Graduate Thesis Or Dissertation
 

Use of Landscape Characteristics to Quantify Hybridization Risk Between Native and Introduced Salmonids

Public Deposited

Downloadable Content

Download PDF
https://ir.library.oregonstate.edu/concern/graduate_thesis_or_dissertations/n583z2616

Descriptions

Attribute NameValues
Creator
Abstract
  • The introduction of non-native species can negatively impact native species through reduced genetic fitness resulting from hybridization. The lack of spatiotemporal data of hybrids occurrences makes assessing hybridization risk difficult. Here, I developed a spatially-explicit GIS Hybridization Risk Model (HRM) between native ESA-listed Bull Trout and introduced Brook Trout by combining an intrinsic potential model (IPM) of Brook Trout spawning habitat and existing empirical datasets of Bull Trout in Oregon. I created the IPM using the geometric mean of several suitability curves of habitat use (i.e., temperature, discharge, gradient, and valley confinement) for Brook Trout based on expert opinions. The HRM included a risk matrix based on the presence/absence of both species as well as the type of habitat (spawning versus others) at 100-m stream segment resolution. Hybridization risk was “extreme” when the respective reach contained Bull Trout spawning habitat and Brook Trout were present with IPM moderate or greater scores. Conversely, “low” risk reaches contained historic or non-spawning Bull Trout habitat, Brook Trout were absent, and IPM scores were low. In Oregon, the HRM was able to classify 34 km of rivers with extreme risk of hybridization, 115 km with high risk, 178 km with moderate risk, and 6,023 km with low risk. The HRM can be used to identify stream reaches with a differential risk of hybridization occurring when either both species coexist in Bull Trout spawning habitat or are absent at multiple spatial scales. It also identifies stream reaches that would have higher risk of hybridization where Brook Trout are not currently present. This approach can be applied to other species, such as Cutthroat Trout and Rainbow Trout or similar freshwater species occurring elsewhere that potentially hybridize.
License
Resource Type
Date Issued
Degree Level
Degree Name
Degree Field
Degree Grantor
Commencement Year
Advisor
Committee Member
Academic Affiliation
Rights Statement
Publisher
Peer Reviewed
Language
Embargo reason
  • Pending Publication
Embargo date range
  • 2021-12-08 to 2023-01-09

Relationships

Parents:

This work has no parents.

In Collection:

Items

Thumbnail Title Date Uploaded Visibility Actions
file details ManningMichaelA2021.pdf 2021-12-08 Public Download