72 REPORT OF COMMISSIONERS OF INLAND FISHERIES. 



afio halibut were exceedingly abundant in Massachusetts bay.* 

 From 1830 to 1850 they were very abundant on George's Banks; 

 since 1850 they have partially disappeared from this region, and 

 the fishermen have been constantly following them to other banks 

 and out into deeper and deeper water. Since 1874 the fisheries have 

 been carried on almost exclusively in the gulleys between the off- 

 shore banks and on the outer edges of the banks in water one hundred 

 to three hundred fifty fathoms in depth. 



II, Migrations. Very little is definitely known regarding the 

 migrations of the halibut. Throughout the year they are present 

 on the edges of all the banks from George's to the Grand Bank in 

 deep water from a hundred to two hundred and fifty fathoms. 

 Whatever annual migrations they undertake are probably not ex- 

 tensive, but, as far as can be ascertained, are limited to relatively 

 small movements between deep and shallow water according to the 

 seasonal changes of the temperature. The only consideration 

 pointing definitely to such a movement is the fact that during 

 winter and early spring halibut are sometimes found to be more 

 numerous in shallow water. They are also found further south dur- 

 ing the colder months of the 3'ear, as is shown by the fact that the 

 months from February to May include the only authentically re- 

 corded cases of halibut in water south of Cape Cod. This seasonal 

 movement, however, can be only very slight in extent, and apparently 

 does not take place with any regularity. 



In the preceding section, mention was made of the fact that there 

 is a larger, more extensive, movement, in which the halibut are 

 moving constantly into deeper and deeper water. The only expla- 

 nation suggested for this is that the halibut live in large schools, and 

 as soon as they have exhausted the food supply in an}^ particular 

 locality, they move on to fresh feeding grounds. None of their 

 migrations have any apparent connection with their reproductive 

 activity. 



III. Reproduction. Comparatively little is known with regard 



* Goode, Na. Hist, of Aquatic Animals, 1884. 



