Students will conduct six basic, very graphic, experiments to explain the relationship of salinity, temperature, density, and pressure to the ocean and its currents. Some of these results will be graphed. Students will then divide into 3 groups to investigate: (1) the effects of a new dam built upon a river that flows into a small bay, (2) what would happen to the oceans and their inhabitants if the polar ice caps were to melt, (3) what would happen to the oceans and their inhabitants if the global temperature dropped to 0 degrees centigrade. Results of the group research will be presented to the class by panel discussions. Duration: 3-4 class periods plus research time. Materials for six student groups.