COD-FISHERIES OF CAPE ANN. 707 



Cod-fish are probably governed iu their movemeuts by the abuudauce 

 and migrations of food, the spawning instinct, and the temperature of 

 the water, though the last named seems to exert but little influence. It 

 is generally acknowledged by the flsliermeu that during the feeding 

 season fish are plenty only Avhere food exists in considerable quantity, 

 and that after •• cleaning up ■' one part of the liank they go to another. 

 They also folktw schools of bait for long distances, living upon them 

 until they are broken up or entirely destroyed. Thus they often follow 

 the capelin (jlFaUotus I'illosiis) into the shoal water, and even drive im- 

 mense numbers of them upon the shore. 



The spawning instinct seems to exert a decided influence upon the 

 movements of the fish, for we find them visiting the same locality year 

 after year during the spawning season, often remaining for several 

 months at a time. The fish that visit the waters of Cape Ann during 

 the winter, doubtless come in for the purj)Ose of spawning rather than 

 for food. This seems clear from the fact that they do not arrive when 

 bait is most plenty, nor do they follow any species to the shore. On the 

 contrary, the i^asture-school usually arrives about three weeks after the 

 large herring have left the coast, and remains on the south side of Cape 

 Ann, while Sperling are abundant in Ipswich Bay. The Ipswich school 

 is also the largest after the sperliug have been driven away by the cold 

 weather, and remains on the sand-flats, which supply almost no food. 

 From these fiicts we are led to believe that food has little influence upon 

 the movements of the fish during the spawning season. 



The instinct that leads the spawning fish to seek the shoal water in 

 such great numbers is certainly a wise one, for they generally select 

 spawning-grounds where the tide runs strong and the water is rough, 

 and the large number of individuals is absolutely necessary, that the 

 water may be filled with germs for their successful impregnation. If, 

 instead of schooling in such numbers during this period, they remained 

 scattered over a large area, almost no eggs would be fertilized. 



Again, while food is not essential to the spawning fish, it is of vital 

 importance to the young, and it seems a wise provision that these should 

 be brought into being where food is abundant, rather than that they 

 should be hatched in mid-ocean, where almost no suitable food exists. 



Cod-fish live at a depth varying from a few feet to over 100 fathoms. 

 They have occasionally been seen schooling or feeding at the surface on 

 the fishing-banks and on the coast of Labrador. In February, 1879, 

 there was good fishing in three fathoms of water within a few rods of 

 the shore in Ipswich Bay ; while in May of the same year large num- 

 bers were taken in 110 fathoms from "the channel" near Clark's Bank. 

 They seem to prefer a depth of less than 70, and by far the greater 

 uum1)ers are caught in from 18 to 40 fathoms. 



In moving from one bank to another, where the intervening depth is 

 much greater, it seems probable that, instead of following the bottom, 

 they swim in a horizontal plane, following a stratum of nearly imiform 



