Efficient Algae in 2006
Chlorophyll to Phosphorus Ratios

As we were preparing the 2006 Data Report, we noticed something interesting. While phosphorus concentrations statewide were generally lower than the long-term average, many lakes had chlorophyll concentrations that were higher than the average. This suggests that algae were very efficient in 2006.

Here is one possible explanation, relating to climate:

A drought occurred across much of the state last year. Less rainfall means less suspended sediment and phosphorus washing into the lake as runoff from the watershed. Suspended sediment tends to shade out light, so less suspended sediment means more light for algae.

More sunlight means more efficient photosynthesis.

Chlorophyll and phosphorus in 2 MO lakes

In the graphs above, it is apparent that while 2006 phosphorus concentrations were lower than in recent years, 2006 chlorophyll concentrations were higher.
Chlorophyll to Phosphorus Ratios - using math to make a point

The chlorophyll concentration divided by the phosphorus concentration gives us the chlorophyll to phosphorus ratio.

This value is useful for comparing the amount of algae relative to the available nutrients.
A high ratio indicates that the algae are efficiently consuming the available nutrients. A low ratio indicates algae are less efficient at using the available nutrients. Low ratios also indicate that algae are likely limited by some other factor.

The graphs below show the chlorophyll to phosphorus ratios of Blue Springs and Grindstone lakes.

Chlorophyll to phosphorus ratios in 2 MO lakes

Chlorophyll concentration ÷ Phosphorus concentration = Chlorophyll to Phosphorus Ratio

Back to 2007 #1 Water Line

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