By Linda MacElwee
7th grade Life Sciences Class engaged in macro-invertebrate study.
Connecting to Creeks, a hands-on stream ecology program designed to connect kids to the creeks adjacent to the school and apply those connections to the larger Navarro River watershed. Launched by AVUSD and the Mendocino County Resource Conservation District (MCRCD) through a Tobacco Settlement grant in 2008, the program had its second successful spring at the Middle School. I had the good fortune, through AVUSD and Ken Montgomery, to work again with Nat Corey-Moran’s 7th grade Life Science classes.We met four consecutive Tuesdays in May/June to conduct mini-units at the confluence of Robinson Creek and Anderson Creek on school property.
Students began with an orientation to the creek trail (now very much improved with new steps) measuring stream temperature and looking at Robinson Creek and Anderson Creek in relationship to the larger Navarro River watershed. Students then gathered leaves from native trees and placed them in what looked like onion bags with labels identifying the student work group and tree leaf species. Leaf packs were anchored in the stream with rocks and set in place for three weeks. The first period class studied Robinson Creek; the fifth period class studied Anderson Creek. Collection sites were split evenly between pools and riffles. The second session consisted of an interpretive walk of the Robinson Creek Restoration Project to review the ten-year recovery to stream health and native and invasive plant surveys of the site.
Week three was spent by the water’s edge on a visual, stream habitat quality survey in the riparian zone. Imagine7th graders sitting quietly just observing the natural environment! All had the opportunity to see steelhead fry in the confluence pools. The fourth week was the big finale, collecting the leaf packs with macro-invertebrate insects and decomposing leaf matter to be sorted.Using a LaMotte Company Stream Ecology kit, kids worked in groups around a poster with circles the size of a petri dish labeled with drawings of the various orders of insects. They sorted the leaves to place the insects into the various petri dishes with stream water.Students discovered amazing creatures in the leaf packs this year!
Robinson Creek leaf packs produced a Stonefly, lots of Mayfly, and true fly larvae as well as tadpoles, snails, water beetles, and water striders. Leaf packs planted in Anderson Creek appeared to be lacking at first glance. But once we began to sort them in the classroom we found an unbelievable diversity of aquatic life. Diversity is an indicator of stream health. The kids found Stoneflies, Caddis flies, Dobson flies, lots of Mayflies and true fly larvae.
Baby lamprey turn up in macro-invertebrate study from Anderson Creek.
The students were most intrigued by three baby lamprey, an actual fish species which the Eel River is named for. Like salmon, lamprey adults swim up into the rivers from the ocean to spawn. Kids were uniformly fascinated by observing the creatures up close under the hand lenses. All of the insects are handled carefully then returned to the stream after class. Students did a rough tally of each order of insect and came up with a biotic index number for the survey. They concluded that the water quality in the selected reaches of Robinson Creek and Anderson Creek is good to very good. Although these stream segments dry up in summer except for rare deep pools, during springtime they seem to have very good water quality. The River Center is presently working with the MCRCD to secure future funding to continue this program and hopefully make it self-sustaining for years to come!