ST. PETERSBURG, Florida — There's an eerie quality to parts of Egmont Key's shoreline.
On the western side are crops of dark tree stalks, some standing straight, others toppled over into the Gulf of Mexico — cabbage palms that have lost their fronds, poisoned by saltwater.
On the island's northern end, the ruins of cannon batteries that once stood more than 100 yards inland are practically overlooking the water.
Once a military outpost with a 19th century lighthouse that still guides ships into Tampa Bay at night, Egmont Key attracts tens of thousands of birds for nesting and about 200,000 visitors each year that come to explore the remains of Fort Dade, sunbathe on pristine beaches or snorkel in the crystal clear waters that surround it.
Without human intervention, though, nature wouldn't allow this island's shifting sands to stay put.
An infusion of 875,000 cubic yards of sand dredged this fall from the adjacent Tampa Harbor channel won't stop that erosion process, but it may slow it down for another decade.
Every nine to 10 years, the U.S. Army Corps of Engineers invests millions of federal dollars in digging out this section of the deep-water channel that allows ships to travel safely from the Gulf into the shallow waters of Tampa Bay.
All that sand suctioned from the shoals that form on the sides of the passage is redirected to help replenish nearby beaches on Egmont Key and Fort De Soto Park.
This year's $13.4 million dredging contract will pump the sand onto the island's diminished northern and western shores and also will replace two 300-foot geotextile tubes that create a protective wave barrier for part of the beach.
"For years and years, it's just been going on — even before me, and I've been here 13 years — the island is slowly eroding," said Tom Watson, a Florida State Park ranger who resides on the island.
"We've been very fortunate over the last few years not to have any major storm activity out here; it's just been a day-to-day slopping of the west side of the island that gets hit on a daily basis."
Toward the end of October, crews from Illinois-based Great Lakes Dredge & Dock Co. will set up a barge along the Tampa Harbor and Mullet Key channel cuts.
Unlike a $16 million Army Corps project this summer to renourish four eroded tourist beaches in Treasure Island and St. Pete Beach, this fall's operation primarily is designed to maintain the depth of the navigational channel and to ensure it remains safe for freight and cruise ship traffic.
The Corps oversees dredging projects every year along various sections of the 67-mile channel.
This year, its focus is on a 17-mile area adjacent to Egmont Key.
"This maintenance has to be done no matter what and we want to beneficially use the sand whenever we can," said Milan Mora, an Army Corps project manager.
Rather than unload the sand on unused spoil islands, the Corps periodically pumps it back onto Egmont's most eroded spots, most recently in 2005.
The sand also has been recycled in the past at Fort De Soto Park, which recently has seen significant erosion on its popular North Beach.
This occasional sand transfusion won't save the island in the long run, and such community groups as the Egmont Key Alliance hope to see the federal government make an investment in a permanent barrier to mitigate the impact of waves.
A study funded by Congress several years ago laid out plans to install a wall on parts of its western shore to protect the historic gun batteries and other structures.
A Dade City company also has proposed putting in a series of concrete pyramids in the water that would act as a buffer to the battering of the waves.
So far, there has been no movement to enact either plan.
Long-term protection for the island isn't part of the scope of the Army Corps' ongoing projects.
"We all recognized that if nothing is done, storms and wave action will continue eroding the shoreline and eventually destroy the historic structures," Mora said in a statement.
"It's only a Band-Aid, but we'd like to continue to beneficially use the dredged sand to help preserve Egmont's cultural and natural environment as long as possible for future generations."
The current dredging and renourishment operation is expected to take about four months.
Crews will monitor water quality as they remove sand from the channel. If they create too much disturbance, they will slow down or move to a different spot.
Environmental observers ensure sea turtles and other marine wildlife that use the channel are not harmed. The project is expected to be finished ahead of the spring sea turtle nesting season in April.
Buoys and signs will be posted along the work area to warn boaters of dangerous spots, but the island will remain open for visitors.
The Egmont Key Alliance and the Florida Park Service are hosting an event Nov. 8-9 that will include historic re-enactments from the heyday of Fort Dade during the Civil War and early 20th century, walking tours, games, food and other activities.
The island is accessible only by ferry or private boats.
While two of the fort's old gun batteries are underwater and likely will never be seen without a mask and snorkel, Watson says it's amazing how much has been preserved on this fragile island, even as the waters have continued to encroach upon it.
"We've been able to save the cultural resources — most of them," he said.
Information from: The Tampa (Fla.) Tribune, http://www.tampatrib.com
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