This elegant project employs a scientific approach that is particularly valuable in Environmental Science, but can be applied to other areas as well. The approach has three steps: 1) from your observations in the field, form a hypothesis; 2) create a simplified model system to test your hypothesis; 3) repeat your experiment in the field (taking into account what you learned from your model). The third step "closes the loop" and helps you to see if your initial conclusions from your simplified system are valid in the real world. Take a look at the project and see how it was done.