Search

Climate change is rapidly affecting species distributions across the globe, particularly in the North Atlantic. For highly mobile and elusive cetaceans, the genetic data needed to understand population dynamics are often scarce. Cold-water obligate species such as the white-beaked dolphin (Lagenorhynchus albirostris) face pressures from habitat shifts due to rising sea surface temperatures in addition to other direct anthropogenic threats. Unravelling the genetic connectivity between white-beaked dolphins across their range is needed to understand the extent to which climate change and anthropogenic pressures may impact species-wide genetic diversity and identify ways to protect remaining habitat. We address this by performing a population genomic assessment of white-beaked dolphins using samples from much of their contemporary range. We show that the species displays significant population structure across the North Atlantic at multiple scales. Analysis of contemporary migration rates suggests a remarkably high connectivity between populations in the western North Atlantic, Iceland and the Barents Sea, while two regional populations in the North Sea and adjacent UK and Irish waters are highly differentiated from all other clades. Our results have important implications for the conservation of white-beaked dolphins by providing guidance for the delineation of more appropriate management units and highlighting the risk that local extirpation may have on species-wide genetic diversity. In a broader context, this study highlights the importance of understanding genetic structure of all species threatened with climate change-driven range shifts to assess the risk of loss of species-wide genetic diversity.

In many parts of the world, human-mediated environmental change is depleting biodiversity faster than it can be characterized, while invasive species cause agricultural damage, threaten human health and disrupt native habitats. Consequently, the application of effective approaches for rapid surveillance and identification of biological specimens is increasingly important to inform conservation and biosurveillance efforts. Taxonomic assignments have been greatly advanced using sequence-based applications, such as DNA barcoding, a diagnostic technique that utilizes PCR and DNA sequence analysis of standardized genetic regions. However, in many biodiversity hotspots, endeavors are often hindered by a lack of laboratory infrastructure, funding for biodiversity research and restrictions on the transport of biological samples. A promising development is the advent of low-cost, miniaturized scientific equipment. Such tools can be assembled into functional laboratories to carry out genetic analyses in situ, at local institutions, field stations or classrooms. Here, we outline the steps required to perform amplicon sequencing applications, from DNA isolation to nanopore sequencing and downstream data analysis, all of which can be conducted outside of a conventional laboratory environment using miniaturized scientific equipment, without reliance on Internet connectivity. Depending on sample type, the protocol (from DNA extraction to full bioinformatic analyses) can be completed within 10 h, and with appropriate quality controls can be used for diagnostic identification of samples independent of core genomic facilities that are required for alternative methods.