Peter Hovingh feeling for mussels on the stream bottom.

Their company, Ecosearch, Inc. was contracted in 1998 and 1999 by the Hoosier National Forest to inventory mollusks in selected waterways. The Forest was concerned that freshwater mussels are a group of animals that are declining nationwide because of habitat losses. The Forest wanted to know what mussel species still existed and where they were distributed. The report for 1999 is not complete, but the men were excited by some of their finds. In one stream, which looked less than promising before they waded in, they found mussels at a density of one per meter. Hovingh was excitedly pulling mussels from the water at virtually every step. Each mussel is inspected and carefully returned in the same position it was found. While only one or two species of mussels were found in most streams, a total of ten living species were found, with four other species represented only as old empty shells. These species may or may not still survive in Hoosier NF waters. One of the species found was a mollusk Clarke and Hovingh hadn't expected to find this far south. Other findings included the widespread abundance of the small exotic Asian clam which has infiltrated most North American waters. Zebra mussels, another exotic wrecking havoc in many watersystems, was not found in any Forest streams. Clarke was especially pleased to find a native fingernail clam (Sphaerium striatinum) thriving in one stream. He explains this little clam is extremely rare because of competition from its Asian counterpart and recommended the Forest protect it's habitat and consider transplanting the tiny native clam to other streams free from the Asian clam.

Clarke with a snail species indicative of good water quality.

Clarke noted several interesting points while inventorying on the Hoosier NF, "there are relatively few mussels in some waterways, probably because of locks on the Ohio River causing pools which restrict movement of riverine fish which are hosts to specific mussels." He found a certain snail in several streams which is indicative of good water quality. He and Hovingh both commented that what may appear to be a good stream for mussels can be decieving. Hovingh waded one stream near a county road, stepping over old tires and piles of trash, to find several individual mussels. "Somehow they're surviving here," he comments as he carefully replaces a mussel near a half-submerged old tire, pointing to snails adhered to the tire, "the trash becomes part of their habitat." Occasionally, in the murky water, Hovingh mistakenly picked up small snapping turtles. He carefully put them back as well. He relates an interesting find in this year's survey. At one particular survey point they found 4 individual mussels all exactly 14 years of age. There seemed to be no other mussels in the area. Aging a mussel is not unlike aging a tree since both put down distinctive rings each year. He and Clarke speculate that a single host fish may have come up the stream 14 years ago and dropped the tiny mussel larvae so all four were siblings.

return to top

For more information, contact us at r9_hoosier_website@fs.fed.us