Forsøksdyr: Research on diet and habitat use of killer whales in Northern Norway

Godkjenningsdato 18.12.2018

Godkjenningsperiode 01.01.2019-30.11.2020

As part of a long-term research project on Norwegian killer whales (Orcinus orca), this application aims at maintaining biopsy sampling and tagging efforts for an additional two-year period. While biopsy samples are being used for dietary and contamination analyses, multi-sensor (bio-logging) suction-cup tagging will provide with multi-scale information about movement patterns. Combining this type of data with photo-identification and behavioral observations collected since 2013 will enable a multi-disciplinary approach to better understand foraging ecology and habitat use of Norwegian killer whales.

Throughout the additional two year-sampling period, a maximum total of 220 killer whales will be used. This include a very maximum of 180 individuals that could be biopsy sampled and 40 that could be tagged using suction-cups. Experiments will be mainly conducted off Vesterålen and Troms regions throughout the year.

Experiments will be conducted remotely from the boat and therefore do not require physical capture or handling of the whales. Biopsy sampling and suction-cup tagging were previously reported as only minimally invasive with only short-term induced disturbance to the whales. Yet, to best comply to the Norwegian legislation in place and in order to maximize animal welfare, key aspects of these experiments were deeply reviewed and best protocols were set up and detailed in the present application.

Because this project consists of fundamental research on a wild-ranging predator, there does not exist any replacement solution to answer the specific research questions. However, in order to achieve the 3R, both reduction and refinement will remain an important focus. Only individual killer whales with known sighting histories and relevant to sample or tag will be target, therefore keeping the number of used killer whales to a minimum. In addition, investigators' previous experience with killer whales and sampling and tagging methods enabled refining protocols for minimally invasive procedures with best outcomes. As such, sampling and tagging protocols were adjusted to only use friendly approaches and best gear in the field to reduce stress on the animals used. Assessment of the behavior, group composition beforehand will ensure exclusive sampling of adult or sub-adult individuals in apparent good health condition. Further identification records of target individuals will prevent double-sampling and cumulative stress.

Collected biopsy samples will be stored at -20°C upon collection and will further be shipped to a laboratory where various analyses of diet and pollution will be conducted. Data files from retrieved multi-sensor tags will be processed using softwares to depict horizontal and vertical movements of tagged individuals.

As outcomes of the project, both results in regards to the research questions and to the induced effects of specific experiments will be reported in the scientific literature. Findings on feeding ecology and contamination and movement patterns will be relevant to status assessment of this regional killer whale population. Results will also assist in better understanding this population in relation to other North Atlantic killer whale populations and for management and conservation purposes.