RMRS scientists have teamed up with the Dixie National Forest (DNF) to develop an environmental DNA (eDNA) assay for boreal toads. Because toads do not persistently inhabit wetlands, determinations of when, where, and how to sample are critical for the development of protocols based on eDNA.
The partnership between RMRS and Region 4 (R4) has been vital for the success of the project for several reasons. First, the ability to use local expertise and manpower allowed this project to be accomplished within budget. Next, because fieldwork will be carried out by biologists on National Forests who will implement the protocol, team members will be able to design an effective protocol in fewer iterations and therefore be able to take advantage of its findings more quickly. On the management side, being able to utilize the expertise of the National Genomics Center for Wildlife and Fish Conservation to develop a reliable assay proved critical.
Current survey methods for boreal toads (Bufo boreas), a species known to be declining in range and numbers across the West, rely on visual observations which are both time consuming and ineffective at locating toads in complex habitats or at low densities. Significant cost and time savings and the ability to more reliably detect boreal toads across a larger geography will be realized with the successful development of the eDNA boreal toad sampling protocol. eDNA sampling, which involves extracting DNA from water samples, has been shown to improve detection rates for amphibians when compared to visual surveys. This approach greatly simplifies detection efforts by allowing a single sample to integrate presence across complex wetlands.
A R4 BeSMART microgrant was used to fund repeat sampling in 4 known toad-bearing waterbodies on the DNF during the summer of 2017. From this we determined that a sampling protocol targeting a period between the last week of May and the first week of July will be most effective. This approach represents a new paradigm for management/research collaboration. This effort is truly collaborative as the team works together to solve a problem, both organizations contributing their unique strengths and abilities to the process.
There are important issues to be addressed prior to finalization of the survey protocol. Specifically, the number and location of water samples necessary for toad detection needs to be optimized. The team’s plan is to design studies to address these unknowns in 2018 and have a first iteration sampling protocol to prototype in 2019.
In 2018, a first-generation working protocol of the boreal toad eDNA will be tested across additional field sites on other forests in R4. This step will bring on additional NFS project collaborators.