Sea Turtles & Beach Erosion
Thu February 21, 2013
Hurricane Sandy Erosion Will Impact Florida's Sea Turtle Nesting Season
South Florida's beaches in late spring through much of the fall resemble something of a crime scene, or rather, dozens of miniature crime scenes. Brightly colored caution tape and wooden stakes can be found scattered throughout the sand, sectioning off areas where sea turtles have left the water to build nests.
That tableau could look a bit different this year, says marine conservationist Dr. Kirt Rusenko, who is based at the Gumbo Limbo Nature Center in Boca Raton.
Hurricane Sandy and abnormally high tides last year caused significant damage to South Florida's coastline. Beach erosion has been a problem for many coastal communities, including Boca Raton, where Rusenko manages the Boca Raton Sea Turtle Conservation and Research Program.
"We've lost beach height and width," Rusenko said of the city's post-storm beaches. "The beach itself is about five feet lower."
Sea turtle nesting season in South Florida is March 1 through October 31, when turtles like the loggerheard, green and leatherback come out of the water to bury eggs in the sand. Less sand places nests at greater risk of being "washed over" during high tide.
"They're probably going to get wet more often," Rusenko said of the nests. If they are washed over early in the incubation stage, the risks are less significant than if the soaking happens closer to the "due date." Exposure to water late in the incubation period can in some cases kill the potential hatchlings.
Rusenko hopes the nesting females this season will "be crawling up in the dunes" to lay their eggs. A dune provides a dry nesting area, though it is not without its own set of risks.
"Predators are a lot more happy in the dunes," Rusenko said.
Rusenko and staff survey the five miles of Boca Raton beaches every morning at sunrise to scout for turtle activity and flag nests. In recent years, they've deployed hot pepper flakes to ward off predators like raccoons who raid the nests at night.
The turtles that swim ashore in Boca Raton are fortunate to have the option of going for the dunes. In cities like Fort Lauderdale, much of the coast is without a natural or restored dune. That was a significant factor in last fall's washout on A1A, Rusenko said. "Healthy dunes" are the key to minimizing beach erosion and protecting property and wildlife, Rusenko said, pointing to Boca Raton as an example.
In recent years, the city has worked with oceanfront condominiums and other property owners to build up a healthy dune. The result was "very little property damage" in the face of Hurricane Sandy and other bouts of extreme weather last year.
The scientist echoes the sentiment of other conservationists when looking at manmade sea walls as a means to prevent beach erosion: "I hate them," he said. Sea walls inhibit the movement of sea turtles and other marine life, while doing little to protect property. Rusenko said places in Florida that build sea walls "lose the beach."
On a positive note, turtle nests in Boca Raton have steadily increased over the last three years. In 2012, crews recorded 994 loggerhead, 116 green, and 33 leatherback, a record high for the species. "It may be due to the conservation practices put in place in the '80s," Rusenko said.
Nesting turtles return to their own birthplace to lay eggs. The timing is such that the influx in recent years may signify that the first generation is making its return to the city's shores.
Sea walls in Palm Beach County
Sea Level Rise
Sea Level Rise