This summer in the New Horizons Education Program (NHEP) science class, students are getting their feet wet – literally – studying stream ecosystems. The students are collecting data from two streams in the South Burlington area to do a comparative study of stream health.
The project started with research on the stream itself. The students investigated the morphology of each stream (the shape of the channels in the stream and how they change in shape and direction over time). To do this, they identified an uninterrupted stretch of the stream and measured the depths across two cross sections and the velocity of the water flow. Students also recorded what material made up the stream bed.
They then moved on to investigate the fauna of the ecosystem by collecting samples of macroinvertebrates – aka bugs that live in the water! They collected samples from two different riffle sites in the designated section of each stream. A riffle site is a shallow part of the stream where water breaks over rocks or stones. Bugs gather at riffle sites due to the flow of oxygen and nutrients in the water at these points. The students collected over 75 bugs from one stream alone! They brought them back to school to identify using dissecting microscopes borrowed from Saint Michael’s College and an dichotomous key. A dichotomous key is a tool that allows the user to determine the identity of items in the natural world, such as trees and bugs, by asking a series of questions each of which has two answers. After identifying and counting the different species of bugs collected from each stream, the data will be combined with the other data collected from each stream. This analysis will be used to determine the streams’ health and water quality. Not only are students learning about stream ecology but they are also making connections between stream health and the bigger environment around them.
