The Sinking of Blackwater
Apr 14, 2011 07:52PM ● Published by Anonymous
During the peak waterfowl-viewing time of October through March, you can spy 20 species of duck and some 250 species of other birds with names so whimsical you feel you’re in a poem: Fulvous Whistling-Duck, Whimbrel, Goldeneye, Brown Creeper, Tennessee Warbler, Merlin. You could also stare through binoculars into the yellow-ringed eye of the migrant peregrine falcon. But you must go see these wonders soon. Blackwater—the emerald gem, the bird-rich “Everglades of the North”—is sinking. According to scientific models of sea-level rise, by 2030 most of BNWR’s marshland will become open water, reclaimed by waves and tides and habitat fit only for rockfish. The refuge was founded in 1932 with 27,000 acres of tidal wetlands, open fields, and mixed evergreen and deciduous forests to provide safe haven, feeding, and resting grounds for a diversity of migrating birds. Since then, over 8,000 acres (or 12 square miles) of marsh have been lost, at a rate of 150 acres per year. Just thirty years ago, the area called Mary’s Pasture was farmland. Today, it’s marshland. In another hundred years, it might be known as Mary’s Submerged Aquatic Vegetation—or it might go unmapped as just another acre of silt on the Bay’s bottom
The year 2030 is within our lifetime—and easily within the lifetimes of our children and grandchildren. You may too soon confront a wide-eyed, dumbfounded stare, followed by the question: A hundred and fifty American bald eagles lived at Blackwater? You’ll say with chagrin: Sweetie, it hosted the largest breeding population on the East Coast north of Florida.
Global climate change and the melting of polar ice caps are to blame for Blackwater’s inundation. The refuge’s unique, low-lying topography makes the problem of sea-level rise worse; because of subsidence, water rises especially fast here. “There are other contributing factors,” explains Suzanne Baird, BNWR’s manager. “Saltwater intrusion, the impact of fertilizer runoff from farms across the watershed, alterations in hydrology because of road building…. And then there’s the nutria.”
Nutria are Rodents of Unusual Size, ROUS, denizens of the fire swamp in the movie, The Princess Bride. However, at Blackwater they are not fiction. These giant rodents were imported from South America to the Eastern Shore in the 1940s to supplement the fur trade. Trouble is, they never politely nibbled on leaves. Nutria ate the salt marsh out of existence; places where they’ve dined are called “eat-outs.” They ripped plants out whole, from shoot to root.
In 2004, the Washington Post ran the headline: “Blackwater Refuge Now Nutria-free.” There was a sigh of relief. The eradication program was finally successful. Keeping the nutria out requires continued vigilance; they breed like rabbits and have no known predators. And the effects of their decades-long chompfest are still being felt. Soggy wetland soil is held together by the extensive root structure of marsh grasses and other vegetation.
According to Baird, “Instead of the natural inland progression of open water, buffering marsh, forest…in Blackwater, we find open water, forest.” Saltwater lapping directly at the roots of trees is not good. The statuesque loblolly pines die and fall (maybe the falls become nest sites for eagles), and the water continues its insidious inland creep. Translate the kids’ game “Rock, Paper, Scissors” into “water, marshland, forest,” and water always wins.
For The Birds
Whenever anything sinks, we think: Atlantis. But instead of a human civilization
lost, lost at BNWR will be a thriving, specialized community of birds. Some are large and charismatic, like the blue heron (which light up all the dinosaur buttons in the small child’s brain) and the American bald eagle, breeding pairs of which make their refuge their permanent home.
Other Blackwater birds are buff-colored and chicken-sized and not much to look at, but they win admirers because of their incredible, globe-spanning migrations. The refuge is smack in the middle of the Atlantic Flyway, which is a highway in the sky that extends from Canada to the Gulf of Mexico and is traveled by thousands of ducks, geese, and many other birds going to and from their summer homes.
