Fumee Lake Natural Area

Limnological Testing   Nutrients

Nutrients are needed by algae and other aquatic plants for growth. Algae is the base of the food chain and is needed in sufficient amounts to promote good populations of higher aquatic organisms. The three major nutrients used by plants are carbon, phosphorus and nitrogen. Carbon is readily available in the form of carbon dioxide and is usually of no concern. Both phosphorus and nitrogen are of greater concern because they are the nutrients that limit the amount of plant and algae growth in a lake. This growth determines the trophic status of a lake. An increase in the level of these nutrients will often result in excess amounts of algae and aquatic plants.
Values for total phosphorus in both lakes was slightly high. The concentrations, however, do not seem to be causing a problem with macrophyte and algae growth. Phosphorus is usually the nutrient that limits plant growth since there is so little naturally. There is a rather high concentration of total phosphorus for the phytoplankton occurring in the lakes. Phosphorus can adsorb certain materials and make it unavailable to organisms.
Nitrite (NO2) and nitrate (NO3) were very similar for Fumee Lake and Little Fumee Lake. In Fumee Lake the values were slightly higher at the surface and the mid-depth than at the bottom which is typical of a shallow lake. Little Fumee Lake had increased values with depth, as is typical of deeper lakes.


August 1994
Station and Depth

Total Phosphorus
mg P/L

Total Nitrogen
mg N/L

Fumee Lake
Surface
Mid-Depth
Bottom
0.051
0.010
0.015
0.025 (avg)
0.073
0.067
0.044
Little Fumee Lake
Surface
Mid-Depth
Bottom
0.010
0.024
0.043
0.026 (avg)
0.059
0.052
0.077

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