CLEAN : To save California coasts, scientists turn to the humble oyster

The video discusses the role of oysters in filtering water and supporting eelgrass, which helps prevent shoreline erosion. Eelgrass also provides habitat for fish and birds. Traditionally, hard structures are used to prevent erosion, but nature-based solutions like reef balls offer habitat value without the need for such structures.

Why is it important to avoid hard structures on eroding shorelines?

What benefits do reef balls provide according to the text?