Forsøksdyr: Sexing and tagging of mature Polar cod (Boreogadus saida)

Godkjenningsdato 21.12.2020

Godkjenningsperiode 22.12.2012-15.03.2021

1 Purpose:
New caught (Sept. 2020) Polar cod have to be sexed and tagged for upcoming experiments in fall 2021 (application for this study will be handed in in due time). Sex can only be assessed, when the fish are in the late gonadal developmental stage (December-February). Therefore, tagging and sexing has to take place prior the study start in 2021 allowing desired sex distribution in fish tanks. In addition, fish length and weight will be assessed at the same time.

2 Distress:
Mature polar cod will be sexed and tagged under anaestesia. This procedure will lead to short term stress, due to handling of the fish (netting fish out of tank, inducing anaestesia and recovering). The tags will not impair the wellbeing of the fish.

3 Expected benefit:
This procedure is necessary to be able to distinguish female and male fish outside of the spawning period, which is crucial for setting up a new experiment in the future. In addition, the acquired measurements are valuable data for the planning of a new project.

4 Number of animals, and what kind:
All newly caught fish (Boreogadus saida) shall be sexed and tagged and moreover, measured and weighted, ~1500 fish in total

5 How to adhere to 3R:
Replace: The fish are intended to be used later on reproductive success studies this type of experiment cannot be performed using other alternatives, thus a replacement is not possible. Reduce: Tagging is an important measure to reduce numbers of animal used in a next study, e.g. common garden set-ups will be possible as well as setting up experiments with minimal amount of females and males to guarantee spawning success. Furthermore, serial sampling of the same animal will be possible, thus reducing the total amount of fish used. Refine: The team has long experience with studies on polar cod and is well trained in the execution of the planned activities (e.g. Søknad # 17724) thus, minimizing any discomfort occurring in the fish.