CONFERENCE ON SALMON PROBLEMS 



Those who participated in the sympo- 

 sium and others interested met for further 

 discussions on Thursday, June 30, 1938, 

 under the auspices of the Fisheries Re- 

 search Board of Canada in the office of the 

 Secretary, Mr. J. J. Cowie, who acted as 

 Chairman. The following is an edited 

 report of these discussions : 



Separate Biological Races 



Mr. W. J. M. Menzies presented the fol- 

 lowing paper : 



The existence of separate types of salmon 

 in individual rivers is too well known to 

 require either emphasis or proof. In some 

 rivers the run may commence in the late 

 autumn and winter months (Rhine, Vis- 

 tula, Tay, Spey). In others it may not 

 commence until the spring (Beauly, Ythan, 

 Laxford) and in yet others the run may be 

 confined to the summer months (most west 

 of Scotland rivers). In some rivers the 

 fish may be predominantly large ; in others 

 grilse may form the greater part of the 

 catch. Such variations might suggest spe- 

 cial local stocks, but at the same time they 

 may equally well be explained by some par- 

 ticular quality in each river which induces, 

 or entices, a run of a certain type of fish at 

 particular seasons of the year. 



Beyond these elementary facts, however, 

 certain other evidence with a more direct 

 bearing may be found. For instance, the 

 size of a river or the type of its mouth has 

 no direct relationship to the number of 

 fish which enter it. The Tay, with a wide 

 open estuary and a considerable body of 

 water, has a run of salmon very many times 

 larger than the Forth, which has an even 

 wider open estuary, separated from the 

 Tay by only a narrow spit of land, and a 

 water flow which, although smaller than 

 that of the Tay, is considerable. Similarly 

 the Ythan has a very much larger run of 

 salmon than the Ugie, although both are of 

 the same type and not markedly different 

 in size. Other instances could be quoted. 



If each river did not have a local stock 

 then the limitation of netting in any par- 

 ticular waterway would not be reflected in 

 later years by an increase in the number of 

 fish in that river. And yet we have the 

 much quoted and well authenticated cases 

 of the Aberdeenshire Dee in former years 

 and the Wye in this century where the 

 stock has been built up from a very low to 

 a very high level by the severe limitation of 

 netting within the river. The increase has 

 not been merely an increase in the stock of 

 fish by reason of the number which escape 

 being netted, but has been an increase from 

 year to year as the progeny of the succes- 

 sively larger spawning stock have had time 

 to develop and return. Ultimately in both 

 cases the stock has so increased that the 

 limited number of nets catch more fish 

 than did formerly a very much larger num- 

 ber of nets. A similar case exists and has 

 been authenticated by definite figures in 

 the Conon where restriction took the form 

 of allowing a fixed engine (a cruive) in the 

 river to remain unfished. A corresponding 

 improvement is at present being brought 

 about in the Ness where for 15 years nets 

 at the mouth of the river have been allowed 

 to remain unworked. 



Evidence of the same type suggests that 

 a local stock must also exist even in the 

 tributaries of at least the larger rivers. In 

 the Aberdeenshire Dee for instance certain 

 tributaries with good spawning ground 

 have a large stock of fish, others with 

 poorer spawning ground have fewer, and 

 up two other tributaries, which are of con- 

 siderable size and with the same quality of 

 water as many others, very few fish indeed 

 go. Both these tributaries have impassable 

 obstructions only a mile or so from the 

 mouth and only a very limited amount of 

 spawning ground exists below these falls. 

 Did salmon enter the tributaries by chance, 

 then as many should go up these last two 

 as go up any of the other streams. When 

 making a special inspection of the water- 

 ways in one of the Scottish outer islands 



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