of the Fishery Board for Scotland. 



kindly supplied to me annually by Mr. Donald M'Lean, factor to the 

 Duke of Sutherland. I have placed them upon the same chart. In 

 all these returns violent fluctuations are present ; the highest recorded 

 excess of grilse is reached, and on only one year, in the case of one 

 return, does the number of salmon exceed the number of grilse. The 

 fluctuations are evident by a glance at the lines ; the maximum point 

 is reached by the line representing North Sutherland, where, in 1906, 

 there were 13*6 grilse to every salmon taken. Gills fishing reaches 

 12-9 in 1899, and Forss 117 in 1885. These Pentland Firth records 

 seem to show little relation to the Helmsdale and Brora results, but 

 the period available is, unfortunately, not very great in any of them, 

 and it is therefore impossible to notice if Pentland Firth features are 

 in any way echoed, at possibly a later period, on the east coast of 

 Sutherland. 



Comparing the fluctuations of grilse and salmon (not shown in the 

 charts), it may be said generally that while both rise and fall together 

 to a considerable extent, the rise in the salmon line very commonly 

 occurs in the one or two years succeeding the grilse rise. But the 

 grilse rise is almost invariably short-lived. A. high peak in the line is 

 quickly followed by an abrupt drop. From this we may argue that 

 the supply for the salmon total being quickly lowered, produces a 

 corresponding depression in the salmon supply, and this is shown in 

 the results of annual takes. To elaborate this, or demonstrate the 

 condition in detail, would involve the production of an altogether 

 undue number of figures, but the condition may be exemplified by 

 the single chart, No. 4, showing the actual takes of the Aberdeen 

 Harbour Commission during a period of 37 years. It is further 

 noticeable that no cyclic recurrence of great grilse runs is shown. 



So far as these returns go, then, and I do not doubt that fuller 

 returns over a wider area would further bear out the results, it 

 appears, 1st, that at the present time, in the case of large river 

 fisheries such as those of the Tweed, Tay, and Dee, the proportion of 

 grilse to salmon is not so great as in other districts in Scotland; 

 2nd, that this proportion is not so great in these large river districts 

 as it previously was ; 3rd, that the decline in the total takes is 

 a decline both of grilse and salmon, but is very largely accounted 

 for, or is chiefly seen, in the decrease of grilse; 4th, that the decline 

 in the total takes is first shown in the reduction of the natural 

 overplus of grilse, which subsequently is reflected in a decrease of 

 adult salmon. 



I do not here deal with the various causes which contribute to 

 decline. An unknown percentage of loss naturally occurs after the 

 smolts enter the sea and before the recognised grilse stage is reached 

 in the sea. We can never hope to deal with loss from natural 

 enemies in the sea. But very many important causes are induced by 

 man, and affect the fish when in fresh water — overnetting, pollution, 

 excessive land drainage, artificial obstructions. These all act as 

 hindrances to the full reproduction of the species. The point I 

 make here is that the various adverse forces show results first in the 

 reduction of the grilse supply. 



I cannot claim that the returns at my disposal are sufficient to 

 make out a case for the whole country, but I think they are sufficient 

 to call marked attention to the important part grilse play in the 



