Photo by Mike Weir
California has been ravaged by an increase in the frequency and intensity of wildfires. During 2018, there were more than 8,400 wildfires that burned nearly two million acres across the state, the most in recorded history. The increase in fire frequency is the result of an interaction between climate change and increased fuel loads and fire suppression over the last century, among other factors. Despite the recent increase in wildfires throughout the state, we know relatively little about how they affect salmonids. Understanding the effects of wildfire on salmonids, however, is important. Wildfire was found to be one of the primary anthropogenic threats affecting inland salmonids in the recent State of the Salmonids Report. Further, recent fires such as the Carr Fire near Redding, California and its proximity to the remaining population of winter-run Chinook salmon suggest we need to better understand the various ways wildfire can affect vulnerable species or populations.
Similar to many large-scale ecological processes, the magnitude of effects of wildfire on salmonids are context specific and depend on numerous factors. Such factors include the location of the fire within the watershed, the amount of area burned, the intensity of the fire, the species and/or populations affected and their status, and the condition of the watershed prior to fire. Similar to droughts and floods, wildfires also represent important disturbances on the landscape that salmonids have evolved to over millions of years. While the short-term effects of wildfire on salmonids can negatively affect populations in numerous ways, similar to floods and drought, some of the long-term effects can be beneficial to salmonids.
How Wildfires Affect Trout and Salmon
The Hat fire scar near Hat Creek and Fall River. Photo: Michelle Titus