phosphorescence

It grew darker with the westing of the moon. There was light on the western tops of the dunes, a fainter light on the lower beach and the breakers; the face of the dunes was a unity of dusk.

The tide had ebbed in the pools, and their edges were wet and dark. There was a strange contrast between the still levels of the pool and the seethe of the sea. I kept close to the land edge of the lagoons, and as I advanced my boots kicked wet spatters of sand ahead as they might have kicked particles of snow. Every spatter was a crumb of phosphorescence; I walked in a dust of stars. Behind me, in my footprints, luminous patches burned. With the double-ebb moonlight and tide, the deepening brims of the pools took shape in smouldering, wet fire. So strangely did the luminous speckles smoulder and die and glow that it seemed as if some wind were passing, by whose breath they were kindled and extinguished. Occasional whole breakers of phosphorescence rolled in out of the vague sea—the whole wave one ghostly motion, one creamy light—and, breaking against the bar, flung up pale sprays of fire.

-- Henry Beston The Outermost House