A 191-mile tributary of the Alabama River, the Cahaba includes a stretch of free-flowing river that's 140 miles long —the longest stretch of its kind in the state of Alabama and one of the longest in the Southeast. What's more, it shelters more fish species per mile than any other river in the country. There are 13 species of snails in the Cahaba that are found nowhere else in the world, Nijhuis writes, and "several years ago, a Georgia botanist named Jim Allison identified eight previously unknown flower species along the river, an almost unheard-of haul in contemporary North America."
Although the Cahaba River has retained a remarkable number of its native species, there have also been devastating losses: "Because of water pollution and other stresses such as sediment from erosion, almost a quarter of its original complement of mussel species has disappeared, and snails and fish are thought to have experienced similar declines."
In fact, Nijhuis reports, "Alabama now leads the lower 48 in extinctions, due mostly to disappearances among its freshwater fauna: the Coosa River, which runs alongside the Cahaba a few dozen miles to the east, lost 34 species of snails—half its entire inventory—in the 50 years between 1914 and 1964. This is considered by many experts to be the largest recent extinction event of any kind in the United States."
In its current condition, particularly after the 2006 demolition of the Marvel Slab dam and road crossing, the Cahaba is both a museum of rare Southeastern river species and a laboratory for their recovery.
Not surprisingly, photographs by Beth Maynor Young accompany Nijhuis's story. Young has been photographing the Cahaba River for more than 20 years. From 5:30-8:30 p.m. on Friday, July 24, she will be signing copies of her new book Headwaters: A Journey on Alabama Rivers at Maralyn Wilson Gallery in Forest Park.
Source: Smithsonian Magazine