Displaced Santa Ana sucker fish are a problem for wildlife authorities
Just weeks after the Station fire ravaged Big Tujunga Canyon, state and federal biologists raced to salvage hundreds of rare Santa Ana suckers from the canyon creek before an advancing storm could inundate the small fish’s last outpost in Los Angeles County with mud and debris.
On Oct. 15, 290 of the federally threatened suckers were stunned with electric currents, scooped from the water with nets and taken to a temporary holding facility in downtown Riverside. Wildlife authorities planned to return the fish to their old haunts this summer.
But it may not be that easy. The hastily arranged rescue effort has presented wildlife authorities with daunting challenges that could leave the suckers marooned indefinitely in an artificial stream at the holding facility.
“The removal was done in anticipation of what was believed would be a very large storm in an area left prone to flooding by the Station fire,” said Jane Hendron, a spokeswoman for the U.S. Fish and Wildlife Service. “Captivity comes with risks. At this time, we don’t know what the final outcome will be. It may not work out.
“But we remain hopeful,” she added, “that the habitat will come through just fine and we will be able to return those suckers back to the Big Tujunga wash.”
The state Department of Fish and Game, the U.S. Forest Service and the U.S. Fish and Wildlife Service are scrambling to ensure the long-term survival of the captive fish in the event that the Big Tujunga ecosystem is destroyed by flooding this winter -- including rain expected to last much of this week.
“All options are open,” said state Fish and Game senior biologist Dwayne Maxwell.
They include searching for streams elsewhere that could accommodate the captive suckers, a bottom-feeding fish that once was abundant in waterways across Southern California, according to state Fish and Game biologist John O’Brien.
Prospective streams must include clear, cool rocky pools, and be currently unoccupied by Santa Ana suckers in order to ensure that the genetic makeup of the introduced fish remains unaltered. The fish, which have large, thick lips and small mouths that vacuum or suck up algae and other organisms for food, also prefer gravelly bottoms and stream-side vegetation.
Concrete river channels, dams and pollution caused by urban runoff have all played roles in the species’ decline, scientists say. Today, Catostomus santannae clings to existence in small, shaded stretches of the Santa Ana and San Gabriel rivers and Big Tujunga Creek.
The decision to rescue the suckers followed warnings of potential massive flooding “that could extirpate aquatic species,” O’Brien said.
“Our primary concern was the Santa Ana sucker, which in Los Angeles County is relegated to a 14-mile stretch of Tujunga Creek between Hanson Dam and Big Tujunga Dam,” he said.
With $10,230 provided by the Forest Service, a special sucker retrieval team armed with electro-shock wands and long-handled nets set to work “just 12 hours before the canyon was to be hit by the first big storm after the Station fire,” O’Brien said.
But the anticipated massive storm fizzled, and the agencies ended up with hundreds of threatened fish and nowhere to put them if, indeed, their native habitat is lost.
The captured fish are 1 to 2 years old and have a life expectancy up to four years. If Big Tujunga gets buried in mud, authorities estimate it could take five years or more before conditions become suitable again for re-population.
No one can say with certainty whether the captive fish would reproduce in appreciable numbers or simply die of old age before they could be returned to their native stream.
In the meantime, they have been temporarily housed in the 300-foot-long artificial stream at the Riverside-Corona Resource Conservation District headquarters in Riverside.
The water is recycled and filtered, shaded, and rich in dissolved oxygen. The fish are fed dried shrimp, protein meal and algae wafers. The stream is surrounded with 10-foot-high wire fences to protect the fish from predators such as raccoons and herons.
Peering through the fence at a 3-inch-long translucent brown sucker that was fluttering around a filtration system, Kerwin Russell, the district’s natural resources manager, said, “They’re doing exceptionally well. We’ve lost a few. But their mortality rate in the wild is about 50%.”
In any case, “We can’t keep these fish forever,” said conservation district manager Sherri Lamb. “I anticipate there will be healthy discussions between the regulatory agencies and this district over their long-term plans for these fish.”
Wildlife authorities are considering the possibility of moving the suckers to a Los Angeles County facility capable of caring for them for years, if necessary.
“So far, we have not located such a facility,” O’Brien said. “But I still think it was a good idea to capture these fish. It’s better to err on the side of caution.”