Like the sun promises to rise each morning, hordes of crimson salmon — numbering in the tens of millions — faithfully return to Alaska’s Bristol Bay each summer.
This land of untrammeled rivers, streams, and lakes is home to the richest run of sockeye salmon on Earth. And largely for that reason, it’s also the realm of Alaska’s gloriously fat bears, who gobble the hefty 4,500 calorie fish — sometimes a dozen each hour — throughout the fleeting summer.
Yet, the Trump administration may allow a Canadian mining company to dig a gold and copper mine one mile wide and 1,970 feet deep into the heart of the Bristol Bay watershed, called the Pebble Mine. Previously, the Obama Administration effectively killed the mining plans, citing “significant and unacceptable adverse effects” to the biologically and economically valuable ecosystem, but the Trump administration has reversed course, and is officially reconsidering the quarry. It’s a move harshly questioned by Bristol Bay locals, scientists, and law experts alike. “How does helping this underfunded Canadian company make America great again?” wondered Joel Reynolds, a senior attorney at the Natural Resources Defense Council.
Razing 73 miles of streams and 3,458 acres of wilderness (while building two water pollution treatment plants) in a corner of Bristol Bay is of little environmental concern to the mining company, Northern Dynasty, whose PR organization’s spokesperson told Mashable in March that overall salmon population numbers would not be impacted. Yet, a new study published in the journal Scienceshows the stability and productivity of these Alaskan rivers is dictated by the vitality of smaller components of the greater watershed. A small portion of the river system may be incredibly productive one year, supporting or stabilizing a river’s salmon populaton while other areas see weaker fish numbers.
“Different chunks, components, and patches tend to be more or less important in a given year,” said Sean Brennan, a postdoctoral researcher at the University of Washington’s School of Aquatic and Fishery Sciences and lead author of the study. “Any given year, some really small area could be disproportionately important.”
Image: Jason Ching / University of Washington
“A landscape or entire river system doesn’t operate as a simple sum of its parts,” added Brennan, noting that different zones “flicker on or flicker off” over time.
This fluctuating activity has salient implications for the federal government’s environmental review of the Pebble Mine permit, which is administered by the Army Corps of Engineers (the agency is currently accepting comments from the public about the Environmental Impact Statement, or EIS). Brennan noted that the fish estimation surveys done in and around the proposed mining area (and interpreted by Pebble Mine to conclude that salmon populations won’t be impacted) do not capture the full story of how critical a relatively small area of water and streams are to the greater river system’s productivity.
“You’re not getting the full picture,” Brennan said. What surveyors get when trying to count fish over a two or three year period, is “a snapshot in time,” he explained. That “snapshot” doesn’t show how productive a particular river tributary is over time, as the zone “flickers” on or off. Rather, it’s an assumption that the area only produces a certain quota of fish each and every year.
“We show that assumption is on pretty shaky ground,” said Brennan. “Habitats and productivity of the habitats tend to fluctuate a lot.”
“When you cut off these little bits it might not sound like a big deal, but it can be a really big deal,” said Mike Fitz, an ecologist not involved in the study who has spent years observing the salmon, bears, and wildlife in the Bristol Bay watershed, particularly those in Katmai National Park (home to the famous bear cams).
“This study really reinforces that it’s hard to select different tributaries that we find unnecessary, given that they may be very important during specific years,” agreed Curry Cunningham, a quantitative ecologist who monitors salmon runs in the Bristol Bay each summer.
The bigger picture is clear.
“The study seems to definitely demonstrate that healthy runs of salmon are dependent on healthy, diverse watersheds,” said Fitz. And accordingly, healthy salmon runs mean healthy, fat bears. (Though, it’s unknown how, exactly, the Pebble Mine — which would operate for 20 years — will impact the bears and wildlife in and around the mining area. That depends on what ultimately happens to the salmon).
