94 Our Food Mollusks 



Success in oyster farming, however, is not so easy of 

 attainment as it may appear to be. There are a great 

 many necessary details to be learned, especially in regard 

 to the natural requirements of the oyster. One should 

 be able to recognize suitable bottoms. Water currents 

 must be considered. One must know the varying ef- 

 fects of muddy water on mature oysters and swimming 

 larvae. A low temperature of the water in the spring 

 or early summer, while not apparently harmful to adult 

 oysters, may be sufficient to prevent reproduction. In the 

 north, water less than a certain depth may be dangerous 

 in winter. It is important to know the extremes of 

 salinity within which oysters can live. The successful 

 oyster farmer should also know the optimum density for 

 adult and young alike. The amount of food in the 

 water, of course, vitally affects rapidity of growth and 

 the condition of oysters. Thus it is not always easy to 

 select areas that conform to all the conditions necessary 

 for success. 



For many reasons the character of the bottom must be 

 carefully considered. A rocky or very uneven surface is 

 out of the question, but bottoms rough from the presence 

 of small obstructions are sometimes made suitable for 

 oyster planting, even in deep water, by a thorough scrap- 

 ing with dredges. 



Over the greater part of the oyster territory bottoms 

 are more or less muddy, and the nature of this mud must 

 be determined. On many of the best northern oyster 

 grounds there is but a thin surface layer of it covering a 

 firmer foundation. This, without any preparation, is 

 found to afford a secure resting place for planted oysters. 

 In many parts of the Gulf of Mexico, however, the bot- 

 tom is composed q^pud so soft and oozy that a pole may 



