Forsøksdyr: Tracking salmon in otter habitat

Godkjenningsdato 21.08.2020

Godkjenningsperiode 21.08.2020-20.08.2022

1 Purpose

The purpose is to track the upriver migration of Atlantic salmon moving through habitat in a river occupied by carnivorous otters, to which locals are ascribing high impacts of predation.

2 Distress

Internal implantation of telemetry transmitters under anesthesia is not expected to result in lasting distress. There will be placed particular caution on inflicting as little stress as possible on the animals during capture. Animals should recover within minutes and resume migration within a few days.

3 Expected benefit

Determining how otters affect this population is crucial to both local and national management and to mitigate conflicts between humans and otters. Data are needed for evidence-based management of the local salmon population to replace narratives about otter predation based on anecdotes.

4 Number of animals, and what kind

We will tag 150 Atlantic salmon in 2020-2022 with radio transmitting tags

5 How to adhere to 3R

By replicating the study in multiple years we will reduce the total number needed for a representative sample (by having temporal replication). We cannot replace wild salmon with alternative species or simulations because we do not have any underlying data with which to simulate. A key refinement is to implant the tags internally under anesthesia rather than externally attach tags. External attachment is faster but can have longer-lasting impacts on the fish.