The literature on the culture of the oyster is replete with more or less 

 quantitative accounts of the destruction of oysters by U. cinerea . A chronological 

 review of a number of these serves to emphasize the historical significance and the 

 current magnitude of predation by this snail . 



In the last century, as early as 1874 Verrill and Smith wrote that in 

 brackish waters in Vineyard Sound, Massachusetts, the drill was the worst enemy 

 of the oyster, sometimes so numerous as to do very serious damage Rathbun 

 (1888) noted that Fields Point and Bullocks Cove, Providence River, Rhode Island, 

 were overrun with drills which destroyed fully 95% of the oysters on beds that 

 formerly were the most productive in the area. Rowe (1894) estimated that in 

 southern New England the damage caused to oysters by drills was approximately 

 one million dollars annually. In 1895, 6, 000 bushels of two year old oysters in- 

 troduced in the Shrewsbury River from the Raritan River, New Jersey, were totally 

 destroyed by drills (Bur. Stat. N.J., 



During the present century such reports have greatly increased in number 

 and in detail. Pope (1910-11) in samples tonged in Buzzards Bay, Massachusetts, 

 in August, 1910, found that 87% of the oysters in a sample of 390 oysters were 

 drilled; in another sample of 548 oysters, 87% were drilled. These figures do not 

 take into consideration the losses due to destruction of very small oysters whose 

 valves soon become dislodged and escape detection. 



T. C. Nelson in 1922 wrote that in Delaware Bay, New jersey, mortality 

 of young oysters due to drills reached 60% by October; and estimated that in this 

 bay annual damage caused by the drill to the oyster industry was in excess of a 

 million dollars (1923; J. R. Nelson, 1931). 



Federighi (1931c) reports that in Hampton Roads, Virginia, when his in- 

 vestigations on the drill were begun, planters estimated the loss of as many as 90% 

 of their oysters to drills . In a survey of this area Federighi found that 10 % of 

 the oysters on cultivated oyster grounds, and approximately 2% on natural rock 

 were drilled. Unfortanately he did not record the size of the oysters drilled. 



In experiments with drill traps in Delaware Bay, Galtsoff et al. (1937) 

 noted that as many as 80% of young spat on one year old oyster bait were quickly 

 destroyed. They state that there are many localities in Long Island Sound, New 

 York, and in Chesapeake Bay, where drills commonly kill 60 to 70% of 'the seed 

 oysters present, and not infrequently destroy the entire crop (also Engle, 1940); 

 and estimate that on the eastern shore of Virginia between Chincoteague and Cape 

 Charles the probable annual loss of oysters to drills was about $150, 000, 



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