OYSTER BOTTOMS OF MISSISSIPPI SOUND, ALA. 



25 



PASS AUX HERONS. 



This bed is continuous with the preceding and the following, without 

 any definite demarcation of its boundaries. It surrounds a hole or 

 blind pass from which it takes its name, in which there is a maximum 

 depth of water of about 18 feet. The depth rapidly decreases, the 

 water becoming quite shoal on each side and at the western end, 

 although a draft of 5 or 6 feet can be carried on to the eastern end at 

 low water. 



This is in every respect the most important and prolific of the beds 

 examined, and with the exception of Sand Reef, which has little or no 

 present economic importance, it is, as arbitrarily defined here, the 

 largest. 



The following table summarizes the data relating to its extent, 

 character of oyster growth, and content of oysters : 



Oystkr Growth in Pass aux Herons. 



A dense growth having an average content of 520 bushels of market 

 oysters per acre covers nearly 75 per cent of the entire area assumed 

 for this bed, and in one place there are 1,170 bushels of market 

 oysters and 1,494 bushels of all sizes per acre. The densest part of 

 the bed lies between the deep water of the pass and Grants Pass, 

 principally south and southeast of Grants Island. There is also a 

 very dense area in a peninsula-like projection into Mobile Bay, about 

 east of Grants Island and surrounded on the northeast and west by 

 soft mud. During the winter of 1910-11 there were many tongers 

 operating on these areas of very dense growth, and the best oysters 

 produced in large quantities came from them. A larger proportion 

 of oysters over 4 inches long was found here than at any other place 

 examined in this vicinity. The areas of scattering growth occur in 

 small patches of 9 and 4 acres, respectively, at the eastern or western 

 limits of the bed. In the larger area the oysters are similar to those on 

 the dense growth, with a considerable proportion of large ones of fair 

 shape and quality. 



There are three areas of very scattering growth, one at the eastern 

 edge of the peninsula above referred to, another along the western 



