22 U. S. BUREAU OF FISHERIES 



A preliminary experiment in October 1937, indicated that when 

 youno- shad about 2i/o inches long- are marked with internal tags, about 

 one-third survive the initial shock of handling- and operation. Un- 

 fortunately, the survivors as well as unmarked controls eventually 

 succumbed to unfavorable aquarium conditions so that it is not known 

 whether such tags will be retained indefinitely. Further experiments 

 will be made in 1938. 



An attempt will also be made to tag spent shad to determine whether 

 they return to the same stream each year. 



If, as is probably true, the increase in abundance in the Hudson 

 River is the result of regulations which permit an adequate escape- 

 ment of spaAvners, the numbers of shad spawning in the Hudson River 

 for the second or third time should be greater than in the seriously 

 depleted southern streams. There are present on some shad scales 

 eroded bands resembling the spawning marks of salmon. If these 

 prove to be spawning marks and if examination of the scales of spent 

 shad indicates that spawning invariably results in the formation of 

 such marks, it is expected that comparison of the numbers and the 

 percentages of "repeaters" in the Hudson River and in southern 

 streams will serve as a basis for judging the effectiveness of such regu- 

 lations as may be adopted in the southern areas. 



A serious obstacle to effective study of the shad fishery is the lack 

 of detailed records of the catch. Better records of the total catch 

 will be needed to convert the estimates of the percentages of "re- 

 peaters" into estimates of the actual numbers of spawners escaping 

 the fishery. Records of changes in abundance in tei'ms of catch per 

 unit of fishing effort will be needed in order to follow in detail the 

 results of such regulations as may be recommended. To correct this 

 lack of data, collection and analysis of shad catch records were begun 

 in the Chesapeake region by Ferdinand C. Latrobe and in South 

 Carolina by Oliver A. Duff. The conservation officials of Maryland, 

 Virginia, and South Carolina and the staff of the Bureau's Division 

 of Fishery Industries are cooperating in this work. 



Should it eventually appear that provision for an adequate reserve 

 of spawning adults is the principal requirement for maintenance of 

 abundance, the problem of determining the optimum escapement will 

 be of primary importance. Protection of spawners in excess of the 

 numbers needed for reproduction is obviously wasteful, and inade- 

 quate protection prevents full realization of the productive capacity 

 of the resource. An attack on this problem was begun by initiation 

 of studies of early life history of the shad in theEdisto River, S. C, 

 by John C. Pearson, assisted by Charles O. Hathaway II. Louella 

 Cable also began studies of,' the plankton cycle and the food habits of 

 young shad in the same /river. 



It is notable that many years of artificial propagation have failed 

 to halt the decline in abundance of shad. Although it is possible 

 that the decline would have been much greater had hatcheries not 

 been operated, it is desirable to test carefully the effectiveness of 

 present methods of artificial propagation and to experiment with 

 methods of carrying fry to the fingerling size. A beginning on such 

 a program of investigation was made by Mr. Pearson\at the Eden- 

 ton, N. C, hatchery. Pond and laboratory facilities have been placed 

 at his disposal at this hatchery and at the Orangeburg, S. C, hatch- 

 ery by the Division of Fish Culture. 



