No permit required. At the edge of a low tidepool a colony of tube-dwelling worms has created a new mound of calcareous tubes and cemented sand. Bioconstruction adds structure and mass to rocky shores. The mound is rock-like to the touch.
Below, at the edge of the same small pool, more bioconstruction. I imagine these mounds are the work of Dodecaceria, but there are alternatives, other colonial polychaete builders.
Lest you think the construction takes place on the sheltered edges of placid pools, behold the scene below. The view from the seaward rim of the pool reveals the backdrop within which the worms do their work.
It’s a wonder tiny worms can build their mounds in such a high energy, erosive environment. Then again, we see plants, algae, mussels, and barnacles making a living on the rocks, and on each other, in the full force of the surf. It can be done.