A river is an important fresh water ecosystem for life, especially for maintaining the water cycle. The existence of certain macroinvertebrates in a river is proven as an indicator for the river's health. Is the river clean and healthy? Is the river polluted?
This is a guidebook for river biomonitoring, especially for highschool students. What animals are living in a river? How to find out its water quality? A story is used in this guideline to attract the audience as well a make them easily understood.