Assessing polar bear (Ursus maritimus) in a changing Arctic using non-invasive DNA metabarcoding
Loading...
Authors
Landon, Emily
Date
Type
thesis
Language
eng
Keyword
polar bear , diet , DNA metabarcoding , blocking primer , Arctic , Canada
Alternative Title
Abstract
Dietary studies of apex predators enhance our understanding of species’ life histories, predator-prey interactions and food webs. Studies of diet over time can reveal changes in these life history and ecology that result from climate change and landscape disturbances. Polar bears (Ursus maritimus) reside at the top of Arctic food webs. Because polar bears use both sea ice and land throughout their annual cycle, they integrate trophic information from both marine and terrestrial ecosystems across their vast territories, including availability and diversity of prey species. Polar bears act as sentinels of environmental change as they are highly adapted to using sea ice as a platform for foraging and are therefore vulnerable to current and projected changes in Arctic sea ice conditions. Given that these changes in sea ice conditions are projected to alter the composition and accessibility of polar bear prey species, and the pressing need for more non-invasive wildlife monitoring strategies, this study investigates what dietary information could be retrieved from 743 polar bear fecal samples from across the Canadian Arctic using novel multi-marker DNA metabarcoding to identify Arctic birds, fish, and mammals at family- and species-level resolution. I designed two novel blocking primers specific to polar bear DNA to maximize detection of prey taxa within fecal samples. Over 8 million metabarcoding sequences were retrieved, identifying 31 prey species, belonging to 19 families, representing 14 orders. As expected, polar bears consume Arctic seal species (Phocidae), present in >70% of successfully sequenced fecal samples – more common than any other prey group. The dietary signature of taxa such as seals, small toothed whales, various seabirds, and caribou confirm previous observations of components of polar bear diet, however, the frequency of detection of several terrestrial taxa and seabird species are consumed may represent novel insights reflecting predator-scavenger relationships and shifts in the diet of the Arctic’s top predator due to climate change. My study is the first to use multi-marker, fecal-based DNA metabarcoding to provide a comprehensive assessment of the relative consumption of fish, bird, and mammal prey taxa by polar bears across the Canadian Arctic. This method offers a cost-effective, non-invasive approach for assessing regional trophic interactions and prey diversity, and reliably monitoring the diets of wide-ranging predators.
Description
Citation
Publisher
License
Queen's University's Thesis/Dissertation Non-Exclusive License for Deposit to QSpace and Library and Archives Canada
ProQuest PhD and Master's Theses International Dissemination Agreement
Intellectual Property Guidelines at Queen's University
Copying and Preserving Your Thesis
This publication is made available by the authority of the copyright owner solely for the purpose of private study and research and may not be copied or reproduced except as permitted by the copyright laws without written authority from the copyright owner.
Attribution-NonCommercial-NoDerivs 3.0 United States
ProQuest PhD and Master's Theses International Dissemination Agreement
Intellectual Property Guidelines at Queen's University
Copying and Preserving Your Thesis
This publication is made available by the authority of the copyright owner solely for the purpose of private study and research and may not be copied or reproduced except as permitted by the copyright laws without written authority from the copyright owner.
Attribution-NonCommercial-NoDerivs 3.0 United States