If built, Pebble Mine would use earthen dams to store hundreds of millions of tons of toxic mine tailings—including selenium, mercury, arsenic, and sulfuric acid—in the headwaters of the Bristol Bay watershed, the world's most productive wild salmon habitat. If the mine tailings were to leach into the water table, the rivers could be poisoned, destroying the homelands of over 25 Alaskan Native tribes and the jobs of 14,000 people who make a living from Bristol Bay's $1.5 billion salmon fishery. The construction of mining infrastructure would also result in permanent habitat loss for brown bears, a keystone species, and risk altering the unique human-bear relationships that make the Alaska Peninsula one of the world's best places to see bears in the wild.
For now, the fate of the region remains uncertain: while supporters of Pebble Mine wish to bolster the local economy, opponents of the mine feel that the consequences of an environmental disaster—to the salmon, the people of the region, and the bears—are simply too great to risk.
National Geographic, 2019