Drifting into Darien: A Personal and Natural History of the Altamaha River

Chapter 5: The Malacologists

chapter 5 The Malacologists Today I am looking for mussels. Looking involves crawling around in shallow water on hands and knees, feeling in the obscurity for hard, clamlike shells protruding from mud. It is July 2000 and I am spending a day on the river with Dr. Eugene Keferl, a tall, lanky professor at Coastal Georgia Community College in Brunswick (now retired) and an expert in freshwater mussels. He calls the creatures unionids, also fluviatile mollusks. We are near Lane’s Bridge, at a mussel bed that Dr. Keferl has studied for a long time. Intermittently one of us pulls a mussel to light. He lifts a big one, stares at it a minute, then tosses it back into the river. Thonk. “Pocketbook,” he says. Dr. Keferl is not yet crawling. He moves a few steps and kneels again. I hand him one I’ve found. He takes it, adjusts his glasses, then hands it back. “Pocketbook,” he says. The mussel is as large as a baseball and shaped something like a pita sandwich. It is black, shining pearly in places the black has worn away. Dr. Keferl pulls up another mussel. “This is a lance,” he says. It’s long and narrow, like an antique case for spectacles. Dr. Keferl examines the mussels we find, some for longer than others , and then we throw them back, until I have learned the common ones. Then I can inspect them and throw them back myself. I want to find a spiny. Spinys used to be common, many decades ago. But those days of abundance are long gone. Finding one isn’t impossible, only improbable. When I find it, the spiny mussel will 143 the malacologists be the typical clam shape, rounded, but with inch-long protrusions from the knob of its shell, like a calcified sea anemone. “You need good healthy fish fauna to have good healthy mussel fauna,” Dr. Keferl says. “Why is that?” I ask. “The life cycle of a mussel includes a parasitic stage, during which they attach to the fins or gills of fish, usually a particular fish.” “Each species has its preferred fish?” “Basically. The mussel parasite drops off in ten to twenty days to burrow in the river sand and begin its mussel life.” “What host do the spinys need?” “Well, that’s a question we haven’t yet answered,” says Dr. Keferl. The fish fauna are not so good in the river. With the introduction of flathead catfish, big cats have almost taken over. (The flatheads have been accepted by many sportfishers as a viable fishery. If you have nothing else, I suppose you embrace what you have. Restoration biologists have curtailed efforts to rid the river of them. In June 2006 a new record was set for a flathead, eighty-three pounds. It took twenty minutes to land the fish.) Because of blank pages in the spiny mussel’s natural history, scientists can’t pinpoint the reason for its decline. Perhaps it is tied to a certain fish, which is also in decline, although a piscine host is not the only factor involved. “Their habitat is stable banks,” Dr. Keferl says. “They need stability. They don’t like tree cutting, stump pulling, ditching. A lot are found in sloughs, backwaters.” “Their future looks bleak,” I say. “The spiny may be headed toward extinction, I’m afraid,” says Dr. Keferl. • I was introduced to Dr. Keferl’s work at a technical meeting conducted in the summer of 1999 by The Nature Conservancy (tnc). Dr. Keferl, a poised man with a shock of graying hair, talked about the distribution and abundance of his beloved fluviatile mollusks. 144 elements About three hundred species of freshwater mussels are documented in the mainland United States. The eastern United States boasts the best freshwater mussel populations in the world. The Tennessee River system, before it was dammed, won top prize for most diversity and abundance. Eighty percent of freshwater mussel species, or 270 of them, live in the Southeast. Soberingly, however, 70 percent of southeastern species are threatened, endangered, or extinct. Let’s say it without the numbers—the Southeast is the most biologically rich and imperiled region for freshwater species. “More than two-thirds of US freshwater mussels are extinct or at risk of extinction,” wrote zoologist Lawrence Master, author of tnc’s report “Rivers of Life: Critical Watersheds for Protecting Freshwater Biodiversity.” One in nine...