Leaving Wildlife High and Dry
As the administration floats new clean water rules, protections for many streams and wetlands are drying up
- T. Edward Nickens
- Jun 01, 2003
IN EARLY FALL, as most salamanders seek out sheltered nooks, marbled salamanders embark on an amazing migration of faith. For months these chunky, chain-striped amphibians have been living largely underground, feeding on earthworms, insects and the occasional snail, in forests across eastern North America. But as summer gives way to fall, female salamanders breed, then seek out small depressions and low-lying swales in the woods. There they lay clusters of up to 100 eggs in dry leaf litter or under a rotting log--and wait for the water to come.
The continent's only pond-breeding salamander species to mate in fall, marbled salamanders lay their eggs before most of the temporary forest wetlands known as vernal pools appear. As fall rains fill these low depressions, rising waters inundate the eggs. They hatch, and within days larvae are on the prowl, seeking out tiny, nearly microscopic aquatic animals. Months later, when spotted salamanders, wood frogs and other spring-breeding amphibians arrive at the pools, marbled salamander larvae are months old and have a leg up--perhaps even four--on the competition.
Photo by TOM AND PAT LEESON
WILDLIFE AT RISK: Streams that house Pacific Northwest steelhead (above) may lose their protected status due to proposed Clean Water Act rollbacks. Though the fish spend much of the year in main rivers and large tributaries, they migrate up the watershed to quiet headwater streams in summer.
They'll need it, for the marbled salamander's faith that last year's vernal pool will again be a safe place to raise a family rests on shaky ground these days. In January, the U.S. Environmental Protection Agency and the U.S. Army Corps of Engineers issued new guidelines directing field staff to limit the kinds of wetlands and other waterways they protect under the Clean Water Act, thereby threatening 20 million acres, or 20 percent, of the lower 48 states' remaining wetlands with pollution or outright destruction. In an effort to officially limit the law's jurisdiction, the agencies also are considering revisions to federal regulations implementing the act, which would imperil even more water bodies. Many are isolated wetlands that, like vernal pools, seem to lack a direct connection to other surface waters. Others are small, intermittent streams that go dry during certain seasons. According to NWF wetlands policy specialist Julie Sibbing, "These changes represent a crushing blow for an enormous number of wildlife species evolved to depend on an equally diverse suite of small wetlands and streams."
Both the guidelines and proposed regulations stem from a 2001 U.S. Supreme Court ruling, Solid Waste Agency of Northern Cook County vs. Army Corps of Engineers, known as the SWANCC decision. The ruling outlawed a long-standing practice of deeming isolated, non-navigable intrastate waters protected under the Clean Water Act as long as they were used by migratory birds. "But the changes we've seen proposed go far beyond the SWANCC decision, which was based solely on migratory bird presence," says Sibbing. "These are radical efforts to open up waters that have long been protected." Safeguarding such resources is critical, she adds, because they recharge groundwater, prevent flooding and ensure clean drinking water, in addition to providing wildlife habitat.
To the untrained eye, these newly threatened pocket ponds, swamps and seeps are unlikely storehouses of biodiversity. But to the animals that require their specific depths, flow rates, water chem-istries and protection from predators, no other water bodies will do. Consider a creature quite unlike a salamander: the massive tundra swan. From their seven-foot wingspans to their long-distance migrations to the Alaskan coastal tundra from Atlantic and Pacific coastal marshes, everything about these birds is larger than life. Everything, perhaps, except one of their favorite places to nest.
Breeding tundra swans flock to unusual tundra wetlands known as polygonal ponds. Like vernal pools, polygonal ponds are small--most measure less than 30 square feet. Occurring in large clusters, these unique water bodies form as permafrost underlying tundra freezes and thaws; think of a lake bed drying and cracking in summer heat. The interior basins of these automobile-sized polygons fill with meltwater, and the slightly raised rims grow lush with sedges and grasses. Swans forage heavily in polygonal ponds, but they really rely on the wetlands for nesting.
"The birds are quite clever about it," explains Susan Earnst, a researcher for the U.S. Geological Survey. "Swans tend to nest where they can see the surrounding tundra, and the edges of these polygonal ponds give them great views." And a good place to hide. Even if their nests rise only a foot-and-a-half above the surrounding ground, the huge white birds display an uncanny ability to disappear behind them.
