XXII EEPOr.T TO THE SECEETARY OF COMMEECE 



performing related duties in connection with the various problems. 

 The rectification of this condition is urgent. 



Continuation of the investigation of the shore fisheries of southern 

 New England and the Middle Atlantic States has confirmed the view 

 that fluctuation in yield of several important species is due to natural 

 causes largely. In the case of scup and butterfish, dominance of the 

 fishery by occasional exceptionally large broods is largely responsible 

 for variation in the yield. In the case of squeteague, the causes have 

 been found to be more complex and are not yet completely- 

 understood. 



Investigations w^ere continued on the seasonal occurrence of pelagic 

 marine fish eggs and young fish at the entrance of Chesapeake Bay. 

 During 1930-31 records of the new winter trawl fishery, which has 

 developed recently off the Virginia and North Carolina coasts, were 

 secured. This fishery is of special interest, since it provides employ- 

 ment for a number of otherwise idle northern vessels, supplies an 

 important fresh-fish market in the seasons of scarcity, and opens to 

 exploitation the species of fish formerly caught only in the summer 

 season. In upper Chesapeake Bay an investigation of the striped bass 

 or rockfish has been undertaken to study the life history and habits 

 of the fish as a basis for regulations, which appear to be badly needed 

 for the protection of the supply. 



To provide further fundamental information as to the lives and 

 habits of the important food fishes of the South Atlantic coast, studies 

 on the development of the young of the shore species were continued 

 at the Fisheries Biological Laboratory, Beaufort, N. C, where special 

 facilities for such studies are available. One report on this subject 

 was recently issued and another dealing with several species is near- 

 ing completion. At this station also improvements in the methods 

 of feeding young diamond-back terrapin have been developed. 



Although of commercial importance for a half century, the shrimp 

 has achieved a place among the important fisheries only within the 

 past 10 or 15 years. The growth of this industry has been so rapid 

 and has reached such magnitude that grave fears as to the perma- 

 nency of the supply have been entertained by the industry, and the 

 investigation started during the last half of the fiscal year gives every 

 promise of providing the necessary information for the enaction of 

 regulatory legislation should that be necessary to insure continued 

 productivity of the resource. 



A special study is being made in Georgia of the effects of the 

 shrimp trawl upon the food and game fishes of the area. 



FISHERIES OF INTERIOR LAKES 



Investigations of the commercial fisheries of the Great Lakes were 

 continued during the fiscal year 1931. Three different types of 

 research were carried on in the Great Lakes, viz, a study of the effect 

 upon the fish stock of commercial fishing gear and studies of experi- 

 mental gear designed to prevent the destruction and waste of under- 

 sized fish; investigations of the life histories of important commer- 

 cial fish of the Great Lakes; and limnological surveys in Lake Erie 

 to study the conditions of the environment affecting fish production. 



Studies of the trap-net fishery in Lake Erie were completed during 

 the year ahd recommendations will be offered for an improved type 



