To define the ecological state of a river, it is necessary to measure some water characteristics, such as pH, nitrate, dissolved oxygen and temperature. Have you ever heard about that? Click here and you will discover what these water characteristics are telling us about the water.

After reading the document and listening the explanations of the teacher, now it’s time for you to practice! In this table you have several situations that can happen in a river. Think, for each situation, if it’s an indication of good or poor ecological status. Here you have the table!