Researchers say vital seagrass is dying off at rapid rates in Florida

Seagrass, a plant that grows underwater and is abundant throughout Florida, is vital to human life. It's also dying off rapidly due to environmental damage and climate change, researchers say.

An estimated 2.7 million acres of seagrass meadows grow along Florida's coastlines, according to the National Oceanic and Atmospheric Administration.

Dr. James Fourqurean, professor of Biological Sciences at Florida International University, explains that the state's seagrass is dying off at an unsustainable rate.

In some areas, like the Indian River Lagoon, "well over half" of the seagrass had died off over the last 50 years.

In other places, like southern Biscayne Bay, the quantity has not been affected as directly, but the quality of the seagrass has diminished with water quality.

Seagrass requires high levels of sunlight, because its roots are planted in soils deep underwater, which contain less oxygen. To produce the oxygen that seagrass needs, the plant photosynthesizes throughout the day - a process which requires sunlight.

Water clarity is important for sunlight to penetrate through to the seagrass, but polluted waters inhibit that process.

"We're losing water clarity because, in Florida, we've largely been polluting our water with nutrients," Fourqurean explained.

As plankton, a type of microorganism, grow in the fertilized waters, the sunlight is blocked from seagrass. Some plankton are poisonous, and these harmful algal blooms can be dangerous for humans and fish as well.

"Nutrient run-off is a direct human health problem, but the bigger problem - the one that's more prevalent that it's causing is this loss of water clarity, and therefore the loss of seagrass," Fourqurean added.

Seagrass is extremely valuable to not only marine life, like manatees, which experienced a mass die-off with the loss of the plant, but also to humans.

"The first worldwide analysis of the value to humans of natural ecosystems - that first one that was ever done back in the late 1990s - pointed to seagrass meadows as acre-per-acre the most important producer of goods and services to support the human population," Fourqurean said.

Seagrass is the base of the food chain for many of the fish that we eat in South Florida, and without seagrass, the fishery industry could decline rapidly.

Conch, lobster, grouper, shrimp and more rely on seagrass. Green sea turtles would die off as well, Fourqurean said.

Not only would the price of fish skyrocket - but home insurance in South Florida would be affected with the loss of storm protection that seagrass provides. The plant protects environments from erosion and storm damage, Fourqurean said.

"They hold down the sediment and the soil so that that doesn't move around and bury things during hurricanes," he explained.

Water quality would diminish too, as seagrass regulate the water quality and "keep it clear," Fourqurean said.

"We would really miss our seagrasses if we didn't have them," he said.

"Our insurance rates would go up, our water quality would go down, and when the water quality goes down people don't want to live next to the water anymore, so our real estate prices would go down. The coastal fisheries that are such an important part of our economy and our diet down here would go way down."

Seagrass also store carbon, so global warming would increase with seagrass die-off as more carbon is released into the atmosphere.

In order to help protect the plant, water and waste need to be managed better throughout South Florida as well, he said.

"Probably the main thing we need to do in the Miami-Dade area and Fort Lauderdale is get rid of all our septic tanks," Fourqurean said.

Septic tanks are a type of sewage management system often used in rural areas. The tanks can occasionally overflow, and they can pose potential for groundwater pollution as excess liquid is treated and dumped into a septic drain field.

The contents of the septic tank flow into the groundwater and eventually into the oceans, Fourqurean said.

"A city of our size - we should not be on septic tanks," he said.

The effects of seagrass die-off have been seen with the loss of manatees in the past few years, but as climate change accelerates, the loss can be felt on land, too.

"We have to stop polluting our groundwater," Fourqurean urges.