PROGRESS IN BIOLOGICAL I^TQUIRIES, 1921. 



35 



FRESH-WATER MUSSELS. 



PROPAGATION OF MUSSELS, 



The Fisheries biological station at Fairport, Iowa, continued its 

 practical propagation of fresh-water mussels in the Mississippi drain- 

 age at Lake Pepin and Lake Pokegama, Minn. ; at New Boston, Oqu- 

 awka, and Dallas City, 111. ; at- Fairport, Iowa ; at Hannibal and 

 Clarksville, Mo. ; and in cooperation with rescue crews along the 

 Mississippi in Wisconsin and Minnesota. The total number of glo- 

 chidia infected upon fish and liberated in public waters during the 

 year was approximately 648,445,000, including 478,705,000 infected 

 upon rescued fish by cooperative agents working in connection with 

 rescue crews of the division of fish culture. 



With a view to demonstrating the possibilities of mussel propaga- 

 tion in connection with the rescuing of food fishes, the National Asso- 

 ciation of Button Manufacturers offered to cooperate with the Bureau 

 by providing men to accompany each rescue crew on the upper river 

 and to inoculate all fishes with the glochidia of the Lake Pepin 

 mucket, the most important of the local mussels. Seven agents of 

 the button manufacturers cooperated with seven crews working under 

 the direction of Supt. Culler, of the Homer (Minn.) station, and dur- 

 ing October and November inoculated nearly 6,000,000 fish with 

 glochidia. 



The localities in which the Avork was done and the number of fish 

 subjected to infection in each locality were as follows: 



Lynxville, Wis 2, 025. 200 



Genoa, WLs 1,214,900 



Ferryville, Wis 907,340 



Fountain City, Wis 86,510 



Nortli McGregor, Iowa 676,100 



Bellevue, Iowa 931, 500 



Total 5,841,550 



Material cooperation of this nature by an association of business 

 men is a source of gratification to the Bureau, not only as evidence of 

 a cordial spirit, but as evidence of faith in the practical value of the 

 service rendered in the propagation of river mussels. 



PROTECTION or MUSSELS. 



A prominent feature of the work of the Fairport station for sev- 

 eral years has been the part which it has played in bringing about 

 a strong sentiment for the protection of fresh-water mussels and 

 the cooperation it has extencled to the several States in giving aid, 

 when solicited, in selecting the areas for closure to mussel fishing. 

 Additional closures of streams or parts of streams has followed the 

 beginning made in the past by Minnesota and Wisconsin. Minne- 

 sota in April closed for a period of five years parts of the Minnesota 

 River, and the entire Cannon and Straight Rivers. Iowa, in the 

 same month, closed for a similar period parts of the Iowa, Cedar, 

 and Des Moines Rivers, and the entire Shellrock River. 



