EXPERIMENTS IN THE ARTIFICIAL PROPAGATION OF 



OYSTERS/ 



By Hebbert F. PKYTHEitcH, Scientific Amistaut, V. H. Bureau of Fisheries. 



CONTENTS. 



Page. 



Introduction 1 



Life history of the oyster 2 



History of artificial oyster culture 3 



Object and scope of the investigation 4 



Equipment used in the investigation 4 



Successful method of hatching and rearing young oj\sters 5 



Keproduction and development 5 



Selection of the oysters 5 



Spawning : 6 



Embryonic development 7 



Setting 7 



Growth of spat S 



Factors of environment 9 



Temperature 9 



Density of water 9 



Light 9 



Water supply 10 



Food and enemies _ 10 



Aeration — ' — 11 



Running water 11 



Filtration 11 



Collection and transplanting 13 



Summary 13 



INTRODUCTION. 



The great 05'ster fisheries of the Atlantic coast have in the past 

 few yeai-s experienced an alarming decline in productiveness. 

 Though the extensive methods of oyster culture practiced by many 

 of the oyster growers have assisted greatly in maintaining a constant 

 supply, they have not been sufficiently reliable to guarantee a crop 

 from year to year. The rapid decline of this valuable industry has 

 been brought about by a constant depletion of the oyster beds from 

 various factors, such as pollution, overfishing, unfavorable climatic 

 and hydrographic conditions, natural enemies, and use of shells for 

 various commercial purposes. 



Careful scientific studies of the life histoiy and environment of 

 the oyster have assisted greatly in improving the cultural methods 

 now in use but have not perfected them to such an extent that an 

 annual harvest can be relied upon from year to year. Briefly stated, 



* Appendix XI to the Report of the U. S. Commissioner of Fisheries for 1923. B. F. 

 Doc. 061. 



85240°— ::i 1 