Polygonal ponds are another example of the many kinds of temporary or isolated wetlands--most with highly evolved connections to wildlife--threatened by the new guidelines. Also at risk are more than 20,000 Southwestern playas, temporary ponds filled by rain from May through September, which provide critical habitat for checkered garter snakes and support 12 million to 15 million migrating birds. Sandhill cranes, for example, skip from one playa to the next as they migrate across arid Texas and New Mexico. In the nation's 50th state, Hawaiian stilts--tall, elegant shorebirds with long, sharp bills--also feed in ephemeral wetlands that can last just a few days after heavy tropical rains. Even the smallest wetlands can be incredibly fertile: Since 1978, researchers at the Savannah River Ecology Laboratory have counted more than a half million individual amphibians breeding in a two-acre Carolina bay.
In the Southeast, Algonquian Indians had an appropriate name for the tangled, briery thickets that grew from wet peat soils of the Coastal Plain: pocosin, or "swamp on a hill." Today pocosins are one of the last strongholds for the tiny pine barrens treefrog, found in widely scattered populations from New Jersey to Alabama. Hiding in the dense evergreen leaves of sweet bay and titi, the inch-and-a-half long frogs are difficult to spot, yet they are impossible to forget. Glistening emerald green, with deep purple racing stripes and bright orange legs, the treefrogs cling to the tiniest twigs with toes outfitted with sticky discs, and call with a nasal honk. They are "a small nugget of hidden biodiversity," says Whitfield Gibbons, a University of Georgia ecologist.
The frogs also point to a critical truth about many small, temporary wetlands. Pocosins appear mostly dry, their spongy ground laced with tiny rivulets that in the driest summers disappear altogether. Yet it is this ephemeral nature that makes them such perfect habitats for many smaller creatures and ultimately links them to the larger landscape. Few, if any, fish can survive in these temporary waters, which allows a flush of reptiles, amphibians and insects to grow in a relatively predator-free environment.
Photo by STEPHEN J. KRASEMANN
SPECIAL PLACES: Some of the nation's most intriguing wildlife species utterly depend on the country's most unusual--and newly threatened--wetlands. In the arctic tundra, polygonal ponds host breeding tundra swans, providing the birds both plentiful food and a place to hide.
"We have to change the mentality that a wetland must be wet all the time," says Gibbons. "That is, in fact, the opposite of true when it comes to these kinds of wetlands. The word itself is more 'land' than 'water,' and the fact that so many creatures of small wetlands spend most of their lives in the surrounding terrestrial corridors links the land and the water together. To protect the one, we must protect the other."
With their peat foundations and dense mats of vegetation, pocosins are an unusual type of wetland. But they are hardly the most peculiar. In portions of the Midwest--Illinois, Wisconsin, Michigan and Missouri--water bubbling up through limestone rich in calcium carbonate creates a special kind of seep and calcareous fen that harbors the federally endangered Hine's emerald dragonfly, an exquisite insect. These slow-moving waters ensure that fragile dragonfly eggs and larvae aren't washed away, and the constant temperature of alkaline waters rising through bedrock is critical for the dragonfly larvae, which live for up to four years before metamorphosing into stunning adults with emerald green eyes and metallic green pinstripes.
In much of their range, Hine's emerald dragonflies live in small wetlands near streams and lakes, which are likely to remain protected. But the karst fens of the rugged Missouri Ozarks are tiny quarter- and half-acre wetlands that could be located halfway up a mountain. Missouri officials calculate that the SWANCC decision and related regulatory changes could strip from federal protection as much as 83 percent of Missouri streams and 35 percent of the state's wetlands. "Right now," says Scott Hamilton of Missouri's Department of Natural Resources, "I'd say fens are fair game for development."
Even some of the nation's most-recognized small wetlands could fare poorly. Many duck hunters know that the prairie pothole region of the northern Great Plains provides the primary breeding habitat for 40 percent of the continent's puddle ducks, including mallards, blue-winged teal and northern pintails. These prairie potholes, gouged by receding glaciers 12,000 years ago, are tiny: 80 percent of those in the Dakotas are less than an acre in size. Warming early in the spring, they fill with a nutritious stew of scuds, mosquito larvae and fairy shrimp just as millions of weary ducks and shorebirds arrive.
