of the Fishery Board for Scotland. 



95 



great extent, and we know that many other predatory fishes in the sea 

 beyond will also endeavour to secure them. Even the comparatively 

 sluggish cod appears to be successful, for a smolt marked with silver wire 

 was once recovered from a cod's stomach. Those smolts which have 

 been fortunate to escape all the dangers, take their own toll at last from the 

 small herring, but it is apparently in this early life in the sea that so many 

 drop out. 



Under natural conditions, if the interference of man is not great, 

 salmon can be extraordinarily numerous, and with all the dangers to be 

 encountered in the sea, the protection of the ova in the redds cannot be 

 poor, nor can the natural process of reproduction yield a small relative 

 hatch. Even dog-fish, which produce very few eggs indeed, but which 

 protect their eggs each in a leathery envelope, can be extraordinarily 

 numerous. And in support of the method of Nature, for it is practically 

 a return to it, I notice that Mr. Babcock, the Deputy Commissioner of 

 Fisheries in British Columbia, recommends in his most recent report that 

 the eggs treated in the various hatcheries over which he has supervision 

 should now be laid in gravel, since after a series of experiments distinct 

 advantage results, both in the health of the alevin and in freedom from 

 disease. 



Granted the high percentage attained in most hatcheries, it is of im- 

 portance to notice at what stage the young fish are turned out, and 

 especially what return in adult fish can be or is secured. The commonest 

 way is to turn out fry, and no doubt this saves an infinite amount of 

 trouble and expense. In America, however, rearing appears to be rather 

 on the increase, in order to carry the young fish beyond the early dangers. 



In the case of the Weser in Germany, the hatching operations of Herr 

 Jaffe show a return of three adults per thousand fry. This figure is arrived at 

 by comparing the return of salmon from the nets of the lower river, and 

 the output of fry from the hatcheries, it being contended that since the 

 weir at Hamelin prevents fish from getting up to spawn in the upper river, 

 and since the bottom of the river below the weir is soft mud where salmon 

 eggs could not hatch, the only upkeep of stock possible is from the 

 hatcheries. There seems some slight reason for the view that possibly 

 more salmon spawn naturally than is supposed, but if this is the case, the 

 return for the artificial hatching is so much smaller. The result of three 

 per thousand may probably be accepted, is certainly accepted in Germany, 

 and is considered satisfactory. 



In the United States, the percentage appears to be somewhat higher. 

 If we refer to the operations on the eastern sea board, where the species is 

 the Atlantic salmon as with us, we find that the return is about five per 

 thousand, but that a certain number of fish are turned out at a later stage 

 than fry. Here again the return is regarded as satisfactory. 



It is instructive to examine a little further the history of the American 

 hatching. In 1868 or thereby the opinion seems to have been held that 

 the Atlantic salmon had become so scarce in the Penobscot and other rivers 

 of the State of Maine that the species was in danger of becoming extinct. 

 The Bureau of Fisheries decided to resuscitate the stock by artificial means, 

 and began buying eggs from Canada. The confidence with which this 

 policy was regarded may be gathered from the fact that at one time as 

 much as ,£9 per thousand seems to have been paid for the ova, a sum 

 estimated as equivalent to <£135 for the eggs of a single female. The 

 Penobscot fishery gradually increased as the hatching increased, and 

 although the hatch of Atlantic salmon still forms but a small part of the 

 immense total reached for other species, about two and a quarter million 

 eggs are now treated annually, and the fishery seems to produce, with 