One of these travelers is the Red Knot. Although the bird’s most notorious stopover is in the Delaware Bay, where they gather in the thousands in the spring to eat horseshoe crab eggs, they can also occasionally be sighted at Blackwater. These “distance kings” fly 20,000 miles round-trip from wintering grounds in the Tierra del Fuego at the tip of South America to summer breeding grounds in the Canadian Arctic. It’s a commute that makes crossing the Bay Bridge to work in Washington seem like a lark.
Red Knot is a conservation case study; so many factors intertwine in the population’s success. One factor is that in their migration, the birds congregate gregariously in certain spots the way people gravitate towards the kitchen at a dinner party. In a single day, nearly 90 percent of the entire population of the Red Knot subspecies C. c. rufa will be present on beaches in the Delaware Bay. Anthropomorphize the situation—and it’s you, your extended family, and all your friends in that party kitchen. If all the hors d’oeuvres you’ve been waiting for don’t turn up, and neither does dinner, everyone goes hungry.
Going hungry is what’s happening to the Red Knot. The heavy harvesting of horseshoe crabs for bait has greatly reduced the availability of horseshoe crab eggs, which the birds need for fattening up and having enough energy stored to complete their migration. It is a crisis. The National Audubon Society and other organizations continue to petition the U.S. Fish and Wildlife Service to list the Red Knot as an endangered species.
Specialized Out of Existence…or Restored?
Marshland birds—residents of BNWR, like the small population of Canada geese that have ceased to migrate, and visitors like the Red Knot and the Saltmarsh Sharp-tailed Sparrow—are specialists and have evolved to depend on the marsh and its unique nesting, resting, and food supplies. Dr. David Curson, Director of Bird Conservation for the Maryland/District of Columbia Audubon Society, says, “It is because of its specialization, that it is found here and nowhere else,” that he’s fond of the Saltmarsh Sharp-tailed Sparrow. Small, unmajestic, and no triumphant flier, they exist in what is for a bird a small geographic range: only the narrow band of coastal marshland from Maine to Florida.
The sparrow’s breeding grounds are even more contracted, with the Delmarva Peninsula as the southernmost area. It makes its nest here on the Eastern Shore, in little seaweed-lined, cup-like hallows on the mud and in the marsh grasses just above the tidal line. “Because their needs are so specific, they are acutely vulnerable to habitat destruction,” says Dr. Curson. He continues, “Birds really are the canaries in the coal mine. How they’re doing is indicative of the health of the environment.” With so many marsh birds watch-listed, it’s obvious the coastal salt marsh is very ill.
This special habitat, so valuable to so many species, is going the way of the dodo. The birds are in the balance, and so are we. The economy of the Eastern Shore is dependent partly on the money spent on wildlife tourism. The annual Waterfowl Festival depends on there being waterfowl. Maybe not so obvious are the small businesses across the Tidewater counties that succeed because of dollars spent on wildlife watching and activities related to it, like the purchase of birdbaths and recovering from days of cold-weather birding in nice hotels. The most recent data from the U.S. Fish and Wildlife Service is stunning: $633,699,000 was spent in 2006 in Maryland on wildlife watching. Consider also the revenue from local fisheries that depend on clear water and healthy, extensive marsh as nurseries for blue crab and trophy rockfish.
Plus, the wetlands provide critical storm-surge protection for southern Dorchester County and the city of Cambridge. Storm surges—and the havoc they can wreak—were made terrifyingly, neighborhood-demolishingly clear by Hurricane Katrina.
Restoration remains within reach. “I know we can restore marsh,” says Blackwater National Wildlife Refuge Manager Suzanne Baird. “We’ve done demonstrations, using on-site dredge material. But it’s a long-term project.” Blackwater’s comprehensive conservation plan has as its goal the restoration of the refuge to its 1930’s contours and condition. It’s possible, but requires a matrix—like the root mat that holds together the marsh—of government agencies, non-governmental organizations, and normal people, from twitchers (the terrific British-English term for an avid bird watcher), weekend ramblers, or Nature-watching couch surfers.