FRESH-WATER MUSSELS AND MUSSEL INDUSTRIES. 41 
SOME LOCAL AND TEMPORARY ASPECTS OF THE FISHERY. 
The mussel fishery is a permanent and important industry, and in scarcely any 
locality where a shell fishery was once established has it ever been entirely abandoned; 
yet the intensity of the fishery in any locality may vary from year to year, as it is sub- 
ject to a variety of influences, such as the demand for shells of certain qualities, the 
stages of the river, the condition of local industries or of the button industry, and the 
degree of exhaustion of the material. 
The natural movement of the territory of fishery from regions more or less depleted 
to virgin streams has been discussed on page 39. A limitation upon the rate of expansion 
is imposed by the cost of transportation of the product from its original source to points 
of manufacture; but the principal determining factor in this respect is the quality and 
abundance of the material, since cutting plants will follow the fishery if justified by 
the nature of the available material. There may be given, first, some illustrations of 
the extent of the fishery in certain localities as they have come more or less directly 
under the observation of the writer. 
The statistical bulletins published by the Bureau show the value of the product 
from the several streams, each taken as a whole, but the high productivity of certain 
beds before the process of depletion has advanced is not brought out in such reports. 
In the Illinois River in 1909 there were estimated to be about 2,600 boats engaged in 
the mussel fishery. One hundred or more boats would be engaged upon the same bed 
at one time, and, as a consequence, cutting plants sprang up all along the river. In 
1911 the writer counted 125 mussel outfits lying idle upon the banks at one point, 
Merdosia, III., while some 15 or 20 were engaged upon the river at varying distances 
from the town and mostly out of view. The exhaustive effect of the fishery of the three 
years preceding 1911 accounted in some measure for the number of idle boats. In 1912 
only about 400 boats could find occupation in the mussel fishery on this river, although 
a more effective method of capture (the dip net) had been devised. 
In each of the two years 1912 and 1913, according to reliable information, about 
$20,000 worth of shells and pearls were marketed at Madison, Ark., a village of about 
300 inhabitants. This represented the product of beds largely depleted but yielding 
shells of high quality. 
In 1910, 1,600 tons of shells, principally niggerheads, were taken in the rapids 
above Keokuk, Iowa, mostly within a stretch of 4 or 5 miles, and these shells represented 
a value of about $30,000. In 1912 a little over 400 tons were taken in the same region. 
This bed has been lost to the industry since the submergence of the rapids following the 
construction of the dam. 
In the immediate region of Ie Claire, lowa, and Port Byron, Ill., in 1910, about 
700 tons of shells were taken, representing a value of some $14,000. Fishing at Le 
Claire, lowa, began about 1897, and the large catch of 1910 was due to the condition 
of very low water, enabling the fishermen while wading to pick by hand the shells which 
could not be taken in ordinary stages because of the rocky character of the bottom. 
These are not insignificant figures, considering that the harvest was reaped without 
expense of planting or cultivating. Such harvests can not, however, be often repeated, 
since the rate of removal exceeds the rate of natural replenishment. 
