So far, this has been the summer of brown. As in rusty brown oil and the devastated brown pelicans it has cast helpless upon the beach. But it's Louisiana's rich palette of wading birds, and the fate of the bayous and salt marshes they live in, that should concern us too.

Here in the Mississippi Delta, long-legged wading birds are everywhere, high-stepping through the shallows in shades of white, purple, pink, green, buff, and blue.

They are just the most visible of the dozens of animal species, not to mention the economies that depend on them, that will suffer as oil pollution ripples through the food web and birds unwittingly pass toxins to their offspring.

They nest together on nameless mangrove islands—some smaller than a suburban backyard—in a riot of color, sound, and smell. To feed scraggly chicks begging from stick nests, they fan out over thousands of tidal waterways that cut through green and beige fields of salt marsh grass.

Silhouettes—just one or a line of them, patiently beating their wings—are constantly crossing the Louisiana sky, as oil from the Deepwater Horizon disaster creeps into the salt marsh on the high tide. I saw this for myself on a boat survey to Bay Jimmy, about 12 miles north of Grand Isle's beaches and the open Gulf waters.

First, a rainbow sheen slid across the water, and soon slicks the size of doormats were slapping at our hull. -- The air filled with a cloying, industrial scent that I had no choice but to breathe in.

A fudge-colored bathtub ring stained every patch of marsh edge and both banks of every tidal channel in every direction. The healthy green tops of the grasses looked like a crew cut, but their bases seemed soaked in hair gel.

Cleanup crews in more than 30 boats and barges spread out along the edge. Workers in white suits vacuumed oily water into 300-gallon tanks, but I didn't see any of them fill up. An estimated 2.5 million gallons are still spewing from BP's leak each day.

Later, at a boisterous mangrove rookery of many hundred pelicans, herons, egrets, night-herons, ibis, and spoonbills, oil had not only drenched the lower two feet of the island's vegetation, it had stained the orange containment boom brown on its way past.

The birds coated themselves as they walked the slicked edges and stood on beached, oil-soaked absorbent boom. I saw Roseate Spoonbill chicks, which should be as pale pink as a high cloud at sunset, tinted the brassy orange color of smog.

These birds won't wash ashore in front of television cameras. Wading birds pick up oil less dramatically than pelicans; they walk and fish the back bays rather than crash-diving into Gulf waters. But they will be among the first victims of oil's lasting effects: injured livers and digestive tracts, anemia, unbalanced hormonal systems, mistimed reproductive cycles, deformed chicks.

These emblems of our nation's beleaguered wetlands, relatives of the great blue herons that stand in quiet elegance at any bend in a river, must remind us that an oil spill doesn't end after the last bird has been cleaned. It's imperative that we trace oil's subtle but pervasive impacts until we're sure every colony, beach, salt marsh prairie, and tidal backwater in this magnificent coastline has been restored to health.

It's a coast of many colors. Don't let it fade to brown.

Hugh Powell, is the Science Editor, Cornell Lab of Ornithology (www.birds.cornell.edu). Read more about birds and the Gulf Coast at our blog: http://redesign.birds.cornell.edu

Fox Forum is on Twitter. Follow us @fxnopinion.