Stream Explorers is a program ran jointly by Collegiate Peaks Anglers chapter of Trout Unlimited (CPA) and Greater Arkansas River Nature Association (GARNA).
Today’s session started with some bug collection. As the water was a bit higher at 900cfs, only one of the adults (Tom) volunteered to go in the river. We didn’t find as many insects — a dozen mayflies, one pretty caddis, a cranefly larva, and a few stoneflies (but no goldens). We brought the insects back into the Scout Hut and looked at them under microscopes. Today’s task was to be a bit more specific — to look at the gills, inside the skeleton, count segments, tails, legs, etc.
Discussion revolved around the previous week’s ecosystems in a bottle — how many things survived, what might have been the factors for better or worse survival rates. One student, who showed restraint last week and took just a single goldfish, brought his bottle back and the fish was still alive! That lead to a discussion about how an increased number of fish requires more oxygen. Some students talked about moving the fish into their aquariums, and water quality, and a number of other related topics.
That discussion lead into talk of temperature and pH, and so we headed back to the river to measure that data. The students split up into two teams and took the measurements in groups. After returning to the classroom, they were given a figure of how much oxygen is in the river (measured separately by Ed earlier in the day) and we were all surprised that the water had a much higher percentage content of oxygen than air!
The main science experiment involved goldfish. The students paired up and took a mason jar with a goldfish. The jar was filled 3/4 of the way with spring water. We first measured water temperature, then counted how many gill beats (“breaths”) the fish took in a minute. Then we added some hot water to increase the temperature in the jar, and counted again. Then we added ice cubes to lower the temperature, and counted again. This led to a discussion, to a scatter plot of results, and more talk of the scientific method. We talked about activity level as it relates to temperature, and looked at how this might affect aquatic insects (hatches/movement) and fish feeding times (winter vs. summer).
And to finish today’s session and to prepare for next week’s the students learned how to set up a fly tying vise, how to insert the hook, and how to start the thread. That was a bit more didactic — we told them how to do it. Next week they will use these few basic skills to let their imaginations run wild — and to construct whatever flies they want.
Thanks to the volunteers: Ed Eberle, Dominique Naccarato, Fred Rasmussen, Wendell Winger, Norm Lastovica, and Alihah Trujillo.