STATUS OF ERESH-WATER MUSSEL STOCKS IN THE TENTJESSEE RIVER 



by 



George D. Scruggs, Jr. 



Fishery Management Biologist 



Bioreau of Sport Fisheries and Wildlife 



Atlanta, Georgia 



INTRODUCTION 



The National Association of Button Manufactiirers, confronted with 

 a decrease in the available supply of fresh-water mussel shells, requested 

 the United States Fish and Wildlife Service to investigate the condition 

 of the resource and recommend measures which would favor an increase in 

 mussels valuable to the industry. 



Because of cheaper manufacturing costs, plastic material has 

 replaced shell material to a large extent in the manufacture of buttons. 

 However, the market demand for good quality pearl shells is high. The 

 economic level of the shell industry will depend on the continued availa- 

 bility of an adequate supply of preferred mussels. There is a good export 

 market for shells, which are shipped to J^pan where they are processed 

 into tiny beads and used in the artificial culture of pearls, in addition 

 to their use in the button industry. 



The objectives of the study reported here were to determine the 

 level of abundance, exploitation rate by fUshing, age composition, and 

 natiiral replacement potential of mussel stocks in the Tennessee River. 

 The program began in 1956 and was concerned primarily with stocks in a 

 6-mile stretch of the river impounded by Wheeler Dam in Alabama. Special 

 emphasis was given to studies of the pigtoe, Pletirobema cor datum , because 

 of its natural abundance and economic value. This report discusses the 

 observations and findings resiolting from studies conducted during 1956 and 

 1957. 



MUSSEL SHELL INDUSTRY 



Historical significance . --The mussel shell industry began in the 

 United States about I89I when J. F. Boepple established a pearl button 

 plant at Muscatine, Iowa. An abundant supply of good shells available 

 from the Mississippi River encouraged the growth of the new industry. As 

 the market expanded, an extensive search was made to find new beds in other 

 streams throughout the nation. 



During the period from I897 to 1937, the U. S. Bureau of Fisheries 

 engaged in various studies of the life history, habits, distribution, and 



