Episode Details

The Benefits of Restoring Aquatic Ecosystems

For over a century, native salmon populations in California have been adversely impacted by human activities such as mining, dam building, and overfishing practices, often leading to the loss of critical habitat and  decreased genetic diversity. With additional environmental stress from climate change, such as rising surface temperatures and changes in freshwater temperature and flow, salmon populations have been quickly declining. In addition, dams trap salmon into the warmest parts of the watershed, where they are more vulnerable to predators and have decreased breeding area necessary for their survival. Salmon are an incredibly important marine species, often referred to as a keystone species, as they play an essential role in the health and function of an ecosystem. Not only are salmon ecologically beneficial through their ability to disperse nutrients throughout streams and rivers, but they are also culturally significant to Indigenous people. Indigenous culture has historic ties to salmon, including reliance on the species for sustenance and livelihood. As a result, indigenous tribes have a particular attachment to and concern for salmon, and issues such as diminished water quality and the burdens brought about by climate change have a deep resonance. In order to restore salmon populations, Indigenous groups and environmental activists have advocated for increased restoration of watersheds, the reopening and improving of ecologically important areas, and the removal of dams that block natural salmon spawning habitats.  

Dam Removal as Solution to Climate Change

As climate change reduces water flows in California and increases temperatures beyond which salmon can tolerate, certain populations of salmon have become endangered species. Drastically reduced population levels have brought about a wave of concern, as their absence can disrupt nutrient cycling, reduce food availability, and negatively impact the livelihoods of people who depend on salmon for sustenance, income and cultural value. The “California Salmon Strategy” outlines actions for state agencies to stabilize and promote recovery of salmon populations. The plan envisions coordination among multiple state agencies, Tribal Nations, and federal agencies for implementation. 

In the late 19th century, treaties between Pacific Northwest tribes and federal agencies gave tribes the right to hunt, gather, and fish in “accustomed grounds” in exchange for land. However, by the mid-20th century, these agreements had largely been abandoned by the federal government, with states outlawing traditional methods of subsistence fishing. Coupled with increased development and resultant large-scale habitat loss, salmon populations have been on a steady decline. Tribal governments have long opposed the construction of dams in California, raising concerns of the devastating effects such construction has had on their way of life and the biodiversity of river