Florida officials ignore decline of the giant land crab
By VIRGINIA SMITH
News-Journal/DAVID TUCKERA large land crab puts up it´s big pincher claw to scare off a intimidating fisheye lens as it walks along Moody Blvd., Wednesday morning July 21, 2005 in Flagler Beach Fl. while curious traffic passes. These crabs are not rare but not seen everyday, this one´s body was as big as a mans fist and claws spread out to about a foot. With a little help it retreated away from the busy road into the city park in background.
"They´d be all over the place," said Randy Richenberg, a New Smyrna Beach city commissioner who was a child when he witnessed his last large migration. "You´d find them in your yard, in the roads."
But then they grew scarce, except as roadkill. Now, even a dead one is rare.
And if you run into a live land crab -- a blue or grayish fellow with a claw he´s not afraid to use -- it´s sort of an occasion. "I haven´t seen one in 10 years," Richenberg said.
The giant land crab, a denizen of mosquito ditches and muddy coastal forests, is not on the state´s endangered species list or even close, though anecdotal evidence suggests its numbers are but a sliver of what they once were.
In the summers, particularly after rains, land crabs crawl out of their long burrows and get frisky, foraging and mating under the full moon.
Then, in the fall, the females march toward saltwater, bearing loads of fertilized eggs. Most of the crabs´ decline is believed to be from roads cutting off the females´ migration (though sea walls likely don´t help). When the females are crushed by vehicles, the next generation dies with them.
The females "don´t make it across the road," said Bjorn Tunberg, a biologist with the Smithsonian Institution´s research station in Fort Pierce.
Tunberg has watched his local land crab migrations shrink since the 1980s. "I´ve even seen people with big trucks aiming for them," he said.
Killing off the reproducing females, year after year, is a good recipe for extinction. And it doesn´t help that land crabs, which also occur in the Caribbean, are sought as a delicacy by immigrants from that region. (They taste, allegedly, just like other crabs.)
But Florida has taken very limited steps to rectify -- or even really investigate -- the decline of its land crabs. Turnberg and another researcher started their work on a now-expired grant from Disney. "It´s weird," Tunberg said, how little attention has been paid to the species.
David Cook, an invertebrate specialist with the Florida Fish and Wildlife Conservation Commission, said he´s not surprised that land crabs haven´t appeared on the state´s conservation radar. "Ninety-nine percent of all invertebrates fall through the cracks," he said.
But invertebrates are important to the ecosystem in ways that aren´t always obvious. Land crabs, which never live more than five miles inland, dig burrows to the water table. The watery bottoms of their holes sustain a species of fish called the mangrove rivulus -- which has nowhere to go when seasonal ponds dry up.
Occasionally a mollusk or crustacean will make it onto the state´s endangered species list, as the Panama City crayfish did in June, but when Cook recently compiled a list of 100 endangered invertebrates, land crabs somehow didn´t make it.
Still, Cook acknowledged, "it´s somewhat of a no-brainer that they would be having more trouble now than they used to with roads and development," and land crabs, he said, might be perfect for the state´s new grants designed for overlooked species.
Until a few years ago, the commission actually encouraged land crab trapping, publishing tip sheets.
But researchers suspected that land crabs had been all but hunted out of South Florida, and commercial trappers with Miami-Dade plates were showing up as far north as Sebastian Inlet. Park rangers were concerned, and asked the state for restrictions. Since 2003, it´s been illegal to take any land crabs between July and November, when they are most active. But land crabbers, using shovels and buckets, have been observed recently on a long stretch of mosquito ditch on Beach Street in Daytona Beach; only last Saturday in a Holly Hill park, a group of Spanish-speaking men were seen setting wooden traps on land crab holes, just below a nature walk.
News-Journal/JIM TILLER"EVERYBODY OFF THE SIDEWALK"...This large land crab uses its large claw to clear a path after it made its way across State Road AIA and then the sidewalk on its way home Friday morning August 13, 1999 around 8:15 in Flagler Beach. These large crabs amble back and forth between the marsh along the river and the seashore in search for food.
"You shouldn´t be messing with land crabs," said Susan Rannie, the city´s supervisor of buildings and parks. Not only is it against the law, she said, but "they´re mean. They´ll take your toe off."
Staff Writer Jay Stapleton contributed to this report.
The giant land crab, Cardisoma guanhumi, lives on land (though portions of its burrows are watery) and travels to the ocean to reproduce. In heavily populated areas, many don´t make it.
Giant land crabs (sometimes known as blue land crabs) prefer mud to sand. When it comes time to molt, they will seal themselves in their distinctive round holes, which lead to burrows that can be 5 feet long.
Land crabs are "highly territorial" in their burrows, said Sharon Ewe, a scientist who worked with land crabs at the Smithsonian Institution´s research station in Fort Pierce. "When one would accidentally end up in another´s hole it would within seconds come shooting out," Ewe said, evicted by the rightful owner.
Serial story: ENDANGERED