An innovative approach for combining marking of phocid seals with biopsy sampling using a new type of livestock ear tags
Marking of seals is done for different purposes such as re-identification of single individuals within a rehabilitation centre, or to conduct capture-mark-recapture studies assessing ecological parameters on a population scale. Until today most studies use conventional livestock ear tags applied to the interdigital tissue of the flippers of seals. Here we present a different type of tag which combines the marking of an animal with the acquisition of a biopsy sample. This combination enables researchers to gain more data within the same handling time, following the three Rs principle (Replacement, Reduction, Refinement) used in animal experiments to optimise the ratio between animal suffering versus knowledge gain. This study describes a first trial within a seal rehabilitation centre, with the aim to assess the application process of this new tag as well as the rate of bleeding and healing following the application. Results show that the new tag type is suitable even in places with unrestricted public access and enables the researcher to gain additional data further supporting ethical justification.