Figure 1.

Vertical structure of Organic Lake. (a) Parameters that varied unimodally with depth showed two zones: an aerobic mixed zone above 5.7 m and a denser suboxic deep zone below. (b) Additional factors that revealed stratification within the deep zone. The peak in concentration at 6.5 m for ammonia was also observed for all other nutrients assayed except nitrate and nitrite (see Table 1). σT=(1000−density); cond, conductivity; DO, dissolved oxygen; turb, turbidity.