Assessment of Oxygen, Temperature and Salinity on Atlantic salmon Broodstock Maturation Phase II

Description

The British Columbia Atlantic salmon farming industry relies on quality gametes from broodstock resident in British Columbia. It is suspected by the salmon farming industry that low oxygen levels in sea pen broodstock holding facilities may be adversely affecting the maturation process and causing poor egg quality and larval abnormalities. A literature search indicates that research into the influence of low oxygen on fish maturation has shown no clear effect (Berg et al. 1996) and has barely been addressed (Dabrowski et al. 2003). The possible consequences of low oxygen levels (Stolt Sea Farms Ltd. reports levels of 4 or less mg/L) may have a direct impact on the broodstock by increasing pre-spawning mortality, as well as influencing the release of sex hormones during vitellogenesis and ovulation. In addition, the influence of salinity exposure during maturation has also been noted by the salmon farming industry; fish brought from saltwater to freshwater holding facilities appear to show varying levels of egg quality dependant on the date they are moved ,the earlier that date, the better the egg quality. The effect of low oxygen on male maturation is thought to be of less concern (because the maturation process is simpler and can be overcome by the use of hormone implants) and will not be studied at this time.

Program Name

Aquaculture Collaborative Research and Development Program (ACRDP)

Year(s)

2005 to 2006

Ecoregion(s)

Pacific: Strait of Georgia

Principal Investigator(s)

John Jensen
Email: JensenJ@pac.dfo-mpo.gc.ca