80 U.S. BUREAU OF FISHERIES 



Page 



Mussel investigations and pollution studies in interior waters 141 



Pollution studies in the Mississippi 142 



Mine pollution in Coeur d'Alene district in Idaho 143 



Laboratory studies of pollution 143 



M ussel propagation 144 



Independent activities of the Fishery biological laboratories 145 



Woods Hole, Mass 145 



Beaufort, N.C 146 



Appropriations 147 



INTRODUCTION 



Performing the original functions assigned by Congress in 1871 to 

 the old United States Fish Commission, the technical staff of the 

 Division of Scientific Inquiry pursued during 1932 the orderly pro- 

 gram of fishery research developed during the past 5 years for the 

 purpose of determining changes in abundance of the food and game 

 fishes of our sea coasts and interior waters, of recommending meas- 

 ures of conservation for the proper protection and utilization of the 

 supply, and of encouraging the farming of aquatic products. 



The major scientific projects that have been continued are included 

 in three fields : Marine and fresh water commercial fishery investiga- 

 tions, investigations pertaining to game fishes, and shellfishery inves- 

 tigations. As may be expected from the systematic pursuit of a 

 well-organized research program, progress has been made in the 

 solution of the problems affecting the fisheries in all these fields. It 

 is difficult to select outstanding accompHshments in projects which 

 require many years for completion and which by their very nature 

 develop slowly. Nevertheless, a few may be cited. 



From the investigations of the haddock fisheries off the New Eng- 

 land coast it is becoming increasingly evident that success or failure 

 of the great trawl fishery, employing nearly 100 of the largest vessels 

 in the fishing fleet, depends upon success or failure of spawning and 

 survival of the young and not directly upon the numbers of spawn- 

 ing adult haddock. The decline of the haddock fishery from its max- 

 imum in 1929 to a minimum in 1932 is thus attributed to failure of 

 reproduction in the years from 1926-28. Improvement in the yield 

 is anticipated because of the relatively successful spawning year of 

 1929 which produced more young haddock than any year since 1924. 



Similar censuses of the mackerel population are providing the basis 

 of increasingly accurate predictions in yield of that fishery, and the 

 study of spawning success and survival in the salmon fisheries in 

 Alaska not only provide the basis for the Bureau's regulations of those 

 important fisheries but also yield predictions of future yields that are 

 accepted by the industry in planning fishing and canning operations. 



For the first time the mystery which has shrouded the Hfe history 

 and habits of the shrimp on the South Atlantic and Gulf coasts is 

 yielding to scientific research. Although the investigation started as 

 recently as 1931, the extreme vulnerability of the shrimp supply to 

 overfishing has been demonstrated. Because of the fact discovered 

 during the year that the important commercial species have a life cycle 

 limited to about 1 year, warning has been issued to the States that 

 the fisheries should be diligently observed for first signs of depletion, 

 which when it appears will almost certainly run a tragically rapid 

 course resulting in disaster for this extensive industry. The major 



