The Protection of Fresh-Water MusselsCoker, R. E. (Robert Ervin)
Science
The Protection of Fresh-Water Mussels
Coker, R. E. (Robert Ervin)
Fishery law and legislation -- United States; Freshwater mussels
The use of shells taken between 1½ and 2 inches in greatest diameter
does not, therefore, like the marketing of those under 1½ inches,
represent absolute waste, but it does denote relative waste or real
short-sightedness from the economic point of view. Shells of this size
will average about 30,000 pairs to the ton, while mussels of such a
practical size as 2½ inches will average only 15,000. The number of
blanks obtained from a ton of shells of the latter size would be just
the same as from a ton of the smaller shells, notwithstanding that only
half as many shells are handled. _We are thus, when using the smaller
shells, depleting the mussel beds at twice the necessary rate without
any corresponding advantage._
WASTE ILLUSTRATED.
There is given below a table that will repay careful examination as
illustrating the wastefulness of using the small shells. While the
figures must be understood to be only approximate, they are based upon
careful weights and counts of a number of shells from several
localities. The shells were all "niggerheads" and were all obtained
after shipment to factories.
The first two columns show the limits of size for each lot used, the
greatest diameter being the basis of measurement.
The third column shows the approximate number of pairs of shells
composing a ton, the unit of purchase; multiplying this number by 2
would give the number of single shells per ton.
In the fourth column there is given, in the case of the critical sizes,
the number of 18-line blanks readily taken from a single shell (which
is one-half the number yielded by a pair of shells, or an individual
mussel).
The fifth column indicates the number of gross of blanks, by
computation, yielded by a ton of shells. This computation is based upon
the cutting of 18-line blanks (not the larger 20-line blanks that have
been taken from some of the larger shells in the illustration). Some of
these shells are cut excessively close to the tips, on account of
taking too many larger line blanks. It must be understood that
different sized shells are adapted for different lines of buttons. The
data herein is for comparative purposes only.
TABLE OF SIZES, WEIGHTS, AND BUTTON PRODUCTION FOR NIGGERHEAD SHELLS
(APPROXIMATE FIGURES).
Public-domain text, read in full here on John Shaqi.
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