A mysterious Alaska seabird that forages in the silty, nutrient-rich waters
off the faces of tidewater glaciers has been disappearing fast -- just like the
ice itself.
Federal biologists John Piatt and Kathy Kuletz have called it "Alaska's avian
'poster child' for global climate change," a possible casualty of widespread
coastal meltdown.
The population of the poorly understood Kittlitz's murrelet has crashed 80
percent to 90 percent during the past 15 years and may deserve protection under
the federal Endangered Species Act, the U.S. Fish and Wildlife Service announced
this week.
A cousin of puffins, murres and auklets, the "glacier murrelet" likes to dive
for fish and krill, often surfacing in the milky runoff from melting ice sheets.
Biologists believe only 9,000 to 25,000 of the small seabirds remain in the
world, with almost all of them summering near Alaska's shrinking coastal
glaciers and wintering in unknown seas farther offshore.
Based on surveys at a few sites where the birds can still be counted, "the
Kittlitz's murrelet is one the rarest seabirds in North America," Kuletz wrote
in a paper describing the problem.
"You just find their population in little pockets along the coast," Piatt said
in a telephone interview on Friday. "There just aren't too many species that you
can say are truly ice-loving."
It is the only Alaska creature among 26 species named May 4 in the Federal
Register as new candidates for listing as endangered or threatened. The list of
281 candidate species identifies animals and plants for more study, but offers
no regulatory protection.
A coalition of environmental groups led by the Center for Biological Diversity
petitioned the agency in 2001 to include the murrelet. Alaska now has 10 animal
and one plant species protected under the act. One more species -- the Southwest
population of the northern sea otter -- has been proposed for a threatened
listing.
The Kittlitz's murrelet evolved about three million years ago when ice sheets
overtook North America, creating a continuous glacial front from Puget Sound to
the Aleutian Chain, according to scientists.
As recently as 1972, biologists estimated that 63,000 of the murrelets lived in
Prince William Sound, with a world population of several hundred thousand. By
1989, the Sound's population had plummeted to about 6,400, then to about 1,000
in 2000.
Kuletz wrote that this 84 percent decline since 1989 matches other areas -- a 83
percent drop since 1976 in the Kenai Fjords area, and a 60 percent decline in
the 1990s in Glacier Bay.
"This corresponds to an almost universal and increasingly rapid recession of
glacier and ice fields throughout Alaska, which itself is likely to be the
result of global warming," wrote Piatt and Kuletz, in the abstract to a report
they gave in February at the Alaska Bird Conference.
"The fate of the Kittlitz's murrelet likely hinges on the fate of Alaska's
glaciers, and therefore may be among the world's first avian species to succumb
to effects of rising global temperatures."
No one knows yet how retreating glaciers harm the birds, Kuletz added in another
report. The birds can be found off remnant glaciers in the Aleutians, and small
populations still exist at the tip of the Seward Peninsula and along the coast
of eastern Russia.
But studies from other areas have found a clue. The vast amount of fresh water
and silt flushing from a receding glacier can reduce the amount of food in a
fjord, Kuletz said. For a hungry murrelet, this might be very bad news. Not only
are there fewer fish, but they're also harder to see.
These ideas must be investigated further, she concluded.
Little is known about the bird's life cycle. Its territory overlaps with the
marbled murrelet, which nests atop old-growth trees. But the glacier murrelet is
much harder to study, said Piatt, a research biologist with the U.S. Geological
Survey in Anchorage. It nests in bare rocky slopes high in the mountains up to
40 miles from the ocean.
With grayish coloring, it is hard to see on land or sea.
"Their ecology is so obscure, and they don't give up their secrets easily," he
said. "There's only been 23 nests found. Ever. All of those were found
accidently by people hiking. So we know almost nothing about their breeding
biology."
Until a few years ago, no one had even recorded their strange croaking call,
Piatt said.
Additional studies will focus on population trends in the Aleutians and Glacier
Bay and other areas, while trying to find out more about what they eat and the
effect of glacial retreat.
What people can do to help the species isn't clear, Piatt said. But the birds do
get taken by gillnets. Relatively high numbers died when the Exxon Valdez
grounded on Bligh Reef in 1989 and dumped 11 million gallons of crude oil into
the Sound.
The birds summer in Harriman and College fjords as well as Blackstone Bay, 20 to
50 miles by boat outside of Whittier, Piatt said.
"On the small scale, people should be sensitive to these birds," Piatt said.