TWELFTH ANNUAL MEETING. 57 
A NEW SYSTEM OF FISH-WAY BUILDING. 
BY MARSHALL M'DONALD. 
It is a well established fact that the river fisheries of the 
Atlantic States have steadily decreased both in value and annual 
production for many years past. In some instances, species that 
were at one time common in certain of our rivers, are no longer 
taken. Indeed, the annual run of these fish which still continue 
their migration to the rivers, has undergone alarming decrease ; 
and in many cases become too insignificant to furnish the motive 
or material for organized fisheries. Several causes, probably, 
have concurred in producing this decrease. 
First—The capture of the greater portion of the run each 
year may not have left sufficient to maintain production under 
natural conditions. 
Second—The erection of dams or other obstruetions in the 
rivers, has in some cases, absolutely excluded certain species from 
their spawning grounds; the result being eventually to ex- 
terminate the species referred to in those rivers. In all cases 
the existence of such obstructions, has determined a decrease in 
the natural productiveness of the stream fro-tanto, with the 
diminution of the breeding and feeding area. 
The remedy for the condition of things above indicated is to 
be found : i 
First—In the enactment of’ such legislation as will control 
excessive, and prohibit destructive modes of fishing. 
Second—In compensating for the insufficient natural supply 
by artificial propagation and planting. 
Third—In extending the area for breeding and feeding, by 
overcoming natural obstructions by means of fish-ways. 
If the anadromous fishes only entered our rivers for the 
purpose of spawning, and their progeny spent no part of their 
life in our fresh waters, then the increase which we could de- 
termine by artificial propagation would be praccically without 
limit. The fish-culturist, in order to maintain supply, would 
only have to produce the young fry in numbers sufficient to 
replace losses by capture or by casualty. 
