Building on past successful years of stocking, the 2010 season started out as another great year. We had a good egg collection with excellent fertilization rates. The hatchery was full and the fish converted to feed very well (which has been a recurring problem in the past). As is done annually, non-lethal disease screenings of the adults and the fingerlings did not detect any viruses. However, a bacterial infection was detected in the fingerlings and successfully treated with an antibiotic. Additional testing, requested based on the finding of the bacterial infection, found a virus (Lymphosarcoma) in multiple muskellunge families.
Lymphosarcoma is known to infect muskellunge and northern pike populations across Ontario and North America. In fish, lymphosarcoma and other similar viruses are not treatable and is fatal for some individuals. MNR tagging studies have shown fish can survive for several years with the virus; however, they may continue to spread the virus.
After considerable discussions with all of the experts and Project partners, it was decided that no stocking or export of muskellunge will occur this year. This decision was not taken lightly and is based on the potential impacts stocking these fish out may have on past restoration/stocking success. Lake Simcoe has a very small (and therefore more vulnerable) population of muskellunge which could be impacted negatively by knowingly stocking out infected fish.
To ensure the continued success of this valued program, we will be working towards developing a tool to detect this virus in future health screenings of muskellunge.
This news is disappointing to all involved and in no way represents the tremendous and collective effort we have all committed to this Project.
Should you have any questions, please feel free to contact Jason Borwick at firstname.lastname@example.org or me at email@example.com.
Ian M. Young