SACRAMENTO, Calif. — The fragile little fish that swim around in dark tanks in a lab are the last hope for their kind. The lab director who oversees their care, Tien-Chieh Hung, explained that when the Delta smelt captives are young, scientists at the UC Davis Fish Conservation and Culture Laboratory put snails in the black interiors of the tanks as a slow-moving mollusk cleaning crew.
The snails must do the work because the fish are so delicate, they could get tangled in a human cleaner’s arm hair and perish.
The whole project of painstakingly raising these temperamental endangered creatures, Hung said, may be futile — the smelt could just keep surviving in the lab because of human intervention, and vanishing in the wild because of human intervention.
With a California Delta habitat especially damaged by the rising temperatures and drought wrought by human-caused climate change and the unslakable thirst of people and farms in California, the smelt are perilously close to extinction.
“We do research, we try to do something for the earth,” Hung said. “There are just so many things to be done.”
It might not be enough to save the silvery fish, but it’s created a bizarre parallel world for these small creatures and the scientists who look after them, as well as for the visiting scientists who have much less experience with the smelt, and accidentally kill a bunch of them every time they handle the fish for research.
Significant Delta smelt populations only exist three places in the world: The Fish Conservation and Culture Laboratory at the mouth of the California Aqueduct, which Hung oversees; the Livingston Stone National Fish Hatchery at the base of the Shasta Dam, where Hung sends emergency fish in case something catastrophic happens to his own lab; and in their native California Delta, in precipitously dwindling numbers — as of this past winter, Hung sends reinforcements there, too.
Probably less than a thousand smelt are flitting through murky waters in the wild. In the rows of tanks in Byron, scientists care for more than 100,000 fish. And Hung, a wry former pesticides engineer, led the charge to release 56,000 captive fish in the winter for the first time, after years of debate.
He wasn’t sure they would make it in the “home” that had never been their home. “They might be too naive,” he said. “They might just become (a) buffet for bigger fish.”
But the scientists thought they had no choice, because with so few smelt in the wild, researchers couldn’t even find them anymore.