Diet analysis of Pacific harbour seals (Phoca vitulina richardsi) using high-throughput DNA sequencing ...

• Main Author: Thomas, Austen Clause
• Format: Text
• Language: English
• Published: University of British Columbia 2015
• Subjects: harbour seal; Phoca vitulina
• Online Access: https://dx.doi.org/10.14288/1.0166747; https://doi.library.ubc.ca/10.14288/1.0166747

Harbour seals have long been perceived to compete with fisheries for economically valuable fish resources in the Pacific Northwest, but assessing the amounts of fish consumed by seals requires estimates of harbour seal diets. Unfortunately, traditional diet analysis techniques cannot provide the necessary information to estimate the species, life stage, and biomass of key prey (e.g. salmonids) consumed by seals. I therefore developed a new harbour seal diet analysis methodology, using scat DNA metabarcoding and prey hard-part analysis to create refined estimates of salmon in harbour seal diet. I also sought to understand the quantitative potential of DNA metabarcoding diet analysis (i.e. the relationship between prey biomass proportions and DNA sequence percentages produced by high-throughput amplicon sequencing of seal scat DNA). Analysis of faecal samples (scats) from captive harbour seals fed a constant diet indicated that a wide range of factors influence the numbers of prey sequences resulting from scat ...