FRESH-WATER MUSSEivS AND MUSSEL INDUSTRIES. 45 



sized shells of the best quality. In the last stages the larger shells constitute a gradually 

 decreasing proportion, while the smallest shells, the very infants, indeed, form a steadily 

 increasing proportion. Here is a fatal defect of the present manner of fishery. The 

 rate of depletion is automatically accelerated, since the fishermen are taking two or three 

 for one. Where formerly from 5,000 to 10,000 mussels, more or less, constituted a ton, 

 at a later time, when small shells prevail, each ton may represent some 30,000 mussels, 

 as has been determined by repeated counts made by the writer in localities where the 

 small shells are being marketed. The fact that the sheller can now take but a few hun- 

 dred pounds a day, as against the former catches of half a ton or more, might lead one 

 upon first thought to suppose that the beds thus automatically receive a measure of 

 protection. The very contrary, however, may in practice be the case. The continued 

 rise in price stimulates the sheller to save everything, and the last stages of impoverished 

 fishery are thus the more exhaustive. 



When shelling in a depleted locality becomes quite unremunerative, it may be 

 practically entirely abandoned and almost forgotten, until after some years, it is found 

 that the growth and natural reproduction of the mussels have so replenished the bed that 

 it has again become a profitable one, and general shelling is resumed. Usually, however, 

 the local shellers keep engaged, though irregularly, upon the same bed, or more exhaustive 

 methods are employed, and the cases of natural recuperation are therefore conspicuous 

 by their rarity. 



In view of the conditions just described, the Bureau has advocated the compulsory 

 closing of portions of rivers for periods of years, in order that the mussel beds might 

 have such a condition of rest and freedom from all injurious disturbances that the process 

 of replenishment would be assured. It has also urged the adoption of size-limit regula- 

 tions which would prevent the needless destruction of the small mussels. With such 

 reasonable protective legislation, supplemented, preferably, by artificial propagation, 

 the depleted regions generally might be aided to recuperate. Several States have in 

 recent years enacted comprehensive mussel laws whose effective enforcement wiU go 

 far to insure the perpetuation of the mussel resources and thereby the permanence of 

 the mussel fishery and its dependent manufacturing industries. 



There is no question that all of the better mussel streams are capable of supporting 

 mussel resources many times as abundant as they do now, for they did so a score or less 

 of years ago. For each stream, therefore, it is merely a question of whether common- 

 sense measures will be applied to restore the abundance of mussels for the benefit of 

 all or whether they will always exist only as scattering survivals of an over zealous 

 fishery. 



The conditions and the measures for protection have been fully discussed in other 

 publications of this Bureau "' and need not be enlarged upon here. It may be said, 

 however, that there is no important stream in which the mussel resources now exist 

 in anything like their former abundance. There have been published photographs 

 showing fishing through the ice in the Mississippi River in the early days, where the 

 persons are grouped closely, each one with a considerable pile of shells about the hole 



a Coker, Robert E.: The protection of fresh-water mussels. U. S. Bureau of Fisheries Document No. 793, 23 p., 2 pi. 

 Washington, 1914. 



Coker, Robert E.: The utilization and preservation of fresh-water mussels. Transactions American Fisheries Society, 

 Vol. XL VI, No. I, New York, 1916. 



Smith, Hugh M.: Freslj-water mussels. Economic Circular No. 43, U. S. Bureau of Fisheries, 5 p. Washington, 1919. 