The northern pintail seems especially tied to prairie potholes. In 2002, numbers of this slender, elegant "greyhound of ducks" bottomed out at a mere 1.8 million birds, down from nearly 7 million in the 1970s. Most scientists point to agriculture as a primary culprit. Unlike most ducks, pintails readily nest in cropland, placing them at great risk of destruction by farm equipment. Yet in the Dakotas, prairie pothole production for the graceful ducks has remained steady. That makes these wetlands a critical population source as biologists work to iron out solutions to the pintail's overall population decline. "If prairie potholes lose federal protection there will be a significant population effect on waterfowl," says Scott Yale, a scientist with Ducks Unlimited.
Photo by LEESON PHOTOGRAPHY
RARE AND IMPERILED: Even the Endangered Species Act may not be enough to save the Southwest's desert pupfish. Because the fish is endangered, the pools it lives in are safeguarded as critical habitat. Yet without Clean Water Act protections, streams that supply such pools may be polluted or destroyed.
That the wetlands of a region as vast and as critical to wildlife as the prairie potholes could, with the swipe of a pen, lose Clean Water Act protection is a chilling thought, but the law's opponents are pressing for even more sweeping changes. "No one has ever questioned whether or not streams were protected by the Clean Water Act," says Sibbing, "but now we've heard language about removing intermittent streams from federal jurisdiction, and stream stretches that lie above culverts. It's an entirely new level of threat."
And an entirely new level of concern. Animals as widespread and common as the Louisiana waterthrush and as rare as the slackwater darter depend on small tributaries called headwater streams for foraging and breeding habitat. But talk of stripping away protection for intermittent streams in particular has scientists up in arms. Tiny headwater creeks that dry up in summer heat aren't biological wastelands, says Mike Evenson, a biologist with the Oregon Department of Fish and Wildlife. Instead, they are "absolutely critical," he says, to world-famous fish such as summer steelhead and coho salmon.
During much of the year, Evenson explains, the Pacific Northwest's mainstem rivers and larger tributaries roil with current. Seeking out quiet head-waters flush with aquatic insects, summer steelhead in Oregon's Rogue River basin migrate to headwater streams far up the watershed. As the water recedes young fish migrate with the falling stream, then pulse back up into the calm, nutrient-rich headwaters with the following year's rains. Some young steelhead might ebb and flow with the rising and falling water levels for several years until they are large enough to migrate to the sea.
In particularly dry years, the stream stretches that host young steelhead during wet seasons might be a mile or more from the nearest flowing water. "My fear is that government officials, developers and landowners will make misguided decisions about what is and what is not a connected waterway," says Jim Martin, NWF board member and recently retired chief of Oregon's fisheries division. "These magnificent fish are part of a world-famous fishery, yet their entire life history is based on the fact that these streams go dry."
And they're not the only example. Another signature species of the Pacific Northwest, coho salmon, depends on intermittent streams and isolated wetlands, especially beaver ponds, as winter rearing habitats. "You could say, 'Oh, that little swamp way over there by that headwall, that's no good for fish,'" says Martin. "But in the winter it will be absolutely filled with juvenile coho salmon, steelhead, trout, minnows and suckers."
Which goes to show that when it comes to wetlands and wildlife, there's not a drop of water wasted. And not a drop to spare.
T. Edward Nickens has waded through pocosins, cypress domes, prairie potholes, scrub-shrub swamps, montane bogs, dunal swales and other isolated wetlands during his 20 years as an environmental journalist.
Protecting Aquatic Habitat
NWF is committed to restoring and maintaining full Clean Water Act protections for all U.S. wetlands, streams and other waterways. In addition to supporting several long-standing water programs, NWF and its affiliates are fighting to prevent administrative and legislative actions that would lead to the destruction and pollution of many of the nation's waters, by filing lawsuits, lobbying Congress, organizing grass-roots campaigns and other actions. At press time, proposals to weaken the act's protections were still under consideration.