We have been studying humpback whales along the north coast of BC for more than 20 years, and we are just starting to understand the depth of the intricate social connections humpback whales have with each other and how these long-term bonds may actually play a role in determining their fine scale habitat usage and behaviours. What remains unclear is the extent to which genetic relatedness contributes to driving this social network, particularly among the whales that consistently return to our research area each summer for feeding.
Learning from DNA
As an organization we wanted the ability to non intrusively explore patterns of genetic relatedness among the seasonally resident population of humpback whales in Gitga’at Territory. By mounting sterile petri dishes to small, customized drones, and flying these through whale breath (or, “blow”) we began this non-invasive genetic sampling and can now sequence the entire genomes of whales without ever actually making direct contact with them.
Through the insights gained from humpback whale DNA, we hope to address significant ecological questions, beginning by mapping the genetic connections of this population. Having closely observed the same population of humpback whales for more than two decades, we identify each whale as an individual based on the distinctive markings on their tail flukes. Integrating the genetic fingerprint into this individual knowledge allows us to tackle broader questions regarding the levels of relatedness within the social network of humpbacks. This, in turn, aids our understanding of social structure, the transmission of behaviour and culture, and the composition of the community.
From algae to whales, the ocean holds genetic evidence of their presence.
The collection and extraction of eDNA from seawater samples is groundbreaking for the scientific community to be able to conduct robust investigations into species presence, species diversity, and community composition. We initiated the collection of eDNA to deepen our understanding of the habitat needs of whales on an ecosystem level, as well as to identify threats to these ecosystems through the identification of invasive and climate-change indicator species.
We have additionally incorporated the collection and analysis of eDNA samples in an investigation of potential drivers of humpback whale hotspots within our research area in northern BC. In the fall months, we observe a shift in the habitat usage and predominant behaviours of the humpback whales along the north coast, whereby congregations form annually in the same, predictable locations. A major question that has arisen from observing these annual congregations, is what is driving the whales to these locations when nearby, oceanographically similar habitats do not support or drive this same phenomenon?
By gaining an unprecedented insight into the community biodiversity of whale hotspot areas, and comparing the results to non-hotspot areas, we hope to begin to unravel the drivers of these congregations.
