This 25 minute movie from PBS highlights the work of a group of female, middle school students in a science club. Very short cartoon portions of the video can be edited off of the beginning and end. The goal of the group of students is to improve their school pond habitat, particularly making it more attractive to turtles. They meet with a scientist studying turtles and ecosystems who shows them how to conduct turtle population studies in a pond ecosystem. They use that learning to conduct this population investigation in their own school pond. Their work then links to engineering as they design a platform to improve the habitat for turtles, by providing them an improved place for basking. The students present their work to their school board, with the goal of convincing the school board to in turn recommend to the city council that they allow these students to put a human-made structure into this natural area (which is normally against regulations).
Alternative url, goes to all of SciGirls season 1: http://www.pbs.org/parents/scigirls/episodes/season-01/