Balancing ethics and conservation: assessing short-term behavioral impacts of biopsy sampling in a recovering whale population

Long-term monitoring programs based on individual identification have provided a sound basis for monitoring the status of endangered and recovering species. However, the impact of such research needs to be understood relative to the benefit gained. Here, we present a case study of a population that has been studied using genetic monitoring since 1995, the New Zealand southern right whale (Eubalaena australis; tohorā). Tissue samples for genetic monitoring were collected using a remote biopsy system, an approach used widely in marine mammal research. Under most ethical frameworks, this is considered a minor impact of short duration, but perceived or potential impact limits sampling of some demographic classes (e.g., calves). We used data collected during surveys from 2020 to 2022 to measure short-term behavioral impact of biopsy sample collection, with 748 responses collected over 52 days in the field from 524 individual whales. Biopsy sampling was overwhelmingly of minimal impact: the majority (90%) of biopsy responses were classified as either ‘no response’ (46%, n = 341) or ‘weak response’ (44%, n = 326). This study also supports previous work that calves do not show a greater reaction to biopsy sampling than adults. The behavior of the whales prior to being approached for biopsy sampling significantly affected the response elicited, but there was no measurable cumulative impact of multiple sampling, based on within-year (n = 113) or between-year (n = 21) comparisons. Genetic data from this monitoring project has been used to revise the conservation status of the population, to demonstrate the effectiveness of conservation polices and to understand circumpolar stock structure. Overall, this study confirms that biopsy sampling is a minimally invasive, data-rich collection method that provides a wealth of information for conservation and management of whales. It typically causes only a minor, short-term behavioral disturbance with wounds that, based on other studies, heal quickly and without discernible adverse health effects.