The Prodnclh'Uy of Fish Food in Oneida Lake 113 



The decrease in number of individuals below the 6-foot 

 contour is marked and shows that the shallow water area is 

 the most valuable for producing hsh food. 



Mussel Population. The apparatus used for collecting; 

 the i() scfuare inch units is too small to obtain a fair sample of 

 the adult mussels. For the purpose of ascertaining the relative 

 abundance of the mussel fauna a tin frame was made, 8 inches 

 square, which covered an area of 64 square inches (about 400 

 square cm.). This was fastened to a line and with this appa- 

 ratus (fig. 2) the number of mussels per unit area could be 

 easily ascertained when the water was quiet and the depth not 

 greater than six feet. In some habitats in shallow water the 

 mussels were so wideh' separated that they could be estimated 

 only per square yard. For the sake of uniformity all 64 square 

 inch units are increased to square yards. The three tables 

 which follow (Nos. 24, 25, 26) indicate the number of mussels 

 per unit area in the hal)itats examined.* 



Table No. 24. Mussels on Boulder and Gr.wel Bottoms 



* Computations for mussel population. 



Boulder and gravel; 43,560 sq. ft. -^9 feet =: 4,840 unit areas of one 

 square yard in one acre, X 20 acres = 96,800 unit areas in 20 acres, 

 X 6.14 mussels = 594,545 mussels in 20 acres. 



Sand; 4,840 unit areas X 85 acres ^411,400 unit areas in 85 acres, 

 X 6.39 mussels :^ 2,630,080 mussels in 85 acres. 



Clay ; 4,840 X 92 = 445,280 unit areas in 92 acres, X 13 = 5,788,640 

 mussels in 92 acres. 



