of the Fishery Board for Scotland. 



55 



and that it must be thrown out of working order altogether by very- 

 slight variations in the water level. I am disposed to think that the 

 probable explanation of the apparently conflicting opinions above 

 referred to is that, although some salmon may ascend it under certain 

 conditions of weather and water, these conditions occur so seldom that 

 the great majority of fish are taken at the foot of the dyke while wait- 

 ing for favourable conditions to ascend it, and that but few, therefore, 

 reach the upper waters until after the close of the net fishing season. 

 I cannot, therefore, conceive that it can be considered to afford a free 

 passage for salmon at all times in terms of the bye-laAv, 



With regard to what should be done to provide such a pa ssage 1 Remedies 

 have no confidence in any alteration or the present pass. Although "^^^^ ' 

 such passes if properly constructed sometimes work in places where 

 there are no conflicting interests, and where, therefore, the fish are 

 allowed to remain undisturbed in the pool below until the conditions 

 are favourable for them to ascend, they are quite ineflfective when nets 

 are used right up to the foot of the obstruction. It must be borne in 

 mind that it requires but a slight obstruction to check the pa ssage of 

 salmon under certain conditions of weather and water ; e.g. in the winter 

 or early spring months, unless the weather is very open, salmon will not 

 ascend obstructions which hardly check their progress later in the year, 

 while heavily-laden female salmon ascending rivers on the eve ol' spawn- 

 ing cannot surmount obstructions which present but little diffi(3ulty to 

 fish entering the rivers in the summer months ; and at all seasons of the 

 year the water level plays an important part in the extent to which a 

 fall obstructs the passage of salmon. In any case, therefore, dam dykes 

 always check the passage of salmon to some extent, and if netting is 

 allowed close up to their foot they not only serve their legitimate 

 purpose of supplying water to mills but facilitate the capture of fish. 

 To check as far as possible their serving this double purpose, which I 

 understand to be the intention of the general provision contained in the 

 bye-law, fish-passes should be formed of a series of pools extending if 

 possible the whole width of the river, so that salmon in following the 

 natural course of the stream have no choice but to ascend them, or at 

 any rate the lower pools should be constructed in such a manner that 

 the greater body of water passing over the crest of the dyke flows 

 through them, thus causing the entrance to the pass to form the main 

 channel of the river. Further, the pools should be made of such length 

 and depth that, in times of flood, the water does not jump from one stop 

 to another or cause undue disturbance, and the rise between each pool 

 should not exceed 12 or 13 inches. In England, where fish-passes must 

 be constructed of such form and dimensions as are approved by the 

 Board of Trade, it would seem that it is now generally recognised that 

 in order to secure, as far as possible, a free passage for salmon they 

 must be constructed on these principles. Mr. Berrington, in the 26th 

 Annual Report on Salmon Fisheries (England and Wales), p. 23, 

 remarks that "it is lamentable going about the country to see the 



numbers of useless fish-passes with which the weirs are studded. 

 " Of these only a small fraction have received formal approval, and of 



those which have been approved but few are really efficient, as will be 



seen by the list on the following pages (24, 25)." 



" In this list it would be difficult to find half a dozen passes of 



magnitude which are really efiective The fish passes 



*' which have been made throughout the country represent the expendi- 

 " ture of a large sum of money, the greater part of which has yielded 

 ^* nothing but experience. This properly utilised is, however, a distinct 



