believed that most of these shad passed through the floodgates of the dams 

 during periods of high water. Both Conowingo and Safe Harbor Dams have 

 floodgates,, but at Holtwood Dam there are no floodgates and the excess 

 water spills over the crest of the dam. Table h shows the schedule of gate 

 operations , 



The relation betv/een the percentage survival after hauling and 

 the percentage recaptured from each planting vias determined for the shad 

 planted above Conowingo Dam, There was no correlation between these fac- 

 tors , so it can be assumed that mortality subsequent to hauling was not 

 directly related to mortality during hauling o This relation could not be 

 tested for the shad planted at Coliimbia because the fishing rate was not 

 uniform during the period these fish were susceptible to capture „ 



Fourteen dead shad w$re recovered during the course of the experi- 

 mento Of these^ 7 were found 'below Conowingo, 1 below Holtwoodj 2 below 

 Safe Harbor, and U at Columbia, Pennsylvania, the stocking site above Safe 

 Harboro Most of the dead shad found below the dams had suffered injuries, 

 such as bruises J cuts, and gashes. These injuries were probably incurred 

 in passing through trash racks and turbines or in passing over the spillway 

 and hitting the rocks below. The fact that most of the dead shad were 

 picked up below Conowingo Dam may be accounted for by the greater height of 

 the dam and the greater boat and fishing activity there. 



That shad were able to descend the dams and live has been demon- 

 stratedo To determine whether any shad actually passed through the tur- 

 bines of the dams and survived, it is necessary to review the recoveries 

 from plantings made during the times when no floodgates virere open at Cono= 

 vfingo and/or Safe Harbor Dams, Table h gives the dates v/hen no floodgates 

 were open. From May 5 to 11 inclusive, no floodgates were open at Conowingo 

 Dam, Of 29 shad released above Conowingo Dam on May 5, two were recaptured 

 alive. One was taken on Ifey 8 at Havre de Grace, Maryland, and the other 

 was taken on May 10 off Worton Point, Maryland, Two shad planted above 

 Conowingo on May 7 were recaptured on May 10, one at Perryville, Maryland, 

 and the other at Port Deposit, Maryland, One shad planted May 7 above Cono- 

 wingo Dam was found dead below the dam on May 11; it vras probably killed 

 while passing through a turbine. From May 2 to 12 inclusive, no floodgates 

 were open at Safe Harbor Dam, One shad planted May 9 above Safe Harbor was 

 recaptured May 11 by an angler between Safe Harbor and Holtwood Dams, It 

 is evident that at least a few shad were successful in passing through the 

 turbines of the Safe Harbor and Conowingo Dams , No information could be 

 found concerning the passage of shad through the turbines at Holtwood Dam 

 because water was spilling over the crest of the dam during the entire 

 time the experiment was in progress. 



Each dam has bar-type trash racks mounted at the entrance to the 

 water intake of the turbines. The spaces between the bars on the racks of 

 each dam are as follows: Conowingo, 5 l/2 inches j Holtwood, some units 2 

 inches and others k inches j Safe Harbor, 6 3/8 inches. To pass through a 

 turbine, a shad must first pass between the bars of the trash racks. It is 

 likely that a shad has much less chance of passing through the Holtwood 

 trash racks than the racks on the other two dams. 



