| What are mussel shells? The bivalve mollusks of the ocean are well known, but Tennessee is justly famous for its fresh water bivalve mollusks. There is a wider diversity of freshwater mollusks in the Tennessee River than in any other river in the country. Mollusk shells are formed of form of Calcium Carbonate (CaCO3) called aragonite deposited by the animal in thin layers, creating a pearly surface.
There is a magnificent book on Tennessee mussels: The Freshwater Mussels of Tennessee Written by Paul Woodburn Parmalee , Arthur E. Bogan , American Pearl Farms Published by University of Tennessee Press (October 1998)
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| Where are they found geographically? Freshwater mollusks are found in all the rivers of Tennessee. Find the watershed in which you live.
When were they deposited? The mollusks we are considering are contemporary. (Cretaceous Period marine mollusk shells are found in McNairy County, but they are not used as resources in the same way as the modern ones.)
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| Quaternary |
| Tertiary |
| Cretaceous |
| Jurassic |
| Triassic |
| Permian |
| Pennsylvanian |
| Mississippian |
| Devonian |
| Silurian |
| Ordovician |
| Cambrian |
| Proterozoic |
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| How were they collected and used? Native people probably ate freshwater mussels from the time they arrived, but as this is a study of mineral, not food resources, that doesn't concern us. Native people did, however, also use the shells to make ornaments. Native people of the Mississipian Period (900ad-1500ad) used crushed mussel shells as an ingredient in their pottery. Europeans-Americans have used mussel shells for buttons and jewelry. Until recently, mussels and mussel shells were collected where they grew naturally. In recent years, because the mussels have become endangered, mussels have been farmed. |
| History of the use of mussels in Tennessee: Mussel shells were used by native people for ceremonial ornaments and as an ingredient in clay for pottery. European-Americans have used them for simple ornaments. In the 19th century, the shells were used to make buttons, and were so overfished that they became endangered. Mussels are now used as the core of Japanese cultured pearls. A native fresh-water pearl industry has also developed. |
| Tennessee Mussels and the Environment. In recent years there has been increasing concern about mussel populations in Tennessee. Mussels are endangered by the damming and polluting of Tennessee's rivers, by over-harvesting and by the introduction of alien species such as the Asian mussel. Zebra mussels have not yet reached most of Tennessee, but when they do they will cause further harm to the native species.
Under current law there are only 10 species which may be harvested. All others must be immediately returned to the rivers where they were found
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