In the first ever Cross-Grade Collaborative Project, Prior Lake High Schoolers led students from Redtail Elementary through an exploration of macroinvertebrates* and how they can help scientists assess the health of a waterway. The lesson was preceded by two days of macroinvertebrate collection (one day of practice, one day of actual collection). Prior Lake River Watch Teams identified 15 different species among the wide variety of macroinvertebrates netted from the Credit River right across the street from both schools.
The day of the lesson, groups of elementary students were paired with 2-4 High School students, who led them through a game and lesson on the importance of macroinvertebrates. The students were then able to view the collection of local macroinvertebrates under microscopes. It was incredible to see the High Schooler’s get to stretch their teaching muscles and engage younger students in a hands-on activity.
I need to extend a huge thanks to all of the teachers involved in planning the activity day, and collaborating with River Watch to bring this amazing experience to fruition!
Macroinvertebrate Lesson Background
Macroinvertebrates are water bugs that are big enough to view without a microscope. The biodiversity of macroinvertebrate species is a good indicator of the health of a stream. On this metric, the Credit River sampling site excels with 15 unique species identified, and more that were not conclusively identified.
More importantly however, is the identification of pollution sensitive macroinvertebrates, like the Mayfly Larvae. Mayfly larvae are particularly sensitive to pollution due to their external gills. Most species of Mayfly have 7 or more sets of external gills, which they use to draw water into their bodies and filter the oxygen from the water. The act of drawing water into their bodies exposes their internal processes to any pollutants to the water. The Prior Lake River Watch collected a staggering amount of mature mayflies, indicating that during the spring season, the Credit River contained low levels of pollution.
