In 2010, the Environmental Protection Agency received requests from Alaska Native tribes, commercial fishermen, sportsmen, and many others asking the agency to stop the proposed Pebble Mine in Bristol Bay, Alaska. In response, EPA began a scientific assessment of Bristol Bay’s salmon ecosystems, the state of large-scale mining, and the potential impacts of such mining – like the Pebble Mine - on Bristol Bay’s world class salmon ecosystem.

After three years of scientific study, the EPA’s final Bristol Bay Watershed Assessment makes clear that the Pebble Mine would cause substantial damage to a globally unique ecosystem that supports a $1.5 billion economy and 14,000 jobs.


As the Watershed Assessment notes, even if all went according to plan, the Pebble Mine would directly remove 94 streams and damage over 5,300 acres of wetlands, lakes, and streams that support Bristol Bay’s salmon. This is the very ecosystem that provides nearly half the world’s catch of sockeye salmon. Drawing on Pebble’s own data, the EPA found that it is extremely unlikely that the mine could operate without degrading water quality downstream, particularly given the perpetual management required to treat and contain the acid mine drainage the waste ore would produce.

While Pebble Mine would be devastating for Bristol Bay’s ecosystem and salmon, it also has serious implications for Bristol Bay’s culture and a native way of life. As the assessment notes, “Because salmon-based subsistence is integral to Alaska Native Cultures, the effects of those salmon losses go beyond the loss of food resources. If salmon quality or quality was adversely affected, the nutritional, social, and spiritual health of Alaska Natives would decline.”

The EPA’s Assessment has clearly confirmed the fears of Alaskans and many others across the country, so much so that Alaska Sen. Mark BegichMark Peter BegichDem Begich concedes Alaska governor race to Republican Dunleavy Democrats gain governorships in red states GOP braces for potential wipeout in governors' races MORE (D) announced his opposition to the mine just days after the release of the final assessment. Begich said for months that science would dictate his opinion on the development of the Pebble Mine; by opposing Pebble, he has joined over 360 scientists from around the country who believe that Pebble simply represents too much potential risk to the ecosystem and people of Bristol Bay.

In its final assessment, the EPA has taken every precaution to ensure that its work contains the most comprehensive available science regarding large-scale mining in salmon watersheds. The report draws on hundreds of peer-reviewed published papers and other scientific findings.  Furthermore, it relies directly on documents and data prepared by Northern Dynasty Minerals (NDM), the company seeking to develop the Pebble deposit.

During two rounds of public feedback – drawing over one million comments – and scientific peer review, national experts weighed in to improve the scope, structure, and content of the assessment in a manner that well exceeds the requirements of traditional peer review. What was eventually produced is an impressive scientific document – and one that provides a solid foundation upon which regulatory action in Bristol Bay can be based.

The commentary from that peer review process is particularly insightful. In its peer review document, the Final Assessment was lauded as “state of science” and its improvement from earlier drafts was described as a “quantum leap.” Fisheries biologist Dr. Dennis Dauble insisted that “this document should serve as a model for completeness. The authors should be collectively proud of their accomplishment.”

Dr. Roy Stein, chair of the peer review panel, explained that he was impressed with the effort the EPA expended to work with the peer review team over the two review periods, and that “EPA has struck just the right balance with regard to summarizing the state of the probable mine impacts on the ecological and cultural resources of the Bristol Bay Watershed.” 

We are two of over 360 national scientists with backgrounds in ecology and natural resource related disciplines who agree with our peers that the Pebble Mine poses an existential threat to Bristol Bay’s ecosystem. We have now written to EPA to not only express our appreciation for their work and applaud the contents of the Watershed Assessment; we are also urging EPA and President Obama to use their authority under the Clean Water Act to protect the salmon ecosystems of Bristol Bay.

The stakes in Bristol Bay have implications from coast to coast. If the EPA ignores the state of science in its Bristol Bay Watershed Assessment, it will send a signal that adherence to science has no place in the regulatory decisions that impact our lands, waterways, and communities.

Lovejoy is a professor of Environmental Science and Public Policy at George Mason University. Schindler is the chair of Conservation in the School of Aquatic and Fishery Sciences at the University of Washington. As a principal investigator of the UW-Alaska Salmon Program, he spends several months of the year in the field in the Bristol Bay region.