MAKE ROADS SAFER FOR HUMANS AND WILDLIFE
Last week was a positive one for me ecologically. First, Matt Aresco (graduate student, Florida State University), Kimberly Andrews (graduate student, University of Georgia), and I captured a mud snake in Lake Miccosukee in Florida. Second, I got to see firsthand the amazing advances in conservation Matt has made at Lake Jackson, near Tallahassee.
Okay, so most people would not like to wade around in a Florida lake on a cold, rainy day in February and catch any kind of snake. But to us, the mud snake capture was exhilarating. For one thing, the presence of a mud snake is usually indicative of a healthy environment. Plus, they are absolutely beautiful--shiny black above, checkerboard red and black on the belly. They are considered rare in most southern regions where they occur, and many herpetologists have never seen one in the wild.
Mud snakes have a remarkably selective diet as adults, eating primarily giant salamanders. When these enormous amphibians are in a lake, crayfish and other invertebrate animals normally abound also, and the aquatic vegetation is usually luxuriant. For the smaller invertebrate creatures to be present, the waters must generally be unpolluted. Mud snakes, sitting atop an intricate food pyramid, are dependent on the lower portions remaining intact, hence they serve as excellent indicators of overall environmental conditions.
But Lake Jackson, a 4000-acre sinkhole lake near Matt's home, offers a different kind of threat to mud snakes than the disappearance of their favorite prey. Relatively clean waters, plenty of vegetation and invertebrates, as well as giant salamanders and mud snakes, are present at the lake. But the road that bisects Lake Jackson was built in the 1920s, when transportation departments considered only the engineering aspects of highway construction, with little attention to environmental consequences. As time progressed, U.S. Highway 27 became a major thoroughfare in Florida, with more than 20,000 vehicles per day.
Each year, as lake-dwelling animals search for food, mates, and nesting or hibernation sites, many travel overland to other lakes. Unfortunately, mud snakes and other aquatic species including turtles, watersnakes, bullfrogs, and even giant salamanders try to make the trip each year across the four-lane highway separating the two parts of Lake Jackson. Few make it alive. Although the list of road mortality victims is long, among the most obvious are the turtles, with an incredibly high road-kill rate of 98%--more than 2,000 per mile per year. Lake Jackson became known as "home to the world's worst turtle-killing highway."
Matt Aresco first became concerned about Lake Jackson's wildlife in February 2000 when on a single day he found 90 road-killed turtles along a short portion of the highway. Over a 3-year period he documented attempted crossings and highway deaths of more than 10,000 individual animals representing more than 40 species. After many phone calls and personal visits, he got permission from the state highway department to set up a barrier silt fence between the highway and the two lakes. He constructed two miles of temporary fencing himself, placing it parallel to the road, leading animals to a single culvert connecting the two bodies of water beneath the highway. Such under-the-road crossings for wildlife are known as ecopassages, a positive ecological step that can reduce or eliminate road mortality for some species.
Matt's next step was to make the local community aware of the constant carnage on the highway in hopes that his temporary solution could be replaced with a permanent wall and multiple ecopassages. The task was not easy, as he faced the obstacles of political and commercial interests that anyone does when trying to set things right environmentally. But he persisted, and ultimately inspired action among others in the community and the state. The Lake Jackson Ecopassage Alliance (http://www.lakejacksonturtles.org/) now comprises a group of environmentally concerned citizens intent on developing permanent guide fences and ecopassages to allow animals to move freely, and safely, between the two parts of Lake Jackson.
serves as a dramatic example of the effectiveness of using barriers to
redirect the travel pattern of animals to avoid highway mortality. More
importantly it shows that we still have heroes around like Matt Aresco,
who will work single-handedly against steep bureaucratic odds to protect
the environment. I imagine the mud snakes appreciate his efforts, too.