314 U.S. BUEEAI7 OP FISHERIES 



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Mussel investigations and pollution studies in interior waters 375 



Fresh-water mussel investigations 376 



Pollution studies 378 



Independent activities of the Fishery Biological laboratories 379 



Woods Hole Laboratory 380 



Beaufort Laboratory 380 



Appropriations 382 



INTRODUCTIOE- 



The work of the Division of Scientific Inquiry involves studies 

 from a biological point of view of the various fisheries, in order to 

 determine which are showing depletion and what methods may be 

 applied toward their conservation as well as studies for the develop- 

 ment of improved methods of cultivating aquatic animals. Kesearch 

 projects during the past year cover three major fields: (1) Marine 

 and fresh-water commercial fishery investigations; (2) aquicultural 

 investigations; and (3) shellfishery investigations. These projects 

 are organized under seven distinct sections, each directed by a 

 responsible and experienced fishery biologist, and are so distributed 

 as to cover each of the major geographical sections of the United 

 States. They include individual researches on more than 30 different 

 species of commercially important food and game fish, shellfish, 

 and crustaceans. 



The various projects engaging the attention of the staff of 43 

 permanent employees were as follows : 



Commercial fishery investigations : 



North and Middle Atlantic fishery investigations: Cod, haddock, mackerel, 

 weakfish, scup, bluefish, and flounder. 



South Atlantic and Gulf fishery investigations : Shrimp and shore fishes. 



Great Lakes fishery investigations : Whitefish, cisco, herrings and chubs, 

 pike perches, yellow perch. 



Pacific coast and Alaska fishery investigations: Red salmon, pink salmon, 

 and herring. 

 Shellfishery investigations : 



Oyster cultural investigations in New England, South Atlantic, Gulf 

 States, and Puget Sound. 

 Aquicultural investigations : 



Improvements in hatchery technique for feeding and breeding trout. 



Pond-fish cultural investigations for warm-water fishes. 



Treatment and cure of diseases of hatchery fish. 



California trout investigations. 



Studies in fish nutrition. 



Investigations in interior waters with respect to pollution and the propa- 

 gation of pearl mussels. 



Stream surveys in the national parks and forests. 



The scientific investigation of the fisheries, or of the fish on which 

 the fisheries are based, provides data essential for the proper con- 

 servation of the resource. We must have information relative to 

 such fundamental facts as the rate of growth, age at maturity, time 

 and manner of spawning, habits of the young, feeding habits of 

 both young and old, extent and direction of migrations, extent to 

 which the various groups of fish mingle, particularly with respect 

 to their interbreeding, and the enemies or other elements in their 

 environment which tend to reduce the abundance of these fish and 

 other forms in which we are mainly interested and from which we 

 obtain our fishery products. 



