Chinook salmon are facing unprecedented challenges as their once-thriving populations struggle to survive. A new study published in the journal Ecosphere suggests that decades of human activities, including ocean harvest, artificial propagation and reservoir construction, have not only reduced the size of these fish, but also disrupted their ability to spawn successfully.

As four aging hydroelectric dams are demolished, tribes and communities along the Klamath River wait anxiously to see what the future holds. “Once a river is dammed, is it damned forever?” experts ask.

A unique ocean-going restoration effort is just getting underway along the Sonoma Coast and its goal is to rescue an underwater forest that's critical to marine life.

As the climate changes, many species are expected to adjust where and how they live. Some are expected to seek cooler elevations as it warms, but what happens to species already at the top of a mountain?