Photo: Peter Mather

Every autumn the largest congregation of Bald Eagles on the planet flocks to the northern Alaskan panhandle to feast on spawning salmon in the Chilkat Bald Eagle Preserve. As many as 4,000 of the imposing raptors hunch in frosty trees, dropping grandly onto gravel bars where they screech and squabble over fish carcasses alongside gorging grizzlies. The 48,000-acre preserve, which Audubon Alaska helped establish, has protected this sweeping valley since 1982.

But the health of water flowing into this eagles’ Eden is at risk. A Canadian mining company, Constantine Metal Resources, has set its sights on a massive copper- and zinc-rich sulfide deposit upriver. It could break ground this year—an outcome many fear would irreparably alter this salmon-rich watershed, and the eagles, bears, and people that depend on it.


Eagles employ a mix of methods to get a meal: snatching salmon from frigid waters, scavenging bears’ leftovers, stealing another bird’s catch. Salmon are the crux of this complex ecosystem, and Chilkat is home to all five North American Pacific species. They feed not only eagles, bears, and the Tlingit people, who’ve lived in this valley for more than 2,000 years, but also the trees, which draw nutrients from decomposing fish carcasses dropped in the forest by predators. Salmon are critical to the local economy, supplying a multimillion-dollar commercial fishery, and tourists flock to watch the charismatic megafauna that eat them. Stressors like climate change, warmer, more polluted oceans, and overfishing are likely responsible for recent steep declines in some salmon populations here, making locals even more concerned about the added impacts of a mine.
Satellite tracking has revealed that Baldies born as far away as California fly to Alaska in the fall. These juveniles depend on plentiful prey to make it through their first year. “And the Chilkat, with its late salmon run, is the last place to eat if you’re an eagle,” says University of California Santa Cruz raptor expert Glenn Stewart. “It’d be a significant loss if this food source goes away.” Eagles’ fish-heavy diet means that pollution from mining upstream would harm them, both due to fewer fish and the heavy metals, hydrocarbons, and other toxins that salmon would pass up the food chain. Salmon are highly sensitive to heavy metals; even minute quantities impair their ability to find spawning grounds or sense danger and can cause birth defects and death.
After completing its initial exploration phase, Constantine Metal Resources cleared the next hurdle in July, when the state granted a wastewater permit. Constantine plans to discharge some 360,000 gallons of effluent daily, passing it through two settling ponds before releasing the still-contaminated water into gravel beds adjacent to a creek that flows into the Chilkat River.
“Living here we are always surrounded by eagles; they’re our closest neighbors and eat the same food we do,” says Tlingit elder Lani Hotch, who lives in Klukwan, one of the continent’s oldest continually inhabited sites, 12 miles downstream of the proposed mine. “We’ve lived this way for generations, and the mine would jeopardize all of it. If we destroy this valley for short-term economic gain, we’ll kill ourselves in the long run.”
The Chilkat Indian Village and other groups are suing the U.S. Bureau of Land Management to halt the mine construction. They’re also fighting to have the Chilkat designated a Tier 3 river, which would preserve it as-is, banning most discharges that threaten water quality or endanger fish; the state has refused to process any nominations, despite a federal directive to do so. And with the Trump administration slowing actions against polluters, it’s unlikely to intervene. “We’re seeing this kind of pattern all over Alaska,” says Audubon Alaska executive director Natalie Dawson. “Several large mining projects are being pushed through with this really aggressive open-for-business approach.” It’s one that may imperil even nature’s strongest predators.
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