Here is a link to a form letter to Congress, via Greenpeace, on behalf of the Pacific Walrus. You can customize the text of the letter, but the supplied text of the letter reads:
The Pacific walrus meets the criteria for listing under the Endangered Species Act and must be listed immediately if it’s to have a chance at survival and recovery.
An unprecedented number of walruses have hauled out on the North Slope of Alaska this summer because their sea ice habitat has retreated hundreds of miles away. Walruses that are forced to haul out on land have a harder time finding food and are more vulnerable to disturbances that could lead to stampeding and trampling mortalities.
The recently-released U.S. Geological Survey study shows a 40% chance that walrus will be on a pathway to extinction by the end of this century. As scary as those odds are, they are likely far too optimistic because the study relied on  modeling that underestimates greenhouse gas emissions, global warming and rates of Arctic sea-ice loss.
The report also dismissed as negligible the impacts from reduced food supply for the walrus. Sea-ice loss in the Bering Sea is already leading to declines in the walrus’s bottom-dwelling prey; ocean acidification is making Arctic waters increasingly corrosive and potentially lethal to the clams and mussels it eats. Still, the USGS determined that these threats have negligible influences on the walrus’s future. The study would have found a significantly worse outlook for  walruses if it had used more realistic assessments of these threats.The Pacific walrus needs the full protections of the Endangered Species Act to survive into the coming century. Please list the Pacific walrus under the Endangered Species Act, designate critical habitat, and design and implement a recovery plan as soon as possible.
Here is the link to the form/letter:
https://secure3.convio.net/gpeace/site/Advocacy?cmd=display&page=UserAction&id=723
At the risk of being added to Greenpeace’s mailing lists – I will be filling out this form.