Thesis
Adapting molecular techniques in wilderness management and restoration in the Sierra Nevada
Washington State University
Master of Science (MS), Washington State University
2016
Handle:
https://hdl.handle.net/2376/103781
Abstract
Analysis of aquatic environmental DNA (eDNA) is a promising tool for monitoring invasive species and determining population density. Previous applications of this method have been hindered by the inability to distinguish whether sources are alive or dead and whether quantities can reliably reflect population size. In part one of this study, we analyzed how the detection of eDNA from dead model organisms differs depending on collection method. In part two, we analyzed how the quantity of DNA collected over time and space relates to population density of trout. We sampled 15 microcosms containing dead or live goldfish using different filter membrane types and pore sizes and at varying depths. We detected DNA from dead individuals less frequently and in lower quantities compared with live individuals. DNA from dead individuals was found only at the bottom of the water column. As pore size increased, the quantity of DNA captured decreased for both treatments. Because dead individuals were associated with less DNA, using filters with larger pore sizes decreased detection of dead individuals. We applied our findings to restoration sites where non-native fish were being removed. We sampled completed restoration sites (sites containing only dead fish, N = 21) as well as active restoration sites (sites containing dead and live fish, N = 9) with 1.2 µm PCTE iv filters. Our field sampling accurately indicated the status of each site, with the exception of one likely false positive (low-level) and one false negative at a low-density site. Our results highlight that collection methods for eDNA can be tailored to maximize the utility of eDNA techniques in aquatic conservation. In part two of the study, we collected eDNA samples once a month for 4 months at 6 active restoration sites and 3 control sites containing populations of trout. We found that the density of DNA collected was related to the density of fish or biomass of fish removed the month prior. Small increases in eDNA density corresponded to large increases in trout density, therefore inherent variation in eDNA collection may provide an upper limit to the precision that can be obtained for abundance estimates.
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Details
- Title
- Adapting molecular techniques in wilderness management and restoration in the Sierra Nevada
- Creators
- Colleen Desiree Kamoroff
- Contributors
- Caren S. Goldberg (Degree Supervisor)
- Awarding Institution
- Washington State University
- Academic Unit
- Environment, School of the (CAHNRS)
- Theses and Dissertations
- Master of Science (MS), Washington State University
- Publisher
- Washington State University; [Pullman, Washington] :
- Identifiers
- 99900525081701842
- Language
- English
- Resource Type
- Thesis