Answer:
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.
Answer is Retrograde motion
Most of the time planet moves in expected path near the ecliptic which is east to west. Some times each planet turns around and moves to the east for a period of time, then it turns around to head in west direction again making a loop or zig-zag against the star background. This is called retrograde motion. Thus retrograde motion is the change of direction of the planets in loop.
A a parrotfish eating coral on a coral reef
Magma chamber
central vent
crater
I think
