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up, and (b) that the shoals break up more or less and pass 

 gradually into deeper water, where although there may not be 

 such an enormous abundance of food as in inshore waters from 

 October to January, a sufficiency may be found under normal 

 conditions to satisfy the hunger of the disbanded shoals as the 

 sea bottom as far as the depths of 30 to 35 fathoms consists of 

 the same fine mud met with in depths of from 2 to 6 fathoms ; 

 there is probably a free growth of diatoms there quite apart 

 from the abundance we find suspended and floating in the water, 

 and on such the sardines probably disperse to feed. This will 

 be a subject for future detailed investigation as will also be the 

 possibility that the sardines may change their dietary at certain 

 seasons and feed freely upon what may be termed mixed plankton 

 instead of confining themselves to diatom scum. 



71. This movement from shallow to deep water, from 

 depths of 2 to 6 fathoms close inshore to greater depths up to 

 perhaps the 30 or 35-fathom line, which we have reason to 

 believe occurs in normal years about March or April, may 

 be termed the minor or normal aimual sardine migration, in 

 contradistinction to that major occasional migration which takes 

 place at irregular intervals of several years, when after several 

 seasons of abundance, sardines forsake their inshore haunts for 

 several consecutive years to reappear suddenly in shoals of 

 immense size. 



72. The occasional disappearance of sardines from inshore 

 fishing grounds for several years in succession is a fact that 

 greatly hinders and handicaps the development of several 

 important industries, to wit, canning and the manufacture of 

 sardine oil and fertilizer, as capital is shy of investing in a trade 

 where the supply of the raw material is uncertain and widely 

 variable in quantity as well as in price from year to year. To 

 discover where the shoals go in those years when they desert 

 the shallows during the usual fishery season and then, when 

 found, to determine how best they may be captured in quantity, 

 is a task so important, because of the enormous loss entailed 

 by bad seasons upon the fishing community and the industries 

 depending on the sardine fishery, that it may well be esteemed 

 the most urgent and most important problem calling for 

 sustained investigation and intensive study on the West Coast. 



73. The present position is one of almost utter ignorance. 

 We have no exact data whatever that will help us except the 

 probability that this major cyclic migration is influenced by 

 causes related to but very much more powerful than those which 

 produce those minor periodic seasonal movements whereof we are 

 beginning to understand the significance. Judging by such 



