Jan 26, 2009

Climate Change Threatens Wildlife Conservation

Blackwater NWROn January 25, The Washington Post published an article that highlights the greatest threat to national wildlife refuges — climate change.

At the Blackwater National Wildlife Refuge on Maryland’s Eastern Shore, sea-level rise threatens to drown the brackish marsh on which migrating shorebirds depend. In Northern California, the shrinking snowpack has reduced stream flows that sustain the delta smelt, a federally threatened fish species. Higher summer temperatures in northern Minnesota have depressed the birthrates of the area’s once-populous moose, and just 20 inhabit the Agassiz National Wildlife Refuge that was designed in part to shelter them.

The article stresses that conservation professionals, environmental groups, and government agencies are coming to grips with the reality that the age-old method of setting aside land for species protection is no longer enough — not when those places are disappearing and the vulnerable species are migrating to more favorable habitat.

“We have focused on one single principle: You protect the place where the animals live,” said Lawrence A. Selzer, president and chief executive of the Conservation Fund. “That’s fine as long as everything’s static.”

Coming up with concrete strategies for coping with warming trends is a tougher challenge. Anne Morkill, who manages the Key Deer National Wildlife Refuge north of Key West, Fla., said her staff is working with the Nature Conservancy and Florida International University on models of sea-level rise to determine to what extent saltwater intrusion will erode the rocky pine habitat that supports the Key deer and other species.

According to the article, experts say more land must be set aside so wildlife will have places to safely migrate, with a particular emphasis on protecting higher elevation habitat with lower temperatures. In addition, invasive species must be driven out of protected habitat to take the pressure off native species. But David Obura of Coastal Oceans Research and Development in the Indian Ocean, points out that the flexibility to move boundaries or protect larger swaths of land must be written into the policies.

One refuge in particular that has become the poster child of global warming in the Refuge System is Blackwater National Wildlife Refuge on the Eastern Shore of Maryland. Since the 1930s, over 8,000 acres — or 12 square miles — of marsh at Blackwater Refuge has been lost at a rate of 150 acres per year. The causes of this marsh loss include sea level rise, erosion, subsidence, salt water intrusion, and invasive species.

The Washington Post reports:

In May, the Wildlife Federation published a report estimating that the sea level would rise 27 inches by 2100 and that the Chesapeake Bay region — including Blackwater — would lose more than 90 percent of its tidal fresh marsh, tidal swamp and brackish marsh by the end of the century. The group said the projections were conservative.

Currently Blackwater NWR is a major stop on the Atlantic Flyway and home to one of the largest breeding populations of bald eagles in the United States. It is also home to the endangered Delmarva fox squirrel.

Government agencies and conservation groups now see they must become more proactive and more creative as they face a future with an unpredictable climate:

Thomas Dwyer, who directs conservation programs for the northern Pacific flyway at Ducks Unlimited, said he is hoping to preserve wetlands for migrating waterfowl by acquiring conservation easements on farmland lying behind dikes along the Pacific Northwest coast to “let the sea migrate inland” as its level rises. If the water rises high enough, Dwyer reasons, some owners might be willing to let conservation groups buy their undeveloped land and breach the dikes.

“We just need to look down the road 30 or 40 years and make sure we can have options to restore these estuaries,” he said.

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