Bay Watch

RETURNING A LONG gaze into one of the best urban wetlands left in the world, a small bird stares back, dark eyes alert and unblinking. Transfixed, the pied-billed grebe is probably hoping to go unnoticed, floating among the lily pads while potential danger passes.

It might be hiding week-old chicks beneath its feathers. But it probably also knows there is a better strategy for survival than hope, or trust. Inside, its spring is wound tight.

There is no apparent trigger; it has just had enough. In the blink of a human eye, it is gone.

The grebe's home is our home, the urban marsh in Seattle, one of the few extraordinary wetlands still flourishing within the tamed cities of the world. The grebe's nest floats on a mat fashioned from cattail reeds just 3.24 miles from the Space Needle. This is an oasis, a transcendent place for man and beast. But it is "wild" only with our permission. And it is in danger of having the life squeezed out of it.

Its ragged marshy edges, the shoreline of Lake Washington's Union Bay, press timidly against the robust right angles of property lines and urban streets in the neighborhoods of Montlake, Laurelhurst and Madison Park, the campus of the University of Washington, the outlines of the Washington Park Arboretum and the Union Bay Natural Area.

On a recent map this area has a new name, the University of Washington Botanic Gardens, a new boundary, encompassing 320 acres, and a claim to 320,000 visitors every year. Most of them likely have no idea of how the place came to be, what it has been or where it's headed.

In an imaginary film featuring the historical life of the bay, the star appears in the opening scene as a wet divot scraped out by a glacier. The background is a curtain of really big trees. The next frames capture Indian camps and longhouses appearing quietly along the shore, the first people gathering food and burying their dead in the trees thriving on spongy islands of peat the glacier left behind. The scene dissolves into pictures of sawmills churning out lumber and hillsides being cleared to the shore to feed them. Special effects show University Village shopping center under water and waves lapping gently at the east end zone of Husky Stadium; then, a quick cut to shots of the water level dropping nine feet as the Ship Canal opens and the surface of Union Bay retreats to within its familiar outline.

The next scene makes us twitch a little: In a dramatic time-lapse sequence, 40 years' worth of the city's garbage is dumped into the cattails. We watch in awe as these mounds are capped with two feet of new dirt and — voilà — buildings and athletic fields and pavement sprout from new waterfront real estate.

In the final scene, everything connects to everything else as the world's longest floating bridge — "the 520" — is built across the lake. Fade to the credits, where we see people much like ourselves.

Over time, the slow stampede of newcomers cut down virtually all the big trees and used the lake as a toilet. We dredged, filled, burned and reshaped the place to suit our needs. Fortunately, awareness evolved before all was lost. Even as the metropolis continues to squeeze, the oasis provides enough for many of the birds, mammals and fish that need to stop by on their seasonal journeys to the Arctic, South America or destinations in between. And though some of the native creatures and plants have disappeared, some, with our help, have survived.

Other species have invaded and settled in. The one now in power at the top of the food chain has chosen to keep what's left of this fragile gem alive, and is responsible for its future.

Another decisive time has arrived. The aging 520 bridge, which floats on the lake surface much like the islands of peat, seems destined to be replaced by a muscular successor as soon as we decide how to proportion its limbs and how we will pay for it. Ahead lie years of construction, digging and disturbance. And at least another year to mediate competing human desires. Politicians, government officials and local citizens have been unable to choose a way forward, so the governor has appointed mediators to work things out by December 2008. In a few weeks, voters will have a say on a larger roads and transit-funding plan that includes more than $1 billion for a new bridge of some sort, but that would be only the first payment. Likely, a new expanse of concrete will dwarf the present one.

Unless, of course, nature intervenes sooner in the form of an earthquake or storm or its own opinion about the lifespan of hollow concrete supports and pontoons that have been propping up human progress for more than 40 years.

SEEN FROM THE window of a jet approaching Seattle-Tacoma International Airport, this wetland is a fringe of Northwest greens and tans surrounding a puddle of water between several bigger pools. It's deep blue when the sun is shining, dull slate when it's cloudy. Oh, and there's that light gray vein of cement running through it.

From the window of a car moving through that vein, the wetland can be little more than a subtle change in scenery on the way to somewhere more important.

