Wetlands was the Buchanan Middle School's science theme last year, so Bob Underly's seventh graders chose to rejuvenate a dried-up pond on their school's property. The students decided first to develop a model to observe up close, and the "classroom pond" concept was hatched.
The class tried to duplicate the sandy, loamy soils of the real pond bottom in a five-foot diameter indoor plastic swimming pool. Once the soil settled, students slowly added plants (horsetails, duckweed, lilies) donated by nature center staff, and carefully watched the system. They tested the water regularly for oxygen concentration (using methylene blue), and when it seemed high enough to sustain animal life, they introduced crayfish, frogs, and minnows, closely observing how they all interacted in the system. Because of the relatively small size and simplicity of the indoor pond, changes were rapid and readily observable.
The students worked in groups to keep records of all aspects of pond life, looking at soils, counting fish, and observing plants for signs of vigor or ill health. "In figuring the differences in depth, volume, etc., between the indoor and outdoor pond, and determining how much of which things to stock it with, kids readily used math skills," said Bob. "We also tied it in to social studies as we researched some of the historical uses (e.g., medicinal) of the local wetland plants."
The class is now taking cuttings of plants that are thriving in the indoor pond and propagating them in a mini-greenhouse so they can move them to the outdoor pond in the spring. "The kids are very excited to keep track of changes. Although we erected barricades, our frogs regularly escape which, of course, also enhances student interest! They love to sit around the pond and observe. Because it's tied in to a natural phenomenon nearby, they can relate it to their environment."
Science Specialist Dan Fitch reported that first grade teachers in his system were interested in tying their animal explorations in with their GrowLab efforts. With some help from Dan, several classrooms simulated natural ecosystems in the GrowLab. They used a board to divide their GrowLab bases into 3/4 land and 1/4 water, and lined the smaller section with double plastic. Vinyl tubing allowed them to drain the "pond" when necessary, and an aquarium-type pump provided aeration for the "pond."
"The kids became most involved," said Dan, "when they introduced a toad or frog that required care." The students researched the types of conditions and frogs need. Then they planted grass, taller beans for shade, and rocks to hide behind, directly into soil mix in the GrowLab. Students fed frogs meal worms and sowbugs. Bit by bit, they're adding crayfish and salamanders to the water and will soon experiment with aquatic plants.
"Kids were really fascinated by the behaviors," said Dan. "Many didn't know the difference between a frog and a toad, but after much observing did notice, for instance, that the frogs spent more time in the water while toads spent more time in the land portion of the mini-system. When the temperature or food supply was low, students noticed the animals burrowing as though beginning to hibernate." Dan recommends, if you try such a project, to seal your GrowLab tent with tape or magnets to keep frogs and other animals from exploring your classroom environment!