Section IV, 1918 [139] Trans. R.S.C. 



Migrations of Marine Animals 

 By C. McLean Fraser, Ph.D., F.R.S.C. 



(Read May Meeting, 1918) 



In a work recently published, Alexander Meek has gone exten- 

 sively into the consideration of the migrations of fish. In this the main 

 stress is laid on a tendency of each species to migrate in one direction 

 towards the spawning period and in the opposite direction after 

 spawning or as fry. It is possible that if similar attention were paid 

 to other marine forms, a similar tendency might be observed in the 

 majority of instances although it might not be possible in so many 

 cases to trace any relationship between these movements and the 

 direction of tidal currents. In the case of sessile forms and others 

 that as adults remain stationary, there cannot be any migratory move- 

 ment in the adult and the free-swimming larva' seem to be carried 

 about by tides and currents without having any special directive 

 movement of their own. Of course this is true of certi^n fish larvée as 

 well. The young Pacific herring, for instance, just after they are hatched 

 out, are often found in almost solid masses in eddies or in situations 

 where two currents meet to bring them together. There is no parallel, 

 however, in the case of the adult and consequently these sessile forms 

 cannot be included. 



Some examples from the Pacific coast of North America and more 

 particularly in the strait of Georgia, in the different phyla and classes, 

 may serve to indicate that there is such a tendency. 



In vertebrates, among the mammals as well as among the fishes, 

 migration is a noteworthy feature. The migratory habits of the fur 

 seal are so marked that the migrations are comparable in distance to 

 those of migratory birds. From the rookeries on the Pribiloff islands 

 the individuals wander southward, even as far as the coast of Califor- 

 nia, 1,200 rniles or more away, only to return to the rookeries for the 

 next pupping season. The return is not restricted to the breeding 

 individuals since the immature males and females appear at the 

 rookeries as well. Sea-lions are much similar in their habits but it is 

 questionable if all the members of the herd go farther from the rookery 

 than is necessary to get a sufificient supply of food. Some of them go 

 long distances although by no means so far as the fur seals. Every 

 spring during the time the herring are in shallow water, grey sea- 

 lions (Eumetopias stelleri) are seen in the strait of Georgia as far north 



