HALL ISLAND -- On this windy, misty August day, there are perhaps 1 million birds clinging to the cliffs that buttress this Bering Sea island. These seabirds, crazy-eyed and with bodies both sleek and clumsy, need solid ground for just a few months to hold their eggs. When their summer mission is complete, the birds scatter to the vastness of the sea.
The temporary human population on Hall Island is six -- five biologists and me. We are intruding on a five-mile-long apostrophe occupied by birds in summer and padded upon year-round by a few arctic foxes that eat voles and birds and bird eggs and who-knows-what in winter. The only signs of people here are a collection of small World War II-era batteries on the interior tundra and a dark green square of turf that might show where a few Russians and their Aleut slaves dug in for a winter in the early 1800s.
The biologists are here for a periodic check on the seabirds, using a protocol they follow on islands throughout the vast Alaska Maritime National Wildlife Refuge. The refuge includes more than 2,500 Alaska islands from Southeast to the Arctic coast, including most of the Aleutian chain. If this sanctuary for wildlife existed in the Lower 48, it would stretch from Georgia to California to Minnesota.
Each summer, biologists stay in camps and tents on nine refuge islands to study seabirds, some of which can live for 40 years. Because Hall Island is so far from anywhere else (it took us 25 hours to get here from St. Paul aboard the refuge's 120-foot boat the Tiglax), it gets a less frequent check from biologists. The Tiglax last dropped anchor at Hall and nearby St. Matthew islands in 2005.
Heather Renner, supervisory biologist at the refuge, leans into the wind above a cliffside of black-and-white murres. She squints out at the seabirds and sees little sentinels of change. Different species of birds sample different levels of the ocean, eating fish and plankton, some from near the surface and some 500 feet deep. If part of the system was in trouble, Renner says, biologists might notice an absence of birds in their usual spots on these and many other Alaska cliffs, some of which researchers have surveyed for 40 years.
On Hall Island today, birds perch on every available stone shelf, with hundreds moshing shoulder to shoulder on larger platforms of rock. Marc Romano, Marianne Aplin and Aaron Poe's 2012 counts reveal about half as many kittiwakes, murres and cormorants as biologists counted here 29 years ago, while there are more northern fulmars than there were in 1983.
When counted and compared to the past, these northern fulmars, blacklegged kittiwakes, common and thick-billed murres, cormorants and auklets help show the health of a rich ocean ecosystem. Though Hall Island is one of the most remote islands in Alaska, it can't dodge changes in climate, the arrival by sea of invasive species and increasing human traffic in a place where sea ice forms for a briefer period each year.
"There's not a lot of places for a ship to hide from weather except here," says Romano, wildlife biologist with the refuge's Bering Sea unit. "There's a concern a ship could wreck here."
The image of this place sullied by an oil spill or of rats swimming ashore from a sinking ship dissolves with the constant show playing out before us, as murres swoop down to the ocean as others deftly trapeze back to their own tiny ledges. On a planet of seven billion people, being so outnumbered by birds is a rare and heartening sensation.
Steve Delehanty, the manager of the refuge, distilled the feeling into a few words as we talked aboard the Tiglax a few days ago. He mentioned the foresight of Teddy Roosevelt, who included Hall and St. Matthew islands as part of America's first wildlife refuges 103 years ago.
"What a great thing it is to have places set aside for wild animals," he said.
Ned Rozell is a science writer for the Geophysical Institute. This column first appeared in 2006.