In this outdoor activity/field trip, learners investigate organisms that live along the ocean's rocky coast. Learners add bare rocks to an intertidal zone, and over the course of 6-8 weeks observe what plant and animals colonize (come to live) on the new rocks. The intertidal zone, covered by water during high tides and uncovered at low tides, is usually densely covered with marine organisms such as seaweeds, mussels, barnacles, snails, limpets, anemones and sea stars. Learners may not only discover pioneer organisms (first colonizers) of their new rocks, but other organisms that replace the first arrivals in the process of succession. This activity calls for multiple, weekly return visits to the intertidal zone.