Wetlands and water quality

In April and May 2016 the Gr 6 classes at Sweet Valley Primary attended an outing to the Keyser’s River in Tokai and the Silvermine River in Clovelly to do an assessment of the water quality.

In the classroom

Before we left they were reminded about all the processes that water enables : evaporating, condensing, raining, dissolving, sinking, mixing, floating etc. They experienced how easy it is to make water dirty with the items we use and discard carelessly everyday.

Water gets dirty by picking up the stuff we throw on the ground

Everyone was disgusted to see the quality of the water once we had added pool water, washing up liquid, dog poo, plastic packets, cans and bottles etc.

We also learnt the difference between a sewer and a storm water drain

Checking out the Keyser’s River

Recording the status of the Keyser's River near Blue Route Mall — Recording the status of the Keyser’s River near Blue Route Mall

We recorded any visible pollution, took the temperature, the pH, looked at the colour of the water and then smelt it to check if we could drink it.

We decided that boiling it would make it safe to drink but were not so keen because of all the items of litter floating around

Silvermine Wetland Conservation Area

Mr O's class at the Silvermine Conservation Areas — Mr O’s class at the Silvermine Conservation Areas

Our next stop was the wetland near the Clovelly golf course in Fish Hoek.

We refreshed our memories about the functions of wetlands and how important they are for filtering out debris before river water enters the sea.

This wetland is in fact a manmade one that has been constructed with gabions to prevent sand being washed away during flooding. Wetland plants have grown over the area and it looks very natural

Catching aquatic animals to do mini-SASS

Catching small animals in the Silvermine River

Aquatic animals are sensitive to their environment and certain animals will not survive in polluted systems. Recording the diversity of species that occur in a river is a very efficient, easy and accurate estimate of water quality.

The South African Scoring System or SASS is based on the assessment of species diversity and has been adapted for non-scientists into a simpler version called the mini-SASS,

Kids love catching bugs in the water and seeing what they can find. They had a simple identification sheet to work out what group of species they had found and record them

Ice cream bakkies and a large white tray are very useful to see the variety of aquatic animals

The larger animals like crabs, fish and tadpoles and are easy to catch but the kids are always disappointed to learn that fish and tadpoles don’t ‘count’. The default is always to get the highest points and I have to stress to them that it is the number of different animals they can find not the total number that matters

Magnifying jars make small animals look bigger

The small fast moving animals are difficult to catch but spark curiosity and questions.

The recording process

Each group completed both these worksheets and then the class worked out an average score for the Silvermine River.

Connecting the species diversity to stream health

The overall average for the four classes was just below 7 indicating that the stream is slightly impacted…….pretty accurate I would say

Jane and Wendy

Jane Foster asked me to design this outing for Gr 6 classes at least 10 years ago. It has evolved and changed over the years depending on weather conditions and assessing what the children really enjoy and what they learn.

Thanks Jane for your support. I love designing new outings.