Main idea

The enrichment of rivers and streams by nutrients or organic pollution leads to changes in the aquatic communities, macroinvertebrates being among the most sensitive. The diversity of these macroinvertebrates can be used to monitor pollution. The presence or absence (or better, the relative abundance) of macroinvertebrates in rivers, lakes, and other water bodies can be recorded. The diversity and composition of the sampled community allow the monitoring of pollution levels in water and a comparison between the different sites and seasons.

Goal

To make pupils aware that certain types of living creatures cannot survive in polluted waters, and to introduce a simple system of monitoring organic pollution through the presence of some macroinvertebrates that children can observe with their naked eye.

Concepts

living conditions, pollution → macroinvertebrates → pollution detection

Introduction: Polluted Rivers?

Have a discussion with pupils about pollution (see Section 4, Lesson 4.2 “Pollution of surface waters”). Explain to them that, in the same way that the water flow velocity or the type of sediments define living conditions for water creatures, pollution also defines living conditions for animal and plant communities.

Activities in this lesson

Water Pollution Detectives – Assessing Water Quality Using Simple Biological Methods
5.1.1
Subject: Biology, Chemistry, Math
Age group: 13 and up
Type of activity: Field activity, Project
Number of participants: Team
Water Transparency (visibility)
5.1.2
Subject: Art and craft, Biology, Chemistry, Physics
Age group: 13 and up
Type of activity: Experiment, Field activity
Number of participants: Paired, Team
Smell of (Cold) Water
5.1.3
Subject: Biology, Chemistry
Age group: All, 4 - 6, 7 - 9, 10 - 12, 13 and up
Type of activity: Field activity
Number of participants: Individual, Paired, Team

Discussion: How to Increase the Quality of Water

  • Rivers and streams with low total scores are polluted with organic pollution. What are the sources of pollution? (The levels of phosphorus and nitrate will be high where there is intensive agriculture or sewage pollution.)
  • What can be done to reduce pollution? (first: combat the source, i.e. reduce pollution by adapting your behavior; second: fight the effect (end-of-pipe solution), i.e. establishing wastewater treatment plants with updated technology).