Without the plants and algae trap and stabilize sediment, it erodes. As coral reefs degrade, habitat for marine life is lost and nearby coastlines become more susceptible to storms, waves and erosion. Corals used to form barriers to protect the shoreline from waves and storms. Without the coral reef structure buffer zones, the shorelines are more susceptible to storms, and floods, property damage, and wind erosion. The seafloor itself erodes too. This means that the seas along those coasts have become unexpectedly deep.
Explanation: i dont know what your answers could be but i would say whichever one has something to do with protecting the cities that have been used as an example because they were all built to protect. hopefully this is helpful and works for your answers!
