PROGRESS IN BIOLOGICAL INQUIRIES, 1931 515 



In summarizing these studies it is evident that partitions, tubes, 

 and brush are commercially practicable as devices for collecting seed 

 oysters in North Carolina waters. When planted on suitable bot- 

 toms they can be utilized for gathering an almost unlimited supply 

 of seed of fine qualitj^, which is the first essential requirement in 

 successful oyster culture. The second requirement is the trans- 

 plantation of the seed to selected growing and maturing bottoms 

 where setting does not occur and interfere with the development of 

 single, well-shaped oysters. Studies of this second phase of the 

 problem are just being started through a series of cruises with the 

 new State boat and United States Fisheries craft to the chief oyster- 

 producing areas in North Carolina. In various localities suitable 

 oyster-growing bottoms will be selected and used as experimental 

 seed-planting grounds. 



Oyster investigations in South G a/rolina. — Preliminary studies 

 have been made at three representative oyster-producing areas in 

 South Carolina for the purpose of determining the most suitable 

 methods for the development of oyster culture in this region. These 

 studies have been made in cooperation with J. M. Witsell, chairman 

 of the South Carolina Board of Fisheries. Various experiments and 

 chemical studies dealing with the setting of oysters and the collec- 

 tion of seed were carried out at Folly Island, Beaufort, and Bluffton. 

 At these stations two definite crops of seed oysters were obtained, the 

 first occurring from the 5th to the 20th of June and the second dur- 

 ing the last two weeks in September. By the 20th of October the 

 first crop of seed had attained an average length of 1^2 inches, while 

 the fall crop measured on the average only one-fourth of an inch in 

 length. The June set was fairly heavy, especially at the State ex- 

 periment station at Folly River, where the partition collectors gath- 

 ered from 2,000 to 5,000 seeds per collector. The September set was 

 much lighter in this locality and ranged from 500 to 1,200 seeds per 

 collector. 



At the Folly River station the partition collectors and oak poles 

 planted shoAved that setting occurs in a zone extending from low- 

 water mark to 3 feet above, but is decidedly heaviest in the 1-foot 

 zone above low-water level. Chemical analyses showed that the copper 

 content of the water increased with the ebbing of the tide and was 

 highest (0.35 part of copper per million) when the tide reached low- 

 water mark. Copper stimulates greatly the attachment of the oyster 

 and was found in this locality to have a direct bearing on the abun- 

 dance of oysters at different tidal levels. 



Similar results were obtained in the experiments carried out at 

 Beaufort, S. C, in cooperation with Capt. John L. Wall, of the 

 Maggioni Oyster Co. and at Bluffton in cooperation with the H. O. 

 Lowden Oyster Co. It was found that the planting of shells or 

 artificial spat collectors on the tidal flats can be more efficiently 

 carried out if particular attention is paid to the time of setting and 

 the selection of tidal levels where seed oysters attach in greatest 

 abundance. Since sedimentation is unusually heavy in this region 

 and may in a short time cover seed collectors with a layer of mud, 

 it is obvious that such devices must be planted just prior to the time 

 of setting to be most effective. Experiments with oak poles and 

 brush show that they are very satisfactory under these conditions for 



