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Drama in an Untamed Ecosystem - Alaska's Copper River Delta - includes related article on federal and state regulations
National Wildlife, April-May, 1999 by Sharon Begley
While people wrestle over the future of Alaska's Copper River Delta, nature has been unfolding her own plans for the habitat and its creatures
Mike Anthony and James B. Grand, who everyone calls Barry, basically spent the month of May last year walking. And walking. Walking as much as 10 hours a day, usually along old sloughs, through brush more than 3 feet tall, in the 5 square miles of Alaska's Copper River Delta they chose as their study site. For the whole month, the two U.S. Geological Survey biologists, along with several helpers, kept a sharp eye out for nests of the dusky Canada goose.
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The dusky, one of 11 subspecies, looks a lot like your basic Canada goose, except for its breast feathers: They're the color of cocoa rather than battleship gray. And unlike Canada geese that spend the summer in south-central Alaska and Anchorage or elsewhere, duskies are more particular: The 11,000 or so left in the world breed almost entirely on the Copper River Delta.
Since the dusky's nesting success has been lousy lately--about one- third of the nests produce goslings--the scientists wanted to know why. So as they came upon nest after nest hidden none-too-well in the underbrush, they occasionally set out a 35mm autowind camera. They then attached a switch to one of five or six tawny eggs in the nest in question and wired the shutter so that if the egg was disturbed the camera clicked. Call it biology's version of a jewelry-store security camera: The setup was meant to collect photographic evidence of what was pilfering dusky eggs.
That evidence has been helping to chronicle part of a momentous ecological drama, and the dusky research put the team in one huge front-row seat. Long considered a wetland of unparalleled importance, "the Copper River Delta is one of the most productive, beautiful and untamed wetland ecosystems in the world," says Anthony Turrini, director of NWF's Alaska Office. It is also undergoing vast change. And although the mineral and timber resources here are rich enough to have tempted miners and loggers for decades, this drama is due to nature's own tampering, not human intervention.
That's because the delta is a tectonic hot spot. In 1964 it rose up-- literally: The Good Friday earthquake of that year lifted the delta 6 to 9 feet and left it in the new position. As a result, says Grand, "The whole area was converted from a salt marsh, which was dominated by sedges and grass and regularly inundated by tidal sloughs, into a freshwater system. The tides do not reach high enough to suppress the growth of brush and trees by delivering brackish water inland." Through natural succession, the tidal marsh gave way to freshwater sedges and grasses, which now are being replaced by willows, alders, cottonwoods and spruces. But these habitat changes alone aren't enough to explain the dusky's problems, and they haven't noticeably created problems for other wildlife here.
Located where the Copper River and other nearby waterways empty into the Gulf of Alaska, the delta fans out from the base of the Chugach Mountains. From there it spreads south in a glorious green, gold and brown tapestry of meadows, marshes and mud flats, all cut through with streams and ponds. Yellow marsh marigolds dot the landscape, jagged snow-frosted peaks loom above and ice-blue glaciers crack and topple into the water, forming icebergs. The delta occupies the eastern one- third of Chugach National Forest and is home to many of the state's big mammals, including grizzlies, black bears, otters, wolves, moose, mink and wolverines.
The ecosystem's greatest claim to fame is its role as the largest wetland on the Pacific coast of North America--a critical staging area for waterfowl and more than 16 million shorebirds. The delta serves as a refueling stop for virtually 100 percent of the West Coast populations of western sandpipers and dunlins on their way between summer breeding sites in the Arctic and wintering grounds in South America. The spring migration "is a spectacular sight," says biologist Dan Logan of the U.S. Forest Service. In early May the migrants stop over en masse (in autumn they tend to dribble through on their way south), making the delta come alive with birds resting or refueling on the tidal flats. Birders attending the Copper River Delta Shorebird Festival, held every May in Cordova since 1990, fill the town.
The delta is protected in a number of ways by federal and state regulations (see sidebar, opposite page). All that paperwork has served the delta well in terms of reining in development by people, but it hasn't meant a thing to certain residents.
Take, for example, beavers, whose population has increased tenfold since the Good Friday quake. The busy creatures have dammed off what had been tidal sloughs, Grand says, "so now you have long, narrow freshwater ponds, ringed by shrubs and small trees." Such changes haven't hurt the commuters, the birds just passing through. But the restless earth and the ensuing vegetation changes are replacing dusky- friendly habitat with one tailor-made for the bird's predators. Dried- up sloughs provide access to wolves, bears and coyotes, which can creep up on duskies thanks to the denser cover. Gulls, jaegers, magpies, ravens--and eagles--thrive in the new habitat.
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