Dechlorination failure results in significant fish losses

UAlberta taking immediate action to mitigate risks after dechlorination system failure.


An electrical short in the University of Alberta’s aquatics research facility has resulted in the deaths of more than 9,000 fish from exposure to chlorinated tap water.

The power disruption caused two dechlorination pumps to stop working sometime between the afternoon of Friday, May 12 and the morning of Saturday, May 13, when staff returned to the facility. That allowed chlorinated municipal tap water to enter the flow-through system of freshwater aquatic tanks, resulting in nearly 100 per cent mortality of trout and the deaths of goldfish, carp, graylings and frogs. Several thousand zebrafish and other warm-water species housed in separate tanks were unaffected.

“The University of Alberta regrets the loss of any animal in our care and we are doing everything possible to ensure this does not happen again,” said Lorne Babiuk, vice-president of research. “We have advised the appropriate regulatory body, the Canadian Council on Animal Care (CCAC), about the incident and our response. We will not resume research in the affected freshwater tanks until the university and CCAC are satisfied it is absolutely safe to do so.”

The incident led to the death of 3,268 adult fish and 6,000 fingerlings (juvenile fish with scales and working fins). This includes:

  • 1,093 adult trout and 6,000 trout fingerlings
  • 2,073 goldfish
  • 96 carp
  • 6 graylings
  • 75 frogs

University response

Located in the Biological Sciences Building, the university's aquatics facility opened in 1969 and houses freshwater and marine species, including fish and invertebrates, used for research and teaching. Much of the research focuses on environmental toxins such as hydraulic fracturing fluid, micro plastics, environmental pathogens, herbicides and pesticides and climate change.

The CCAC has advised the U of A against restocking the aquatics facility with any species of fish or frogs without conducting a thorough analysis of the building’s electrical system and installation of fail-safe redundancies and monitoring alarms.

Babiuk said facilities and operations staff have been working with researchers and the animal service unit that oversees the aquatics facility to implement interim and long-term solutions. He credited the quick thinking of the animal support unit staff, who managed to save as many fish and frogs as possible.

Babiuk confirmed the power disruption was due to a corroded switch that has since been fixed. The sodium thiosulfate pump that’s used to dechlorinate the water has been replaced and an alarm has been added to warn on-call animal care staff if it or the backup fails. That will give the university time to shut off the flow of chlorinated water. Plans are also in the works to add a chlorine alarm system that would be monitored 24/7 from the U of A’s central control centre. These interim improvements could be in place within four to six weeks, Babiuk said.

Babiuk said the university veterinarian has been in contact with the CCAC advising them of the university's response. All research involving animals follows CCAC animal care standards to ensure they are treated humanely. Projects are also reviewed by the U of A’s animal care and use committee, which falls under the Research Ethics Office.

Facility failure stalls important fish biology research

The U of A’s fish biology research group is internationally renowned and consists of 15 faculty and more than 40 postdoctoral fellows, graduate students and undergraduate research assistants, all of whom use the aquatics facility for research. The research areas covered include developmental biology, neuroendocrinology, fish reproduction and behaviour, immune responses to pathogens and toxicology.

Greg Goss, a professor in the Department of Biological Sciences, was among the most seriously impacted. He is leading a study into the environmental impact of hydraulic fracturing fluids.

Hydraulic fracturing is a process of injecting pressurized water, sand and chemicals into shale rock to recover gas and oil and the “world is clamouring” for research on its environmental implications, Goss said. His team recently published a study that showed fracking fluids harm rainbow trout, even if significantly diluted.

“We are the only facility in the world that I am aware of that is using hydraulic fracturing fluids for toxicological research,” said Goss. “I gave an online webinar recently and had regulators from at least five different countries—including Canada, the United States, Australia, United Kingdom and Brazil—all online and listening to find out more because they had no concept about what the differences are between frack fluid and normal oil and gas.”

Goss said it’s impossible to do this type of research without fish; computer modelling provides a limited picture. Fish are routinely used by scientists around the world for toxicology research, he added.

“It’s a key regulatory species. It’s the one that’s used by many places in the world to see how toxicants impact on fish. We want to protect our fisheries, which are an important food resource and important sports and cultural resources. Fisheries are a key sentinel for a healthy ecosystem.”

University working to limit impact on students

Goss said his fracking research and several other projects have now halted. That means graduate students and postdoctoral fellows who chose the U of A for its leadership in toxicology research will be set back weeks and possibly months, affecting thesis timelines and deliverables to granting agencies and industry partners.

“I have people who have lost four to six months worth of work, so very significant losses.”

The university will be working with faculty and students to mitigate the impact of this disruption and identify specific accommodations as needed, Babiuk said.

Long-term renewal plan in the works

The aquatics facility’s water treatment system was flagged as a “serious recommendation” by the CCAC during recent visits. The university responded last year by hiring an independent consultant to evaluate the facility and future space needs. That led to the creation of a $25-million renewal plan that would be phased in over five years, pending funding, to address not only current issues but plan for growth.

Babiuk said the CCAC was informed during a regularly scheduled site visit on May 12—just hours before the electrical short—that the university had identified $2.4 million to complete Phase 1 of the renewal project. This phase includes replacing the water supply system and installing a continuous chlorine monitoring system. This work is expected to begin later this year.

“It’s unfortunate that this incident occurred before we could begin that important renewal work,” he said.

The aquatics facility incident occurred about one month after a freezer unit and alarm system failed in the U of A’s Canadian Ice Core Archive and damaged a portion of the collection. Babiuk said it’s unfortunate that two significant laboratory failures happened in such a short timespan, but stressed the two are not connected.

Babiuk noted the university has a backlog of $938 million in deferred maintenance projects related to building infrastructure, but upkeep for research facilities and programs falls outside the scope of that list.

“Given the scale of the university’s research enterprise and breadth of our facilities—some of which are many decades old—funding for research maintenance is an ongoing challenge,” he said. “We are doing what we can to mitigate those risks, but the reality is that even with a new facility, failures can and sometimes do occur.”