Image: Brennan et al. / Science, 2019
To gauge Bristol Bay’s fluctuating productivity, Brennan and his team caught some 1,400 salmon between 2011 and 2015 as the fish traveled up towards Bristol Bay’s Nushagak River watershed — one of the bay’s largest and most productive river systems. Each fish has an oval-shaped ear bone, which form rings as it grows, similar to a tree ring. This preserves the animals’ life history. The researchers used this bony data bank to measure chemical traces of an element, strontium, that naturally exists in the rivers. Critically, this element exists in different ratios in different parts of the river system — giving the researchers insight into where these fish lived and thrived during specific years. Brennan, then, saw how different regions of the river “flickered on” with productivity, while others “flickered off.”
“The earstones represent a chemical record, like a GPS tracker, of each fish’s life,” explained Brennan.
Ear bone measurements might seem like an unusual scientific tool to assess life history. But not to a fish scientist. “[The earbones] are particularly well-suited for addressing the goals of this research,” said Cunningham.
The Mine
Well before this study came out, the Pebble Mine incited a slew of environmental headaches.
Of note, the greater Bristol Bay region can boom with fish, but it can also bust; a food shortage in the ocean or disruptive weather patterns can drive fish numbers down. Accordingly, an ecologically harmful, or perhaps devastating, mine, can exacerbate the down years, and also hamper the recovery. “Why on top of [those bad years] would we want to risk really screwing this thing up?” wondered Bristol Bay resident Norm Van Vactor, president of the Bristol Bay Economic Development Corporation.
“At the end of the day, do we really want to risk what is truly one of mother nature’s wonders of the world for copper and gold? I don’t think we do,” Van Vactor told Mashable in March.
A vibrant fishing industry, valued at $1.5 billion each year, is critical to the Bristol Bay region. “It’s economically important, it’s culturally important, it’s nutritionally important,” said Brennan.
Image: Jason Ching / University of Washington
And beyond the economic bounty of the richest sockeye salmon fishery on the planet, there’s an unparalleled wilderness, something that’s vastly diminished in our heavily-developed society. The Lower 48’s wilderness, particularly the rivers, is a shell of its former self.
“Basically every major river system in the U.S. is modified by humanity in a significant way,” said Fitz. “Very few people alive today know what a free-flowing Colorado River is like.”
But in Bristol Bay, the rivers are untrammeled, and the natural world is flourishing. “Nothing really compares to the productivity we’re currently experiencing in Bristol Bay,” said Fitz. Consider, for example, rivers red with salmon and bears so rotund their bellies nearly scrape the ground.
This productivity is now on display each summer, as the Explore.org live webcams show Katmai National Park’s brown bears gobbling up bounties of fish, and growing profoundly fat.
The Army Corps of Engineers will soon weigh a plethora of comments from the U.S. public about the impact of a mine in the heart of the Bristol Bay region. Aside from the public comments, the 1,400-page EIS contains a number of scientific assessments about the region’s fisheries, but, according to the study’s authors, doesn’t responsibly account for the mine’s impact to fish.
Image: Sean Brennan / University of Washington
“The Pebble Mine environmental impact statement, which is supposed to be a mature, state-of-the-science assessment of risks, really does a poor job of assessing risks of this specific project,” Daniel Schindler, a professor at the University of Washington School of Aquatic and Fishery Sciences and study coauthor, said in a statement.
When asked if the Army Corps of Engineers would consider this new Bristol Bay research, an agency spokesperson did not give a definitive answer, but said that “new data that is received through the course of the public comment period and made aware to the Corps is taken into consideration leading up to development the Final Environmental Impact Statement.”
It’s likely, though, that each portion of the greater Bristol Bay watershed, however small, plays a sizable role in sustaining one of the richest, and purest, places left on Earth.
Yet one open pit mine, with its 188-mile pipeline, water treatment plants, and roads is how the transformation starts. It’s how it’s always started.
“We can’t keep killing watersheds with death by 1,000 cuts,” said Fitz, pointing at the devastated salmon fisheries in New England and the Pacific Northwest.
“What we consider normal today is a degraded environment,” he said. “We just accept it because that’s what we’ve grown up with.”
