16 REPORT OF THE COMMISSIONER OF FISHERIES. 



fish at the time of delivery, and to avoid constant weighing an aver- 

 age weight of 11| pounds per fish has been established as a basis for 

 computing the cost, this being conceded by the fishermen as a very 

 fair average. The fish thus purchased are released immediately after 

 their ef^gs are secured, and they undoubtedly return to the river in 

 appreciable numbers in subsequent years. The point of greatest im- 

 portance, however, is the salvage of a very large percentage of the 

 immature spawn contained in the fish at the time of capture for 

 market. 



The shad hatcheries on both the Potomac River and Albemarle 

 Sound were adversely affected by peculiar climatic conditions that 

 prevailed during the spring of i921. In the former field the first 

 eggs were taken on March 22, the earliest recorded date for spawn- 

 ing shad on the river. This premature spawning was undoubtedly 

 brought about by the warm weather and consequent high water-tem- 

 peratures prevailing in the latter part of February and ii> March, 

 the minimum water temperature recorded at the Potomac River sta- 

 tion during March being 40° F. An unfavorable reaction Avas occa- 

 sioned b}^ the abnormally cold weather in April and early May, when 

 the season was brought to a close. Equally unsettled weather pre- 

 vailed in the Albemarle Sound region, and to this fact, together with 

 the very extensive fishing operations permitted in the sound, the re- 

 duced output of the station is due. 



It should not be necessary to emphasize the great need for imme- 

 diate restrictive measures if the shad is to be saved in the few remain- 

 ing rivers where the run still persists in sufficient volume to be com- 

 mercially attractive. The subject has been a prolific source of dis- 

 cussion, but the various States most intimately concerned and re- 

 sponsible for the conditions have apparently made no progress toAvard 

 ameliorating the situation. It is pertinent to note that the weather 

 which was so unpropitious for the hatcheries actually favored a large 

 catch of fish in the pound nets in the lower reaches of Chesapeake 

 Bay and Albemarle Sound. 



Verv^ good results attended the initial attempt to propagate the glut 

 herring or alewife on Albemarle Sound, and over 55,000,000 eggs 

 were collected for the Edenton hatchery and nearly 44,000,000 fry 

 were produced. The hatching of striped bass on the Roanoke River 

 was conducted as usual in the spring of 1921, and, notwithstanding 

 unfavorable weather, the collection of eggs, amounting to 24,(320,000, 

 was larger than in any previous season. 



PROPAGATION OF COMMERCIAL FISHES OF THE GREAT LAKES. 



The most important commercial species of the Great Lakes — white- 

 fish, ( isco, lake trout, and pike perch — were handled along the custom- 

 ary lines, and, with the exception of the lake trout, all showed a 

 Siitisfactory increase in output as compared with the previous 5^ear. 

 This increase was made possible largely by favorable weather con- 

 ditions, although in the case of the cisco the egg collections were 

 greatly augmented by the receipts from new fields in the Canadian 

 waters of Lake Ontario. 



The need of a hatchery at some point on Saginaw Bay to take care 

 of the immense numbers of pike perch and yellow perch eggs avail- 



