THE 



POPULAR SCIENCE 

 MONTHLY. 



DECEMBER, 1881. 



DETERIORATION OF AMERICAN OYSTER-BEDS. 



Br Lieutenant FEANCIS WINSLOW. 



II. 



AN oyster-bed, in its natural and undisturbed state, consists of a 

 long, naiTow ridge of shells and oysters, lying generally in brack- 

 ish water, on and surrounded by sticky bottoms, a mixture similar to 

 clay and mud being the most favorable. 



The form and area of the bed are variable, but, naturally, the 

 length is greater than the breadth, and the greatest dimension is 

 usually in the direction of the current. The bed itself is made up of 

 masses of shells and oysters, covering areas of different sizes, and 

 separated from each other by mud or sand-sloughs, though frequently 

 it is unbroken, and the animals spread evenly and continuously over 

 the entire area. This separation and detachment of the groups of 

 animals are much more noticeable upon a bed which has been much 

 worked. Upon an unworked bed, or one in its natural state, the 

 oysters grow in clusters, and are firmly cemented to the bottom. 

 Upon a bed which has been frequently dredged, the animals are single, 

 and have no hold upon the bottom. 



The fauna of the bed varies with the locality ; in the Chesapeake 

 it is somewhat sparse. 



The bottom is usually of clay or mud, and of sufficient consistency 

 to support the oysters ; certain varieties of bottom are more favorable 

 than others, but, except within wide limits, the character of the bot- 

 tom does not appear to be of great importance, so long as it is suffi- 

 ciently firm to prevent the animal from sinking into it and thus smoth- 

 ering. 



The oyster thrives best in slightly brackish water, and the finest 

 varieties are usually found in water of a lower specific gravity than 



VOL XX. 10 



