8 OYSTEK BOTTOMS OF MISSISSIPPI EAST OF BILOXI. 



This furnishes an exact statement of the condition of the bed at 

 the spot, which can be phitted on the chart with error in position 

 of not more than a few yards. From the data obtained a close esti- 

 mate may be formed of the number of bushels of oysters and shells 

 per acre in the vicinity of the examination, and, by multiplying the 

 observations, for the bed as a whole. In the course of the survey 

 472 observations were made at various places, principally on the 

 natural rocks, but some on the barren bottoms also. 



In estimating the productiveness of the bottoms it appeared 

 desirable to use the method employed in Delaware Bay " rather 

 than that followed in the James River survey. 



Wliere tongs are used exclusively a bed with a given quantity of 

 oysters lying in shoal water is more valuable commercially than one 

 with the same quantity of oysters in deeper water, owing to the fact 

 that the labor of the tonger is more efficient on the former. As has 

 been pointed out, the area covered by a "grab" decreases with the 

 depth, other factors being the same; and, moreover, the deeper the 

 water the greater is the labor involved in making the grab and the 

 smaller is the number of grabs which can be made in a given time. 

 Wliere, however, the depth is practically uniform and shoal, as in 

 the region treated in this report, it is unnecessarily refined and 

 laborious to make such allowance for depth, and it is nearly as accu- 

 rate and satisfactory to rate the bottoms in accordance with an 

 arbitrary standard. 



In this report the classification of the relative productiveness of 

 the various beds and parts of beds, as exhibited on the chart and dis- 

 cussed in the text, is as follows: 



Dense growth Bearing over 150 bushels per acre. 



Scattering growth Bearing between 75 and 150 bushels per acre. 



Very scatteruig growth Bearuig between 25 and 75 bushels per acre. 



Depleted bottom Bearuig less than 25 bushels per acre. 



This classification refers solely to oysters of a size assumed to be 

 large enough for the market, in this case to those 3 inches or more in 

 length, although the cull law of Mississippi permits oysters 2h inches 

 long to be taken from the public beds. As the classification takes 

 no account of the smaller oj^sters, certain areas bearing a heavy 

 growth of young may be described and shown on the chart as depleted, 

 owing to the paucity of mature oysters. A case of this character is 

 the depleted part of West Pascagoula, where there are but 3 bushels 

 of market oysters per acre and 279 bushels of small ones. Wliile the 

 charts can not indicate this, the descriptions of the beds show it in 

 all cases. The charts show in general terms the character of the beds 

 in respect to the product available for market, so far as mere size 



o Condition and extent of the natural oyster beds of Delaware. By H. F. Moore, assistant, United 

 States Bureau of Fisheries. Bureau of Fisheries Document No. 745, 1911. 



