The coastal area at the Mouth of the Columbia River has changed a lot in the last century. The construction of jetties caused the inlet to deepen and stabilize, the outer ebb delta to move northward, and the shorelines to grow. Recently, erosion has been happening at a fast rate, especially in parklands. A study was done to figure out why this erosion is happening. The researchers looked at how the shoreline and ebb delta changed over time and how sediment supply played a role. They found that the erosion is linked to changes in sediment supply and the movement of the ebb delta.