Noah Andexler, Northern Michigan University

For omnivorous species such as brown bear (Ursus arctos), diverse diets make forage identification challenging using traditional methods (e.g., scat dissection and stable isotope analysis). However, recent advancements in next generation sequencing, such as whole genome sequencing (WGS), provide an opportunity for high resolution diet analysis, as well as the possibility of deriving additional specimen information (e.g., host and sex identification). In this study, we used WGS on the PromethION nanopore platform to sequence DNA from 151 brown bear fecal samples to identify prey species, confirm host ID, and to assign specimen sex. Brown bear fecal samples were collected across three coastal meadows along Cook Inlet in Lake Clark National Park and Preserve, Alaska. We matched basecalled DNA sequences to the National Center for Biotechnology Information reference databases, and aligned sequence fragments to corresponding taxon, resulting in read abundances. Brown bear dietary breadth revealed a median species richness of 39 species, with a mean Shannon diversity index (Hˊ) of 2.65. Across all samples, 51% of reads were Carex spp., with other supplemental dietary species such as seacoast angelica (Angelica lucida), silverweed cinquefoil (Potentilla anserina), and beach pea (Lathyrus japonicus). We also identified a diverse array of intertidal species (n=25) in bear diets with the most notable species being common octopus and soft-shelled clams, suggesting brown bears forage intertidal resources. Samples were verified as brown bear based on genomics data, and sex identification is currently underway. Our research presents a framework for future comprehensive metagenomic analyses and provides a novel understanding of dietary breadth for a generalist species using noninvasively collected samples. Further development of WGS methodologies can provide broad application to ecological research, making it a potentially essential tool in the developing field of metagenomics.