Tracing the effects of diets in freshwater fish using fatty acid profiles
type: CreativeWork
description: The aim of the research included in this dissertation is to contribute to our knowledge of how fatty acids can be used as diet indicators in freshwater systems. More precisely this work was an effort to explore a tool that can be used to describe what salmonids have consumed during the foraging period of the year and relate that to the materials allocated to embryos. As stomach contents of salmonids are often empty due to stress of capture and since any items that are present offer data only on the most recent meal, other methods of gleaning diet information are gaining popularity. Biochemical tracers, such as fatty acids, accumulate in consumers in patterns that reflect diet compositions, thus providing a view of what has been consumed and assimilated into tissues over many months. Through the use of controlled feeding experiments, this dissertation explores the efficacy of using fatty acid profiles to both describe and quantify the composition of diets of salmonid species. Much of the work conducted exploring fatty acids in reference to a diet have used diets formulated from dry ingredients whereas the experiments described within this dissertation use natural prey to create diets. As such, data described herein offers a unique look at how fatty acids in a piscivore reflect that of their potential prey items in the wild. In Chapter 1, I illustrate how fatty acid profiles of prey are reflected in lake trout (Salvelinus namaycush) after 14 weeks of feeding. Juvenile lake trout were fed one of three prey species and individuals were sampled at 4, 8 and 14 weeks. Through comparison of consumer fatty acid proportions to those of their diet, it was determined that each diet is assimilated into a consumer in slightly different patterns. Such a finding is important as it suggests that one cannot simply compare fatty acids in a predator to those of prey without accounting for diet-specific patterns of assimilation. In Chapter 2, data from the feeding experiment described i…
abstract: The aim of the research included in this dissertation is to contribute to our knowledge of how fatty acids can be used as diet indicators in freshwater systems. More precisely this work was an effort to explore a tool that can be used to describe what salmonids have consumed during the foraging period of the year and relate that to the materials allocated to embryos. As stomach contents of salmonids are often empty due to stress of capture and since any items that are present offer data only on the most recent meal, other methods of gleaning diet information are gaining popularity. Biochemical tracers, such as fatty acids, accumulate in consumers in patterns that reflect diet compositions, thus providing a view of what has been consumed and assimilated into tissues over many months. Through the use of controlled feeding experiments, this dissertation explores the efficacy of using fatty acid profiles to both describe and quantify the composition of diets of salmonid species. Much of the work conducted exploring fatty acids in reference to a diet have used diets formulated from dry ingredients whereas the experiments described within this dissertation use natural prey to create diets. As such, data described herein offers a unique look at how fatty acids in a piscivore reflect that of their potential prey items in the wild. In Chapter 1, I illustrate how fatty acid profiles of prey are reflected in lake trout (Salvelinus namaycush) after 14 weeks of feeding. Juvenile lake trout were fed one of three prey species and individuals were sampled at 4, 8 and 14 weeks. Through comparison of consumer fatty acid proportions to those of their diet, it was determined that each diet is assimilated into a consumer in slightly different patterns. Such a finding is important as it suggests that one cannot simply compare fatty acids in a predator to those of prey without accounting for diet-specific patterns of assimilation. In Chapter 2, data from the feeding experiment described i…
author: Happel, Austin
language: en
keywords: Fatty acid, Salmon, Quantitative fatty acid signature analysis (QFASA), Lake trout, Diet composition
date published: 2017-09-29T17:45:13Z
date modified: 2026-07-22T22:24:35Z
provider: University of Illinois - Urbana-Champaign
publisher: Networked Digital Library of Theses and Dissertations
type: WebPage
source organization: University of Illinois at Urbana-Champaign

PropertyValue
property ID: Handle
value: http://hdl.handle.net/2142/98174