The Relation of Shellfish to Fish in Oneida Lake 29 



For the deeper water, a larger dredge 16 inches wide was 

 used which was dragged over an area carefully estimated to 

 cover 64 square feet. The deeper water dredgings were 

 reduced and averaged to the equivalent of the small 16 square 

 inch unit scraped up in shallow water; each large dredging 

 equalling 48 of these smaller units. Upwards of 600 sepa- 

 rate samples of the bottom were collected and the contents 

 carefully sorted, the animals and plants counted and the 

 different species named by specialists. By collecting such a 

 large number of samples it was possible to reduce the prob- 

 able error made in taking samples and to calculate with a 

 considerable degree of accuracy the total number of indi- 

 vidual animals living in the bottom on the different kinds 

 of bottom in Lower South Bay and vicinity. 



Abundance of Animals in Shallow Water. Many inter- 

 esting and significant features were brought out during this 

 investigation of lake bottom animals. It was computed that 

 over seven billion individual animals lived in the area of 

 1,164 acres. Of this life 88 per cent occurred in water 

 one to six feet deep; and only 12 per cent in all the water 

 deeper than six feet, or in round numbers, 6,786 million 

 individuals lived in water six feet deep, and 983 million 

 individuals in water more than six feet deep. From the 

 standpoint of area, it was found that a population of almost 

 seven billion individuals lived in 205 acres, in water six 

 feet deep, and beyond this depth a population of less than 

 one billion animals lived in 959 acres. Reducing this popu- 

 lation to acres we find that 33 million individuals live in one 

 acre in water less than six feet deep while but one million 

 individuals live in one acre in water more than six feet. 

 This decrease in density of population is striking, showing' 

 that the greatest development of plant and animal life on 

 the bottom is found in water six feet or less in depth. When 

 we remember that fish are more abundant in this shallow 

 water, and that this is where most adult fish breed and the 

 young fish live, the significance of this richness of bottom 

 life is at once realized, and indicates that this is the most 

 important depth for the culture of fish even in large lakes. 



