580 MARINE PRODUCTS OF COMMERCE 



Tabi^; 127. Approximate Composition of Clams. 



Source: Langworthy, C. F., "Fish as Food," U. S. Dept. Agr., Farmers Bull., 85, 

 Revised ( 1907 ) . 



Contamination by Pathogenic Organisms 



Clams are liable to bacterial contamination by the same organisms found in 

 oysters growing in polluted saline waters. Oystermen are able to establish their 

 beds far from shore where there is danger of contamination by sewage from 

 nearby cities and towns. Since the soft clam {Mya arenaria) and the razor clam 

 {Siliqua patula) are found chiefly on the shore between tide lines, there is much 

 more danger of contamination by polluted waters. Clams dug in the vicinity of 

 large cities should always be cooked before being eaten. Steaming, baking, and 

 frying quickly kill pathogenic organisms, such as Bacillus typhosus which may 

 be present. 



During certain seasons of the year clams taken from areas where they have 

 been feeding on a reddish or pinkish colored organism may cause sickness. This 

 organism is particularly prevalent on the Pacific Coast and the resulting sickness 

 is commonly known as "mussel poisoning." State Health and Fisheries authorities 

 usually post notices in the affected areas and prohibit the digging of clams for 

 either commercial or individual use until the area is clear. 



Clam Culture in New England 



Because of the great decline of the New England clam fisheries much has been 

 done to encourage clam farming. Numerous detailed reports concerning its feasi- 

 bility have been published by the Fish and Game Commission of Massachusetts. 

 The culture of both the hard and the soft clam is carried out in a limited way in 

 New England. Small areas are found in nearly every harbor where small soft 

 clams (seed clams) are found in enormous numbers at certain seasons of the year. 

 These heavy sets run as thick as 2,000 per square foot of surface. The seed clams 

 are usually obtained from the areas of heavy set by washing the small clams out 

 of the sand or mud by means of a cradle-shaped sieve. The small clams are 

 "planted" on suitable tidal flats and grow to marketable size within a year or two. 



In many areas where the water is polluted with both sewage and industrial 

 wastes the clams are removed to water which is free from contamination. Clams 

 so handled soon become clean and suitable for marketing. One plant in operation 



