Kynard, B. and J. O'Leary (1993).  Evaluation of a bypass system for spent 
American shad at Holyoke Dam, Massachusetts. North American Journal of Fisheries 
Management.  13:782-789.
	
A bypass system for post-spawned American shad Alosa sapidissima began operation 
in 1980 on the Connecticut River canal system at Holyoke Dam. The purpose of the 
bypass was to enable downstream migrants that enter the canal to exit and avoid 
death due to delay or passage through hydroelectric turbines at water use 
facilities. The bypass system had the following elements: (1) an underwater AC 
electrical or acoustic barrier to prevent American shad from leaving the bypass 
area, (2) an underwater DC electrical field to immobilize fish for collection, 
and (3) a collection box with transfer pipe to carry fish to the river below the 
dam. During studies of the bypass system from 1979 to 1983, we found that the 
fish barriers were ineffective, the collection system was partially effective 
for American shad but not for anadromous species that passed through trashracks, 
and American shad could be immobilized and transported at high velocity through 
a pipe and have only low mortality (4-9%). Radio-tagged American shad, unwilling 
to pass through trashracks at water exits on the canal, behaved like trapped 
fish and were delayed an average of two or more days before dying or exiting the 
canal. An estimated 10 of 47 (21%) of the radio-tagged fish were passed. In 
1980, when the greatest number of American shad were passed, an estimated 
142,000 (37% of the fish lifted at the dam) survived spawning and used the 
bypass. After several years of operation, it was evident that, even with major 
improvements, the bypass could not pass the available American shad, and it was 
not useful for protecting other anadromous migrants that did not avoid 
trashracks.