Data Info

Secchi Depth
Trophic State Index
Lake Grades
Chlorophyll
Nutrients

GIS

Aquatic Plant Surveys

Chlorophyll is a measurement of how much algae is in the water. It is a more direct measurement than secchi depth. Every algal cell contains chlorophyll-a, the pigment that captures sunlight for photosynthesis. Measuring chlorophyll usually requires collecting a water sample and taking it to a laboratory for analysis. There are also probes or instruments now available that can measure chlorophyll directly in the water and eventually we hope to purchase one for the RUSS units. Right now we do it the old fashioned way in the lab. The graphs are average values for each year we have summer chlorophyll data (summer = May through September).

Much more information can be found in the Limnology Primer and the Trophic State Index section to find out more about chlorophyll and its typical range in Minnesota lakes.