During the 1953 shad-fishing season, v;e canvassed the fishery at 

 the head of the bay for tag returns from the two groups of shad. The 

 following table gives the recovery data. 



X^ - Oo2337, 1 d.f„, P-Oo65 



A chi-square analysis reveals no significant difference in the 

 proportion of recaptures for the t.-o groups of tagged shad. The inferences 

 are these; (1) There was no difference in the survival rate between shad 

 that were planted at Peach Bottom, Pennsylvania, and descended Conowingo 

 Dam, and those that were tagged at the head of the bayj hence, the shad 

 that descended the dam suffered no lasting ill effects j (2) the estimate 

 of the number of shad that descended Conowingo Dam and lived appears to be 

 fairly accurate. 



Of the 967 shad planted at Columbia, Pennsylvania, 26 were recap- 

 tured in Maryland between the time of planting and June 5, 1952, when the 

 fishing season ended. These 26 shad were subjected to a fishing rate less 

 than 5I06 percent since they were recaptured near the end of the fishing 

 season. If this group of shad had been subjected to a fishing rate of 5lo6 

 percent, an estimated 50 shad from this group would have descended the 

 three dams. Since the fishing rate was less than 5l»6 percent during the 

 period of recapture, probably more than 50 shad descended all three dams. 

 We obtained no tag returns from this group in 1953 5 so we can assume that 

 not many more than 50 shad from this planting descended the dams. If there 

 had been, we should have expected tag returns in the approximate ratio of 

 lgli.0 as observed in the other areas. 



The 2U2 tagged shad at the head of the bay that escaped the fish- 

 ery in 1952 must have suffered a high natural mortality or a considerable 

 loss of tags, since only 6 of these fish were recaptured during the 1953 

 shad season. Some of the natural mortality was probably due to deaths fol- 

 lowing spawning. The shad that remained above the dams probably experienced 

 a similar mortality after spawning. Those that survived probably had diffi- 

 culty in locating the turbine intakes or would not enter them. Eventually, 

 warm water and lack of food meant likely death for those shad that did not 

 descend the dams. 



11 



