The Productivity of Fish Food in Oneida Lake 53 



ber of plants also occurred in moderately shallow water, from 

 two to four feet deep. 



It is interesting to note that the greater number of species 

 as well as of individuals, occurred within the 6-foot contour. 

 It is to be noted that the same is true of the animal popula- 

 tion. Thirty-three species of plants were recorded from this 

 area, of which 22 were submerged and 11 emergent species. 

 Between the 6-foot and 12-foot contours 13 species have been 

 observed, of which 12 were submerged and but one, Scirpus 

 occidentalis, emergent. Beyond the 12- foot contour there are 

 but few records, the only species noted being the Wild Celery 

 or Eel Grass (Vallisneria), which was dredged from a depth 

 of 14 feet near the entrance to the bay (Habitat No. clxi). 

 It is probable that below 12 feet the gross vegetation is scanty 

 or wanting. This fact is noted by Pieters ('01) in Lake St. 

 Clair, who states that little or no vegetation flourishes below 

 this depth. In Lake Erie the same author ('94, p. 15) observed 

 that the plants disappeared when the water reached a depth of 

 15 feet, and were already scarce in water 10 feet deep. 



In deep lakes the vegetation may descend on the slope of the 

 subaqueous terraces to greater depths, Reighard ('15, p. 222) 

 indicating a limit of 25 feet in Douglas Lake, Michigan. Davis 

 ('08, p. 219) also limits plant life in Walnut Lake to a depth 

 of 25 or 30 feet. Ekman ('15, pp. 160-162) records Chara 

 at a depth of 120 meters (about 131 feet) in the Swedish Lake 

 Vatter, but the majority of the species of plants were found 

 in water not exceeding 16 meters {17 /^ feet) deep. 



The zonal arrangement of plants is not a striking feature 

 of the vegetation of Lower South Bay. In the majority of 

 habitats the species grow in a mixed mass with no evident 

 arrangemicnt of species, and some of the species grow in 

 colonies of greater or less size. Such colonies, consisting of 

 Elodea, some Potamogeton, Vallisneria, Myriophyllum, Ponte- 

 deria, and Sagittaria were noted in many places along the 

 shore. In a few habitats in Short Point Bay and in the west 

 and southwest side of Lower South Bay a zonal arrangement 

 was observed, which was usually as follows : 



