292 BULLETIN OF THE BUREAU OF FISHERIES. 
Whether the effects of fishing are of appreciable injury to the fish depends 
upon the time, place, and amount of fishing, as well as upon the habits of the 
fish and the number caught. If the fish have a limited spawning ground to 
which they resort every year—for instance, a small bay, estuary, or mouth of 
a stream—constant fishing with purse seines and obstructive pounds and traps 
must necessarily seriously affect the number of fish reaching the spawning 
ground, consequently the number produced that season. And if such fishing 
is carried on at or near every spawning place of the species, as well as at a dis- 
tance from it, the injurious effects would obviously be still greater, and in time 
would result in a diminished number of the species. If the species is greatly 
reduced in numbers, then the food supply of the fishes depending upon this 
particular species for subsistence is correspondingly reduced. The consequence 
of this would be that this species would be reduced by starvation or would be 
forced to depend upon other species for food. ‘The latter is the most natural 
effect, and this in turn would deprive still other species of their food or reduce 
their numbers either as adults or young, or both. Other species being deprived 
of their food would repeat the process, and thus it would go on until nothing 
remained. 
While such a condition is theoretically conceivable, it is not so in fact, 
except to the extent that if for any reason the food of a species is withdrawn 
the species disappears, doubtless in search of food elsewhere, and when its prin- 
cipal food is abundant the fish feeding upon it would naturally be plentiful. 
Exceptions that might be cited may be only apparent, for, as has been pre- 
viously suggested, probably no fish feeds exclusively upon any one thing or 
depends upon any one species. The shark, tunny, or bluefish would hardly 
be likely to distinguish schools of menhaden from schools of other silvery fishes 
like the alewives, which sometimes equally abound with the menhaden along 
the coast. Thus the absence of bluefish from any section when menhaden 
are present or the presence of bluefish when menhaden are absent in each 
instance is due to the same thing—the presence of satisfactory food in one 
place or the other. There is no doubt that the bluefish disastrously pursues 
menhaden, but it is known to pursue other species with equal disaster. 
The effects of the complete extermination of menhaden from the seas may 
be inferred from the effects of local disappearances for a term of years and 
where there is no evidence that the fishes that fed upon them there suffered 
in consequence of their departure. It may with propriety be stated here that 
such “unaccountable” disappearances took place long before modern fish 
traps and purse seines were known. Subsequent like disappearances and 
reappearances, again disappearances without reappearances, can not, then, 
logically be laid to the purse seines and steamers. But there can be no doubt 
in the minds of those who have observed the operations of menhaden and 
mackerel purse seines that there is at least a temporary more or less modifying 
