farms, Open Space

Florida Gov. Rick Scott declared a state of emergency for seven counties in Southwest Florida over an unusually severe red tide outbreak. Unfortunately, red tide is now another symptom of sewage mismanagement on land. Florida, like most states, now thinks of sewage as fertilizer.

Red tide, which scientists call a harmful algae bloom, is partly caused by a naturally occurring alga (a plant-like microorganism) called Karenia brevis or K. brevis. When K. brevis appears in large quantities – typically in the Gulf of Mexico – it can turn ocean water red, brown or green. K. brevis is fueled by some of the harmful toxins that it encounters in the ocean, much of which comes from sewage and surface water runoff from cities and rural areas alike. The toxins absorbed by red tide can impact the nervous systems of fish, birds and mammals (including humans).

Ironically, at least one form of agriculture fertilizer also attacks the nervous system—human sewage. Some health advocates believe that water runoff from these farms and dumping sites are fueling the red tide and the rise in neurodegenerative disease around the world.

Red tides are not unusual in the Gulf of Mexico and the western coast of Florida. The strong smell; eye, nose, and throat irritation; and large fish kills related to the event have been documented as far back as the 1840s. Red tides are caused by tiny algae that grow on the surface of the ocean, occasionally giving it a reddish-brown tint. Thus, scientists can use satellite imagery to map the extent of red tides and monitor how they spread over time. Satellites detect changes in the way the sea surface reflects light. These changes can be linked to concentrations of chlorophyll, showing where algae and other ocean plants are concentrated in the ocean.

red tide Florida

In his declaration, Gov. Scott’s office made two points: The state is supporting communities struggling with the scourge, and in an attempt to defend the agriculture industry he said that the siege of seafaring microorganisms is “naturally occurring.” Unfortunately, the problem and the solution aren’t that simple.

The declaration will provide money and resources to address a problem that’s lingered since October in Charlotte, Collier, Hillsborough, Lee, Manatee, Pinellas and Sarasota counties.

At 10 months, the current bloom is testing the resilience of communities and the priorities of government. Red tides have lasted as long as 24-months in southwestern Florida since the turn of the century. The frequency and the duration of these deadly tides appears to be rising.

Indeed, scientists and historians note fish kills triggered by the infestations dating back as early as the 1500s. While scientists today acknowledge the natural roots of Florida’s red tides, they also are investigating the possibility that persistent blooms, like the one besetting the Gulf Coast this summer, might be getting a “booster shot” from man-made pollutants that spill into the ocean.

Both the coastal red tide and the inland blue-green algae have beset South Florida through the summer, killing vast numbers of fish and other wildlife, including dozens of dolphins, manatees, sea turtles, sharks and eels. Humans also have been sickened by brevetoxins, which are emitted by the tiny organisms — karenia brevis — that create the red tide. Breathing the fallout can constrict the lungs’ bronchioles and send asthmatics to emergency rooms with coughs and shortness of breath.

Scott last month declared an emergency because of the blue-green algae bloom that began in giant Lake Okeechobee, before spreading to multiple rivers and canals. 

The declaration helped pave the way for assistance, including the deployment of biologists and other scientists from the Florida Fish and Wildlife Conservation Commission to rescue wildlife and to clear away the innumerable creatures that could not be saved.

Along with Scott’s action comes a $900,000 grant to Lee County, home to Fort Myers and the epicenter of the red tide, to help cope with the cleanup. That brings the total amount granted to the county, where some tourists have cut short their summer vacations, to $1.3 million.

Another $500,000 will go to Visit Florida, so the agency can support local tourism officials in mounting a campaign to try to bring visitors back to the red tide zone — which stretches more than 100 miles from Sarasota nearly to the tip of the state.

“We will continue to deploy all state resources and do everything possible to make sure that Gulf Coast residents are safe and area businesses can recover,” Scott said in a statement.

The red tide initially tends to thrive in low-nutrient environments, where it does not have to compete with other organisms. But when the blooms take hold and move closer to shore, they can thrive on nitrogen and other elements that could be fueled by pollution.

One researcher recalled his recent sampling trip along the coast, seeing the pollutants that brought the blue-green algae to the Caloosahatchee River spill into the Gulf just a couple miles from where the red tide exploded, near Fort Myers.

“It seems pretty damned obvious there is a connection,” Mitsch said, adding a cautionary note: “But that doesn’t mean there actually is one. That is why we are investigating. We have to dig deeper.”

Farming fertilizers already are blamed for fueling another Florida plague — the blue-green algae that chokes inland lakes, rivers and canals in the south part of the state, including giant Lake Okeechobee. This farm runoff also includes tons of human sewage, which has been pawned off on farmers as fertilizer since the early 1990s. Wastewater treatment plants throughout the east and southeast are paying farmers and other managers of open space, including golf courses, parks and playgrounds, to dump this toxic, infectious waste (biosolids). Florida and other states in the southeast get more than their share. It’s killing more than fish.

Such a finding likely would reinvigorate calls for greater regulation of the prime source of the pollutants —agricultural runoff from sugar cane and other farms in South Florida.

Read The Full Story About Florida’s red Tide

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