20 U. S. BUREAU OF FISHERIES 



The natural oyster beds in Georgia are situated either along the 

 shores of the rivers above low-water mark or in the open sounds. 

 These beds are in the form of large reefs, composed chiefly of long, nar- 

 row oysters (the so-called "coon" oysters) of inferior quality. The 

 bottoms of rivers in the tidewater region present a great variety of con- 

 ditions from very soft mud, unsuitable for planting, to hard, sticky, 

 blue mud suitable for oyster culture. Many of the natural oyster 

 beds that are easily accessible and are situated in shallow water have 

 become depleted. In many places nothing remains but shells; in 

 others even the shells either have been taken away or are covered by 

 silt. On the other hand, the abundant oyster larvae present during 

 the spawning season cause a very heavy set and overcrowd every suit- 

 able object above low-water mark. One of the remarkable peculiari- 

 ties of the Georgia oyster beds is the fact that sets are never found 

 below low-water mark. Insufficient cultch is responsible for crowded 

 conditions on the beds and the formation of "bunch oysters", but 

 there is nothing to prevent the production of the best type of oyster 

 in Georgia waters by transplanting seed oysters to deep water. The 

 survey shows that the extensive coastal waters of Georgia are suitable 

 for oyster culture and can be exploited with profit. 



The following specific recommendations for the development of the 

 oyster industry in the State were based on this survey: 



1. Existing laws with respect to returning shells to the natural 

 oyster beds, including supervision thereof and control as to time and 

 place of planting, should be strictly enforced. 



2. Small-scale experimental oyster farming should be developed at 

 once. It was suggested that brush or shell be scattered between tide 

 marks on several particularly favorable sites in order to obtain set, 

 and that later the seed oysters be transplanted below low-water 

 mark. These beds should be kept under constant observation, and 

 salinity and temperature records should be taken at least once weekly. 



3. Seed or adult oysters should be planted on depleted beds in 

 order to restore them, and these beds should then be closed to fishing 

 by the public for at least two years. 



4. New oyster beds should be established in suitable localities above 

 low-water mark. 



In the summer and fall of 1925 experiments were conducted by 

 Dr. P. S. Galtsoff at Woods Hole, Mass., to determine the effect of 

 temperature on the feeding of oysters. With apparatus built espe- 

 cially for this purpose, it was possible to measure accurately both the 

 rate of flow and the volume of water passed through the gills. It 

 was found that sucking water is a function of temperature. The 

 water reaches its maximum flow at 77 ° F. and retards with the low- 

 ering of the temperature. Below 45° F. no current is produced, 

 although the cillia of the gill epithelium continue to beat; at 41 ° F. 

 all motion ceases. 



These observations furnish direct evidence on the much discussed 

 theory of hibernation advanced several years ago by the bacteriolo- 

 gists, Prof. F. P. Gorham and Dr. H. D. Pease, who made the inter- 

 esting statement that during the cold season the bacillum coli scores 

 or ratings of oysters taken from the polluted beds are always very 

 low. The present experiments show that this is because no water 

 is taken in by the oyster when the temperature is low. 



