Water levels are 5 feet below normal.

If carbon emissions continue at current rates, so much mercury will leach from thawing permafrost that fish in the Yukon River could become dangerous to eat within a few decades.

The sea lions have posed a long-running conundrum for wildlife officials, pitting mammals protected under federal law against protected — and valuable — fish runs.

Like its old-growth trees, the Northwest’s big, old chinook salmon are largely gone, a new study finds, with implications for Puget Sound’s critically endangered southern resident killer whales.

The counts of fall Chinook at Bonneville Dam are 29 percent below preseason forecasts, and ongoing fisheries are approaching the allowable catch limits under the Endangered Species Act (ESA).