Hey Blog! Yesterday we went to the stream in a local wood to test the water quality and check for some cool creatures with the Eco Group!
The person leading the session was the manager of the hostel in the wood. She hired out to us a fire pit for my birthday party last week, my first party, for my twelfth birthday. When we got there, the first thing we did was go straight from the campsite where our base and campfire was to the stream, to check for aquatic invertebrates. Animals like mayflies and dragonflies spend most of their lives as nymphs in streams and ponds, before one day climbing out of the water, moulting, and becoming their adult form. Certain animals can be used as a water health rating, showing how healthy the stream they live in is. Leeches and water worms can live almost anywhere, so their rating is quite low, but caddis flies and beetles are much higher, as they require more specific conditions. My team found two mayfly nymphs and a beetle larva, denoting the stream was quite clean. Another group found caddis fly larvae, which are super-cool because they build cases out of stones and sticks from the river bed. The process for finding all these animals was: Insert a net into the water about a foot downstream of where you want to sample, then gently kick the streambed where the sample should be. Wait thirty seconds, then withdraw the net and empty into a plastic tray that has been filled with the stream/pond water. Check your sample for critters.
We also did water testing. There were two ways we did it. The first was with a disk with different grades of black and white on it and the second was with a PH strip. I could see the second faintest on the colour disk, and PH was approximately 7. All in all, the stream was very healthy!
We then went back to the fire pit for lunch. I had bought a bag of marshmallows on the way, so we toasted these for lunch pudding. There were also hot chocolates, so everybody was happy. After this we went back down to the stream to measure its width and depth. Here is a picture of me and one of my friends measuring the width of the stream. We found it varied a lot, but then there were rocks in the middle, as seen by the photo. You can also measure speed, by dividing distance by time, like this: Speed = distance travelled ÷ time taken to travel.
You can measure many streams like this, and it would be rather fun to do so. The most exciting part, though, was finding out what creatures the stream is holding in its depth!
Picture credits: my friends’ mums