Article from Pathos #1-2013
- Neither Yersinia nor IPNV have been found in the 2012 batch at Aakvik Settefisk AS. This is the first time in many years, and indicates that the work has been successful.
Åsta Bergmann Stølen
Former Fish Health Biologist at Aakvik Settefisk AS
In 2011, a project was started together with PatoGen to map the problems with IPN and Yersinia in the freshwater facility where broodstock recruits are produced. PatoGen’s surveillance model was used to find out where the challenges lay so that the necessary measures could be implemented. Samples were taken from all fish groups, from starter-fed fish and the various growth phases. In addition, in-house produced roe and bought roe were tested, as well as biofilm from various sites in the facility. The extensive test program revealed house strains of IPNV and Yersinia ruckeri in the facility’s recirculation department and, when the fish were sorted, the infection was being spread to other parts of the facility.
Fish Health Biologist, Åsta Bergmann Stølen, at Aakvik Settefisk AS, explains that as a result of this, large-scale washing and disinfection of the facility was instigated in May 2012. The bioblocks in the recirculation department were replaced, as it would have been difficult to get these completely clean. The rest of the department was dismantled, and each of the sections was washed and disinfected. The pipelines were roughly flushed before they were filled with a corrosive disinfectant, and the ground around the vessels was treated with bleach.
“In collaboration with PatoGen, samples were taken before the next generation was transferred to the recirculation department, and samples were taken regularly until release into the sea in the spring of 2013. The result is that neither Yersinia nor IPNV were found in the 2012 batch at Aakvik Settefisk AS. This is the first time in many years, and indicates that the work has been successful,” says Stølen.
At the time of writing, the next generation of broodstock is in the starter feed phase, and will be checked carefully to ensure that IPNV and Yersinia are still absent from the facility. Because the smolt at Aakvik Settefisk AS is not being exposed to IPNV or Yersinia, the roe we produce is not a potential infection route, and we can deliver an even better product”, says Stølen.