Please use this identifier to cite or link to this item:
Appears in Collections:Biological and Environmental Sciences Journal Articles
Peer Review Status: Refereed
Title: Minimising the limitations of using dietary analysis to assess foodweb changes by combining multiple techniques
Author(s): Horswill, C
Jackson, J A
Medeiros, R
Nowell, R W
Trathan, P N
O'Connell, T C
Contact Email:
Keywords: DNA
Macaroni penguin
Stable isotope analysis
Stomach contents
Issue Date: Nov-2018
Date Deposited: 17-Apr-2024
Citation: Horswill C, Jackson JA, Medeiros R, Nowell RW, Trathan PN & O'Connell TC (2018) Minimising the limitations of using dietary analysis to assess foodweb changes by combining multiple techniques. <i>Ecological Indicators</i>, 94, pp. 218-225.
Abstract: Dietary studies of marine predators offer an immediate signal of foodweb changes occurring at lower trophic levels, and therefore are often used to assess the ecosystem status of marine systems. Conventionally, these studies are based on morphological analysis of prey remains in stomach contents, involving invasive and destructive techniques to collect samples. More recently, the number of dietary studies based on less invasive biochemical and molecular approaches has dramatically increased. However, all three methods, morphological, biochemical and molecular, have well-documented limitations for resolving taxonomy, temporal variation or biomass composition. In this study, we minimise these limitations by considering multiple techniques in combination. As a case study, we report the target prey species and diet composition of a marine predator that has been used to assess annual change in managed fishing areas for several decades, the macaroni penguin Eudyptes chrysolophus. We use biochemical (stable isotope) and molecular (DNA) analysis of faecal samples collected across the different phases of a single breeding season, and compare the resolved diet to a 26-year dataset of stomach contents collected from a closely located colony (0.25 km apart) that exploits identical foraging grounds. Molecular analysis increased the known target prey species for this highly monitored population by 31%, including a fish species of commercial importance. Biochemical analysis detected subtle changes in the proportion of fish and krill in the diet, demonstrating promising opportunities for using a combined molecular and biochemical method to assess inter-annual foodweb changes at lower trophic levels. The combined approach offers a less invasive sampling methodology, compared to morphological analysis, and provides more information regarding prey species diversity and the overall trophic signature of the diet. Further studies are required to examine the feasibility of using this approach for long-term dietary studies of different marine predator species.
DOI Link: 10.1016/j.ecolind.2018.06.035
Rights: This is an open access article distributed under the terms of the Creative Commons CC-BY license, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. You are not required to obtain permission to reuse this article. To request permission for a type of use not listed, please contact Elsevier Global Rights Department.
Licence URL(s):

Files in This Item:
File Description SizeFormat 
Horswill 2018 Ecol Indic - Minimising limitations of dietary analysis to assess foodweb changes by combining multiple techniques.pdfFulltext - Published Version488.98 kBAdobe PDFView/Open

This item is protected by original copyright

A file in this item is licensed under a Creative Commons License Creative Commons

Items in the Repository are protected by copyright, with all rights reserved, unless otherwise indicated.

The metadata of the records in the Repository are available under the CC0 public domain dedication: No Rights Reserved

If you believe that any material held in STORRE infringes copyright, please contact providing details and we will remove the Work from public display in STORRE and investigate your claim.