58 



INVESTIGATION OF THE CHESAPEAKE BAT WEST OP TANGIER AND SMITH'S ISLANDS. 



The only information that could be obtained with regard to the ground outside the Sounds 

 was that there were a number of beds of different areas lying in the Bay, on the eastern side of the 

 ship channel, especially about and on the shoals off Smith's Islaud and Kedge's Strait. 



The ground being so little known, aud the accurate delineation of the beds being so difficult 

 when attempted with a sailing vessel, I considered it better to employ the limited time at my 

 disposal in running tentative lines, off and on shore, and other lines crossing them, with a view 

 to discover the location of the beds and to mark these localities for a more thorough and ex- 

 haustive investigation in the future. 



In accordance with this plan I dredged over the bottom of the Bay, from Tangier Island 

 northward, running the lines sufficiently close to detect any beds of importance or the presence of 

 scattered oysters. The distance over which the dredge was dragged was always measured; and, 

 when the depth of water was not too great, the bottom was probed with a view of determining 

 whether it was suitable for the oysters. 



By reference to the projections it will be seen that these areas occur quite frequently on the 

 shoal ground making off in a southwesterly direction from Tangier Island; that between Tangier 

 Island and Cheesman's Islands there are, in the deep water, no oysters; and that from abreast 

 Cheesman's Islands as far north as the investigation extended were found large areas upon which 

 oysters were living, and in some cases in great numbers. The depth of water does not appear to 

 influence the formation or growth of these beds, some of them lying on the shoals and others in 

 deeper water. Generally speaking, here as in the Sounds, the original beds were formed on the 

 side of the shoals, and wherever there was a sudden change of bottom. 



Wherever the solid beds or "Bocks". were encountered, they were found to be long and narrow 

 ridges, extending generally in a northerly and southerly direction, except when near Kedge's 

 Strait, where they ran more to the eastward and westward; and we could, in standing across the 

 beds, but rarely obtain more than one or two hauls of the dredge before we were off the "Bock." 

 The major axis appears here, as elsewhere, to lie in the direction of the current, and probably all 

 natural extension and growth of any bed are in that direction, the spat being carried backward and 

 forward by the ebb and flow of the tides. The large number of beds near and off Kedge's Strait 

 is probably due to the large number of spat brought out from the Sounds through the Strait. 



The bottom is generally of hard sand covered with sponge and grass. Near Kedge's Strait 

 some mud sloughs were found, and in some cases the substratum of the beds was of clay; but in 

 most of them the stratum of oysters and shells was too thick and hard to be penetrated. 



The beds outside the Sounds have been comparatively free from dredging, and thus present 

 marked differences from those inside. 



They are comparatively longer and narrower, and much more sharply defined. Very few 

 scattered oysters are found near them, and the beds are much more solid, unbroken, and much 

 harder, requiring heavier dredges than those used in the Sounds. The most remarkable difference 

 is, however, in the shape and growth of the oysters. 



On the undredged beds they are long and narrow, with the lower shells very deep, and bills 

 very thin and sharp. In no case did we find any single oysters of any class, but all grew in 

 clusters of from three and four to twelve and fifteen. The shells were clean and white, and free 

 from mud and sand. Generally there was found a tuft of red or white sponge attached to the 

 clusters, and the mature first and second class oysters were covered and the interstices between 

 them filled with those of the third and fourth classes; numbers of barnacles were also found, and 

 some crepidula, but tubicola were present only in small numbers. 



The oysters found upon beds that have been much worked differ materially, being single and 

 broader in. comparison to their length, round and with blunt bills. They are usually dark in color, 

 aud have a considerable amount of mud and sand on the shells. The sponges do not appear to be 

 as abundant, and the amount of dredging on any bed may always be known by the appearance of 

 the oysters brought up. Upon an overdredged and almost exhausted bed the oysters will be 

 large and single, blunt-billed, with dirty shells, and with an almost entire absence of sponges, 

 barnacles, and crepidula ; but the shells will be covered with tubicola and bored in many places 

 by the boring pholad. 



