THE SEA FISHERIES OF EASTERN NORTH AMERICA. 47 



ring in great numbers, so that a few men, with proper apparatus, can 

 capture a large number of pounds in a day. The salmon and shad may 

 perhaps be included in this group. 



c. 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. Tbey, however, appear 

 to be contiuually 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 

 offish 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 pursuer — man. On the 

 other hand, the Gadidce, 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. 



