X 



Report on Salmon Fisheries. 



inspections in The inspections made in 1905, which are reported upon 

 separately by Mr. Calderwood, were of the Bladenoch, Girvan, 

 Doon, Ayr, Loch Lomond and liiver Leven, and Deveron Districts. 



Results of 



In order to obtain fuller information as to the migratory habits 



b nV Mal^ ti0nS °^ sa ^ mon ' ^s mcrease m length and weight, and the 

 Saimot). anS relative times spent in fresh and salt water, the marking of fish, by 

 the attachment of a silver label to the dorsal fin, has been 

 continued since 1890. In the three reports which have been made 

 by Mr. Calderwood on these investigations, particulars of 277 

 recaptured fish are given (20th, 22nd, and 24th Annual Reports). 

 The greatest number of these are from the Spey (115) and the Tay 

 (77), but important results have also been obtained from fish 

 marked in the Deveron, Kyle of Sutherland, Brora, Helmsdale, 

 Thurso, and Annan. At the present juncture it may be profitable 

 to attempt a brief summary of the results obtained. 



(1) Return of Fish to their own Rivers. — The great majority of 

 river recaptures confirm the belief that the salmon after visiting 

 the sea returns to its own river. The exceptions to this rule 

 represent about 8f per cent. 



(2) Movements of Fish along the Coast. — Recaptures in sea nets 

 on the North and East Coasts, and in rivers other than those in 

 which the fish were marked, seem to indicate that, when fish 

 forsake their own rivers, they travel for the most part in an 

 easterly and southerly direction, as from the Moray Firth to the 

 neighbourhood of Aberdeen (vide Chart in Appendix II. infra). 



(3) Descent of Kelts. — In small streams descent is more rapid than 

 in large rivers. In the Tay, the river of greatest volume, grilse of 

 both sexes descend at once after spawning; male salmon kelts 

 descend more rapidly than females, and the latter, especially when 

 large fish, may take as long as three months to descend forty miles 

 of river. Kelts of both sexes frequently remain for some time in 

 brackish water, and, after rapid descent, may even occasionally 

 re-ascend to fresh water. 



(4) The Time of Return from the Sea. — A two-fold habit of short 

 and long periods of marine sojourn exists. Young kelts, of uniform 

 class, marked in January or February, return as clean salmon 

 in the summer or autumn of the same year, or as spring fish of the 

 year succeeding. The same two-fold habit continues throughout 

 the life of the adult salmon. This habit does not imply two dis- 

 tinct strains of fish. The length of time spent in the sea is subject 

 to great variation. The grilse stage is passed in the sea by many 

 fish. Some salmon spawn in consecutive breeding seasons, many at 

 longer intervals. Throughout each winter a considerable proportion 

 of clean salmon remain in the sea. 



(5) Increase in Weight. — Fish marked as kelts and recaptured 

 as clean salmon show great variation in growth and increase of 

 weight. This is chiefly influenced by the length of time spent in 

 the sea, but also to some extent by locality. A grilse kelt may 

 double its weight in 88 days or longer. A Tay kelt of 6 lbs., 

 remaining in the sea during the next spawning season, may enter 

 the Tay, after fourteen months, as a spring salmon of 19 lbs., 

 having increased to fully three times its kelt weight. A record 



