15. sea urchins Activity 2 Directions: Fill in the blank with the correct answer from the box. Write your answers on your answer sheet. temperature mud solid rocks seashores high tide decomposing 1. Salt marshes are filled with seawater during and drained during low tide. 2. A quick change of water may cause death of fishes. 3. Sea stars and sea urchins can be found in 4. Salt marshes are marshy because of the presence of plant matter. 5. Rocky shores are areas in intertidal zones where are found.​