OYSTER BOTTOMS OF MISSISSIPPI SOUND, ALA. 51 



bottom is Wiithin the rights of riparian owners. The total area is 

 about 1,110 acres. 



Tliere is some good bottom near the shore in He aux Dames Bay, 

 but the middle of the bay is soft. 



GRAND BAY. 



Practically aU of Grand Bay, with the exception of a semicircular 

 area near its mouth, has a hard or moderately hard bottom, which 

 could be utilized with safety for purposes of oyster culture. Near 

 the mouth there is some very soft bottom and the sand bars between 

 which the deep channel passes are composed of unstable material 

 shifting under the influence of the waves. The area of good bottom 

 in the bay is about 5,000 acres. 



SOUTH OF GRAND BAY. 



Within the boundary formed by a line beginning about one-half 

 mUe off Point aux Plqs and running south for about 5 miles, thence 

 westerly toward Grand signal, to the State lioe, thence northward 

 to within about one-half mile of Dunn signal, thence parallel with 

 the shore of Grand Batture for about 2J miles, and thence to the 

 point of begianing is an area of bottom ranging in general consistence 

 from hard to soft. A considerable part of this is, m its natural state, 

 sufficiently firm to support oysters and sheUs, and much of the re- 

 mainder could be rendered suitable at comparatively small expense. 

 This is the largest continuous area of like nature within the limits of 

 the survey, containing 8,000 acres. In places it appears to offer 

 supreme advantages for the growth of market oysters from seed, 

 as it will probably be found that the drill will kill off any undesir- 

 able set of spat without attacking the seed. 



GENERAL PHYSICAL AND BIOLOGICAL CONDITIONS. 



TIDES AND CURRENTS. 



Staff tide gauges were established at Grants Pass and at the can* 

 nery wharf at Coden. The former was maiataioed from November 

 18, 1910, to January 19, 1911, and the latter from January 6 to Jan- 

 uary 29, 1911. The former was referred to the bench mark estab- 

 lished on Grants Island by the United States Engineer's Office, 

 which is. described as follows : 



The bench mark is the top of a 2-inch pipe which was driven in the ground, a fence 

 placed around it and filled with concrete to within one-half inch of the top of the pipe. 

 The letters IJ.S.B.M. were written in the concrete before it set. The bench mark is 

 at the northwest side of and near the keeper's house on Grants Island. It has an 

 elevation of 2.654 feet above mean low tide in Mobile Bay as determined by this 

 oflSce. (J. M. Pratt, Assistant Engineer, United States Engineer's Office, Mobile, Ala., 

 Dec. 10, 1910.) 



