30 Report of the Board of Shell Fish Commissioners. 



tribution than now. The bottoms which were stocked with living 

 oysters at the time of the survey, September and October, 1909, 

 were confined to the open part of the bay near mid-channel and they 

 have been reserved for the public oyster fishery within the limits of 

 three natural bars 1 aggregating an area of 3010 acres. 



Several shelly bottoms, aggregating an area of about 2000 acres,, 

 which have been more or less productive within recent years, were 

 found to be entirely barren of living oysters at the time of the sur- 

 vey and were not included within the limits of natural bars. Boxes 2 ' 

 were occasionally found at some of the examination stations on 

 these exhausted bottoms near the lower end of Hart Island, but 

 none on the bottoms off Millers Island. 



Observations made at Tolchester wharf from August 6 to 11. 

 1909 indicate a maximum range of the tide for the section of 1.8 

 feet — a mean range of 1.01 feet. 



Specimens of water collected at the examination stations during 

 the period occupied by the survey (the dry season) showed a density 

 of 1.0082 at low tide and 1.0108 at high water, a condition very 

 favorable at that time, for the attachment of spat and growth of 

 oysters, being thereby indicated. No exact measurement of the 

 density of the water in this section during the early spring (wet 

 season) has been made, 3 but it is a well known fact that at this 

 season the water becomes so fresh from the inflow of the Susque- 

 hannah River and other head water tributaries, that the oysters are 

 stunted in their growth, and that spring freshets are sometimes so 

 heavy and so long in duration as to kill practically all of the oysters. 

 The quantity of sediment brought down during these freshets is 

 enormous, and when deposited on the oyster beds, adds to the injury 

 done by the fresh water by smothering the oysters and burying the 

 shells. That conditions had been severe over this section during rhe 

 spring of 1909 is shown by the large number of "boxes" taken at the 

 examination stations. 4 



1 See table of oyster bars, on page 33. 



2 A "box" is an oyster shell in which the hinge has not been broken. The 

 inference from such a shell is that the oyster is but recently dead. 



8 Arrangements have been completed for making a series of simultaneous 

 observations of the density of the water at several stations throughout the 

 Chesapeake Bay from the Capes to Poole's Island Light during the months of 

 April and September, 1911. 



* See page 32. 



