Dune fencing (or sand fencing) creates a subtle but important boundary between the ocean’s shifting energy and the fragile sand‑dune habitat trying to re‑establish itself along the shoreline. The fences catch blowing sand and help rebuild low dunes that once formed naturally, giving native plants a foothold and reducing the scouring effect of wind and foot traffic. Even though they look simple, these structures are part of a broader effort to protect coastal ecosystems that have been worn down by storms, rising tides, and decades of heavy recreation. Around Southern California’s Doheny State Beach, the fencing also guides visitors toward designated paths, keeping the most sensitive areas from being trampled…