40 Report of the Board of Shell Fish Commissioners. 
toms adjacent to the depleted areas and natural bars, which 
are nearly as well adapted for oyster culture as the depleted 
areas. 
Nearly all of the bottoms thrown open for lease for oyster 
culture are so situated as to make it possible to protect them 
from shore. 
The kind of bottom which predominates over the greater 
part of the section occupied by the belt of natural oyster bars 
is considered ideal for growing oysters. It is composed of 
a mixture of sand and black or blue mud in proportions such 
as to be sticky. It is firm enough to support shells and oysters 
at its surface but can not be shifted by storms. It contains 
organic material, derived from deposits of sediment, in 
abundance, and therefore produces at its surface a rich 
growth of the microscopic plants which constitute the food of 
oysters. 
In a few places areas of mud too soft to support oysters are 
found and in others pure sand forms the bottom. Hxamina- 
tions of the bottom along a line drawn from almost any point 
on shore to deep water would show a gradual change from 
pure hard sand to very soft oozy mud, the proportion of mud _ 
with the sand increasing directly with the distance from — 
shore. 
On the natural bars which have not been exhausted through _ 
over fishing, oysters begin to be found at depths of 3 to 6 — 
feet and continue to be found until depths of about 35 feet — 
are reached. The width of the oyster producing belt varies 
considerably but averages about .75 mile. In the vicinity of 
Plum Point the width of the natural bar is more than one | 
mile. The factor which prevents the spread of the natural | 
bars to deep water is not to be found in the depth of the — 
water, however, but rather in the character of the bottom. 
The deposit of organic silt upon the bottoms of the Bay — 
covered with water deeper than 35 feet seems to be sufficient — 
in quantity in most localities to render the bottom too soft 
to support oysters. That the pressure of the water in depths — 
greater than 35 feet has no harmful effect upon oysters is — 
proved by the fact that oysters thrive in the Patuxent River 
near Point Judith where the depth of water reaches 130 feet. 4 
Oyster planting has been successfully carried on in Rhode — 
Island and New York on bottoms covered by water from 60 
to 80 feet. 
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