Spawning Success of Farmed Atlantic Cod (Gadus morhua): Effects of Photoperiod on Gonad Development in Sea Cages in Eastern Canada IES CM 2009 ...

• Main Authors: Trippel, Edward A., Puckrin, Olivia A., Neil, Steven R.E.
• Format: Conference Object
• Language: unknown
• Published: ASC 2009 - Theme session Q 2024
• Subjects: Fisheries and aquaculture; Canada; atlantic cod; Atlantic salmon; Gadus morhua; Salmo salar
• Online Access: https://dx.doi.org/10.17895/ices.pub.25074449; https://ices-library.figshare.com/articles/conference_contribution/Spawning_Success_of_Farmed_Atlantic_Cod_Gadus_morhua_Effects_of_Photoperiod_on_Gonad_Development_in_Sea_Cages_in_Eastern_Canada_IES_CM_2009/25074449

No abstracts are to be cited without prior reference to the author.The use of extended daylength to suppress sexual maturation of Atlantic salmon (Salmo salar) in sea cages has been successfully adopted by fish farmers. The same methods when applied to Atlantic cod (Gadus morhua) however, have been disappointing as gonadal development of cod in sea cages exposed to extended daylength is seasonally delayed but not arrested. Results of a set of photoperiod trials using 20 h and 24 h light in sea cages indicated that between 87-100% of fish achieved sexual maturation. The use of lights did however delay sexual maturation such that females were gravid for several months through summer. Grower diets currently used in Atlantic Canada have led to enlarged livers and this may also have played a role in disrupting normal gonadal development and affected gamete quality. Hepatosomatic indices were also well above those of wild cod. In Canada, the fate of drifting eggs from sea cages has not been evaluated. We discuss ...