Collecting baleen whale blow samples by drone: a minimally intrusive tool for conservation genetics

In coastal British Columbia, Canada, marine megafauna such as humpback
whales (Megaptera novaeangliae) and fin whales (Balaenoptera physalus
velifera) have been subject to a history of exploitation and near
extirpation. While their populations have been in recovery, significant
threats are posed by proposed natural resource ventures in this region, in
addition to the compounding effects of increasingly severe marine
heatwaves. Genetic tools play a vital role in informing conservation
efforts, but the associated collection of tissue biopsy samples can be
challenging for the investigators and disruptive to the ongoing behaviour
of the targeted whales. Here we evaluate a minimally intrusive approach
based on collecting exhaled breath condensate, or respiratory ‘blow’
samples, from baleen whales using an unoccupied aerial system (UAS),
within Gitga’at First Nation territory for conservation genetics. Minimal
behavioural responses to the sampling technique were observed, with no
response detected 87% of the time (of 112 UAS deployments). DNA from whale
blow (n = 88 samples) was extracted, and DNA profiles consisting of 10
nuclear microsatellite loci, sex identification, and mitochondrial (mt)
DNA haplotypes, were constructed. An average of 7.5 microsatellite loci
per individual were successfully genotyped. The success rates for mtDNA
and sex assignment were 80% and 89% respectively. Thus, this minimally
intrusive sampling method can be used to describe genetic diversity and
generate genetic profiles for individual identification. The results of
this research show the potential of UAS-collected whale blow for
conservation genetics from a remote location.