There is a massive seagrass die-off in Florida Bay that experts say “is the latest sign we’re failing to protect the Everglades.” Since the middle of 2015, approximately 40,000-acres of the bay have been affected with dead seagrass clouding the waters and creating a perfect environment for algae blooms; and this is not the first time this has happened..
[James Fourqurean, a Florida International University marine scientist] and government Everglades experts fear they’re witnessing a serious environmental breakdown, one that gravely threatens one of North America’s most fragile and unusual wild places.
Florida Bay is located at the southern tip of the Florida mainland, and is the terminus of the Florida Everglades. Covering around 1,000 square miles, it is approximately one-third of the Everglades National Park. Florida Bay is home to bottlenose dolphins, manatees, loggerhead sea turtles, Roseate Spoonbills, and the American crocodile. It is also the source of more than $80 million in the shrimp, lobster and stone crab industries, and it’s sport’s fishing “worth $ 1.2 billion per year, according to the Everglades Foundation.” The Florida Bay estuary is fed by the fresh water system that flows through the sawgrass prairies of the Everglades from Lake Okeechobee, and it is the disruption of this fresh water flow that may be the cause of the seagrass die-off.
Fourqurean and fellow scientists think they know the cause of the die-off. It’s just the latest manifestation, they say, of the core problem that has bedeviled this system for many decades: Construction of homes, roads, and cities has choked off the flow of fresh water. Without fast moves to make the park far more resilient to climate change and rising, salty seas, the problem will steadily worsen.
“The southern Everglades, Biscayne Bay, Florida Bay are starving for water. It’s basically a permanent man-made drought, created by the drainage and development patterns to the north in the Everglades,” according to Robert Johnson, director of the National Park Service’s South Florida Natural Resources Center. “We’ve cut off the flow that historically passed through the Everglades and we’ve sent it to tide for flood control or we’ve provided it to urban and agricultural use for water supply.”
The result, he says, is a hyper-saline condition that negatively impacts Florida Bay.
In very salty conditions, waters hold little of the oxygen that seagrasses need to live. At the same time, other marine organisms turn to a different “anoxic” process – one that goes forward without oxygen – that has a nasty by-product: hydrogen sulfide.
The chemical “is a notorious toxin,” said Donald Boesch, president of the University of Maryland Center for Environmental Science. “It kills life, including human.”
And that’s just the beginning. Once the seagrass dies off, it becomes a feedback – the water becomes filled with dead grasses that release nutrients, and those can stoke huge algal blooms (which happened the last time around, but so far have not appeared en masse). That clouds the water and prevents light from reaching remaining seagrasses, which then also die, because they need the light for photosynthesis.
Other scientists blame fertilizer runoffs from large-scale agribusinesses like “Big Sugar” for creating the algae blooms “on which bacteria feed, grow and then consume all the oxygen in the water. Further microbes thrive in this oxygen free environment, but produce toxic gases where nothing grows.”
Whatever the exact cause, it’s a man-made problem, and we need to fix it.
Interior Secretary Sally Jewell recently visited Everglades National Park, plucked dead seagrass from Florida Bay, and told reporters, “This is what we get when we don’t take care of Florida Bay.”
For more on this story, be sure to read Chris Mooney’s full article in The Washington Post.