48 American Fisheries Society 



have devoted time and great powers of mechanical ge- 

 nius, as well as vast practical experience of fish and 

 fishing, to the subject of fish passes. Not only engineer- 

 ing and mechanical skill, but much scientific knowledge 

 has been brought to bear on this fishway problem. There 

 are probably three hundred kinds of fish passes in exist- 

 ence, diflfering endlessly in regard to details, but grouped 

 as I have shown in a report published in 1902, under 

 about 16 or 18 headings acording to the essential prin- 

 ciple embodied in their design.* 



PURPOSE OF FISH PASSES. 



Now it will hardly be disputed that a Perfect Fish 

 Pass should enable such a number of fish to ascend at 

 their special time of migration, and to reach their accus- 

 tomed breeding grounds, as to restore and permanently 

 maintain their former abundance. 



RESULTS DISAPPOINTING. 



Salmon rivers on this continent, and in other countries, 

 formerly produced every season vast numbers of fish, 

 but it must be confessed that the building of fishways 

 at great cost and the efforts of fish culturists have in 

 no instance brought back the fish to their pristine pleni- 

 tude. In the case of shad, alewives or gaspereaux, 

 striped bass and other anadromous species they have not 

 been restored, even to a moderate degree, in many rivers 

 personally known to me. Indeed these fish are on the 

 verge of extinction in spite of all the exertions of hatch- 

 ery officers, of governments — state and federal — of fish 

 and game clubs, and the true friends of fish generally. 

 It is plain that no hatcheries can really benefit a river to 

 the fullest extent if the fish are cut off from access to the 

 upper waters. No salmon river can resume its pristine 

 productiveness if one or more dams block all access to 

 the best pools and spawning shallows. 



*Canada, Marine and Fisheries Report, "The Fish Way Problem," 

 E. E. Prince, pp. LXXI-LXXVIII, 1902. 



