This activity can be used in the classroom to introduce students to the difference between saltwater and freshwater organisms. Students gain experience in planning experiments, utilize their problem solving skills, and work cooperatively. The students are faced with a problem…it is the year 2025, the earth has stopped spinning, the sun shines constantly, and all the water is running from lakes and streams to the oceans. As “”environmental scientists,”” how will they save the freshwater organisms? Upom completion of this activity, students will be able to realize the importance of niches in an ecosystem and learn about the physiology that allows freshwater organisms to survive in freshwater and saltwater organisms to survive in salt water.