REPORT OF COMMISSIONER OF FISH AND FISHERIES. 121 



make had he available some method of fattening- his 03^ste^s as they 

 were needed. To overcome this difficulty in a measure, it has been 

 customary in some places to resort to "floating'' or "drinking," 

 which consists essentially of transferring the oysters to fresh or 

 brackish water. That practice, while giving them an illusive plump- 

 ness, injures them in both flavor and nutritive value. 



The experiments which have been carried on by this Commission 

 have nothing in common with this method, but are designed actually 

 to fatten and improve the oyster in weight, flavor, and food value. 

 The progress of the work has been briefly noticed from time to time 

 in the annual reports of this Commission. Each year the results have 

 approached more nearly the desired end, and during the season 1901-2 

 the work has been attended with such success that it is considered 

 desirable to give a more extended account of the plant and its opera- 

 tions than has been before attempted. The work, however, is still in 

 an experimental stage, and the linancial results have not yet demon- 

 strated the practicability of the method. During the coming season 

 it is believed that the operations can be so simplified and cheapened and 

 the output so increased as to show pecuniary advantages. 



The plant at present consists of a 2-acre pond having an average 

 depth of 2i feet. Originally it was a cove with a narrow mouth, giving 

 tidal communication with the main body of Lynnhaven Bay. Across 

 the mouth a substantial dam has been constructed of such height as to 

 exclude all save exceptionall}^ high tides. There is some drainage 

 into the pond from the surrounding land, so that after it was dammed 

 it became practically a claire according to the French method. 



During the first season of its operation oysters were spread on the 

 bottom of the pond in limited numbers, but there was practically no 

 improvement in their condition during the season, and it was evident 

 that the diatoms, which constitute the principal food of the 03'ster, 

 would not multiply to a measurable extent under these conditions. 

 In the meantime laboratory experiments carried on in Washington had 

 demonstrated that the growth and multiplication of these microscopic 

 plants, like that of other vegetable organisms, could be stimulated and 

 increased by using certain salts in solution; in other words, by the 

 application of fertilizers to the water in which the}^ were growing. 

 During the following year ordinary commercial fertilizers, such as 

 are commonly used for potatoes and similar crops, were placed in the 

 pond and the number of diatoms increased very considerably, and 

 during that season about 50 or 60 per cent of the oysters in the pond 

 became reasonabl}^ fat, some of them excessively so, but the others 

 remained poor and lean. It was evident, as a result of the season's 

 work, that the food suppl}^ was ample, but that for some reason it was 

 not equally accessible to all of the 03'sters, and a comparison of the 

 conditions in the pond with the open waters of the bay indicated that 

 th(^ cause probably lav in the absence of the currents necessary to 



