Net Primary Productivity
...f a limiting factor in Lake I because the NPP increases whenever there is light with no stabilization. b. Explain how water temperature could account for the differences in productivity measurements for the two lakes: DO saturation, which is the percentage of dissolved oxygen available in the water, increases with temperature. The differences in the productivity measurements despite having the same light intensity may be accounted for by differences in temperature. Perhaps the temperature in Lake I was lower than that of Lake II, which would have resulted in higher DO saturation. c. Explain how eutrophication could account for the differences in productivity measurements: Eutrophication, or the overproduction of nutrients in a lake (which eventually kills the lake) could account for the differences in productivity measurements because it might have caused the stabilization of Lake II, and most likely has not taken place in Lake I yet. It is plausible that in Lake II, the photosynthetic producers in the lake are creating a massive amount of DO, but at around 0.14 mg O2/L/Hr, this massive increase in producers and DO is used up by the parallel increase in decomposers which use up the DO created. In this case, instead of killing the lake, it stabilized it. In Lake I, eutrophication does not seem to have taken place because t...