560 REPORT OF COMMISSIONER OF FISH AND FISHERIES. 



culture in all proportions yields an inconsiderable and even in many 

 cases no profit at all. 



It is attempted now, chiefly with the object mentioned, to clear the 

 path through the long extent of our large rivers, to which, partly by na- 

 ture, partly by art, their approach is obstructed, by the construction of 

 salmon ladders in different places; however, curiously enough, not in 

 the place most important of all in this respect in the whole countrj^, a 

 place which by itself is more important than most of the other rivers 

 combined, namely Sarpen. It might appear that since no increase of 

 the abundance of salmon has been gained by the introduction of such 

 ladders, and the larger field thereby found for the salmon, owing to the 

 increased natural culture, it will be useless to continue such a scheme. 

 This is, however, by no means the case. Such a plan must on many ac- 

 counts be considered in a high degree profitable, even if it should cost 

 what one might regard a large sum of money. 



Access to the hatching of eggs is nowhere unbounded, while common 

 interest demands that it should be prosecuted on as large a scale as pos- 

 sible. The waters of springs, which may be used for such hatching — and 

 it is only those which have pure water, in the greatest possible degree 

 free from miuerals of all kinds in solution — limit the quantity of spawn 

 which can be hatched out, and their occurrence is not particularly fre- 

 quent. One may, of course, by appropriate arrangement of apparatus, 

 provide for the replacing in the spring- water the oxygen which was 

 gradually consumed during the hatching of the embryos, but one has 

 no means of removing from the water the carbonic acid generated in the 

 place of the oxygen consumed. This will steadily increase by the con- 

 tinued use of the water, and quickly reach such a point that the water 

 will become deadly for the embryos and the young. Long before such a 

 point has been reached the water must be regarded unsuitable for hatch- 

 ing. One cannot generally calculate that people who never see, as adult 

 salmon, any young which they may have hatched out will interest them- 

 selves in such hatching. It is vain to expect that the si)rings which must 

 occur along the upper courses of our rivers will ever be employed for 

 the hatcliing of salmon to the desired extent as long as the way is not 

 cleared for them to return to their birthplace and they are retained near 

 the mouth of the river for the advantage alone of those who live there. 



If one wishes to advance the hatching of salmon in the greatest pos- 

 sible degree, he must, by means of ladders, clear the way to the upper 

 sources of the river, and then hatching on a large scale will not fail to 

 take place along the extent of the rivers wherever the necessary condi- 

 tions are present. The profit hereof will of course substantially fall to 

 the residents along the lower portion of the river and along the coast 

 outside of its mouth ; but some profit will accrue to those resident on 

 the upper waters, and this probably sufficiently great to incline them to 

 regular hatching. This would especially apply to the men on whose 

 rivers sportsmen will be required to buy permission from the owners to 



