Protecting Bristol Bay From The Pebble Mine

Jordan Cox

Map of Southwestern Alaska

Bristol Bay, located in southwest Alaska, and covering approximately 40,000 square miles, has the biggest sockeye salmon population in the world. Rivers and streams flowing into this basin, including the Nushagak River and Kvichak River, support more than 190 bird species, 40 land species, and 29 fish species as well as around 7,500 people, over 65% of whom are Native Tribes. Salmon, grizzly bears, and bald eagles are among the many aquatic and terrestrial species that depend on the Bristol Bay waterways for survival, along with its indigenous communities. 

This watershed has been continuously threatened for the past twenty years by a gold and copper mine known as the Pebble Mine. The Northern Dynasty Minerals company has been seeking mine permits for years in this area, but the Army Corps of Engineers has recently stalled the proposal, arguing that it violates regulations established by the Environmental Protection Agency’s Clean Water Act. There is a critical need for the public to understand the value of Bristol Bay and the threat that the Pebble Mine poses. In addition, people need to learn why the bay should be protected from not only the Pebble Mine, but from any future mining claims that threaten the vitality of this basin and the waterways that feed into it.

Fishermen in Alaska


There are five different species of salmon that live in Bristol Bay – coho, chinook, chum, sockeye, and pink – and every year approximately 40 to 60 million of these salmon return to the watershed, providing food for both the people and wildlife. According to the World Wildlife Fund, Bristol Bay is “the most productive salmon ecosystem in North America, and it is unmatched in its productivity.” The abundant fish population in Bristol Bay makes it an acclaimed spot for commercial, local, and sport fishing. The salmon industry as a whole supports over 15,000 U.S. jobs, and sport fishing alone contributes $250 million to the local economy, along with $1.5 billion from commercial fishing. Its natural beauty, as well as the thriving fishing industry, make Bristol Bay a popular tourist destination as well.

Sockeye salmon in Alaska

Within the Bristol Bay region, there are thirty-one federally recognized tribes, twenty-five of which are located directly on the watershed. Considering numerous tribes have practiced subsistence living for thousands of years, many locals have strong cultural and spiritual ties to the land they call home. As a matter of fact, around 80% of the protein consumed by over 4,000 people in Bristol Bay comes from the hunting and fishing seasons, 52% of which is directly from the salmon populations. If the Pebble Mine were to be constructed, it could alter these people’s way of life. This is because copper, one of the minerals that would be mined, is toxic for salmon, potentially reducing the salmon population in the waterways that feed directly into Bristol Bay. 


Listed below are just a few of the many different aquatic and terrestrial species that reside in the Bristol Bay region, which rely on its waterways for survival:

  • Fish: rainbow trout, lake trout, grayling, northern pike, orca, beluga
  • Mammals: beluga whale, north pacific right whale, pacific walrus, harbor seal, northern fur seal, brown bear, black bear, gray wolf, moose, caribou, wolverine
  • Birds: bald eagle, waterfowl, various shorebirds and landbirds

If the proposed Pebble Mine were to be passed and constructed, the wellbeing of these species amongst many others would be threatened.

Brown bears in Alaska


If constructed, the Pebble Mine is estimated to be around a mile long and a quarter mile deep. Some sources estimate it to be up to two miles long, which would make Pebble the largest open-pit mine in North America, and it would produce approximately 10 billion tons of waste. Multiple artificial dams would be required to contain this waste, which could spill into nearby surface and groundwater, according to the National Wildlife Federation. Dam failure has also been examined in the EPA’s 2014 publication “An Assessment of Potential Mining Impacts on Salmon Ecosystems of Bristol Bay, Alaska” since the mine would rest directly on top of a seismically active region, which threatens the durability of a dam’s infrastructure. 

If there were to be seismic activity big enough to result in a dam’s failure from the Pebble Mine, there is an extremely high probability that it would pollute nearby waterways that feed directly into Bristol Bay. Located very close to the Kvichak and Nushagak Rivers, two out of the eight most important rivers that feed into Bristol Bay, the Pebble Mine would destroy over 3,500 acres of important waterways and 21 miles of salmon streams. The mine would require roughly 35 billion gallons of water each year it is active.

Bingham Canyon Mine (example of an open-pit mine) in Salt Lake City, Utah

Because it is an open-pit mine, the Pebble Mine would also generate thousands of tons of solid and water waste due to stripping topsoil. Not to mention, this mine would require heavy machinery, the construction of a transportation route, and transportation vehicles, which will have impacts on the local air quality. Noise pollution must also be considered when discussing the impacts of this mine. In addition to the Pebble Mine, the vitality of Bristol Bay is increasingly being threatened by global warming and climate change with warming river temperatures, reduced rainfall, and rising sea levels. 

All in all, if this mine were to be built, it would have a huge impact on Bristol Bay’s biodiversity and habitat stability, for both land and water. It is crucial that we raise awareness about the importance of Bristol Bay and why we need to protect it from the Pebble Mine. 

Sources: NRDC, The National Wildlife Federation, Trout Unlimited, United States Environmental Protection Agency, United Tribes of Bristol Bay, Wild Salmon Center