40 American Fisheries Society 



flourished in our streams and lakes were not established in a short 

 period of time. Consequently it cannot be expected that the 

 resources can be perpetuated by artificial propagation and half- 

 way methods of protection. While the Bureau of Fisheries is at 

 present carrying on the propagation work over a large territory, 

 the protection is in itself purely a function of the individual 

 states. Concerted action between the states is necessary for the 

 best interests of all. The Bureau has and is at present carrying 

 on its work where the beds are being worked and reworked by 

 clammers. As a result the young mussels are subjected not only 

 to the naturally destructive agencies, but also to the injuries 

 imposed by the implements of capture. 



The provision for closing certain waters to commercial shelling 

 makes it possible to conduct the work of artificial planting under 

 most propitious and favorable conditions, and to note to a certain 

 extent the results that are being obtained. 



The practical application of this closing feature may be illus- 

 trated by the work that is being done in Minnesota waters. 

 Lake Pokegama, in Pine County, Minnesota, supported a good 

 mussel fishery up to a few years ago, when the beds were brought 

 to a condition bordering on depletion. During this fishery 

 probably more and finer pearls were taken from this lake, for its 

 size, than from any other body of water in the country. On this 

 evidence of depletion the Minnesota Game and Fish Commission 

 closed the lake to commercial fishing for a period of four years 

 and, since this closing, the Bureau of Fisheries has carried on the 

 artificial propagation of mussels, and I may say in this connection 

 that there is evidence that the mussels are on the increase as a 

 result. 



As a further evidence of the value of the protective measure 

 and its practical working, the Minnesota and Wisconsin Com- 

 missions are going to confer relative to closing certain portions 

 of the Mississippi River bordering on the two states. Such 

 a conference is also going to take place between the Commissions 

 of Illinois and Iowa. 



Further, in line with the above, the state of Iowa is preparing 

 to close certain of its interior streams, such as the Iowa, Cedar 

 and Des Moines Rivers, to commercial shelling for a period of 



