28 College of Forestry 



area. In addition, the dried animal matter contained in this 

 Tinit area was weighed, so that it was also possible to deter- 

 mine the amount of animal matter in one square meter 

 (10%. square feet) of bottom. Petersen was able to ascer- 

 tain, by these studies and by the examination of the stomachs 

 of fish and other animals, that the fish consumed about one- 

 tenth of an ounce (three grams) per square meter and the 

 whelks (snails) and starfishes, predaceous animals, about one- 

 fifth of an ounce (six grams) dry weight per square meter, 

 lie estimated that the total amount of dry matter on the 

 bottom was about one ounce (30 grams) per square meter and 

 that the bottom inhabiting animals consumed several times 

 their own weight in a year. The food supply was found to 

 reproduce itself several times during the year. 



The fine material on the bottom in the area studied by 

 Dr. Petersen was found to be rich in organic matter, and 

 was found to be used as food by both fish and other bottom 

 inhabiting animals. This material is called " dust-fine 

 detritus " by Dr. Petersen, and is believed by him to form 

 a large part of the food of bottom-feeding animals. A con- 

 siderable amount of the same material is held in suspension, 

 and with the other floating minute animals and plants, called 

 the plankton, constitutes a food supply of large proportions. 

 This dust-fine detritus is largely the product of disintegra- 

 tion and decay of a marine plant called Sea Wrack 

 (Zostera). 



Quantitative Studies in Oneida Lake. Investigations 

 comparable to those carried on by Dr. Petersen have not 

 previously been conducted in America, and the results ob- 

 tained by a similar study of Lower South Bay in Oneida 

 Lake is therefore of much interest. A somewhat similar 

 study has been made in the Swedish lake Vetter. This is 

 the only study of this character of the bottom of inland 

 waters of the world previous to those of Oneida Lake. An 

 area of 1,164 acres, including the bay and its immediate 

 vicinity, was carefully studied. A dredge was attached to a 

 long handle which scraped up an area about four inches 

 square or 16 square inches, in water up to six feet depth. 



