Presentation Title

Detection of California tiger salamanders (Ambystoma californiense): comparing eDNA and traditional net-based survey methods for maximum sensitivity

Faculty Mentor

Dr. Christy Wyckoff

Start Date

17-11-2018 2:00 PM

End Date

17-11-2018 2:15 PM

Location

C161

Session

Oral 3

Type of Presentation

Oral Talk

Subject Area

biological_agricultural_sciences

Abstract

California tiger salamanders are especially hard to survey since they spend the majority of their lives underground in mammal burrows, making the status of each population difficult to monitor. Despite this challenge in detection, it is well established that California tiger salamanders (Ambystoma californiense, CTS) are at risk due to several environmental factors–habitat destruction, hybridization with invasive salamanders (Ambystoma mavortium), and climatic changes in rainfall patterns. This project assesses the sensitivity and specificity of environmental-DNA (eDNA) detection for the California tiger salamander compared to the traditional capture-and-release methods using dip nets and seins. We performed field monitoring and sample collection at the Santa Lucia Preserve and Palo Corona Ranch Regional Ranch, Monterey Peninsula Regional Parks District, both located in Monterey County, CA using an integrated technique of visual surveys, protocol surveys, and eDNA sampling to assess perennial stock ponds for the presence or absence of California tiger salamanders. The eDNA experimental design includes a negative control (known CTS-negative pond), three known positive controls (reliable CTS-positive ponds), and seven ponds unlikely, but unconfirmed, to support CTS breeding. The eDNA detection of the California red-legged frog (Rana draytonii, CRLF) is used as a proxy for eDNA sensitivity. This study evaluates the efficacy of eDNA detection compared to traditional net-based surveys, correlation of net-based results and eDNA signal intensity, seasonality of CTS pond use, and the relationship between vegetation and detection success using traditional net surveys. Preliminary eDNA results show promise with increased sensitivity over net-based surveys and clean controls. Application of these methods to other sites could increase our confidence in presence-absence detection efforts, reduce sampling efforts and impacts, and improve conservation protections of vulnerable habitats.

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Nov 17th, 2:00 PM Nov 17th, 2:15 PM

Detection of California tiger salamanders (Ambystoma californiense): comparing eDNA and traditional net-based survey methods for maximum sensitivity

C161

California tiger salamanders are especially hard to survey since they spend the majority of their lives underground in mammal burrows, making the status of each population difficult to monitor. Despite this challenge in detection, it is well established that California tiger salamanders (Ambystoma californiense, CTS) are at risk due to several environmental factors–habitat destruction, hybridization with invasive salamanders (Ambystoma mavortium), and climatic changes in rainfall patterns. This project assesses the sensitivity and specificity of environmental-DNA (eDNA) detection for the California tiger salamander compared to the traditional capture-and-release methods using dip nets and seins. We performed field monitoring and sample collection at the Santa Lucia Preserve and Palo Corona Ranch Regional Ranch, Monterey Peninsula Regional Parks District, both located in Monterey County, CA using an integrated technique of visual surveys, protocol surveys, and eDNA sampling to assess perennial stock ponds for the presence or absence of California tiger salamanders. The eDNA experimental design includes a negative control (known CTS-negative pond), three known positive controls (reliable CTS-positive ponds), and seven ponds unlikely, but unconfirmed, to support CTS breeding. The eDNA detection of the California red-legged frog (Rana draytonii, CRLF) is used as a proxy for eDNA sensitivity. This study evaluates the efficacy of eDNA detection compared to traditional net-based surveys, correlation of net-based results and eDNA signal intensity, seasonality of CTS pond use, and the relationship between vegetation and detection success using traditional net surveys. Preliminary eDNA results show promise with increased sensitivity over net-based surveys and clean controls. Application of these methods to other sites could increase our confidence in presence-absence detection efforts, reduce sampling efforts and impacts, and improve conservation protections of vulnerable habitats.