It’s a watershed day for Arctic conservation.

Facing dramatic evidence of climate change in the Arctic, the North Pacific Fishery Management Council voted unanimously on Thursday to prevent the expansion of industrial fishing into all U.S. waters north of the Bering Strait. There are no large-scale commercial fisheries currently operating in the U.S. Arctic, and now there won’t be.

Nearly 200,000 square miles of pristine Arctic waters — an area bigger than California — will remain untouched by the extensive fishing nets, miles of hooked longlines, and destructive bottom trawls of industrial fishing. This means that the unknown but crucial fish species such as Arctic cod will stay put as the heart of the ecosystem.

The decision, which follows years of work by conservation groups including Oceana, Audubon Alaska, Ocean Conservancy, and the Pew Environment Group, is precedent-setting: It’s one of the largest precautionary measures in fisheries history.

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As we’ve all heard by now, climate change is causing the Arctic to warm twice as fast as the rest of the planet, leading to a dramatic reduction in Arctic sea ice cover. As previously ice-covered waters beckon to new industry, and fish populations expand northward in search of cooler waters, commercial fishing was inevitably headed for the Arctic’s watery frontier. Not anymore. The Council’s decision will prevent such expansion unless and until science shows that commercial fishing would not threaten the health of Arctic ecosystems or opportunities for the subsistence way of life critical to indigenous peoples.

The National Marine Fisheries Service is expected to approve the Council’s decision and issue final regulations later this year. And once the Obama administration approves it, the United States will be — dare I say it? — a leader in Arctic conservation.

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I’m celebrating today, but commercial fisheries aren’t the only industry threatening the survival of the Arctic. Will the drilling and shipping industries follow suit in freezing their Arctic footprints? Let’s hope so.