PROGRESS IN BIOLOGICAL INQUIRIES, FISCAL YEAR 1924^ 



Bj- Willis H. Rich, Assistant in Charge, Division of Scientific Inquiry 



CONTENTS 



Pag« 



Introduction 13 



Iiive.stigations of fish and fisheries. 17 



Atlantic coast 17 



Life history and migrations of 



cod, pollock, and haddock 17 



Fishes of the South Atlantic 



coast 19 



Salmonidae and smelts It) 



I'lsh an<l fisheries of Key West- 21 

 Larval fishes of the Woods Hole 



region 21 



Chesapeake Bay 22 



North American Committee on 



Fishery Investigations 22 



Interior waters 23 



Coregoninse of the Great Lakes. 23 



Mississippi River fishes 25 



Pacific coast and Alaska 25 



Alaska salmon 25 



Salmon of the Pacific Coast 



States 27 



Fisheries of California 28 



Fisheries of EI Salvador 28 



Page 

 Investigations of shellfish and terra- 

 pin 29 



Oysters 29 



Alaska clams 31 



Fresh-water mussels 32 



Terrapin 33 



Ecological andoceanographicstudies- 35 

 Control of mosquitoes by means of 



fish 35 



Oceanographic work 36 



Studies of marine plankton in re- 

 lation to the fisheries 37 



Ecology of fresh-water lakes 38 



Fouling of ships' bottoms 39 



Investigations pertaining to flsh-cul- 



tural operations 40 



Pathology of fishes 40 



iS'ew method of oxygen determina- 

 tion 41 



Physiology and nutrition of fishes_ 41 



Experimental work in fish culture- 43 



The biological laboratories 4& 



INTRODUCTION 



The importance of the part biological investigations play in the 

 work of conserving and developing our fisheries has come to be al- 

 most imivei'sally recognized. The old idea that the resources of the 

 sea are practically inexhaustible is no longer held by anyone in- 

 formed on the subject, and the necessity for measures of conserva- 

 tion is admitted. 



The rapid growth of our population and improvements in methods 

 of conducting the fisheries and of transporting and marketing fish- 

 ery products have increased the demand for these products and the 

 strain on the resources, and at the same time have increased the pol- 

 lution of both coastal and inland waters to such an extent that many 

 regions formerly productive are now barren of aquatic life or 

 show serious depletion attributable solely to this cause. In other 

 regions the erection of dams or other obstructions in streams and 

 the establishment of extensiA-e irrigation systems have shut off im- 

 portant spawning regions or destroyed their value. The present 

 condition of our fisheries is thus the resultant of a large number 

 of interacting forces, and the greatest care must be taken if these 

 resources are to be preserved. 



• Appendix II to the Report of the Commissioner of Fisheries for 1924, B. 

 No. 971. 



F. Doc. 



13 



