6 4 The Salmon 



to give the percentage caught on their second and third return would 

 not be of any great value. What I have said above also applies to 

 the autumn fish. In my opinion, in order to form a correct idea, one 

 would require to keep a record extending over a period of ten years. 

 The number of fish returning for the second and third time caught in 

 the nets on the Tay from 5th February 1911 to 2Oth August was 872. 

 Of that number 46 were got in February, 26 in March, 15 in April, 

 20 in May, 51 in June, 323 in July, and 391 from ist August until the 

 nets went off on the 2Oth of that month. 



In a good season double this number are caught in the nets, 

 and more than double left in the river, besides those caught by 

 the rod. This would mean at least 4500 of these fish returning a 

 second and third time, showing that the much-despised kelt is worth 

 protecting. 



It also shows the fallacy of the old theory that if you kill all the 

 kelts you will have no large salmon, for many of the latter are on their 

 first return from the sea, and have not yet spawned. It will be seen 

 from what I have written above that to take and examine a few 

 hundred, or it may be a few thousand scales from fish at intervals 

 throughout the season, and give the percentage, conveys no real 

 meaning. In my first addition I made out that in the autumn as many 

 as 19 per cent had returned a second and third time, figures arrived 

 at by counting the fish twice daily during several weeks. From closer 

 observation, this does not give the true percentage, as I did the same 

 last July (1911) when fish were scarce, and found the numbers far 

 more than 19 per cent in fact, some days quite 34 per cent. To 

 arrive at the true percentage, one collecting scales would require to 

 examine every fish coming into our fish-house twice daily throughout 

 the whole season. This would be found quite impracticable, especially 

 when a big run of fish had to be dealt with, as thousands would require 

 to be examined daily. One can, however, overcome this difficulty by 

 picking out the fish that have spawned from their outward appearance, 

 and if any uncertainty exist, the gills can be examined for maggots, 

 w r hich are always present. 



