Evaluating the potential of cetacean blow for non-invasive dietary DNA analysis

Abstract This study proposes the utility of blow sampling for DNA analysis as a non-invasive approach to examine the feeding ecology of cetaceans. Conventional methods such as stomach content analysis and stable isotope profiling, although informative, are inherently invasive and have notable limitations. In contrast, blow analysis offers a non-invasive alternative and, when integrated with unmanned aerial vehicles, facilitates the assessment of endocrine function and health status in free-ranging whales. In this study, fish- and bacteria-derived DNA was detected in the blows of captive orcas and dolphins, indicating that breath may contain trace amounts of dietary DNA. Additionally, detection accuracy was enhanced through DNA purification and repeated PCR amplification. These findings suggest that blow sampling represents a promising tool for dietary analysis in wild cetaceans.