of the Fishery Board for Scotland. 



93 



the normal pelagic life, including the small crustaceans upon which 

 the herring principally feed, disappeared. The herring subsequently 

 were found at great distances from land. 



The interest in this to the salmon fisher is that the herring is the 

 chief food of the salmon, and that the salmon in following the herring 

 through this abnormal period may have assumed, temporarily, different 

 habits. 



Then again it has been pointed out that in 1905 somewhat similar 

 hydrographical conditions obtained, with a similar incursion of salpw. 

 If we refer to the curves showing the marketed salmon, we see that 

 the weight of salmon sent to market between places on the coast from 

 Berwick to the entrance to the Moray Firth rises to a high level in 

 that year, though not to so high a level as in 1921. The three other 

 curves in 1905 did not respond. 



In the research observations we have been making recently, and 

 more especially in the scale reading investigations, indications have 

 been appearing, similar to those found by Mr. Hutton in the case 

 of Wye fish in England, pointing to the conclusion that the nutrition 

 and growth of parr and smolts in their early river life have a direct 

 bearing upon the growth which may be expected in the sea, and to 

 the time at which the fish may be expected to return to the river 

 after their seaward migration. 



During 1921 nearly 7000 scales from seven different Scottish districts 

 were examined in an attempt to make a sufficiently wide comparative 

 study of such matters as seasonal runs and local races. With every 

 sample of scales the fish is measured at four different points, and 

 particulars of weight, place and date of capture are also noted. We 

 have now amassed a very large number of percentage calculations, 

 and have been actively engaged in working out certain issues. Data 

 from the Aberdeenshire Dee and the Spey bulk most largely in the 

 calculations meantime, and the particulars from those two rivers are 

 almost equally represented. 



In the case of a specially interesting year such as that of 1921, in 

 which, as I have already explained, there may be considerable abnor- 

 mality of habit, the value of comparisons with other and more usual 

 years is of great importance. It is greatly to be regretted, therefore, 

 that for reasons of economy, involving the loss of two trained workers, 

 these investigations have received an abrupt check. With a little 

 clerical assistance we still hope to be able to work through the 

 calculations, and even to continue the collection of more data in 1922, 

 our desire being, if possible, to follow out the generation of the fish 

 already dealt with. Otherwise 'the value of the great amount of scale 

 reading and calculation already done will be much reduced. 



The coast salmon marking work, recommenced in 1920 after the in- 

 terruption due to the war and continued in 1921, has now had meantime 

 to be entirely suspended. 



Pollutions. 



It is remarkable that, although Salmon and Fresh Water Fisheries 

 are most seriously affected by pollutions, the Fishery Board for Scotland 

 has never been given any power to deal with the matter so as to protect 

 the fisheries from this danger. It may be noticed, in consequence, 

 that those suffering local injury to their fisheries have been re- 

 commended in the past, by Fishery Associations, to apply to the 

 Local Government Board, now the Board of Health, or directly to the 

 Secretary for Scotland. 



