“It’s very, very important for the future of conservation science that we learn from this event and that it never happens again,” said Nann Fangue, a physiological ecology professor at UC-Davis who uses the fish for her lab’s research.

The fish were found dead Tuesday morning, when researchers were doing their usual check of the tanks. About three-quarters of the fish that died were being used in Fangue’s lab, and many of the students and staffers who found them work with her, making the already shocking loss “really, really hard,” she said.

“We share the grief of the faculty, staff and students who worked to care for, study and conserve these animals,” UC-Davis said in the news release.

The chlorine exposure killed a variety of fish species at the center, including green and white sturgeon and endangered Chinook salmon.

From environmental stressors to fish diseases, the topics of study at CABA are dedicated to conservation, Fangue said. Some of the research at the center will be delayed by years after the loss.

“This event is a very, very sad thing for all of us who spend our careers in the service of the conservation of California’s native fishes or fishes more generally,” she said.

About 100 fish — mostly tilapia and two sturgeon — survived the exposure, UC-Davis spokesperson Andy Fell said.

The source may have been a chlorination system that is used to prevent pathogens from entering the environment outside CABA, Fell said.

The incident at CABA echoes a 2017 case at the University of Alberta’s aquatics facility, where a power failure caused dechlorination pumps to fail, killing about 9,000 fish. The incident occurred before the university could carry out its plans to replace the facility’s water supply system, according to Folio, a publication at the University of Alberta.

Since the fish were found dead at the UC-Davis research center, the university has focused on caring for the survivors and providing resources to support staffers’ mental health.

“It was a very traumatizing and devastating event for all of us,” Fangue said.

She added that UC-Davis has also committed to replumbing the aquatic center, to give the tanks a “fresh start.” The university is evaluating its other aquatic-research facilities.

For Fangue, the priority has been to support her team members, reminding them of why they began their research — and reminding herself.

At CABA, there were unhatched Chinook salmon eggs in the tanks exposed to chlorine. Some of those eggs hatched Monday, and they may survive.

“It may not have been a total loss,” she said.