PROGRESS IN BIOLOGICAL INQXJIKIES, 193 555 



from overfishing, and the factors that govern fish reproduction are 

 being examined so that advance information regarding fluctuations 

 in abundance may be made avaihable to the industry. On the Pa- 

 cific coast inquiries of a simihir sort are being prosecuted, and in the 

 Alaska fisheries, the results of such investigations find immediate 

 application in the drafting of fishery regulations imposed by the 

 Federal Government. Fisheries in the interior Avaters, aside from 

 those in the Great Lakes, are prosecuted primarily for sport and 

 recreation. The tremendous increase in the army of anglers, coupled 

 with industrialization and resulting stream pollution in the eastern 

 half of the country have placed an intolerable strain upon the fish 

 supply ; and investigations are, therefore, directed toward the intelli- 

 gent restocking of depleted waters, toward the perfection of fish 

 cultural methods for such purposes, and toward overcoming the 

 pollution menace. The shellfish resources of our coast line have 

 been an important food resource since earliest times, and recent 

 researches as to their dietary values enhance rather than detract 

 from their importance as a healthful food. Unrestrained harvest- 

 ing of the natural supply has led to marked depletion in many areas, 

 and the view is rapidly gaining popular acceptance that the adop- 

 tion of modern methods of farming of oysters, clams, and other 

 mollusks, either by private initiative or through rigid State regula- 

 tion, is the only practicable means of restoring the productivity of 

 our shellfish beds. The bureau investigations are, therefore, directed 

 to that end with gratifying results that appear to be fully apprecia- 

 ted by the industry. Minor problems of research conducted by the 

 division all tend toward the solution of these practical problems of 

 the fisheries. The period of exploration and description reached 

 its height during the last century and has passed. More modern 

 methods of experimental biological and statistical analysis have 

 taken its place, and fisheries research is rapidly assuming the form 

 and content of an exact science. 



In previous reports mention has been made of extensive cooperation 

 in fishery research by States and other institutions. During the past 

 year, cooperation still greater than ever before has been accorded. 

 In addition to the occasional support and encouragement in specific 

 projects such as the furnishing of boats, men, gear, or other services 

 rendered by the various States and which have been continued 

 through the past year, large-scale projects have been assumed by 

 several States on scientific programs, supervised by the bureau's 

 staff. So complete has been the States' confidence in certain under- 

 takings that considerable funds have actually been deposited in the 

 United States Treasury for disbursement on these cooperative projects 

 by bureau investigators. Such cooperation, which is gratefully 

 acknowledged, is in most cases mentioned in connection with the 

 various investigations in the following pages. 



Investigators of the division of scientific inquiry have continued 

 to participate in the activities of the North Amercan Council on 

 Fishery Investigations. The seventeenth meeting of this organiza- 

 tion was held in Washington on November G and 7, 1930. The nations 

 represented were Canada, Newfoundland, France, and the United 

 States. All of these nations have important interests in fisheries of 

 the western North Atlantic and all of them are engae-ed to a greater 



