Researchers investigate first case of deadly bacterial disease found in wild chinook salmon
“The disease itself is not new. It’s one of the most diffused diseases that occur in farm fish,” said Dr. Outbreaks occur in farms when juvenile fish are transferred from freshwater to saltwater, and the disease spreads quickly because of the high concentration of fish in an enclosed area. C. Diagnosing marine disease in wild fish has proved challenging for researchers.
“Finding a sick fish in the ocean is very hard because usually, they either get picked up by predators or get weak enough that eventually they cannot catch their own prey and die of starvation or die from the disease,” said Dr. C. “The DFO is currently treating this bacterium like it can only occur in farms,” said Di Cicco. ” The specimens were not collected near a salmon farm.
” “This study describes fish that became sick after they were caught, handled and held in tanks – the authors say so themselves,” said the association’s executive director Brian Kingzett in a press release. “Based on what we have found, there is reason to think that DFO should update and redo their assessment, including the species we identified as T. The observation period lasted 10 days, which is longer than the usual time to observe fish in captivity.
Dr. Di Cicco and his team were brought in to sample the fish. Using gill sampling, histology, molecular and genetic screening, the team diagnosed the tenacibaculosis disease and identified the Tenacibaculum dicentrarchi as the causative bacterium. “Conservation depends on understanding why salmon die, not just how many die.
Human impacts on salmon’s health In the original study, led by Zinn, the fish that did not have scale loss, mucus loss or were not injured did not get the disease even if they shared a tank with fish that did. The mucus layer of a fish functions to keep pathogens like the Tenacibaculum dicentrarchi outside the fish. During the study, the infected fish showed ulcers mostly around the mouth, belly and the caudal peduncle.
These were the areas where researchers touched the fish during collection, transportation, and observation. One is avoiding putting fish in a net to not remove their mucus layer. “There’s many things that the public can do to reduce the odds of having an impact in that way,” Zinn said. ”
“Finding a sick fish in the ocean is very hard because usually, they either get picked up by predators or get weak enough that eventually they cannot catch their own prey and die of starvation or die from the disease,” said Dr. C. “The DFO is currently treating this bacterium like it can only occur in farms,” said Di Cicco. ” The specimens were not collected near a salmon farm.
” “This study describes fish that became sick after they were caught, handled and held in tanks – the authors say so themselves,” said the association’s executive director Brian Kingzett in a press release. “Based on what we have found, there is reason to think that DFO should update and redo their assessment, including the species we identified as T. The observation period lasted 10 days, which is longer than the usual time to observe fish in captivity.
Dr. Di Cicco and his team were brought in to sample the fish. Using gill sampling, histology, molecular and genetic screening, the team diagnosed the tenacibaculosis disease and identified the Tenacibaculum dicentrarchi as the causative bacterium. “Conservation depends on understanding why salmon die, not just how many die.
Human impacts on salmon’s health In the original study, led by Zinn, the fish that did not have scale loss, mucus loss or were not injured did not get the disease even if they shared a tank with fish that did. The mucus layer of a fish functions to keep pathogens like the Tenacibaculum dicentrarchi outside the fish. During the study, the infected fish showed ulcers mostly around the mouth, belly and the caudal peduncle.
These were the areas where researchers touched the fish during collection, transportation, and observation. One is avoiding putting fish in a net to not remove their mucus layer. “There’s many things that the public can do to reduce the odds of having an impact in that way,” Zinn said. ”
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