Brown bears wait patiently along the banks of the major rivers of southwestern Alaska. They have fished these waters for eons, generation after generation following in the steps of their ancestors. The peninsula here is mostly treeless, with a few scrubby spruce, alder and birch, the tundra giving way to silty, shallow rivers, miles wide, along its shore and cloud-shrouded volcanoes at its crest.

This stark, often dreary locale is witness to an incredible spectacle each summer as millions of sockeye salmon return to spawn, filling the rivers with nutrients and protein and feeding the water and critters that depend on them.

Bristol Bay is home to the largest sockeye salmon run in the world. Nearly 70 percent of all sockeye return to “the Bay” each summer. They come back in a three-week torrent that builds steadily from the third week in June and peaks around the Fourth of July. Roughly 30 million fish return baywide. Imagine a horizon studded with hundreds of fish leaping simultaneously from the water, for days. More powerful still is the unnerving, unknowable force at work, the sheer wild pace and pageantry of millions of animals compelled to act in concert.

The Bay is one of the most lucrative and important salmon fisheries in Alaska. It supports local, native communities and employs thousands more who come north each summer to work in canneries and on fishing boats. Most important, the ecological integrity of southwestern Alaska hinges on the well-being of these sockeye. Bears, birds, plants and humans all profit and thrive alongside these fish.

This will be my 17th season in Alaska. What has always attracted me to this fishery is its elemental link with wild nature. I have the most primitive job imaginable − I catch fish and get paid to do it. We set our nets to hang like a curtain in the water. The salmon swim into the meshes of the net, attempt to back their way out, and are caught by the gills. Dreadfully simple. And we catch only salmon. There is no bycatch. Catching sockeye and picking them out of the net is immediate and thrilling. It is never glamorous. During the peak of the run, when every set nets hundreds of fish, I still see something unique, a fish so filled with energy that I notice it tossing about. Or I sense rowdiness within its lidless stare. And while everyone concentrates on something else, I quietly wish it luck and let it go. I imagine this fish eluding all other nets, swimming past the bears that crowd the river farther on, and finishing what it set out to do.

This has always been a sustainable fishery. Commercial fishermen began sailing here in the 1880s, and native peoples first fished here centuries ago. Now, state resource management scientists set catch levels and escapement goals to safeguard against overfishing and to encourage future healthy fish returns. Management decisions are made scientifically, kept out of the battered hands of the fishermen themselves. Crucial to sustainability, the spawning grounds of Bristol Bay are nominally protected. Undammed, unroaded, unsullied and remote. Protected reproductive habitat is one component of the salmon cycle that truly determines overall health of the species. Managing harvest levels and how many fish escape are both almost easy, or significantly less challenging, when upstream habitat issues are constant and consistent.

It is a cliché to report this area as under threat. A Canadian company, Northern Dynasty, proposes the Pebble Mine Project, an open pit gold and copper mine just north of Lake Iliamna that promises to be the largest gold mine (and second largest copper mine) in North America. The mine would straddle two incredibly important and sensitive watersheds and would change everything. The ore milled every day, 224,000 tons of it, would be 20 times the ore output of the Red Dog Mine in northwest Alaska. (According to the EPA, in 2002 the Red Dog Mine was the single largest source of toxic pollution in the United States.) Imagine an open pit over two miles long and a mile and a half wide, 1,600 feet deep. A tailings lake over 20 square miles. Add to that the miserable track record of the mining industry – its damage to water quality and inability to completely contain either cyanide or acid generation within vast tailings ponds and wastage fields. Ever. Northern Dynasty wants the mine to be at peak capacity by 2011, the life cycle of a sockeye spawned this summer.

Bristol Bay is not an untrammeled wilderness, untouched by the ravaging hands of industrial man. But it is a prime example of a sustainable fishery where we as participants perpetuate a delicate, visceral connection with ecological process. A place where we play a supporting role in a seasonal wonder and not the starring role. That is left to the salmon. Any mine, but especially a colossus like the Pebble, will have an adverse effect on the salmon. I am not fortune-telling; I am reading the past. We have the tools and skill to live and work as part of the oceans’ great web, but only if we lay off a little. Even the vast, open oceans carry our heavy hand. But if we can learn to live within this natural framework, we will find ourselves nourished and sustained by the seas around us − our success linked inexplicably, inescapably to the cycle of the sockeye.