36 THE SALMON FISHERIES. 
CHAPTER IY. 
Other causes of the Deterioration of the Salmon Fisheries—Dams 
and Pollutions—Navigation originally opposed to Weirs—lIntro- 
duction of Pound Locks—Canals—Pollutions—Value of Mining 
and Manufacturing Industries contrasted with Salmon Fisheries— 
Evil of Weirs—Examples of the Advantage of their Removal. 
THE old laws forbade in general terms the destruction of 
the fry of salmon, but their provisions were ignored, and 
they did not prohibit the killing of the spawning fish at all, 
except so far as an ill-regulated close season attempted 
to afford them protection. While the population was com- 
paratively sparse, and the fish were plentiful, no very great 
harm was done; but, with an increasing population, the 
effect of these onslaughts became more marked, and Parlia- 
ment stopped them in the interests of the fisheries. The 
spawning fish and the spawning beds were protected ; the 
use of lights and spears was prohibited ; and, as the enlarge- 
ment of the mesh saved the smolts from destruction in the 
estuary, so they were saved from falling a prey to the hook 
of the angler in the river by a general prohibition of their 
capture. Throughout the country the adoption of these 
measures was followed by a remarkable increase in the 
number of fish, and all the evidence points to the conclusion 
that these provisions of the law are of as vital-importance 
to the salmon fisheries as any of the other enactments to 
which we have yet alluded. Theoretically, the protection 
of the spawning fish and the young fry is the key to 
the whole problem. If we kill the goose we cannot 
