124 U.S. BUEEAU OF FISHERIES 



for this work. In cooperation with the various State Shellfish Com- 

 missions, oyster farming operations were carried out on a small com- 

 mercial scale for the purpose of determining and demonstrating the 

 most efficient methods for oyster culture in each particular region. 

 The results of these experiments and field surveys of natural oyster 

 beds are described briefly according to the States in which these opera- 

 tions were conducted. 



Experiments in North Carolina, South Carolina, and Georgia. — Oyster 

 spawning occurred almost simultaneously throughout this section dur- 

 ing the first week in May or about 2 weeks earlier than in 1931. A 

 fairly heavy set was obtained by June 1 on the various spat-collecting 

 devices planted on the tidal flats. Brush poles, cement-coated paper 

 tubes, and mats were found to be of practical value for gathering seed 

 oysters. The myrtle and oak poles (2 to 4 inches in diameter and 3 

 to 4 feet long) collected from 75 to 250 seed oysters per pole. On the 

 paper tubes an average yield of 300 seed per tube were obtained while 

 the expanded mat collectors gathered from 500 to 3,000 seed oysters 

 each. By the use of poles and tubes it is possible to utilize thousands 

 of acres of barren mud bottoms for collecting and growing seed oysters. 

 The mat collectors proved to be particularly suitable for planting over 

 oyster beds or on shell bottoms and are so designed as to prevent 

 crowding of the seed, allow ample room for growth, and eliminate the 

 detachment operations required by other types of collectors. In sev- 

 eral localities plantings of seed oysters and shells were made to dem- 

 onstrate these phases of oyster farming and show the value of such 

 methods for the rehabilitation of barren bottoms and natural oyster 

 beds. 



At the Beaufort laboratory, research was continued on the problem 

 of improvement in oyster-shucking methods and the* preparation of 

 this sea food for market. 



In the marketing of oysters the raw-shucking trade is of greatest 

 importance both as regards the quantity of oysters handled and num- 

 ber of persons employed. At the present time approximately 60 per- 

 cent of oysters produced for the fresh trade are shucked before mar- 

 keting. The total quantity of oysters marketed raw amounts annually 

 to nearly 5,500,000 gallons for which it is estimated over $1,500,000 

 are expended each year for shucking alone. 



Experiments conducted by Drs. Vera Koehring and H. F. Prytherch, 

 dealing particularly with this phase of the industry, show that oysters 

 can be easily narcotized by chemical means so as to produce automatic 

 opening of the shell and facilitate removal of the meats. The prelimi- 

 nary studies and fundamental aspects of this process are described in 

 Investigational Report No. 15 of the Bureau of Fisheries. 



Subsequent research has shown that oysters receiving mechanical 

 stimulation previous to their immersion in the narcotizing solution 

 will be open and ready for shucking in but a fraction of the time re- 

 quired previously. By simple mechanical procedures, such as drop- 

 ping the oysters on a hard surface or hitting the shell a single sharp 

 blow, it has been possible in numerous experiments to completely nar- 

 cotize 100 percent of the oysters in a period of from 10 to 30 minutes. 

 This has greatly increased the practical value of such opening opera- 

 tions as from 6 to 12 hours were required previously to accomplish the 

 same results. This improvement in the method makes it from 30 to 

 50 percent cheaper as a smaller amount of acid is employed and the 



