PROGRESS IN BIOLOGICAL INQUIRIES, 1923. 



REPORT OF THE DIVISION OF SCIENTIFIC INQUIRY FOR THE FISCAL YEAR 1923/ 



By Willis H. Rich, Assistant in Charge of Scientific Inquiry. 

 (With the collaboration of investigators.) 



CONTENTS. 



Page. 



Introduction 2 



Investigations of fish and fisheries 3 



Atlantic coast 3 



Fishes of the Gulf of Maine 3 



Studies in fish migration — tagging operations 4 



Chesapeake Bay g 



Salmonidffi and smelts 5 



Larval fishes of the Woods Hole region 5 



Fishes of Key West 6 



International Committee on Marine Fishery Investigations Q 



Interior waters 7 



Coregoninse of the Great Lakes 7 



Mississippi River fishes 7 



Destruction of trout by pelicans in Yellowstone Park 8 



Pacific coast and Alaska 9 



Alaska salmon 9 



Salmon of the Pacific Coast States 10 



Investigations of shellfish and terrapin 11 



Oysters 11 



Clams and crabs of Alaska 13 



Fresh-water mussels 13 



Terrapin 15 



Ecological and oceanographic studies 16 



Control of mosquitoes by means of fish 16 



Oceanographic work 17 



Studies of marine plankton in relation to the fisheries 18 



Ecology of fresh-water lakes 19 



Fouling of ships' bottoms 20 



Investigations pertaining to fish-cultural operations 20 



Pathology of fishes 20 



Physiology and nutrition of fishes 23 



Experimental work in fish culture 24 



The biological laboratories 26 



INTRODUCTION, 



The work of the division of scientific inquiry consists primarily in 

 the investigation of the bioloo;y of those species of fish and shellfish 

 that form the basis of the fishery industries. In common with much 

 scientific work the service of this division is. in the main, one step 

 removed from direct contact with the business man. The biological 



' Appendix VII to the Report of the U. S. Commissioner of Fisheries for 1923. B. F. 

 Doc. No. 956. 



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