Some of the earliest applications of eDNA methods were in studies of animal diet and this work helped shape subsequent eDNA research. I will present an overview of dietary eDNA studies and outline some key insights that have come from the field. One of the initial challenges in working with dietary samples (i.e. faeces or stomach contents) was the abundance of consumer DNA and the degraded nature of food DNA. The food DNA can be targeted with group-specific markers, or by using selective PCR blocking. The troublesome consumer DNA excreted in faeces likely makes up a substantial component of the eDNA now routinely characterised in biodiversity studies of aquatic ecosystems. There has been considerable effort put in to get quantitative diet information from high-throughput sequencing data and several innovative approaches have been used to convert these compositional values to estimates of absolute abundance. The impact of biases in DNA metabarcoding datasets on overall diet estimates and use of DNA-based data in food web networks has also been investigated. Despite the substantial amount of research in the field there are still challenges implementing dietary eDNA approaches in routine management and plenty of scope for exciting future research.
Biography:
Bruce is a CSIRO Science Leader based at the Australian National Fish Collection in Hobart, Tasmania. He received his PhD in Zoology in 2006 from the University of Tasmania working on DNA-based methods to study the diet of marine predators. This research contributed to the initial development of eDNA metabarcoding approaches for measuring animal diversity. During post-doctoral fellowships in Canada and Australia his focus shifted to population genomics of fish and Antarctic krill. At CSIRO Bruce continues to lead innovative projects on fish genomics and assessing biodiversity in marine ecosystems using eDNA. He’s had a hard time letting go of his PhD work, so is still involved in a few eDNA diet projects as well.