680 BULLETIN OF THE BUREAU OF FISHERIES. 
Total length of nets in use seems, therefore, not to have affected the total 
catch of whitefish. The explanation of this apparent contradiction is probably 
as follows, although this explanation is offered with much reserve: When fishing - 
is begun in a virgin water, the catch depends necessarily on. the amount of appa- 
ratus in use. As the rate of catch per unit of apparatus diminishes, which it 
invariably does, there comes a time when it ceases to be profitable to multiply 
the amount of apparatus, and as a consequence the number of units of apparatus 
ceases to grow. The relation of the amount of apparatus to the catch per unit 
of apparatus is, where no restrictions exist, a self-regulating one. The apparatus 
is sure to increase to the point where its use barely affords a profit to the user. 
The total apparatus is not in the water because required in order to catch the 
total amount of fish actually taken; it is there rather because each fisherman hopes 
to take the fish which would otherwise fall toanother. If, now, the amount of 
apparatus be diminished, the same number of fish will still be taken in the dimin- 
ished number of nets until the rate at which they are caught falls below the 
natural rate of increase of the fish, when, of course, the total catch of fish will 
increase. If these considerations are well grounded, the regulation of the number 
or length of nets per unit area does not act to preserve the fisheries unless that 
regulation proceeds to an extreme that it is not likely to reach in practice. So 
far as the preservation of the fisheries is concerned, the regulation of the length 
of nets to be used on unit area may well be left to competition, provided com- 
petition is in some way insured. These remarks do not apply, however, to 
regulation of the length or location of those nets which might impede the move- 
ments of fish during the spawning season; they assume, rather, that the spawning 
season is a close season. ) 
To reduce the length of nets per unit area is, however, advantageous in 
another way, since it tends to lessen the cost of taking the fish and should 
make it possible to furnish them to the public at a less price. If fishing grounds 
are leased in such a way as to insure competition among lessees and to prevent 
the leases falling into the hands of a single lessee, and if the length of nets per- 
mitted on unit area is then restricted, the fish should come to the market at a 
lower price, for each fisherman would be compelled to take the fish at a less 
cost to himself and competition would compel him to market them at a less 
cost. This principle is commonly applied in another way by the licensing of 
hunters and sport fishermen and the limitation of the catch that they are per- 
mitted to take. Here, where pecuniary profit is not an inducement to increase 
the catch, it is not regulated by the cost of getting it. The sport fisherman 
tends to get all he can no matter at what cost, and hence it is necessary to regu- 
late the size of his catch by law in order to prevent his exhausting the supply 
of fish. In commercial fishing exhaustion does not take place, because it is not 
profitable and ‘it is necessary to regulate the apparatus used only in order to 
