About the thesis:
Do happy fish produce more offspring? Is it possible to make Arctic charr (Salvelinus alpinus) aquaculture greener by reducing the amount of hazardous chemicals used? Is freshwater fish farming in cages vulnerable to parasites?
These are some of the main questions Tom Robin Olk evaluated during his PhD project on Arctic charr aquaculture in southern Norway. Good holding conditions for brood-stock are indeed largely responsible for the survival of offspring until hatch. It may be possible to reduce the amount of formalin used to disinfect eggs in the future by timing the use of the chemical correctly. There are parasites in southern Norway that can cause harm to freshwater aquaculture in cages. The risk of an outbreak seems relatively low.
Three studies lead to these conclusions, one being an extensive literature review on pre-hatch survival in cultured Arctic charr. The use of formalin was evaluated by testing egg survival under four different disinfection protocols. In the final study, freshwater parasites were collected from wild fish in a lake that would be suitable for fish farming in cages. Their abundance was linked to properties of the fish, such as habitat, age and length.
Tom Robin Olk’s studies aid the establishment of Arctic charr aquaculture in southern Norway by addressing the global problem of low offspring survival, as well as local conditions in southern Norway are being evaluated.