Return of the native
By Bret Bradigan

The Ventura River and its tributaries seem an unlikely laboratory for an experiment in which many of the current streams of controversy in Ventura County run together.
Long stretches run dry for at least some of the time in most years, and most of the time in some years. Despite having been scoured clean in the devastating flood in 1969, structures, including homes and outbuildings, have crept back into the flood plain. Despite the apparent death and unlikelihood of resurrection of the Petrochem plant, plumes of contaminants continue to seep into the watershed. A dam that has outlived its usefulness, but for which no political or financial will has been mustered for its removal, continues to impede upstream progress and access to prime spawning beds for the endangered Southern California steelhead trout.
An expensive proposal to build a ladder to allow these dwindling few fish to get past the Robles Diversion, which channels the water of Ventura River into Lake Casitas, and reach spawning grounds untouched for a half century, has met with resistance and bureaucratic delays. If the fish ladder is built, important questions remain unanswered. Where will the water come from? And at whose expense?
The final few
No one knows for sure how many steelhead trout still seek to pass on their genetic legacy amid the braided gravels of the Ventura River and its tributary creek beds.
Some estimate as few as 50, perhaps none in a dry year.
Jim Edmondson, CalTrout's conservation director, said 50 is only a guess, too few, even, to justify hiring a crew to probe the pools with electric prods that stun the fish momentarily, long enough to take their count. But enough, according to the National Marine Fisheries Service, to justify spending $4.5 million XXX to build a fish ladder to allow the endangered species to swim past the Robles Diversion dam, which channels the waters of Ventura River into Casitas Lake.
As is most probable, a few schools of steelhead, lured by ancestral imprinting, by some scent or sensation only found in waters that drain through Casitas gap, wait patiently offshore of the river's mouth until the torrents of a storm breach the sandbars and give them a clear run to their birthplace creeks.
Steelhead are anadromous, or migratory, rainbow trout. They spend part or most of their life in the ocean, returning to their home creeks to spawn. The fry spend one to three years in the creeks before migrating to the ocean for their adult phase. Usually beginning with the first hard rain of winter, the fish head back to their native streams to spawn and complete their life cycle. Steelhead, unlike Pacific salmon such as chinook or coho, do not die after spawning, and can complete three or four return trips.
According the National Marine Fisheries Service, as many as 5,000 steelhead once surged up the river from the ocean, completing their spawning cycle amid the trickling brooks of the Matilija forks, or up through San Antonio Creek perhaps as far as Thacher School. While the main stem of the river may dry up for long stretches, streams higher in the drainage - covered by shade and protected by steep valleys - run year-round unless afflicted by unusually severe and enduring droughts.
The entire watershed drains 228 square miles of a basin rimmed by the coastal mountains reaching more than 6,000 feet above sea level. The longest stream course available would be up the river to Matilija's main forks, which, together, take up 32 miles, or about 16 miles each.
The spawning females fan pea- to marble-sized gravel with their tails to create their spawning beds, or redds. They deposit their eggs, which are then fertilized by the males' sperm, or milt. The most desirable spawning areas contain gravels loose enough to allow water to percolate through them, bathing the eggs in a rich flow of oxygen.
The way it was
Anecdotal accounts of the great sport these fish once provided local anglers are not hard to come by. Jim Coultas, Casitas Municipal Water District board member, remembers hearing his grandparents talk about limiting out one day in 1916, with the smallest of the trout measuring 18 inches. The limit at the time was 100 fish per day per person.
The Ventura County Fish and Game Commission prepared a report for the Board of Supervisors in March 1973, in which they "initiated an investigation into the nature and scope of pollution in the Ventura River. Out of this investigation, an interest developed in protecting the river's existing resources and restoring its historic trout and steelhead fisheries."
One fisherman, Henke, said the runs of steelhead would begin right after the first of the fall rains and continue through April. "These later runs were much larger fish and I can remember seeing schools where the average was 10 to 13 pounds," he said. A 1946 census showed 248 fishermen along the Ventura River on opening day, with an estimated economic impact of $100,000.
All that changed in 1948 with the construction of Matilija Dam, which cut off steelhead from prime spawning habitat in the middle forks of Matilija Creek, and with the construction of Casitas Dam in 1959, which further blocked the fish from spawning beds along Coyote Creek. Factor in industrial development along the river plain below Foster Park and the conditions were set for dwindling runs of steelhead, along with dwindling opportunity and interest from fishermen.
A few souls continued to chase those remaining fish, however, with steelhead catches reported "every year the rains were sufficient to allow the river to run into the ocean for a week or more," according to Milo Bugg. Bugg reported taking 12 steelhead measuring 18 inches below the confluence of San Antonio Creek in the 1960s.
Malibu Creek had been regarded as home to the southernmost active steelhead population, though Rindge Dam, a mere two miles upstream from the Pacific, blocks access to nearly all of the prime spawning grounds. The most recent census, according to Edmondson, put the number of returning steelhead in that stream at 37.
But in 1997 an enterprising college student in Orange County hooked a large trout in San Mateo Creek, near Camp Pendleton, which later proved to be a steelhead. And steelhead historically ranged as far south as mid-Baja Peninsula, though there is little data available on Mexican steelhead.

The way it will be
As if present perils weren't enough, a new threat to steelhead has emerged.
The National Resources Defense Council global warming models, using emissions scenarios from the Intergovernmental Panel on Climate Change, predicts a dire future for all fish that depend on cold water, particularly the Southern California steelhead that are already at the limit of their range. By the year 2030, trout and salmon could lose 5 to 17 percent of their habitat, 14 to 34 percent by 2060 and 21 to 42 percent by 2090. "Loss of habitat in the South, Southwest and Northeast could be particularly severe, although significant losses are expected through the current geographic range, with greatest losses expected for California," the study concluded.
Generally, trout require water cooler than 68 degrees. While they can withstand higher temperatures for short periods of time, the warmer the water, the less oxygen it can carry, and the more stress the fish endure as a result.
"Southern California steelhead, which have had to adapt over millennia the Mediterranean climate, are thought to possess unique abilities to remain healthy in the highest range of water temperatures for the species throughout its entire range along the Pacific Coast," said Edmondson.
CalTrout commissioned water temperature studies on Malibu Creek below Rindge Dam in 1989, during a particularly dry year. During July and August, mean temperatures between 69.8 and 73.4 degrees were recorded, and maximum temperatures briefly exceeded 80 degrees. None of the researchers "observed any adverse effects to steelhead below Rindge Dam during this warmer period, thus confirming the high temperature tolerance of Southern California Steelhead," according to the report.
As global warming renders present habitat unsuitable in the future, those temperature-tolerant fish will become even more important, Edmondson asserts, as broodstock for restoring populations further north. These southernmost fish, including Ventura River steelhead, "are the parent genetic materials for all steelhead on the Pacific Coast," he said, citing Aldo Leopold's edict that "the first rule of intelligent tinkering is to keep all the parts."
Edmondson said, "For that point alone, they are important."

© 2003 The Ojai Valley News

Back to the news