A new status report on Florida Bay describes the marine seagrass ecosystem as “fairly stable” — at least it was until a massive 2015 seagrass die-off.
The Florida Fish and Wildlife Conservation Commission’s report released this week gives Florida Bay seagrass an overall color-coded “green” rating, indicating a healthy or improving system.
Research for the Florida Bay report, including aerial mapping and surveys, is based on the most recent information available. But in Florida Bay’s case, that monitoring data relies heavily on science ending in 2011 to 2014.
“It’s a great report but it doesn’t apply to what’s happening now,” said Xavier Figueredo, an Islamorada fishing guide and founding board member of the Florida Bay Forever advocacy group. “The 2015 die-off is worse than the 1980s die-off. It’s devastating.”
“It’s a lag in the collection of data.... Sometimes that’s just the way science works,” said Jim Fourqurean, a leading seagrass ecologist at Florida International University who frequently consults with the Florida Keys National Marine Sanctuary.
“There was no attempt or intent to deceive or to minimize,” said Fourqurean, who is involved with the bay research but did not write the final version. “The scientists at FWC understand the resources; they know what’s happening.”
In the preface to the 12-page Florida Bay section, part of a statewide report nearly 300 pages long, the authors write: “Unusually hot and dry conditions in summer 2015 resulted in high-salinity, anoxic [low oxygen] bottom water and build-up of high concentrations of sulfide” in sediments below seagrass beds in Rankin Lake and Johnson Key Basin.
“This in turn led to die-off of large areas of seagrass in these basins,” it continues. “The die-off appeared to be expanding to seagrass beds in Rabbit Key Basin and Whipray basin as well.”
A recommendation in the report urges additional aerial imaging and water-quality studies to determine the extent of the 2015 die-off that still clouds large areas of the bay.
“There’s got to be some other way to assess it,” said Figueredo, co-owner of the Bay and Reef Co. “Aerial imaging isn’t going to show them anything. The water is too turbid” because of floating sediment and dead material remaining from the die-off.
“On any given day, I’d guess that 25 to 30 percent of the bay is too murky to see the bottom,” he said.
The balance of the Florida Bay assessment largely uses reports that chart the improvement of seagrass over the last two decades until the 2011-14 period.
“Florida Bay suffered significant losses in the late 1980s and early 1990s as the result of a massive, apparently natural die-off. Seagrass appears to have recovered from this event, based on data from the most recent imagery,” says the introduction to the 12-page overview. Turtle grass and manatee grass are the predominant seagrass species in Florida Bay.
“The report was accurate in 2014” when the most recent research was logged, Fourqurean said. “Then in 2015, the alarm bells started going off.”
The 1980s Florida Bay die-off “was unprecedented. There’s no evidence anything like it ever happened before,” he said. “Now it’s happening again.”
“The bright spot is that Florida Bay seems to be pretty resilient,” Fourqurean said. “Given time, it can recover from a single event - if you stop the injury.”
“If these kind of things increase in number or intensity, the bay may not have time to recover. We need to do a better job managing the [freshwater] inflows into the bay.”
Another section of the report focuses on seagrasses along the Florida Keys reef.
Kevin Wadlow: 305-440-3206
Copies of the Florida Fish and Wildlife Conservation Commission’s report can be found online: http://myfwc.com/research/habitat/seagrasses/projects/active/simm/simm-reports/state.