Date of Award

11-7-2015

Degree Type

Thesis

Degree Name

M.Sc.

Department

Earth and Environmental Sciences

First Advisor

Johnson, Timothy

Second Advisor

Drouillard, Ken

Keywords

aquatic invasive species, bioenergetics model, consumption, metabolism, risk assessment, trophic impact

Rights

CC BY-NC-ND 4.0

Abstract

Energy requirements of aquatic invasive species (AIS) relative to native species may help explain differences in trophic impact, as species requiring more energy must consume more food, depleting resources more quickly. Variables relating to energy use were compared between co-existing invasive and native fish species in invaded habitats. Most comparisons (8/12) demonstrated higher rates in invasive species (1-46% greater), suggesting high trophic impact is a characteristic of AIS and should be of consideration in management. Bioenergetic mass-balance principles indicate energy consumed by a fish is offset by metabolic (~40%), waste (~30%), and growth (~30%) demands. Since routine metabolic rate data are copious, this rate was used as a surrogate for trophic impact. Non-parametric analyses were used to find relationships between RMR and traits, creating models to predict trophic impact. The models performed poorly, yet age-at-maturity, maximum total length, and eye diameter-to-head length ratio were consistently important in describing RMR.

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