Project Description

In Alaska, it is estimated that less than 50% of waterbodies (e.g., streams, rivers or lakes) with the potential to support anadromous fishes have been documented. Identification and protection of these unsampled water bodies will be critical in light of increasing threats (e.g., climate change, fishing pressure, and land development) to fish populations, yet challenging when budgetary and logistical limitations are considered. Newly developed, non-invasive rapid-assessment techniques can reduce costs and sampling effort while increasing detectability (i.e., probability of observing an individual) across life stages. We are using a GIS-based habitat model to predict juvenile Chinook salmon habitat potential throughout the Chena River, a clear water tributary of the Yukon River located in interior Alaska. We will divide the Chena River into 149 tributary catchments (> 20 km2 surface area) and use the model and the State of Alaska Catalog of Anadromous Waters (AWC) to classify each tributary as high rearing potential, low rearing potential and known rearing habitat used by juvenile Chinook based on the AWC. Ten tributaries from each category will be randomly selected (N=30) for environmental DNA (eDNA) analysis and snorkel surveys. Three replicate water samples will be collected at each site, filtered and analyzed for presence of Chinook salmon DNA present in the environment. Snorkel surveys will also be conducted for visual confirmation of presence/absence and to quantify the range of juveniles within tributary habitats. Our results will provide tools for managers to rapidly and efficiently map critical rearing habitats and prioritize sampling efforts to expand the known distribution of juvenile salmon in interior Alaska streams.

Project Funding

Alaska Department of Fish and Game
Start Date: 2014-01-01
End Date: 2016-08-01

 

 

Research Team