Not-so-tiny Bubbles, in the Brine

 

The other day at high tide, I kept seeing little geysers of bubbles working their way to the surface. More so from the gravel than the mud, but not just emanating from the rocks, where you would expect the instices to harbor air until the relentless tide forced them to exhale. As if from a pod of tiny sub-benthic whales, a spout would appear, then peter out, only to appear somewhere else.

As a kid, growing up near swamps and lakes where turtles lurked--and not just harmless sliders sunning on logs, but big cooters waiting to snap off the supposedly worm-like toes of kid--someone in the pack would always identify bubbles as a big snapper. We'd tiptoe across fallen trees, but keep our fearful feet high and dry. Now, I'm more inclined to suspect decaying plants, farting, especially if it's a place where I happen to know that organic material was recently buried. Besides, any turtles caught in Puget Sound in January are not gonna be breathing.

The simplest explanation is that this was a really high tide, and when the ocean over-runs land, air makes it's way out of not just the interstitial spaces in gravel, but from burrows, worm-holes, old root channels, and all the other disorderliness that happens in the living soil.

Trouble focusing? It's not you, It's The Water.

The simplest explanation is often right, and no doubt it had something to do with all the tiny bubbles in the brine, escaping, amassing, and enlarging before drifting off on the ebb or effervescing into air. But leaning in for a closer look, another answer could be seen. Where bubbles rose, the water swirled, its transparency changed to a thousand warped tendrils. This is fresh water entering salt, rain that fell a day or month or decade ago coming to the surface. Any other day, this water would seep slowly, maybe even stick to itself just below surface, but with a half foot of saltier water above, fresh water joins the bubbles in an eruption. Eventually it mixes, helping the South Sound keep it's corner of the sea a low-salt haven. Ah,...sweet entropy.