Procedure
Classify your lake (above) into one of the four lake categories (below).
If you choose the correct classification, you will then collect macroinvertebrates
from the water to check the health of your lake. Please refer to the
Lake Monitoring Summary before you
begin this activity.
You will need the Lake
Type Key to identify your lake. Print out the key for clarity.
Generally, the lake types are:
- Shallow, small high-elevation lakes
- Low to middle elevation lakes in mostly forested watersheds
- Moderately productive, high elevation lakes
- Minimally productive, high elevation lakes
Definitions
Lake Productivity - The base of the food pyramid in lakes is either
algae or organic matter that enters the lake from tree litter and
plants. If these organic materials exist, then lakes can support other
forms of life, such as aquatic plants, macroinvertebrates, amphibians
and fish. If a lake has a large base (lots of algae or decaying plant
matter), it is considered to be highly productive.
Talus - To classify lakes at North Cascades, scientists measure the
percentage of a lakeshore which is talus. A talus field is composed
of rocks which are fist-sized or greater.
