OYSTER BOTTOMS OF MISSISSIPFI SOUND, ALA. ] 1 



regarded as the index of the bottom consistency. The following 

 arbitrary scale is adopted in this report. 



Hard bottom Penetration less than 4 inches. 



Stiff Penetration between 4 and 8 inches. 



Soft Penetration between 8 and 13 inches. 



Very soft Penetration between 13 and 18 inches. 



Ooze Penetration over 18 inches. 



On the accompanying chart the consistency of the bottom is indi- 

 cated by symbols which are more readily read than lettering — a 

 black circle indicating hard bottom; a black semicircle, stiff mud; a 

 black quadrant, soft mud; a circle containing two crossing diameters, 

 very soft mud; and a circle with one diameter, ooze. Bottom falling 

 within the first two classes, provided it be not shifting sand, is firm 

 enough for oyster planting; the harder the bottom the more thickly 

 the oysters may be planted without danger of becoming engulfed. 

 Soft bottom should be used with care, and towar-d its upper limits 

 may reouire preliminary hardening with sand or shells. Very soft 

 bottom and ooze should not be considered. The instrument described 

 has been given a thorough test and has shown itself to be satisfactory 

 for the purpose of oyster surveys. Its readings are reliable where 

 the consistency of the bottom is fairly uniform in the stratum pene- 

 trated, but there is likely to be an error of interpretation in the case 

 of a hard sand or shell bottom overlaid by several inches of soft mud. 

 Such cases are readily detectable, however, by probing with a pole, 

 as is always done where the instrument is used. 



In the prosecution of the work previously described, 357.1 miles of 

 soundings were run and the chain was dragged over the bottom for 

 the same distance, 16,960 soundings were made, and 3,340 angles for 

 position of the boat were taken. Oysters were tonged, counted, and 

 measured, and other biological observations made at 464 stations, 

 and the consistency of the bottom was tested at 311 places exclusive 

 of those on the oyster beds, a total of 775 places at which the bottom 

 was examined. The survey covered a total area of 93,000 acres, of 

 which 4,000 acres were oyster beds in which the sounding lines were 

 closer together and the examinations made in more detail than on 

 the barren bottoms. 



The account of the oyster beds which follows proceeds from a 

 detailed description of the several beds, with the data of all productive 

 observations, to a consideration of the region as a whole and the 

 requirements for its economic development. 



