THE HOMING OF THE SALMON 41 



The first thing noticeable in the Smolt-marking records 

 is that no recaptures were made in the year of marking, thus 

 refuting the idea still held by some that Smolts returned as 

 Grilse in the year of their descent. 



The first recapture was on ist June 1906, when a Grilse 

 of 2 lb. 15 oz. was captured. All the other fish recaptured in 

 1906 were Grilse, and several of the 43 were as heavy as 

 7 lb. The Tay Grilse run heavy, but up to the end of August 

 fish between 4 and 5 lb, were also taken. Doubtless more 

 Grilse may have returned than 43, just as more than 2 per 

 cent, of the total fish marked may have returned. We have 

 no certain knowledge of the actual numbers, but only of the 

 number recaptured. 



The most important year was 1907, or two years after the 

 descent of the Smolts. A total of 57 was taken that year. 

 Most of them were small spring fish ranging from 7 to 10 lb., 

 but the summer fish were from 12 lb. up to 27 lb., which 

 latter weight is above the average of the large spring fish 

 in the Tay. 



In 1908 the eight large spring fish, i.e. the five-year-olds, or 

 fish which as two-year-old Smolts went to the sea, from which 

 they returned in three years, ranged in weight from 13 to 

 35 lb. Up to the end of that year all returning fish were 

 doing so for the first time. That some fish had not been 

 noticed was evident when, in 1909, two large so-called "Bull 

 Trout" were captured. From a previous study of those 

 so-called " Bull Trout " it had been shown that they are 

 simply Salmon which have previously spawned. They are 

 fish showing many black speckles, chiefly above the lateral 

 line in the region of the "shoulder," and almost invariably 

 they retain the gill "maggots" which became attached during 

 their previous ascent of fresh water. The scales always show 

 the "spawning mark." 



With regard now to the marking of adult fish, which has 

 been carried on by the Fishery Board for twenty years, 

 and concerning which many reports have been published, I 

 may explain first that the method employed is to attach a 

 numbered silver plate to the base of the dorsal fin, so that 

 the plate lies flat against the base of the fin. A silver wire 

 I 23 AND I 24 F 



