Current Affairs

by Nancy Sefton

As our small boat approached Deception Pass, just south of Anacortes, it felt like all of Puget Sound was trying to rush through the narrow opening ahead of us. The ebbing water streamed, gurgled and boiled, eager to return to the wide welcoming arms of the Strait of Juan de Fuca. We swept through the pass by the grace of Nature’s forces.

This twice-daily exchange of water is as timeless as the rise of sun and moon, and of course, all are locked in a rhythmic dance, sometimes frenzied, sometimes slow, across the globe.

In our own waters, tides may rise or fall as much as 12 feet in a few hours, depending on the alignment of sun, earth and moon. All this moving water fosters the richness of marine life in areas where tidal currents are most strongly felt, in narrow passages where water must accelerate in order to meet its hectic tidal schedule. As the current pushed our boat through steep-walled Deception Pass, I knew instinctively that several fathoms below our hull, life was exploding.


At the lowest tides, a steep rocky shore displays four horizontal zones, each playing host to different groups of marine animals and plants, arranged according to their tolerance for exposure to air. Here, the water level is about 12 feet below the splash zone. Two sets of high and low tides daily accounts for considerable water movement in our area.

Triggered by the ebbing current, tentacles were reaching out for passing food particles. Bivalves with their shells open were sucking in nutrients. Bull kelp was absorbing energy through every tiny pore in stem, blade and bulb. Any marine creatures not securely attached to the rocky bottom were probably hunkered down in some handy crevice, like a family crouching in a storm cellar.

Moving waters deliver life-giving protein to support a marine food web that reaches right up through herring and salmon, to our illustrious orcas…and nourishing every living thing in between, including seabirds and land mammals that feed on marine life.

Puget Sound is part of a giant watershed, an area that drains the surrounding mountains. In the Sound and Straits, fresh water from hundreds of rivers and streams interacts with ocean tides in such a way that deeper, nutrient-rich salt water is pulled toward the surface to further enrich the food web.

These currents have an advantage over many other natural systems; humans cannot tamper with the tides. But we CAN make the mistake of relying on the tidal cycle to clean up our mess. A mere 5% of Puget Sound waters are actually exchanged by our northwest tides. Most of our toxic substances, oil, excessive nutrients and other unwelcome additions to the Sound’s waters aren’t conveniently flushed out to sea by currents. We’re forced to live surrounded by our own waste, constantly challenged to try to reduce it.