THE SEA FISHERIES OF EASTERN NORTH AMERICA. AT 
ring in great numbers, so that a few men, with proper apparatus, can 
capture a large number of pounds in aday. The salmon and shad may 
perhaps be included in this group. 
¢. Pelagic fish.—These consist largely of species belonging or allied 
to the mackerel family, and, next to the group just mentioned, furnish 
the most important supply of food. The prominent members of this 
group are the common mackerel, the bluefish, the menhaden, the sword- | 
fish, the bonito, and other kinds. Sometimes members of this group 
are found hundreds of miles from the land; at others they come close 
inshore, either in pursuit of food or for purposes of reproduction, when 
they can be taken from the shores or in nets. They, however, appear 
to be continually on the move, showing more or less at the surface, re- 
maining in proximity to the shore during the warm season, then dis- 
appearing during the winter. 
d. Deep-sea fish.—This constitutes a group, of which until within a 
few years very little was known, occasionally being found floating at the 
surface either dead or dying, or caught at great depth on cod or halibut 
lines. It is only within a few years, or since the labors of the Chal- 
lenger and other vessels, provided with apparatus for fishing at great 
depths, that the number of species has been realized. While some of 
the fishes belonging to the second section occur not unfrequently at 
depths of many hundreds of fathoms, such as the cod, halibut, hake, 
&c., very few of this fourth group are taken in waters of less than 100 
fathoms, and thence to 1,000 and even to 2,900 fathoms, by the Chal- 
lenger. This group is of little ecomomical value, especially on account 
of their small size and apparently scant numbers, even apart from the 
practical difficulty of their capture, although it is not at all impossible 
that there may be edible species sufficiently large and abundant to be 
worth pursuing if they were more within reach. : 
The status of fish in the sea is very largely determined by the ques- 
tion of temperature. This, however, will be considered more definitely 
under the next head of the migrations and movements of fish as influ- 
enced by various causes. 
MIGRATIONS AND MOVEMENTS. 
The human race is more concerned in the movements and migrations 
of fish than in the question of their permanent abode. It is when they 
are aggregated in large bodies, and moving from place to place, either 
under the stimulus of search for food or other causes, that they furnish 
the best opportunity to man for their capture and utilization. 
Little is known of the salmon, the shad, the herring, the menhaden, 
the mackerel, and the bluefish during a large portion of the year; but 
at certain periods these species collect in large bodies, and by a change 
of place come within the reach of their relentless parsuer—man. On the 
other hand, the Gadida, the cod, especially, and the halibut, are within 
reach throughout the greater part of the year, either on the offshore 
banks while feeding or inshore when spawning. 
