Over the last 150 years, the effects of human activities such as agriculture, mining, damming, logging, and overfishing have led to declines in Pacific salmon species. For decades, efforts have been made to help salmon persist through the challenges they faced. Now climate change is adding to the suite of challenges threatening the long-term viability of salmon and the cultures, traditions and economies of the communities that depend on them. In the Pacific Northwest, the populations of many salmon species have declined significantly, with some protected under the Endangered Species Act. In Alaska, a place with historically healthy salmon runs, the decline of some runs has caused tremendous hardship and concern.