14.— ATMOSPHERIC AND OTHER INFLUENCES ON THE MIGRATION OF 



FISHES. 



BY J. J. ARMISTEAD, 



Solway Fishery, Dumfries , Scotland. 



The subject now before us is one that plays a highly important part in the eco- 

 nomic history of our food- fishes. During- the last ten or fifteen years the migrations 

 of birds have been extensively worked out by experts, and much light thrown upon 

 the movements of these creatures. To put the matter in a practical way, what we 

 want is a somewhat similar arrangement of forces, by which the migrations of fishes 

 can be taken note of by any one who in any way comes in contact with them, and 

 who is sufficiently interested, or can be sufficiently interested, in their existence to 

 record the smallest facts concerning their movements and send in these records to 

 some central station, where they may be made good use of and the results made 

 known to science. The case in the matter of fishes is not so easy perhaps as in the 

 case of birds, and yet what could be simpler than for a fisherman on some particular 

 date to record such a series of facts as the following: 



May 29, 1893; first large run of salmon, on flood tide, 17 feet 10 inches; wind light, WSW. f 

 showery. 



On being received at headquarters probably other similar reports would arrive 

 from various stations in the same district, and in case of any rivers not reporting, 

 application should be made for information. In this way much valuable information 

 might be collected, condensed, and published. Although an individual observer can 

 do comparatively little, yet a number working together might do a great deal. 



I have endeavored, as opportunity has offered, to make a few observations which 

 I have recorded from time to time, and refer to them now in the hope that others may 

 be interested and stimulated to similar effort. The more we work out the facts about 

 the migration of fishes, the more complex very often does the question appear to become. 



Primarily, there are two causes which lead to migration, (1) food supply and (2) 



reproduction of species. It has frequently been asserted that salmon do not feed, 



but every one who is acquainted with the life-history of that fish (tialmo salar) is well 



aware that they not only feed, but feed voraciously. It is not necessary to go to a 



fish-culturist to make sure of that fact. Salmon have been kept in fresh water from 



the time of their birth to maturity, and after the absorption of the umbilical sac have 



fed and continued to feed very much in the same way that other members of the 



family are known to do. 



93 



