While it's not certain, Sklar expects a number to die and become ghost islands, losing habitat that can take centuries to build.
"No one has successfully brought back a tree island that has turned into a ghost. That doesn't mean it's impossible," he said. "But you have to get the hydrology right first."
Getting the hydrology right is part of the slow-moving Everglades restoration work being done by the district and the U.S. Army Corps of Engineers. A move by lawmakers this year to speed up work on a 14,000-acre reservoir is supposed to provide some relief during the rainy season, when dirty lake water fouled by decades of farming, ranching and urban run-off gets flushed into coastal estuaries. Releases in the summer of 2016 left the Treasure Coast coated with slimy, smelly algae and killed oyster beds and seagrass in the Caloosahatchee.
But it's not yet clear how much relief it will provide.
It's also not clear when the new reservoir will be complete. Lawmakers have required the district and Corps to strike a deal and get a plan before Congress in two years, but extensions are possible. A status report is due in January.
In the meantime, the district has come up with another idea to end the releases: pump the lake water 3,000 feet underground into the boulder zone in deep injection wells normally used to store treated wastewater.
The plan would likely take two years to finalize and would be used only to avoid flushing the lake into the Caloosahatchee and St. Lucie rivers, said district lead hydrologist Bob Verrastro.
"Consider them estuary protection wells," he said. "We're trying to minimize the damaging flows to the estuaries."
Environmentalists oppose the plan, saying injecting the water underground wastes it.
"Once that water is gone, it's gone. And while there's times when there is way too much water in the system, there are times when there's not enough. It's freshwater that's just gone," said Cara Capp, the National Parks Conservation Association Everglades program manager.