A National Academy of Sciences report says the planned $7.8-billion restoration of the Everglades may not return Florida Bay to the "gin clear" character it had 30 or 40 years ago.

(Photo courtesy of South Florida Water Management District)

The report produced by a committee of NAS's National Research Council and released Aug. 8, says that there is enough evidence that the restoration plan will affect the bay "in ways...that may be perceived as undesirable," that targeted further study is needed.

Stu Appelbaum, Everglades plan project manager in the Corps of Engineers' Jacksonville District, noted that the Corps has a feasibility study under way to look at issues related to Florida Bay and the Florida Keys.

Florida Bay, which lies at the state's southern tip, is large, covering about 850 square miles, and shallow, with an average depth of about three feet. Most of the bay is situated within Everglades National Park and the Florida Keys National Marine Sanctuary.

For decades, Florida Bay had clear water and thick meadows of turtle grass. But about 1987, the turtle grass beds began to die in the bay's western and central portions, "for reasons that remain uncertain and controversial," the NAS study says. Water in the western and central sectors is now murky because of blooms of phytoplankton and resuspension of sediment. There also has been a decline reported in fishing for some species, the study notes.

Some scientists have assumed that increasing fresh water flows to the bay--one result of the Everglades restoration program-- will help restore Florida Bay. But the science academy panel says that "these assumptions may not be correct." For one thing, the report says, scientists disagree whether higher water salinity levels caused the turtle grass to die. Moreover, the flow of surface water into the bay is expected to be about the same in 2050 as it is now, regardless of whether the Everglades restoration is carried out. It adds, "If this is correct, there will be little effect on salinities in central Florida Bay and no relief to any associated ecological problems that may exist."

Moreover, the committee says, if the restoration plan's goals are reached, it may result in more blooms or phytoplankton and algae, which could pose a threat to seagrass.

The panel adds that "the consequences of the [Everglades restoration program] may be a Florida Bay that differs markedly from the 'gin clear' bay of the 1960s and 1970s."

The Corps' Appelbaum said in a statement, "During the development of the [Everglades restoration program] we recognized the need for significant additional study of the problems of this area and the importance of this area to the overall restoration effort. "