Rock breakwaters are used to protect marsh shoreline from erosion

Detailed Description
The estuarine shoreline of barrier islands along the Gulf of America are vulnerable to shoreline erosion. Structures, such as this rock breakwater, can be used to protect the shoreline from erosional waves. Structures like these are often called "living shorelines" or green infrastructure because they also provide habitat for marine organisms, such as oysters and small fish.
Sources/Usage
Public Domain.