On a day last spring when the mercury climbed to the 40s, Peter Lockuk Sr. steered his blue aluminum skiff across the flat, calm waters of Togiak Bay.

He pointed the bow southwest, toward a tiny island oasis of tundra and rock 30 miles away. It's called Shaiak Island, and it's peppered with the nests of seabirds.

Gull and murre eggs are a popular and traditional table fare in northern climes, and the village of Togiak in Southwest Alaska is no exception. Lockuk collects the eggs in 5-gallon buckets.

"We crack the eggs and if we need to store them a long time we freeze them and put them in Ziploc bags. When we want eggs, we just get them from our freezer," Lockuk said. "It's no different than cooking chicken eggs when you boil them. Or you can even scramble them."

On Lockuk's first visit, he finds the speckled eggs of the glaucous-winged gull. Within weeks, when the murres are nesting, he'll return with the same buckets for more.

In recent years, on Lockuk's trips to the island he has collected eggs not only for the tables of his extended family but also for a crew of biologists. He is one of several Alaska Natives with whom federal biologists have contracted to collect eggs for an investigation into the levels of contaminants -- such as mercury and flame retardants -- in seabird eggs.

"I grew up subsistence hunting for them. We know where to go and find them," he said.

U.S. biologists working with Lockuk are part of a long-range international effort to monitor Arctic and sub-Arctic environments for the quantity and identity of what are called persistent bioaccumulative toxins.

These toxins are especially long-lived chemicals that often collect in the fatty tissue of living organisms.

The eggs of these murres and gulls contain a precise record of contaminants found where the birds live and forage. For this reason, the egg is the perfect capsule of environmental data.

"What we're looking at is what females are passing on in the form of an egg. They're nice little packages. They give you a pretty decent picture of the trends in the environment. In other words, where is it high and where is it low?" said Dave Roseneau, a U.S. Fish and Wildlife biologist in Homer.

Roseneau helps lead the government's Seabird Tissue Archival and Monitoring Project.

FALLOUT FROM INDUSTRY

Contaminants borne of the industrial world have been appearing in distant Arctic and sub-Arctic regions for a long time.

In 1970, scientists documented the first traces of the pesticide DDT in the blubber of ringed seals. Federal policymakers banned DDT's domestic sale in 1972, and though it's on the decline, traces linger even in Arctic seabirds. Measurements taken by Roseneau and his colleagues can confirm the effectiveness of environmental policy decisions.

The findings of these long-term monitoring projects show nobody escapes the unintended consequences of the world's industrial advancement. Even the wildlife -- and human residents -- of the Far North contain traces of toxins.

Among those of highest concern are mercury, PCBs, DDT and flame retardants treated with bromine. These toxins appear worldwide in the fat layers of polar bears, human breast milk and babies' umbilical cords.

And the Last Frontier is not immune.

"Some of these chemicals are everywhere on the planet. We have a lot lower levels of these things than other places, but we are a part of the globe," said Lori Verbrugge, a toxicologist at the Alaska Department of Health and Social Services.

The explanation lies in the dynamic movements of air and ocean currents -- the true, original forces of globalization.

Because these toxic compounds are slow to break down, they're able to travel long distances -- as distant as the cold Arctic. In such low temperatures, many persistent organic pollutants "sink" out of the atmosphere to mingle with plant and animal life.

What's toxic?

The Seabird Tissue Archival and Monitoring Project is on the lookout for items to add to its list of industrial dirty laundry. Most of these, such as PCBs and mercury, are already household words.

The polybrominated diphenyl ethers used as flame retardants are so new that the seabird contaminant analyses didn't even know to look for it until 2005.

Other contaminants are out there, scientists say. The trouble is, they don't yet know their names. They don't even know what they look like.

For this reason, Roseneau's project preserves its egg specimens. Convenient capsules, remember, of a recorded chemical history.

This means eggs Lockuk collected on Shaiak Island were later shipped, frozen at minus 150 degrees Celsius, to the lab amid palm trees on the Carolina seacoast. There, the eggs are tapped with a Teflon-wrapped hammer until they break into pieces. Even a tiny quantity holds an inventory of contaminants.

By preserving eggs from eight years of field collections in giant freezers at minus 180 degrees Celsius, chemists can later return to "hindcast" the presence of newly emerging pollutants.

WHAT'S SAFE?

Even as research has documented the continued presence of toxic compounds in animal tissue in the Far North, public health authorities still encourage the consumption of a traditional diet, rich sea mammals, waterfowl and seabird eggs.

"We recommend that people continue to enjoy their traditional foods," said Verbrugge, the toxicologist. "Just because the toxin is there doesn't mean it's having a toxic effect."

And in light of the alternatives available in most village groceries -- generally foods highly processed -- traditional foods remain part of a healthy diet for Alaska Natives.

"They don't have a lot of healthy choices for replacement foods. The replacements often have more severe implications for health effects," Verbrugge said.

While the eggs are not free of the toxics now appearing in the Earth's ecosystems, scientists say the levels of persistent bioaccumulative toxins are not high enough to warrant dietary restrictions.

The most concrete guidelines come from Health Canada. It suggests a 110-pound person can safely eat 0.8 gull eggs and 0.6 murre eggs a day for a year, according to its "acceptable" or "tolerable" daily intake guidelines. On average, that's five gull eggs or four murre eggs per week.

Yet crafting dietary guidelines remains a nebulous science. And because research into contaminant levels in Native foods is poorly funded, it's likely to remain that way.

"We're scrounging" for funding, Roseneau said. By cobbling together funding from a number of government sources, he has conducted the contaminants research on a budget of about $40,000-$50,000 per year. Analysis of a single egg costs $500.