From that same window, but jerking ahead a few feet at a time in the forced rhythm of red and green on-ramp lights, it can offer a glimpse of an aluminum canoe, a needle-shaped kayak, a great blue heron perched on a bare gray branch, a great white sunbather, possibly bare.

From that canoe the wetland is a course of well-paddled channels between flotillas of lily pads. It's a steady push through, a quick appreciation for whatever attraction presents itself along the way, and then a return to the dock before the next hour of rental fees ticks over.

But from a kayak, tuned to the wetland's own rhythms, it can offer a window into the competition and connection between man and nature. In the first spring sunshine, turtles pack a floating log like new cars pack a truck on its way across the bridge. Outflow from a drainpipe discolors everything in the water, as it has for many years. An errant golf ball rips through cottonwood leaves and plops into the channel 20 feet from the bow. A pair of bald eagles call from their nest above the 17th fairway of the golf club in Broadmoor. Cliff swallows dart in and out of mud nests stuck to the underside of 520, separated from whitewalls by a few inches of concrete.

Beneath the surface, where the color of the sky doesn't reflect, the water is sort of black, sort of green, most often the color of dark tea. It changes with the light, the density of microscopic life and the amount of peat that has been stirred up. Each summer a forest of lilies emerges in stages, the pads red as they sprout from the bottom and unfurl, the stems a tangled mass on their way to the surface, the final canopy a green platform for millions of insects and invertebrates until it turns brown and decays in the fall. There are frogs eggs, beer cans, minnows, bass, sunglasses and charred wood. The silty bottom offers little resistance to an arm pushed in to the elbow. What exactly is buried below, how nasty is it, and how likely are we to see it again? All the salmon from the rivers of Lake Washington pass through here twice in their lives, though mostly without our notice.

And always, everywhere, the hum. The constant whoosh from traffic on the bridge is almost impossible to tune out. It won't let us forget that this is not wilderness. A paddler can actually feel the difference between a passing Metro bus and a passing Subaru by paying attention to the hard plastic seat of the kayak; the vibrations are borne through air, water and concrete into the hull, and strum the spine. What happens during the brief maintenance periods when the bridge is closed to traffic? Do creatures acclimated to this aural environment experience the equivalent of a total solar eclipse, when day turns to night?

THE SUN CAN shoot a particle of light to one of those cattails growing on the shore in about 8.3 minutes, but I can leave our front porch on foot, or leave our driveway with a kayak on top of my car, and get there faster. I am one of the lucky thousands who can almost claim this place as our backyard. Luckier still, everyone can claim this wetland as a special place. My neighbors in Ballard and Bellevue can get their toes wet here with less trouble than it takes to get seats at most movie theaters. Out-of-towners drive into the middle of the big city to find nature. Wetland watchers around the world can keep an eye on the debate about the future marsh and highway with a quick keyword search. UW students spanning decades and continents still carry memories of study breaks splashing in a canoe or leaping from the infamous "ramps to nowhere."

Two people who entwined their lives intimately with the marsh were Harry W. Higman and Earl J. Larrison, whom I will never meet. Seven years before I was born they published "Union Bay: The Life of a City Marsh," a book written from the long perspective of boys exploring the marsh and later as scientists and university teachers. They studied and recorded its natural history by canoe and kayak, observing as the seasons and the years and the growing community brought change. As a measure of what has been lost, bear in mind that the first bridge was still a futuristic dream when they wrote:

"Man is therefore responsible for the marsh. If the present trend continues, man, by continual filling, drainage, and building, will some day destroy it." And, "We found that some wild creatures could continue to carry on their normal lives with little friction, while the lives of others were influenced by man to the point of extinction."

Widely accepted estimates tell us that half of all the wetlands that existed in this country when the first Europeans arrived are now gone. In the urban areas of Puget Sound, the loss could be 70 percent or more.

I'll just go ahead and say it: We paved paradise and put up a parking lot.

What's the value of this particular paradise? Pristine nature, it is not. But it does have the power to reconnect an individual with the larger world — a modern human longing not easily satisfied inside an office building or behind the wheel of a car.

What we see in marshes depends on what we see in ourselves. How much do we feel a part of nature? How much have we separated ourselves from it, and did we really mean to do that? Can we control nature? Do we get to select which parts we want to keep and which we can do without? Even if we wanted to do this, are we smart enough to know how?