By Katy Budge
(Ed. note: A version of this article appears in the current issue of Edible San Luis Obispo magazine, available by subscription and at various spots throughout SLO County. This was one of my favorite recent pieces to research and write, plus it was beautifully illustrated by the very talented Anna Takahashi.)
San Luis Obispo County has abundant seafood resources off its coastline, but it might come as a surprise that the creeks often teemed with steelhead trout. Sadly, the local population of steelhead was federally listed as threatened in 1997.
“Historically there were over 20,000 adult steelhead returning to our central coast streams, today
there are less than 500,” says Don Baldwin, a California Department of Fish and Wildlife Environmental Scientist for Steelhead Habitat and Population Assessment in San Luis Obispo County.
A page in Robert A. Brown’s The Story of the Arroyo Grande Creek describes how “… steelhead would fill the creek as they propelled their great silvery bodies inland.” Anecdotal estimates in the book put the number of trout in Arroyo Grande Creek at about 3000-5000 in the early 1940s.
John Piatti, Jr. remembers populations like that, and notes that “All the streams leading to the ocean had steelhead.” A council member of the Salinan Tribe of Monterey and San Luis Obispo Counties, he grew up in Morro Bay and avidly fished every one of those local waterways with his father and many other family members.
In the 1960s and 70s, they would eagerly await the first good rains that John says “would break the streams open”, allowing ocean-going steelhead access to their inland spawning grounds. John recalls that as he stood in the water casting his line, the steelhead were so plentiful “they’d be running into your legs.” When he caught a really good keeper, it would be about eight pounds and 30 inches long.
What Happened?
It’s easy to lump steelhead in with other species and assume that the population crashed because of overfishing. But steelhead’s demise in San Luis Obispo County came from other forms of human activity. That’s because this trout is a unique type of fish.
Technically, steelhead trout and rainbow trout are the same species, Oncorhynchus mykiss. Both spawn in freshwater. But, while rainbow remain inland after they hatch, steelhead make their way to the ocean before returning to their spawning grounds. It’s a trait they share with salmon, making them both anadromous fish.
Yet unlike salmon, steelhead don’t die after spawning. And what’s next for them varies. After heading back to the ocean, they might come back the next year to spawn. Or, at any point in their lives, they might just choose to remain ocean-going fish.
How Have Humans Impacted Steelhead?
What has proved nearly fatal for local steelhead populations is eliminating that “choice” – for lack of a better word. Being able to return to their native spawning grounds means physically being able to get there, being able to take advantage of when those first rains break open the streams.
Human activity on the Central Coast has made that very difficult. John remembers catching steelhead well into the 1980s, but he knew the population was already compromised.
“Steelhead need the Four Cs: Cold, Clean, Complex, and Connected,” explained Zach Crum, a San Luis Obispo-based District Fisheries Biologist with California’s Department of Fish and Wildlife. “Cold” and “Clean” refer to water temperature and quality, while “Connected” is the ability to get from fresh water to the ocean and back.
“Complex” indicates the diversity of habitats needed to support steelhead throughout its life cycle, notes Zach. For example, juveniles need woody debris for shelter, adults seek areas such as shady ponds for resting, and the entire ecosystem has to provide varied and adequate food sources.
With the exception of Chorro and San Luis Creeks, most of the steelhead’s local channels no longer come close to providing those conditions. Banks have been stripped of protective vegetation, streams have been polluted, dams have been constructed, and overall riparian (creekside) habitats have been degraded.
A particular low point came in 1966 when San Luis Creek was described by a state pollution analyst as “an open sewer”. (Tribune, February 2015) Hard to believe that about a waterway that’s now a jewel in San Luis Obispo’s urban crown.
What’s Being Done?
Though securing and maintaining funds for research and restoration is always a challenge, there are some significant efforts being made to protect San Luis Obispo County’s steelhead and its habitat.
Among those projects are removing physical barriers to migration, harvesting rain water to maintain water levels, and improving riparian corridors. Essentially, trying to restore and provide those Four Cs.
Other threats to steelhead are invasive species such as pikeminnow. A project to eradicate them is currently underway in Chorro Creek under the aegis of the Morro Bay National Estuary Program (MBNEP). These non-natives were probably introduced as bait fish in the 1960s or 70s, said Carolyn Geraghty, MBNEP’s Restoration Program Manager. The pikeminnow not only compete with steelhead throughout their life cycle, but also have a voracious appetite for juvenile trout. MBNEP’s data estimate that physically removing just one pikeminnow out of the creek can protect about 40 steelhead annually.
Of course, it can certainly be said that Mother Nature is what happens when humans are making other plans. Part of California’s natural cycle includes wildfires and boom-to-bust rain years, conditions that are only being accelerated by climate change. And, as Zach Crum put it, “How can we manage for fire and drought?”
Why Bother Saving Steelhead?
Though steelhead provided a reliable subsistence fare for indigenous people and later inhabitants, they weren’t considered an essential, year round food source. And, there was only a fleeting commercial steelhead market in San Luis Obispo County circa the 1980s. So why care about their dwindling numbers?
“Steelhead are a top predator in these ecosystems,” Zach explains. “Their loss would have impacts throughout the food chain, and they’re a charismatic and integral part of the cultural history here.”
“The loss of steelhead may not directly affect other species, but would show a collapse of the ecosystem,” Don adds. “It would allow non-native or invasive species to populate the habitat, drastically changing the ecosystem.”
As Carolyn further pointed out, “Steelhead are a keystone species.” In other words, they’re part of the glue that holds the local ecosystem together. If you think of them as the proverbial canaries in the coal mine, what else might we lose if we lost them?
For John Piatti, Jr., something has already been lost – that multi-generational camaraderie of angling for steelhead and bringing one of those keepers home. “Anybody that has a passion for fishing has to admire them,” he said. “They’re twice as ferocious as salmon, and when you see that big silver fish jumping …” He paused a bit wistfully before adding, “It’d be tremendous to see them come back.”