Guest blogger: Michael Paccassi
Fire and drought. No, I’m not talking about the coming apocalypse—I’m talking about summer in California. Every year around this time, the entire state seems to go up in flames (quite literally). As I write this now, the 33,000-acre Rey Fire continues to engulf the drought-stricken vegetation of Santa Barbara’s Los Padres National Forest (LPNF), and plumes of smoke shroud the South Coast. From an ecological point of view, the Rey Fire is not surprising; large wildfires often occur after extreme drought. Despite this winter’s El Niño, five consecutive years of below average rainfall have left the LPNF desiccated and increasingly vulnerable to wildfires, and caused scientists to wonder what the impacts are going to be on its fragile ecosystems.
For the past few months, I have been working with Blue Tomorrow—a local environmental consulting firm started by two Bren alumni—to help quantify the effects of the 2007 Zaca Fire on steelhead habitat in the area. As many may remember, the Zaca Fire was massive. Eight times the size of this week’s Rey Fire, it burned over 240,000 acres of wilderness in the LPNF. What remained were steep, exposed hillsides. With little vegetation to hold the slopes in place, large amounts of sediment eventually eroded into nearby streams. While the fire’s direct effect on human beings was minimal (only one building was destroyed), its impact on the species, environment, and water quality in the LPNF remains largely unknown.
The endangered Southern California Steelhead (Oncorhynchus mykiss)—particularly sensitive to water quality changes caused by wildfires—makes an excellent indicator species to assess the overall health of a river system due to its numerous ecological needs at different life stages. In efforts to collect data on this species habitat needs, each week our crew of four gears up to go backpacking in the LPNF. We spend four days hiking through creeks and gathering information about critical steelhead habitat affected by the Zaca Fire.
Maybe I should have seen this coming, but I never thought that the most difficult challenge would be finding flowing water in the first place. Sure, it’s supposed to be dry in the mountains above Santa Barbara during the summer. And yeah, we are in the midst of an extreme drought. But, just how hard could it be? As it turns out, very hard. After hiking hundreds of miles of trail and over 50 miles of stream in search of surveyable steelhead habitat, we managed to find flowing water in a mere 5 miles of stream. For perspective, hundreds of miles of steelhead habitat were affected by the Zaca Fire.
From my personal experience, here’s what that means for steelhead. Areas that were historically identified as “perennial” (or flowing year-round), are now dry. Streams that were previously identified as prolific steelhead habitat, now have non-existent trout populations. While five consecutive drought years appear to have had a major effect on the extent of year-round steelhead habitat, high levels of sediment—likely from the Zaca Fire—continue to choke many of the streams. And, surprisingly, there are still small populations of wild trout! Although the situation for steelhead in the LPNF is dire, many fish still exist in these meager 5 miles of flowing stream. It is quite amazing to find that these fish have managed to survive in such harsh conditions, exacerbated further by large fires and prolonged droughts.
As we begin closing the chapter on another large fire season in California, we must not forget that fire and drought affect more than just human populations. Yes, Southern California Steelhead have evolved to cope with the ecological implications of fire and drought—this is why they are so amazingly resilient and can exist in such harsh conditions—but steelhead habitat destruction and degradation have already put pressure on steelhead survival. Now, their very existence relies on the ecological integrity of the LPNF. We are so lucky to have the untamed wilderness of LPNF close by, and there is still an abundance of wild river for steelhead to thrive in—we just need a little bit of water. For the sake of the Southern California Steelhead, here’s to hoping that this winter will be a wet one!
Michael Paccassi is a second year MESM specializing in Water Resources Management at the Bren School. He is Crew Leader for the Blue Tomorrow backcountry stream survey crew in the Los Padres National Forest.