KEPORT OF COMMISSIONERS OF INLAND FISHERIES. 47 



Perhaps the most important of the questions connected with the 

 migrations of the mackerel is — where do the fish go after leaving 

 the coast in the autumn? To answer this question with complete 

 certainty is, at the present time, as impossible in the case of the 

 mackerel as it is with most other migratory fishes. The theory once 

 held that the mackerel hibernate at the ocean bottom not far from 

 the regions of their summer sojourn, is now considered highly improb- 

 able. There are, then, at the present time two possible theories 

 regarding their winter habitat. 



The first theory is that during the winter the mackerel ma}' con- 

 tinue to live in the surface waters of the sea where the temperature 

 is suitable. In order to reach this region extended coastwise migra- 

 tion toward the south would be necessary. But it is practically 

 certain that this is not the case, since there is no record of mackerel 

 being taken during the cold months of the year south of Cape Hat- 

 teras, or in the West Indies, or on the coast of Africa. Neither have 

 any ever been seen in the warm waters of the open ocean. On the 

 other hand, it is possible that the schools may break up with the 

 approach of winter and that individual fishes may wander about 

 independently, thus possibly escaping detection. Yet this is scarcely 

 probable, and is contrary to what is known regarding the habits of 

 the fish. On the whole, however, with regard to this theory it must 

 be said that " until the contrary is shown to be the case, it must 

 remain one of the possible solutions of the question, although it is 

 not very probable, since were it so, specimens would almost certainly 

 have been captured at some time or other." 



According to the second theory, the mackerel may live in the 

 deeper layers of the sea, at a greater or less distance from their 

 summer home. At the present time this seems a much more probable 

 view of the case. 



The fact that on the American coast the spawning season becomes 

 later as the schools appear further northward indicates that a large 

 number of fishes probably move in from waters more northerly than 

 off Cape Hatteras, where they first appear. There is also little to 



