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Tag team of scientists scrutinizes EPA's Bristol Bay watershed assessment

  • Author: Jill Burke
  • Updated: September 27, 2016
  • Published August 8, 2012

A 12-member panel of scientists assembled to scrutinize the U.S. Environmental Protection Agency's recent study about the possible effects of mining to fish and waterways in the world's most prolific wild salmon fishing grounds wants to send the EPA back to the drawing board. The independent group is charged with analyzing 14 portions of the study of the proposed Pebble Mine in southwest Alaska. And on Wednesday, as it deliberated during a public forum at a convention center in downtown Anchorage, many panelists said the agency's inquiry should be more comprehensive.

Who was on the panel? Water flow experts, geologists, fish biologists, anthropologists, watershed scientists, wetland ecologists, environmental toxicologists, a civil engineer who is also an expert on sustainable mining practices, and a wildlife ecologist. These researchers, consultants and academics were selected to sit on the scientific peer review panel as a component of the EPA's public process, finalizing its Bristol Bay watershed study.

The panel is evaluating several questions:

• Did the study adequately capture what might happen under certain scenarios?

• Did it correctly determine how mining activities will affect streams, fish and people?

• What can be done to counteract the environmental impact of mining?

• Was the hypothetical mine created by the EPA for this evaluation realistic?

"It is neither realistic nor sufficient," Dirk Van Zyle, professor of mining and the environment at the University of British Columbia, said of the scenario. "My biggest concern is the idea of using good practice instead of best practice. To me, that is not the way any mine in this scenario will be developed."

Commercial fishing's impact

Paul Whitney, a wildlife ecologist and private consultant, said a balanced report needs to include the impacts of commercial fishing on stream productivity, too. He questioned whether commercial fishing depletes the river environment by keeping marine nutrients -- returning fish -- from coming back. This would be a component in analyzing the total effect of a mine on the watershed, he said.

His suggestion took a more pointed turn when he further questioned whether reducing commercial fishing catches might be a way to counteract fish habitat depleted by mining. In some projects, mines are required to rehabilitate a substitute habitat to replace what it alters. But in Bristol Bay, where everything is pristine and largely untouched, is this even possible?

One commercial fisherman in the audience, didn't appreciate Whitney's musings. Sure, the concept of reducing catch so another resource can be exploited isn't new. Alaska fisherman often limit their catch of one kind of fish to conserve it or allow the take of another. But in the context of a mine, the method would be used to compensate for the destruction of habitat instead of managing fish allocation. Chip Treinen fishes for sockeye salmon in Bristol Bay and serves as chairman of the environment committee of United Fisherman of Alaska, a group of Alaska commercial fishing interests. "That doesn't sound like a very good idea to anyone who uses those fish," he said. "Taking extra fish or trying to increase the number of fish in one area to compensate for what's lost in another area doesn't work very well."

The EPA study, published in draft form in May, found that any mining is likely to have an impact. Up to 87 miles of fish spawning or rearing habitats -- and as many as 4,200 acres of wetlands -- could be lost in Bristol Bay. Changes in water flow could affect streams' productivity, resulting in less in-river food for fish. Shifts in water temperature could also affect the size, timing and health of hatching fish. And if a dam gave way, the impacts could be severe. Tailings and slurry flooding into a nearby stream could wipe out fish, the study found.

Millions of salmon

Because copper and mineral deposits are located in a watershed of the Bristol Bay region that accounts for 50 percent of the area's salmon population, hazards are being closely scrutinized.

Bristol Bay, located in the southwest corner of Alaska,, is a rich place for fish, birds and animals. It is a world- class commercial and sport fishery for salmon, trout and other species of fish. Freshwater rivers that drain into local bays support nearly half of the world's wild sockeye salmon population. This abundant fish returns annually by the tens of millions each summer.

The EPA found that Bristol Bay's productivity is partly due to it being untouched by development and infrastructure, while supporting a diverse ecosystem that thrives on a web of close interconnections between water and land. What's good for fish tends to be good for brown bears, bald eagles, gray wolves, moose, caribou and birds in the area.

Indigenous cultures of the region have lived off the land there for more than 4,000 years. More than half of their diet comes from fish. All together, subsistence harvests can account for up to 80 percent of the protein families eat in a year.

The Bristol Bay watershed's abundant wildlife and fish support not only commercial fishing, but sport fishing, hunting and other recreation-based tourism, bringing in $480 million and creating 14,000 jobs each year.

The region is also rich with copper and gold deposits. If the Pebble deposit were fully mined, the EPA found that it would produce more than 11 billion metric tons of ore, making it, without question, the largest mine of its type in North America.

Craving specificity

Most panelists noted that if the study remained narrowly focused on salmon impacts instead of impacts to the overall watershed. Consequently, it should state in plain language its limited parameters and the reasons behind it.

The group craved more specificity. More details, the scientists said, would yield a better analysis. A real mine proposal with real scale and a real footprint would have helped, many said.

But even sticking with the hypothetical scenario, the group wanted to know more.

• Could scenarios other than the best case and worst case be considered?

• Could the impact of salmon health to the overall watershed, including to wildlife and humans, be explored more fully?

• Why not also consider collateral impacts beyond the construction and operation of a mine. How about the noise it emits? Or the impact of water use for treatment at the plant, or to tamp down dusty roads?

On the other side, the potential benefits of mining -- bringing roads and power generation and jobs to the area – could have been better documented, too.

Yet for all of the criticism, the group also complimented the work of the EPA in its nearly year-long inquiry. They seemed to view it as a good start while emphasizing the need to make it more comprehensive. Still, many panelist felt were uneasy dealing with so many unknowns.

"It is unsatisfactory because we want more detail. We want to know what the right answer is," said William Stubblefield, a senior research professor in the Department of Molecular and Environmental Toxicology at Oregon State University. "I think that they (the EPA researchers) have attempted to recognize the uncertainties associated with the assumptions that were laid out. It's unsatisfying, but it is where we are."

Critical eye

The comment brought the group back to its core mission. They were asked to find the weaknesses in the report, and they brought a critical eye to the task.

One purpose of the EPA study was to collect information that will help the agency determine whether to use its authority under the Clean Water Act to preemptively veto or restrict mining at the Pebble site, said panelist John Stednick, a professor and program leader of the Watershed Science Program in the Department of Forest and Rangeland Stewardship at Colorado Sate University.

In that spirit, the 12-member panel of scientists also acknowledged that they are a part of a longer process. This fall, their evaluations will be forwarded to the EPA, which has not committed to any timelines or regulatory actions.

At the close of the day panelist Dirk Van Zyle may have summed it up best: "This shouldn't be an end all. This is a starting point."

Contact Jill Burke at jill(at)

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