Assessing waterways
Focus
This activity provides opportunities for students to assess the current health of a local freshwater ecosystem.
Students collect information about riparian vegetation and ‘waterbugs’. They can then draw conclusions about possible strategies to maintain or enhance their waterway.
Science
Life and Living
5.3 Students evaluate consequences of interactions which occur between the living and non-living parts of environments.
Materials
- dip nets - either commercially bought nets from aquarium suppliers (6 inch, fine mesh) or home-made nets prepared before the field activity (see Resource Sheet 6 - Making your own Dip Net (PDF, 89K)*
- small buckets (e.g. large yoghurt containers)
- small paintbrushes
- white ice-cube trays
- forceps
- hand lens
- a large white shallow tray (e.g. tote box)
- Resource Sheet 7 - Stream Habitat Assessment (PDF, 242K)* and Resource Sheet 8 - Conducting a Waterbug Survey (PDF, 119K)* for each group.
Teaching considerations
Safety
Ensure that students are wearing covered shoes, and are aware of the potential hazards of the collecting site and of handling live organisms. As this is an outdoor activity, adequate sun protection will also be needed.
Habitat protection
It is important for students to understand that the field study area must left as it was found. Instruct students to take care in walking in the riparian zone so that they do not trample vegetation or cause erosion problems. If they pick up rocks to look for waterbugs, they need to be replaced as they were found.
Waterwatch
If students are interested in monitoring waterway health on a regular basis, you might like to become part of a community group monitoring the local waterway health. For more information, contact your local council or regional natural resource management body.
Working scientifically
Time: 60 minutes for data collection and 15 minutes for class discussion
- collecting information
- identifying
- examining and evaluating
Guided by the teacher, students discuss the uses of land and waterways in the local area over the last 50–100 years (or longer). They also discuss importance of riparian vegetation to the health of waterways. Students then use the information contained in Resource Sheet 7 to perform a riparian vegetation assessment. From this, they assign a disturbance rating to the verge and bank vegetation.
Working in groups, students use dip nets (Resource Sheet 8) to collect and identify waterbugs. They list those they find on Resource Sheet 8. Each group then pours their waterbugs into the large container to display them briefly to the class, after which they are returned to the waterway. A sensitivity index is then used to calculate a ‘stream pollution index’.
These assessment activities could also be conducted as part of the ‘Catchment crawl’ developmental activity.
Guided by the teacher, students discuss the results of the riparian and waterbug surveys. Discussion questions could include the following:
- How would you describe your waterway: as healthy or degraded? Give your reasons.
- Have there been any attempts to improve the quality of waterways in the area?
- What measures could be used to protect or improve your waterway?
Gathering information about student learning
Sources of information could include:
- students’ data tables
- anecdotal records of students’ contributions to discussion.
* Requires Adobe Reader
Last updated 2 August 2010
