Fall-run Chinook salmon—which swim upstream in the fall—are less affected by the dams than their spring-run cousins, because temperatures are typically cooler when they return to freshwater.

The journey of salmon swimming miles upstream to lay their eggs is nothing short of a natural marvel. This epic journey, ...

These fish perform a mighty metabolic feat when they swim hundreds of miles upstream without food to spawn. Experiments in the field and in the laboratory help to clarify how the feat is accomplished ...

“Salmon swimming upstream is a symbol of the arrival of autumn in Shiretoko,” said Katsunori Seki, an underwater photographer who has been observing salmon in the rivers here. “I hope we can ...

Fish ladders look like a series of small waterfalls alongside a dam. Salmon swim upstream, and they "jump" from one waterfall to the next, until they reach the reservoir at the top of the dam.

Chinook salmon were once abundant in the North Yuba River in California’s Sierra Nevada. But since 1941, they’ve been kept ...