Genome-scale target capture of mitochondrial and nuclear environmental DNA from water samples.

Environmental DNA (eDNA) provides a promising supplement to traditional sampling methods for population genetic inferences, but current studies have almost entirely focused on short mitochondrial markers. Here, we develop one mitochondrial and one nuclear set of target capture probes for the whale shark (Rhincodon typus) and test them on seawater samples collected in Qatar to investigate the potential of target capture for eDNA-based population studies. The mitochondrial target capture successfully retrieved ~235× (90× - 352× per base position) coverage of the whale shark mitogenome.

Using vertebrate environmental DNA from seawater in biomonitoring of marine habitats.

Conservation and management of marine biodiversity depends on biomonitoring of marine habitats, but current approaches are resource-intensive and require different approaches for different organisms. Environmental DNA (eDNA) extracted from water samples is an efficient and versatile approach to detecting aquatic animals. In the ocean, eDNA composition reflects local fauna at fine spatial scales, but little is known about the effectiveness of eDNA-based monitoring of marine communities at larger scales.

Population characteristics of a large whale shark aggregation inferred from seawater environmental DNA.

Population genetics is essential for understanding and managing marine ecosystems, but sampling remains challenging. We demonstrate that high-throughput sequencing of seawater environmental DNA can provide useful estimates of genetic diversity in a whale shark (Rhincodon typus) aggregation. We recover similar mitochondrial haplotype frequencies in seawater compared to tissue samples, reliably placing the studied aggregation in a global genetic context and expanding the applications of environmental DNA to encompass population genetics of aquatic organisms.