Spectacled eider losing winter feeding grounds to global warming

WASHINGTON – The spectacled eider’s winter feeding grounds in the Bering Sea are shrinking and changing because of global warming, which will likely lead to a food shortage for this already threatened sea duck, according to the tenth and final chapter of Defenders of Wildlife’s “Navigating the Arctic Meltdown” series.

The spectacled eider, named for its unmistakable white eye patches with black rims, is especially vulnerable to the warming temperatures in the Arctic. The entire world population gathers for the winter in a small area of the Bering Sea southwest of Alaska’s St. Lawrence Island. Several factors combine to create this unique section of the sea that provides the ideal haven for diving ducks. Sea currents and the river deltas that drain into the sea bring nutrient-rich water from, respectively, the North Pacific and the mainland, feeding a host of clams and other creatures on the sea floor that serve as the eider’s winter food. Strong winter winds that drive sea ice away from the coast create openings in the ice, allowing the ducks to dive for food. And persistently frigid waters discourage competition from fish for this rich food source.

However, global warming is now upsetting this delicate balance and threatening the spectacled eider’s winter stronghold by warming the water and attracting fish that compete with the eider for their limited winter food source.

“The spectacled eider’s American population was being decimated by lead poisoning, which resulted in the species being listed as threatened under the Endangered Species Act in 1993,” said Jean Brennan, senior climate change scientist for Defenders of Wildlife. “Now the struggling American population, along with every other spectacled eider in the world, is facing additional peril because of the changes that global warming is creating in their feeding grounds and breeding habitats.”

Global warming also threatens to dry up the small ponds and wetlands that dot the Arctic coastal plain on Alaska’s north slope, on which the spectacled eider and many other bird species rely for breeding habitat. These vast areas of tundra wetland exist because of permafrost, the permanently frozen layer of ground that prevents water from draining away. As climate change accelerates the melting of permafrost, it is transforming the eider’s nesting habitat as wetlands give way to shrublands and forests.

"The changes to the Arctic caused by global warming are creating almost year-round problems for the spectacled eider. The breeding grounds they use in spring and summer are drying up. In the winter, they return to an altered seascape where much of their shellfish diet is being depleted by the fish that now flock to the warmer waters. This is all on top of their early autumn molting when eiders cannot fly, so they congregate in small areas where they are vulnerable to potential fuel spills and entanglement with fishing gear or floating trash,” said Brennan.

In its series on global warming and the Arctic, Defenders of Wildlife stresses the need to reduce greenhouse gas emissions as a key to reducing the effects of global warming over the long term, both in the Arctic and worldwide. But in the meantime, immediate action must be taken to reduce the other pressures on species being negatively impacted by global warming, and to better understand what steps we can take to preserve Arctic animals and plants.

For the spectacled eider, much more research is needed into the birds and the ecology of their wintering grounds, which were only discovered in 1999. In particular, we need to find out more about how global warming is changing the Bering Sea and what those changes mean to the spectacled eider and other Arctic wildlife.

Second, protecting the eider while they are in their breeding habitat is key to helping them survive global warming. Experts believe that lead poisoning, contracted when ducks accidentally eat lead shot, caused the steep decline that led to the species’ listing under the Endangered Species Act. Lead shot was banned in waterfowl hunting in 1991 because of the devastating impacts it was having on ducks and geese nationwide. In the remote region of western Alaska where the eiders breed, this ban has been difficult to enforce, but wildlife and public health officials must continue their efforts and stress the impacts that lead shot has on wild birds, and on people who eat birds that have been killed with lead shot.

Finally, fishing and ship traffic should be curtailed in areas where molting birds are present. The spectacled eider gathers in large groups in tightly concentrated areas just off of the Alaskan and Siberian coast to molt, so any oil spill or other human-caused catastrophe in these areas would be devastating to the species, especially in light of the new threats that global warming presents.

“While it may take 100 years or more to begin to reverse some of the harmful changes we’ve already caused to the Earth’s climate, it is our responsibility to step up our efforts to protect wildlife that is being affected by global warming today so our children and grandchildren will be able to enjoy wildlife tomorrow,” says Rodger Schlickeisen, president of Defenders of Wildlife.

The entire “Navigating the Arctic Meltdown” series can be found at www.defenders.org/globalwarming. It includes all ten chapters of the series, which describe how global warming is threatening the polar bear, ivory gull, wolverine, red-throated loon, Arctic cod, Kittlitz’s murrelet, caribou, orange-crowned warbler, walrus and spectacled eider.

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Defenders of Wildlife is dedicated to the protection of all native animals and plants in their natural communities. With more than 900,000 members and activists, Defenders of Wildlifeis a leading advocate for innovative solutions to safeguard our wildlife heritage for generations to come. For more information, visit www.defenders.org.